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.