ABF transcription factors are collectively referred to as basic leucine zipper proteins that can specifically recognize and bind to ABA-responsive elements (ABRE), participating in ABA signal transduction and serving as regulators of ABA signal transcriptional responses. This study analyzed the protein encoded by the BnaABF2 gene in Brassica napus. Subcellular localization results showed that the BnaABF2 protein is localized in the nucleus. Analysis of transcriptional activity in the yeast system indicated that BnaABF2 has no transcriptional activation activity; qRT-PCR detection revealed that the expression level of BnaABF2 is highest in leaves. We also found that ABA treatment, simulated drought, and salt stress can induce the expression of BnaABF2; BiFC results showed that BnaMPK1/2/6/7/9/12/13 can interact with BnaABF2. Dual-LUC results suggested that BnaMPK7 may enhance the transcriptional regulation of BnaABF2 on downstream target genes through phosphorylation. This study initially explored the basic characteristics and interacting proteins of the transcription factor BnaABF2, providing theoretical guidance for understanding its functions and mechanisms.

INTRODUCTION: The CPSF family (cleavage and polyadenylation specificity factor) is a crucial protein family that is responsible for polyadenylation signal recognition in mRNA precursors, cleavage and the addition of poly(A) tails to mRNAs in plants. This family plays crucial roles in the regulation of flowering time, the environmental response, and seed development. Currently, the function of the CPSF family genes in Brassica napus is unclear.

 
RATIONALE: To explore the function and expression patterns of the CPSF gene family, this study cloned BnaA02.CPSF6 from B. napus variety Zhongshuang No.11 and conducted bioinformatics analysis, subcellular localization, expression pattern, and functional characterization of the gene.

 
RESULTS: These results indicate that the coding region of the BnaA02.CPSF6 gene is 1 938 bp in length and encodes 646 amino acids without intron structures. Its promoter region contains multiple cis-acting elements involved in light responses and MYB binding sites. Additionally, there are six genes homologous to BnaA02.CPSF6 in B. napus. The BnaA02.CPSF6 gene expressed in the roots, stems, leaves, flowers and different developmental seeds of B. napus, especially significantly higher in 15-35 d developmental seeds, and its encoded protein was localized in the nucleus. The BnaA02.CPSF6 gene expression is upregulated under salt and drought stress. Under treatment with hormones such as ABA, IAA, GA₃, SA, and MeJA, the expression of BnaA02.CPSF6 gene is initially inhibited and then gradually recovers to normal levels. Under normal conditions, the overexpression of the BnaA02.CPSF6 gene in Arabidopsis thaliana results in an early bolting phenotype, along with a reduced number of rosette leaves.

CONCLUSION: In summary, the above results indicate that the BnaA02.CPSF6 is involved in abiotic stress responses, is regulated by phytohormones, and may also play a promoting role in flowering regulation.

Taihangia is a monotypic genus of the Rosaceae and endemic to the southern part of Taihang Mountains. Two varieties (T. rupestris var. rupestris and T. rupestris var. ciliate) are circumscribed currently under the species T. rupestris. However, the taxonomic status of these two varieties is still controversial and very few studies on the evolutionary history of this genus. In this study, a plastid phylogenomic analysis of Taihangia was conducted and the temporal evolutionary history of the genus was investigated. The results showed that the monophyly of the genus and also the two varieties were all recovered with strong support. In addition, the genus started to diverge at ca. 2.60 million years ago (Ma) near the Pliocene-Pleistocene boundary, and diversification events within the two varieties were estimated mostly during the late Pleistocene, which is highly consistent in time scale with the recent uplift of the southern part of the Taihang Mountains that occurred during the Pliocene and Pleistocene. Thus, we propose that the uplift of the southern part of Taihang Mountains may have played an important role in triggering the lineage diversification within the genus Taihangia. The present study not only enhances our understanding on the evolutionary history of Taihangia, but also provides a case study in understanding the relationship between diversification of plant lineages and mountains uplifting occurred in Asia.

Rice (Oryza sativa) is one of the most important food crops in the world. Improving its antioxidant ability and stress resistance is an important way to ensure high and stable yields. In this study, we used the indica rice HZ and the japonica rice Nekken2 as parents and the 120 recombinant inbred line population constructed from them as experimental materials to determine the hydroxyl radical scavenging rate, total phenol content, flavonoid content, and anthocyanin content in sword leaves, glume shells and grains of parents and their progeny at three stages: the tillering stage, the grain filling stage and the maturity stage. Additionally, a total of 62 QTLs related to rice antioxidant damage were identified on the basis of the constructed high-density genetic map for QTL mapping, with an LOD value of up to 4.36. A quantitative analysis of candidate genes related to antioxidant damage ability in these regions revealed that thirteen candidate genes, including LOC_Os06g01850, LOC_Os12g07820, LOC_Os12g07830, and LOC_Os03g60509 were significantly differentially expressed between the two parents at different growth stages. A multitude of QTLs associated with antioxidant damage resistance in rice were identified, providing a foundation for further mapping and cloning of related genes and the development of new rice varieties with increased resistance and nutritional value.

INTRODUCTION DNA methylation is one of the important epigenetic modifications involved in the regulation of plant genome stability, development and stress responses. DNA methylation introduces methylation groups into DNA molecules, thereby altering the activity of DNA segments. DNA methylation is catalyzed by DNA methyltransferase, a process by which methyl groups formed from S-adenosyl-L-methionine are transferred via covalent links to specific locations in the DNA sequence to form N4-methylcytosine, 5-methylcytosine, N6-methyladenine, or 7-methylguanine. However, there are few reports about the effects of DNA methyltransferase on leaf variegation formation and stress response of Begonia.


RATIONALE  Studies have shown that DNA methylation is involved in regulating the formation of leaf color, flower color and leaf variegation, as well as responses to stresses and hormones. As an endemic species of Begonia, Begonia masoniana has unique and beautiful leaf markings, pink, dark green and light green in different developmental stages. It has high ornamental value and is an excellent foliage plant. Therefore, based on the genomic data, this study conducted genome-wide identification and expression pattern analysis of DNA methyltransferase genes, aiming to explore the genetic resources that regulate the formation of leaf variegation.


RESULTS  To investigate whether DNA methyltransferase is involved in the regulation of leaf variegation formation and stress response in B. masoniana, bioinformatics analysis was used to identify the genes encoding DNA methyltransferase. Five genes were obtained from the genome of B. masoniana. According to the protein structural characteristics, their encoded proteins were divided into three categories including CMT, MET and DRM. The sequence length and intron number of these genes were significantly categorized into different subgroups, but their structure and conserved domains in the same subgroup were highly conserved. In addition, all the encoded proteins were predicted to locate in the nucleus. The promoters of these genes contain a large number of cis-acting elements such as light response, MYB binding, and plant hormone response elements. Analysis of hormone response patterns showed that the gene expression of CMT3 was significantly decreased under GA, SA and NAA, and the gene expression of CMT2 was significantly decreased under MeJA and NAA, while MET-type and DRM-type genes displayed significantly increased expression under GA and ABA treatments. In addition, tissue specific analysis showed that the expression levels of BmaCMT2-5 and BmaDRM2-2 in leaves were significantly higher than those of other tissues, while the expressions of these two genes and BmaMET1-15 in red part of leaves were significantly higher than that of green part, implying that these three genes may be involved in regulating the formation of leaf variegation.


CONCLUSION The structure and function of DNA methyltransferase genes vary significantly across different categories in B. masoniana. However, within each category, members display high conservation in gene structure, conserved domains, motifs, and evolutionary patterns. These genes are likely to play crucial roles in the growth and development of diverse tissues and organs, as well as in responding to various biological and abiotic stresses. Moreover, based on the differential expression patterns of BmaCMT2-5, BmaMET1-15, and BmaDRM2-2 genes between leaf variegation and non-variegation areas, coupled with the abundance of MYB regulatory elements related to anthocyanin synthesis in their promoters, it is hypothesized that these genes may contribute to the formation of leaf variegation. As the current understanding of the functional roles of these methyltransferase genes is largely speculative, future research should focus on their functional validation, which will involve utilizing reverse genetics techniques coupled with phenotypic observations to determine their involvement in specific biological processes. Additionally, physiological, biochemical, and molecular biological methods should be employed to elucidate the precise mechanisms of their actions.

Relative expression levels of DNA methyltransferase genes in different tissues and organs of Begonia masoniana

The phytochrome gene family play a critical role in mediating photothermal responses during Arabidopsis thaliana seed germination. Here we evaluated the germination rates of phyA, phyB, phyC, phyD, and phyE single mutants under 12 different light and temperature regimes, using wild-type (Col-0) seeds as controls. Our results indicate that phyA mutant seeds germinate under red light but are inhibited under far-red light and high temperatures (35°C). phyB mutant seeds germinate at low (15°C) and moderate (25°C) temperatures under both white light and far-red light, but not at high temperatures (35°C). phyC mutant seeds show consistent germination across all conditions except under white light at high temperature (35°C). Both phyD and phyE mutant seeds germinate at low (15°C) and moderate (25°C) temperatures, and under red and white light, but not at high (35°C) temperature, darkness or far-red light. These observations suggest that phyB, phyC, and phyD mutants may have impaired integration of light and temperature cues, whereas phyA and phyE mutants appear to maintain this integrative function. Overall, our findings demonstrate that mutations in phytochrome genes can modify seed germination adaptability to varying environmental conditions.

Phosphorus is one of the indispensable nutrients for plant growth and development. Orthophosphate (P) content in the soil is particularly rich, but due to the fixation of the soil, the effective phosphorus content that can be absorbed and utilized by plants is not high. Therefore improving the absorption and utilization capacity of plants to soil phosphorus, or optimizing the application of phosphate fertilizer has become an urgent problem that needs to be solved. The content of phosphite (PH) in soil is second only after orthophosphate, which has the characteristics of higher solubili- ty, two-way transport between plant xylem and phloem, but is not easy to be fixed by soil. Research on phosphite as phosphate fertilizer to replace orthophosphate fertilizer and phosphite-tolerant crop varieties breeding has rarely been reported. Therefore, in this study, five introduced potato (Solanum tuberosum) genotypes and one commercial variety Qingshu No.9 (QS9) were selected as research materials, and the seedlings were directly planted into the test field after domestication and refining, and normal phosphate fertilizer treatment and phosphite substitution treatment were set up to determine the phenotype, photosynthesis, dry matter and other indicators of different genotypes. Moreover, the phosphite tolerant coefficient (PTC) of each indicator was used as the measurement basis. Comprehensive evaluation of the PH resistance of different potato genotypes was conducted based on principal component analysis and other methods. The obtained results showed that the six potato varieties can be classified into three types: highly phosphite-tolerant (C115, and D13), weakly phosphite-tolerant (C20, C31, and QS9) and phosphite-sensitive (C80). This study evaluated the tole- rance of different potato genotypes to phosphite, thus providing scientific basis for the selection of phosphite-tolerant varieties and the development of new phosphite fertilizers.

Plants inevitably face a multitude of abiotic stresses during their growth and development stages. Drought stress significantly hampers crop growth and reduces yield. The plant HVA22 protein is characterized by the TB2/DP1 structural domain and is implicated in the modulation of plant growth, development, and responses to abiotic stress. However, its precise function in the context of drought stress response in tomato remains to be elucidated. Therefore, in this study, we investigated the functional role of the tomato SlHVA22l gene in drought tolerance. The results showed that the amino acid sequence of SlHVA22l exhibits a higher degree of sequence similarity to that of homologous HVA22l proteins found in other dicotyledonous plants. Furthermore, the expression pattern analysis revealed a significant upregulation of the SlHVA22l gene in response to drought stress and phytohormones (ABA and MeJA). Moreover, the function of the SlHVA22l gene in drought tolerance was subsequently verified by yeast heterologous expression and silencing of the endogenous SlHVA22l gene in tomato via virus-induced gene silencing. The silenced plants exhibited higher H₂O₂ and malondialdehyde contents, as well as lower O₂^-. scavenging after drought treatment. Moreover, the activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase were significantly decreased in the silenced plants compared to those in the control plants. Collectively, these results indicate that the SlHVA22l gene plays an important role in tomato resistance to drought stress.

This study utilized the γ-ray-induced early-maturation, fresh-green mutant line pe-1 from indica rice as an experimental material. At the trilobal stage and the tillering stage, we observed differences in morphological characteristics between pe-1 and wild type. In addition, we measured the activity of antioxidant-related enzymes and their regulatory genes expression, chlorophyll content and chloroplast synthesis and degradation-related gene expression, and photomorphogenesis-related gene expression to detect the differences in the low light response between the pe-1 and wild type. The results showed that pe-1 exhibited less leaf yellowing, taller stature, and larger leaf area compared to wild type post-stress. The changes in chlorophyll content differed between leaves at the trilobal stage and the tillering stage. Additionally, pe-1 resulted in increased chlorophyll content and elevated levels of the stress-responsive enzymes catalase and peroxidase, as well as increased expression of related genes. This indicates enhanced reactive oxygen species sca- venging and stronger adaptability to adverse conditions under low light conditions. Moreover, pe-1 exhibited increased expression levels of genes associated with photomorphogenesis, indicating superior light perception ability under low light intensities. In summary, the pe-1 mutant shows immense potential for survival under low light stress, contributing to the breeding rice with low light tolerance.

INTRODUCTION: Phosphoenolpyruvate carboxylase (PEPC) is a key enzyme for C₄ photosynthesis that help plants to resist adversity under abiotic stress. Suaeda aralocaspica, an annual halophyte, has gradually developed a single-cell C₄ photosynthetic pathway by compartmentalizing a chlorenchyma cell into distal and proximal ends to delineate and form the four-carbon (C₄) and three-carbon (C₃) cycles through long term of evolution. This unique biochemical compartmentation pattern holds promise for introducing “C₄-like microcirculation” into C₃ plants without establishing Kranz anatomy.

RATIONALE: The PEPC gene act as an essential component of C₄ photosynthesis, but few studies have reported on the PEPC gene in single cell C₄-pathway species. To reveal the impact of the SaPEPC2 gene from S. aralocaspica on the photosynthetic performance and drought resistance of C₃ plants, we evaluated the drought resistance function and photosynthetic performance of transgenic tobacco (Nicotiana tabacum) overexpressing the SaPEPC2 gene driven by its own promoter (Pro_SaPEPC2::SaPEPC2) through physiological measurements and gene expression analysis methods.

RESULTS: Our findings demonstrated that overexpressing the SaPEPC2 gene in tobacco improved leaf water retention, maintained chlorophyll stability, promoted the accumulation of osmotic adjustment substance, enhanced antioxidant enzyme activities, reduced ROS levels, mitigated the extent of membrane damage, upregulated the expression of drought-related and endogenous photosynthesis genes, and increased PEPC enzyme activity and net photosynthetic rate.

Overexpression of SaPEPC2 in tobacco results in stronger drought resistance and higher photosynthesis efficiency compared to non-transgenic plants.

INTRODUCTION  Sexual differentiation of plants, as known as dioecy, is the phenomenon of sexually dimorphic traits, which means that the female and male reproductive organs are on different individuals. In agronomic or economic ap- plications, dioecy is not a desired character for various reasons. Therefore, a simple and effective method for distin- guishing female and male individuals is a common goal for the people in many fields. As so far, molecular marker is a gold standard for sex identification genetically. It is necessary to develop a molecular technique to detect sexual systems in the dioecious plants.

RATIONALE  In plants, the origin and evolution of sex chromosomes was independent in many species, therefore sex determination region/chromosome was different among them. Idesia polycarpa is a deciduous tree, making it an attrac- tive model system with which to study sex determination mechanism. We characterized the re-sequence data of female and male individuals from natural population. We used these data to identify the sex determination systems by statistics unique sequences in females and males. To detect the sex chromosome, we analysed the single nucleotide polymor- phisms (SNPs) by genome-wide association study (GWAS).

RESULTS  The information of genome contains the secret code of various traits, so we mined the re-sequenced data of females and males. We calculated the common and unique reads in females and males, compared the unique reads between them, and found that the unique reads of females were much more than that of males. The result suggested that the sex determination system of I. polycarpa was ZW/ZZ. We then identified 30 million high quality SNPs in the population by mapping to the reference genome, calculated the p value of each SNP, drew a Manhattan plot. The result showed the highest peak on the end of 19 chromosome. We analysed the heterozygote of SNPs in this peak, and the result showed that the SNPs were heterozygotic in females, but homozygotic in males. The result confirmed that the sex determination system in I. polycarpa is ZW/ZZ. Further, a cleave amplified polymorphic sequences (CAPS) mo- lecular marker was developed according to the significant SNPs, and was successfully applied to different female and male individuals.

CONCLUSION  In the Salicaceae family, there were two kinds of sex determination system, one is XX/XY (females are homogametic XX, and males are heterogametic XY), another is ZW/ZZ (females are heterogametic ZW, and males are homogametic ZZ). At present, most studies on the sex-determining regions and genes in the Salicaceae family are carried out by methods such as genome, transcriptome, and resequencing analyses. Our results showed that the sex determination system in I. polycarpawas ZW/ZZ, and the 19^th chromosome is most likely associated with sex determination. And a CAPS molecular marker was developed, which is a simple and fast method for efficient identification sex at seedling stage. The research provided a useful way to the planting pattern of I. polycarpa.

Identification of sex determination molecular marker of Idesia polycarpa. Trees of I. polycarpa are indistinguishable as to sex without examination of the flowers. A CAPS molecular marker was developed based on genome wide analysis study on a natural population.

Flower size is a key factor in plant evolution and speciation, and also an important trait that determines plant ornamental value, so it is of great scientific significance and practical value to study the inheritance law and regulatory mechanism of floral size. To clarify the inheritance law of flower size in petunia, the inbred lines and wild species of Petunia hybrida with different flower sizes were used to make cross combinations and construct genetic populations in this study, including large-flowered line × medium-flowered lines (W × S26 and W × S) and large-flowered line × small-flowered line (W × S6). The results showed that all F₁ generation of W × S26 were large-flowered plants, while the flower size appeared separation in F₂ population with the ratio between large-and medium-flowered individuals of about 3:1, and the segregation ratio between large- and medium-flowered plants was close to 1:1 in the BC₁ backcross population. For the W × S combination, all F₁ individuals were large-flowered, while the flower size appeared separation in the F₂ population, with large- to medium-flowered plants close to 2:1. The F₁ progenies of W × S6 are all medium-flowered plants, while the flower size of the F₂ generation showed evident variation and continuous distribution. Performing mixed major gene plus polygene inheritance model analysis, the optimal models for W × S26 and W × S combination were 1MG-AD and 2MG-EAD, respectively, according to the standard of minimum AIC value. It is reasonable to conclude that the large flower trait of the inbred line W is controlled by a single dominant gene related to the middle flower trait of S26, with additive dominant effect, whereas the large flower of the inbred line W is controlled by two major genes related to the small flower of the inbred lines with equal additive dominant effect. In addition, nine genes that may regulate flower size of petunia were selected based on the transcriptomic analysis of large and small flowers, and their expression levels were detected in the petals of various strains with different flower sizes by qRT-PCR. The results showed that the expression levels of cytokinin receptor gene PhHK and Type-A RRs in response to cytokinin signal were generally higher in large flowers than in medium and small flowers, suggesting that cytokinin signaling pathway may be a key factor involved in regulating the large flower trait in petunia.

Xyloglucan endotransglucosylase/hydrolases (XTH) belongs to glycoside hydrolase, family 16 (GH16) and it is a class of enzymes that mediate the construction and recombination of xyglucan-cellulose skeleton. To explore the potential biological functions of XTH family genes in Antirrhinum majus. In this paper, bioinformatics analysis, RNA-seq analysis and qRT-PCR were used to investigate the expression levels of the family genes in the petalized and non-petalized stamens and disease-resistant materials. The results showed that the main conserved motif from 33 identified AmXTH proteins was ExDxE, which could be divided into 3 subgroups. Most of the cis-acting elements of AmXTH promoter are growth and development, disease resistance and stress resistance. RNA-seq and qRT-PCR revalidation finally unearthed four positive candidate genes (AmXTH3, 14, 18, and 33) and one candidate genes (AmXTH23) for nagatively mediated Sclerotinia sclerotiorum resistance. There were 12 positive AmXTH candidate genes (AmXTH1, 7, 9, 11, 21, 22, 23, 24, 26, 28, 29 and 33) and 2 negative AmXTH candidate genes (AmXTH15 and 31). Among them, AmXTH23 and 33 may play a role in both of the A. majus resistant to S. sclerotiorum and stamen petalization. In this study, the candidate AmXTH genes involved in S. sclerotiorum resistance and stamen petalization of A. majus were preliminarily excavated, which laid a foundation for further revealing the gene function.

As an essential enzyme in plant secondary metabolism, cinnamyl alcohol dehydrogenase (CAD) plays a key role in regulating plant growth and development, as well as biological/abiotic stress resistance. Agropyron mongolicum is a traditional forage grass widely distributed in the desert grassland areas of northern China, which exhibited high tolerance to drought and cold stresses. To explore the role of cinnamyl alcohol dehydrogenase in A. mongolicum, in this study, a CAD gene was identified from the full-length transcriptome data of A. mongolicum and subsequentially analyzed in vitro. The 1 083 bp coding sequence of AmCAD encodes 361 amino acids, which has typical conserved CAD region containing two Zn²⁺ binding motifs and NADP(H) cofactor binding motifs, belongs to the typical CAD protein, and its three-dimensional structure is similar to AtCAD5. AmCAD is highly expressed in the stem. The AmCAD recombinant protein showed a robust catalytic ability to different cinnamaldehyde substrates, with the highest substrate affinity of coniferyl aldehyde and sinapaldehyde. Under drought stress condition, the expression level of AmCAD was significantly induced, indicating a potential function of this gene in stress tolerance. The experimental results indicate that AmCAD may play an important role in lignin biosynthesis and drought stress tolerance in A. mongolicum. Our research provided potentially valuable genetic resources for molecular breeding of A. mongolicum to improve biomass quality and stress resistance.

Rice panicle traits have a distinct effect on yield, and the exploration and research of related genes play a crucial role in ensuring national food security. In this study, we used the indica rice HZ, the japonica rice Nekken2 and 120 recombinant inbred lines population constructed from them as experimental materials to measure panicle length, grain number per panicle, seed-setting rate, stigma exsertion rate, number of primary branches and other panicle traits. We combined the high-density genetic map for QTL mapping, a total of 31 QTLs were detected on chromosome 1, 2, 3, 4, 5, 6, 10 and 11, among which 2 LOD values were as high as 5.45 and 5.28. By analyzing the candidate genes in the QTL interval, the related genes that may affect the panicle traits were screened out, and qRT-PCR was used for gene expression analysis, which revealed that the expression levels of LOC_Os05g05490, LOC_Os05g06150, LOC_Os03g11700, LOC_Os03g12430, LOC_Os05g28720, LOC_Os05g30890, LOC_Os05g31740 and LOC_Os02g17880 were significantly different between the parents. Among these genes, the first five genes encode tripartite pentapeptide repeat proteins, while the latter three genes encode glycosyltransferases. This study identified 31 QTLs related to panicle traits, laying a theoretical basis for further localization and cloning of related genes and breeding new high-yield rice varieties.

Squamosa promoter binding protein (SBP) gene family is widely involved in plant growth and development, signal transduction, and many physiological and biochemical processes. Here, we identified a total of 25 SBP genes in the proso millet (Panicum miliaceum) genome, which were divided into 6 subfamilies through phylogenetic analysis. The members of the same subfamily had similar gene structure and conserved motifs. The collinearity analysis revealed 7 pairs of orthologous genes with Arabidopsis thaliana AtSBP and 31 pairs with Oryza sativa OsSBP. The analysis of cis-acting elements showed that the promoter region of SBP genes in P. miliaceum was rich in elements related to stress, plant light response and plant hormone signal response. The analysis of gene expression patterns showed that the SBP genes in P. miliaceum had obvious tissue specificity, variety specificity, and developmental stage specificity, suggesting important roles of SBP genes in the growth and development of P. miliaceum. The results provide a basis for further studying the biological function of SBP gene family in the growth and development of P. miliaceum and a reference for studying the SBP genes in other crops.

Bacterial leaf streak (BLS), caused by Xanthomonas oryzae pv. oryzicola (Xoc), is one of the most important diseases of rice, which is now highly prevalent in rice-growing regions of China, especially in Southern China (including Jiangsu, Zhejiang, Fujian, and Guangdong). Planting resistant varieties is considered as the best approach to control BLS. However, no resistant cultivars are available owing to limited genetic resources for BLS resistance. Two highly BLS-resistant materials (M1 and D1) have been discovered in our research by screening germplasm against BLS via syringe inoculation. Multi-strain inoculation showed that M1 had the characteristics of race-nonspecific broad-spectrum resistance (RNS BSR). The genetic population analysis showed that the cultivated rice M1 harbored a single dominant new gene Xo-3 of resistance to BLS. Through BSA-seq and association analysis, Xo-3 was initially mapped in a candidate region on chromosome 2. The mining of germplasm resources of BLS-resistant and the analysis of the genetic basis of its resistance will help our understanding of the interaction mechanism between rice and Xoc, so as to cultivate new varieties of BLS-resistant rice and development scientific strategies in controlling BLS.

The erection of rice leaf is one of the important agronomic traits that determine plant architecture, photosynthetic efficiency, and crop yield. Cytokinin is one of the most important plant hormones that regulate crop morphology, stress resistance and yield, but its role in the lamina joint development and leaf angle is still need to be further studied. Here, we report that rice CYTOKININ OXIDASE/DEHYDROGENASE9 (OsCKX9) controls lamina joint development and positively regulates leaf angle. Histological sections indicated that the leaf inclination changes in the WT and osckx9 resulted from the asymmetric proliferation of cells and vascular bundles in lamina joint. qRT-PCR showed that OsCKX9 was highly expressed in lamina joint. Quantification of cytokinin content in osckx9 mutant lamina joint showed that there were a mass of cytokinin accumulated. Moreover, the osckx9 showed insensitive to eBL. Therefore, our results revealed that OsCKX9 played a positive role in regulating leaf erectness, which provides genetic resources for analyzing the genetic basis of leaf angle and molecular-breeding of the ideal plant architecture rice.

To further understand the molecular mechanism underlying miRNA regulation of growth and development of Dryopteris fragrans, we screened the differentially expressed dfr-pri-mir160a through the miRNA database established earlier in the laboratory, and predicted its target gene as DfARF10. The target relationship between dfr-pri-mir160a and DfARF10 was verified by tobacco transient co-transformation, together with double luciferase (LUC) activity. The results showed that the GUS and LUC activity in tobacco leaves co-injected with dfr-pri-mir160a and DfARF10 decreased significantly. qRT-PCR analysis showed that dfr-miR160a and its target gene DfARF10 were expressed in the gametophytes, roots, petioles, leaves and sporangium of D. fragrans, with the highest expression in the leaves and the lowest in the roots. We analyzed the effects of drought, NaCl, high temperature and low temperature stress treatments on dfr-miR160a and its target gene DfARF10 through qRT-PCR. Under drought and high temperature treatment, the relative expression of dfr-miR160a was up-regulated, but under NaCl treatment, the expression of dfr-miR160a was down-regulated. Under low temperature treatment, the expression of dfr-miR160a was down-regulated at 0-1 h and was up-regulated at 3-48 h. The expression of DfARF10 was up-regulated under NaCl, high temperature and low temperature treatments. However, under drought treatment, the expression of DfARF10 decreased, distinct from dfr-miR160a. The above results indicated that target gene of dfr-miR160 was DfARF10, and both of them can respond to abiotic stress treatment. This study provides a new scientific basis for revealing the abiotic stress resistance mechanism of D. fragrans at the molecular level.

Phytochrome is an important receptor for red and far-red light sensing in plants, and it plays a vital role in regulating the plant flowering period, improving crop yield potential and regulating plant stress resistance. Identification of PHY family genes in Gossypium, exploration of the patterns of inheritance and regulatory network of domestication and improvement, and identification of the key phytochrome genes in Gossypium, provides insights into the de novo domestication and breeding of early maturing Gossypium species. To identify the phytochrome genes of Gossypium, we used bioinformatics methods to analyze 5 phytochrome genes in Arabidopsis thaliana. Phylogenetic analysis showed that the PHY genes in Malvaceae species consisted of 4 subfamilies (PHYA, PHYB, PHYC and PHYE). Moreover, the domestication selection analysis of PHY genes among different populations of G. hirsutum showed that the domestication process of PHY genes could be divided into two stages: domestication and improvement. Furthermore, the gene expression of the PHY gene family was analyzed using leaf RNA-sequencing data obtained from wild and cultivar genotypes of G. hirsutum under short-day (SD) and long-day (LD) conditions. The results showed that the expression of GhPHYA1Dt and GhPHYB1Dt were significantly different between SD and LD conditions. After 14 hours of long-day treatment, the expression of GhPHYC1At and GHPHYE1At in the cultivar was significantly lower than that in wild species. These results lay a foundation for further study on domestication selection and functional mechanisms of Gossypium PHY genes and provide a theoretical basis for breeding new early maturing Gossypium varieties and de novo domestication.

To investigate the effect of potassium (K) nutrition on leaf growth and phyllosphere microbial community in oilseed rape (Brassica napus), a field experiment with three K fertilizer application rates (0, 30, and 180 kg K₂O∙hm^‒2), referred to as K0 (deficient K), K30 (insufficient K), and K180 (sufficient K), was conducted. Typical leaves were selected to measure the phenotypic parameters during the seedling stage. The composition of the phyllosphere microbial community was determined using high-throughput sequencing of the 16S RNA gene. The main findings revealed K fertilization significantly affected leaf K content. Compared to the K0 treatment, the K content increased by 66.7% and 158.3% for the K30 and K180 treatment, respectively. Significant differences in the structure and components of oilseed rape leaves were observed under different K nutritional conditions. Leaf K content exhibited a significant positive correlation with leaf area, and content of soluble sugar, sucrose, fructose, and starch, while it showed a significant negative correlation with leaf stomatal density. K fertilization had a remarkable impact on the diversity of phyllosphere microbial community. K fertilization led to a significant increase in the diversity index, while no significant difference was observed between the K30 and K180 treatments. However, the K30 treatment displayed greater dispersion in terms of community β-diversity compared to the K180 treatment. K deficiency increased the relative abundance of Proteobacteria, resulting in an obvious enrichment of Xanthomonadaceae. The application of K fertilizer simplified the bacterial co-occurrence network but increased the interaction between high-abundance species and other species. A comprehensive analysis of leaf phenotypic parameters and phyllosphere bacterial communities revealed that leaf sugar components (soluble sugar, sucrose, fructose, and starch), dry matter weight, and leaf area were the key factors influencing the phyllosphere bacterial communities and dominant species. In conclusion, K fertilizer application influenced the material compositions of oilseed rape leaves and regulated the microbial community structure. The establishment of "homeostasis" within phyllosphere microbial communities by maintaining sufficient leaf K nutrition status might serve as a potential pathway for enhancing crop biological stress resistance.

Raw lacquer is a valuable natural coating material with exceptional properties, including heat, corrosion, and acid resistance, which make it an important resource in various industries. Revealing the changes in metabolites during its growth process of lacquer is the key to excavate its applications. We analyzed phloem sap samples of Toxicodendron vernicifluum at different developmental stages (based on the time of lacquer harvesting) using broad targeted metabolomic analysis technology, including principal component analysis, orthogonal partial least squares discriminant analysis, and cluster heat map analysis, to investigate the differences and changing patterns of metabolites. Our analysis identified 529 metabolites in raw lacquer, which can be classified into 13 major groups, including flavonoids, phenolic acids, alkaloids, tannins, sugars and alcohols, and lipids. Multivariate statistical analysis revealed that the metabolic characteristics of raw lacquer in the second, third, fourth, and fifth developmental stages were similar, but significantly different from those in the first stage. By comparing and analyzing the metabolites in raw lacquer at different developmental stages, we identified 92 common differentially abundant metabolites. Notably, flavonoid compounds primarily accumulated in raw lacquer during the first stage, while amino acids and their derivatives, sugars, and alcohols had relatively higher contents in raw lacquer at later stages. Our findings provide a comprehensive understanding of the metabolic characteristics of raw lacquer at different developmental stages, which could have significant implications for the development and utilization of lacquer resources.

Soil potassium deficiency has severely reduced the potato field production in China. Fortunately, different potato varieties respond to low-potassium conditions very differently. Therefore, the utilization of potato varieties with low-potassium tolerance is an important approach to reduce potassium application by increasing potassium utilization efficiency, thus promoting the sustainability and the green development of agriculture in China. In this study, 17 biological features of 30 potato varieties were examined under normal potassium (202.5 kg∙hm^-2 K₂O) and low potassium conditions (0 kg∙hm^-2 K₂O), and nine representative features, including leaf area index, root-shoot ratio, shoot dry mass, root dry mass, tuber yield per plant, large tuber yield per plant, small tuber yield per plant, tuber dry mass, and tuber potassium accumulation were selected for subsequent analysis. The results showed that all feature values went down under the low potassium condition. Principal component analysis revealed that the nine features can be transformed into 4 independent comprehensive components, with a cumulative contributive rate of 87.1%. According to the comprehensive evaluation value (D value) and cluster analysis, the 30 varieties can be divided into 6 categories, including seven high tolerant varieties to low potassium: Lucinda, Favorita, Kexin1, Xisen6, Xingjia2, Helan15 and Chuanyin2, and six varieties with moderate tolerance to low potassium: Longshu20, Dingshu3, Jizhang12(W), Jiuen1, Longshu19, Jizhang12(Y). Furthermore, we developed a regression model Y=-0.595+0.247X₅+0.155X₄+0.138X₃+0.167X₈+0.088X₁+0.081X₆+0.097X₉+ 0.053X₂ (R²=0.999, P=0.000) to distinguish the 30 varieties from each other with an accuracy above 90%. In summary, under low potassium condition, several features, including tuber yield per plant, root dry mass, shoot dry mass, tuber dry mass, leaf area index, large tuber yield per plant, tuber potassium accumulation and root-shoot ratio can be used to rapidly identify low potassium tolerant varieties.

Plant epidermis is crucial in regulating photosynthesis, respiration, heat dissipation, and water utilization. Significant progress has been made in the study of stomatal development in dicotyledonous plants, such as Arabidopsis thaliana. Three important bHLH transcription factors (SPCH, MUTE, and FAMA) have been reported to be specifically expressed at different stages of cell division and differentiation in the stomatal lineage. They form heterodimers with another transcription factors SCRM/ICE1 and SCRM2/ICE2 to regulate the morphological transformation and changes of stomatal lineage cells across three stages of division, finally forming the stomatal complex. However, in monocots, especially in Poaceae plants such as maize (Zea mays), studies on genes regulating epidermal morphogenesis are less reported. In this study, two single-gene recessive mutants, Zmice1-1 (inducer of cbf expression1-1) and Zmice2-1, were isolated using reverse genetics approaches. Compared to the control B73, Zmice2-1 exhibited dwarfism, leaf chlorosis, reduced fertility, significantly lower stomatal density and index, disrupted arrangement of epidermal long cells, and absence of spacing between stomata. Zmice1-1 leaves gradually turned yellow from the five-leaf stage and displayed complete chlorosis at later stages. The homozygous Zmice1-1 plants are growth-arrested and sterile, but the stomatal density showed no significant difference compared to the control. Different allels of Zmice2 were obtained using CRISPR-Cas9 genome editing technology. Phenotypic identification showed that Zmice2-2 had an abnormal stomatal phenotype similar to Zmice2-1, indicating that ZmICE2 is involved in the regulation of stomatal development. Transcriptome analysis of B73 and Zmice2-1 revealed that ZmICE2 primarily regulated stomatal development by affecting cell division and differentiation, participating in the formation of maize epidermal morphology. These results contribute to a better understanding of the mechanisms of epidermal morphogenesis in maize and provide valuable genetic resources for improving crop resilience and yield traits.

Lodging of rice is one of the main factors reducing rice yield. The mechanical strength of stem affects lodging resistance of rice and is closely related to the content of stem cell wall related components. Improving lodging resistance of rice by regulating the related components in the cell wall of stem is an effective way to improve the yield and quality of rice. In this study, indica rice variety Huazhan (Oryza sativa subsp. indica cv. ‘HZ’) and japonica rice variety Nekken2 (O. sativa subsp. japonica cv. ‘Nekken2’) were crossed to obtain F₁ generation. A total of 120 RILs (recombinant inbred lines) population were obtained by successive multigeneration self-crossing and the genetic linkage map was constructed. Based on the constructed high-density genetic map, the QTLs related to the content of cellulose, hemicellulose, and lignin in the cell wall of rice stem were located and analyzed. The results showed that 4 QTLs related to cellulose, 12 QTLs related to hemicellulose, and 8 QTLs related to lignin. At the same time, candidate genes analyses were conducted on the detected QTLs’ intervals, and a total of 13 candidate genes were screened. The expression levels of candidate genes were detected by qRT-PCR. Except for LOC_Os02g58590 and LOC_Os12g41720, the other candidate genes showed significant differences between parents. The results laid an important foundation for exploring genes that regulate the mechanical strength of rice stems, further screening and breeding rice varieties with strong lodging resistance.

Marigold (Tagetes erecta) is an important ornamental plant of the genus Tagetes in the Asteraceae. The morphology of its ray floret corolla varies from smooth, undulate to different degree of incision. An F₂ population was constructed from a cross between the mutant marigold JH with five-lobed corollas and fertile stamens in the first round florets and the inbred line S5 with smooth corolla of ray florets and aborting stamens. Inheritance analysis showed that the mutation trait of JH was controlled by a single-dominant gene, named Tagetes erecta lobed ray florets (Telf). Histological and cytological observations showed that the first round ray florets of JH were disk-like, with five lobes formed at the top of the corolla tube, the middle and lower parts were tubular, and the development of anthers and pollen grains are to normal. Using BSR-seq and comparative genomics methods, the gene Telf controlling lobed ray florets was mapped in the interval of 37003-SCAR and 34032-CAPS. 37003-SCAR marker was 3.684 cM from the Telf gene. On the other side of the gene, 34032-CAPS marker was placed about 3.517 cM from Telf. This study laid a foundation for the subsequent fine mapping of the target gene Telf, and also provided a new method for the selection of molecular markers in marigold.

(reed) is a cosmopolitan species, with huge biomass and high environmental adaptability. Restricted by its polyploidy genome, it is very difficult to study its unique properties at the genetic level. Using third-generation sequencing and multiple methods, we comprehensively studied the type, structure, expression, and localization patterns of RCA genes (encoding Rubisco activating enzyme) in two reed ecotypes (2n=8x). There are four types of RCA genes in Phragmites genome, all belonging to the RCA2β category. At the transcriptional and protein levels, we adopted immunogold method to detect the localization of RCA proteins. We found that RCAs have obvious ecotype specificity. Compared with swamp reeds (SR), desert-dune reeds (DR) have low RCA expression and RCA2-β2 are preferentially expressed. Six highly expressed RCA isoforms were identified though two-dimensional electrophoresis (2-DE) and mass spectrometry (MS), and were distributed in a high proportion in membrane fraction in DR. This result supports the hypothesis that RCA may transfer to the membrane area as the environment deteriorates, thereby giving RCA a protective function on the chloroplast membrane.

miRNAs are involved in plant growth and response to stress by regulating the expression of target genes. We conducted a functional study on a single miRNA identified by our group, Bna-miR43. The function of Bna-miR43 under drought stress was investigated by constructing a Bna-miR43 overexpression vector. Degradation group sequencing has predicted that the four target genes of Bna-miR43 belonged to the F-box protein family. Under simulated drought conditions, the expression of Bna-miR43 in J572 roots decreased gradually, while the expression pattern of target genes was shown to be opposite to that of Bna-miR43. With the increaseing time of drought treatment, the expression of target genes increased gradually. Expression pattern analysis showed that Bna-miR43 could respond to drought stress by negatively regulating the expression of target genes. Transgenic experiment showed that under drought stress, the Bna-miR43 overexpressed lines were extremely sensitive to drought. It was shown that the germination rate of the overexpressed lines decreased significantly, the plant dehydration was serious, and more MDA and H₂O₂ were accumulated in the body. After drought treatment, three coding superoxide dismutase (SOD), catalase (CAT) and glycolate oxidase (GOX) were identified in the Bna-miR43 overexpressed lines, and their expressions were down-regulated in the Bna-miR43 overexpressed lines. The results showed that Bna-miR43 plays a key role in regulating plant drought tolerance by regulating the osmotic accumulation and ROS homeostasis in Brassica napus.

Chitin, a major component of the fungal cell wall, is a kind of typical microbe associated molecular pattern (MAMP) that is recognized by two plasma membrane located LysM receptors, CERK1 and LYK5, and trigger immune response in plants. In this study, the intracellular kinase domain of CERK1 was cloned and used to screen the yeast cDNA library, and identify its interaction with HSP1. Using CRISPR-Cas-mediated gene editing technology, we knocked out the HSP1 gene in wild-type Arabidopsis thaliana Col-0 and obtained hsp1 v63 deletion mutant. We showed that the expression of downstream defense-related genes and the phosphorylation pathway of mitogen-activated protein kinase were inhibited in the hsp1 v63 deletion mutant compared to the wild type Col-0. We also showed that the protein level of CERK1 in hsp1 v63 mutants was lower than that in the Col-0, and that reduced CERK1 levels in this mutant were associated with the endoplasmic reticulum degradation system. These results indicate that HSP1 is a key gene in the chitin-induced defense response pathway, thus revealing the important roles of molecular chaperone in regulating receptor protein level and improvement in crop resistance.

Soil cadmium (Cd) pollution seriously restricts the yield and quality of facility vegetables. Melatonin (MT) can enhance the resistance to various stresses in plants. However, the downstream signals, which regulated by MT during tomato seed germination under Cd²⁺ stress remains unclear. The effects of Cd²⁺ stress and exogenous MT on seed germination were investigated using tomato (Solanum lycopersicum) wild-type Alisa Craig seeds. The results showed that the germination of tomato seeds and seedling growth were significantly inhibited by Cd²⁺ treatment with more than 0.5 mmol·L^-1. Exogenous MT (0.15 mmol·L^-1) reduced the content of Cd²⁺ in the underground and above-ground tissues of seedlings, effectively alleviating the inhibitory effect of Cd²⁺ stress on tomato seed germination and seedling length. The expression of phytochelatin and transporters-related genes (PCS, NRAMP1, ABCC3, HMA3, and ABCG5) in tomato radicles were significantly increased by MT under Cd²⁺ stress, showing the positive regulation of MT in transmembrane transport and vacuolar sequestration of Cd²⁺. In addition, MT alleviated the oxidative damage induced by Cd²⁺ stress, which was related to the enhanced activities of CAT, APX, and ALDH enzymes apart from its own scavenging ability. Furthermore, MT significantly down-regulated the expressions of abscisic acid (ABA) synthesis genes (NCED1 and NCED2) under Cd²⁺ stress, and up-regulated the expression of ABA decomposition gene ABA8ox1, leading to the decrease of ABA content, which effectively regulated the GA/ABA ratio and promoted the germination of tomato seeds under Cd²⁺ stress.

Heterostyly is a kind of floral morph polymorphism in angiosperms, which is characterized by the reciprocal herkogamy and accompanied by physiological self- and intra-incompatibility but inter-compatibility. And the homostyly (H) is a kind of self-compatible floral morph with stigmas and anthers at the same position within a flower, which occurs during the formation and evolution of heterostyly. It has been reported that distyly appeared earlier in Goniolimon than in other genus in the Plumbaginaceae. However, our field survey found that a large number of floral morphs with the same length of pistils and stamens (H-morphs) appeared in the natural population of Goniolimon speciosum in Xinjiang, similar to homostyly. It is not clear how the H-morphs emerge, whether the H-morphs have been self- and intra-compatible, and what kind of relationship between the H-morphs and the typical floral morphs with long- (L-) or short- (S-) style flower. Thus, we investigated the floral morph composition and frequency, measured the floral parameters and stigmatic pollen loads among floral morphs, and also examined the accessory polymorphism and heteromorphic incompatibility system of G. speciosum in five natural populations. The result showed that all populations were composed of L-, S- and H-morphs, but each population still had dimorphism of pollen-stigma morphology and strictly disassortative mating, which showed that the floral morphs with different pollen ornamentation and stigma papilla cell morphology were compatible regardless of the reciprocal herkogamy, but incompatible if the floral morphs were the same. Conclusion: H-morphs may the result of the variation of reciprocal herkogamy between floral morphs by shortening of stigma in L-morph or shortening of anther in S-morphs, but have not transformed into the homostyly. For this species, the variation of reciprocal herkogamy and the transformation of physiological incompatibility may be independent of each other.

Although resistant cultivars have been widely employed as the most economical and effective way to control bacterial blight (BB) in rice, the outbreak of BB reoccured in Southern China in recent years. In order to investigate the cause for the recent outbreak of BB in China, we collected the rice leaves with typical BB symptom from paddies in eight southern provinces (Hainan, Yunnan, Guangxi, Guangdong, Fujian, Hunan, Zhejiang, and Jiangsu) in 2019 to 2021. A total of 97 Xanthomonas oryzae pv. oryzae (Xoo) strains isolated from the BB-diseased leaves were divided into 10 genotypes by Southern hybridization detection of transcription activator-like effectors (tale), of which genotype V was the representative of the dominant population. The representative strains of each genotype were applied to inoculated rice accessions with different resistance (R) gene. The inoculation results revealed that traditional major R genes such as Xa3 and Xa4 were only effective against a small number of the newly isolated Xoo strains, whereas Xa7 and Xa23 still had broad-spectrum resistance to all (or the majority of) these strains. We concluded that the cause for the recent outbreak of rice BB in Southern China is most likely the insufficient use of effective BB resistance genes in the new rice varieties. Exploring and utilizing excellent resistance gene resources is still the most ideal way to prevent and control BB.

Lutein can effectively reduce incidence of atherosclerosis, diabetes, cancer and multiple eye diseases. The lutein biofortification through food crop has gained more attention with improvement of daily diet. In this paper, 194 Shanxi wheat cultivars planted in three environments were used to extract lutein by organic solvent extraction, and the content of lutein in different germplasms was determined by high performance liquid chromatography (HPLC). The broad-sense heritability of lutein content in wheat and its relationship with grain color, winter/spring types, geographical origin, accession types, and main agronomic traits were analyzed, and the genetic loci associated with lutein content were identified through genome-wide association analysis. Results showed that significant variation in lutein contents occurred among Shanxi wheat accessions, the coefficient of variation was 33.12%-48.57%. Genotype was the main factor affecting lutein content. The average lutein content in three environments was 0.67-4.03 μg·g^-1, 0.16-5.05 μg·g^-1 and 0.16-3.63 μg·g^-1, respectively. The average lutein content of winter types and irrigated-wheat accessions were higher than those of spring types and dryland-wheat, respectively. There was no significant effect of grain color and released years on lutein content. Heading date, plant height and 1 000 kernel weight were significantly negative correlated with lutein content. The other agronomic traits had no significant effect on lutein. Genome-wide association analysis found four major loci related to lutein content on chromosomes 1B, 3A and 7A, among them, QLuc.3A and QLuc.7A.1 are new loci affecting the lutein content. These results provide valuable information for breeding and cultivation of wheat lutein bioaugmentation varieties.

The PLATZ transcription factor family is a class of plant-specific zinc-dependent DNA-binding proteins that play an indispensable role in plant growth and development and stress resistance. However, the PLATZ family genes have not been systematically analyzed in foxtail millet (Setaria italica). In this study, 17 PLATZ genes in the foxtail millet genome were identified and systematically named. The SiPLATZ genes were divided into five subfamilies by phylogenetic analysis, and members of the same subfamily have similar gene structures and motifs. Cis-acting element analysis demonstrated that the SiPLATZ genes may play a role in endosperm development and various stress-resistant responses. The K_a/K_s ratio analysis indicates that duplicated genes are subject to purifying selection. There were significant differences in the expression of SiPLATZ genes in different tissues and developmental stages, which were mainly divided into two categories: high expression in roots, leaves, and stems, and in spikes and seeds. This reflects the complexity of the physiological functions of SiPLATZ genes and their possible involvement in regulating seed growth and multiple stress responses. In addition, the co-expression network constructed in combination with WGCNA analysis revealed that SiPLATZ6, SiPLATZ8, SiPLATZ9 and SiPLATZ11 may be the candidates for genetic improvement of foxtail millet yield and functional gene research. These results lay the foundation for further studies on the biological functions of PLATZ transcription factors in foxtail millet growth and development.

Borneol is one of the most important pharmacodynamic components in Artemisia argyi, which has antibacterial, anti-inflammatory, analgesic and other pharmacological activities. The synthesis and metabolism of borneol are affected by many kinds of enzymes, and borneol dehydrogenase is one of the key enzymes that oxidize borneol to camphor. In this study, the contents of borneol and camphor in 35 germplasm of A. argyi leaves were determined by Gas chromatograph-mass spectrometer (GC-MS). We found that the amount of borneol and camphor was highly varied among the varieties, and some germplasm contained more camphor than borneol, indicating that a large proportion of borneol was oxidized to camphor in A. argyi leaves. Based on the full-length transcriptome of A. argyi and homology comparison analysis, we cloned the first borneol dehydrogenase encoding gene AArBDH1 in A. argyi. The AArBDH1 contained 2 exons and 1 intron, and encoded a protein of 289 amino acids. The AArBDH1 gene expression levels were measured by real-time quantitative reverse transcription PCR (qRT-PCR) technology, which showed that AArBDH1 was differentially expressed in different tissues and in leaves at different development stages, and highly expressed in stem and 30 days old leaves. The enzymatic reactions of AArBDH1 with borneol as substrate and NAD⁺ as coenzyme showed that AArBDH1 could catalyze the dehydrogenation of borneol to camphor. Our study provides a theoretical basis and gene resource for further analyzing the regulation and potential improvement of borneol accumulation in A. argyi leaves.

Aluminum (Al) is one of the common metal contaminants in acidic soils. To reveal the effects of exogenous organic acids on the physiological characteristics and root DNA damage of Helianthus tuberosus under Al stress, we used Al resistant H. tuberosus cv. ‘Xuzhou’ and Al sensitive H. tuberosus cv. ‘Ziyang’ as materials. The effects of exogenous organic acids on the physiological responses and DNA damage of H. tuberosus at various periods (7, 14, and 21 d) under Al stress were investigated by setting 0, 350 and 700 µmol∙L^-1 Al concentration treatments and applying 0, 30, 60 and 90 µmol∙L^-1 compound organic acids, respectively. The results showed that Al stress inhibits root elongation and root activity, severely inhibited the photosynthetic and antioxidant systems of H. tuberosus, and the DNA damage in the root system increased with the increase of Al concentration. In contrast, the application of compound organic acid effectively alleviated Al stress. 60 µmol∙L^-1 compound organic acid improved the activity of the antioxidant system, maximum photochemical efficiency and organic acid secretion in root tips, secretion of citric acid was 2 times (H. tuberosus cv. ‘Xuzhou’) and 0.75 times (H. tuberosus cv. ‘Ziyang’) higher than the control, reduced root tip Al content and improved root activity. Besides, H. tuberosus cv. ‘Xuzhou’ and H. tuberosus cv. ‘Ziyang’ oliver tail moment decreased by 51.53% and 35.10%, and compound organic acid reduced the DNA trailing phenomenon and repaired DNA breaks to a greater extent. In conclusion, high concentration of Al causes serious damage to H. tuberosus, which is difficult to mitigate. 60 µmol∙L^-1 compound organic acid could enhance the H. tuberosus physiological responses under low Al stress, reduce DNA damage and thus improve the stress resistance. The alleviation effect was better in H. tuberosus cv. ‘Ziyang’. This study reveals the regulatory role of exogenous organic acids on the physiological responses of H. tuberosus under Al stress, and provides a theoretical basis for planting and production of H. tuberosus and production of other cash crops in the acid-aluminium areas of southern China.