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.

Chimeric soybean plants with transgenic hairy roots is very important for soybean functional genomics. In this study, we used three soybean genotypes to compare their hairy root induction rate and plant survival rate under different co-cultivation conditions. Our results showed that co-culturing the explants infected by Agrobacterium rhizogenes for 1 d under dark conditions was an effective strategy to induce hairy roots. We also found that removing the adventitious roots (AR) at hypocotyl significantly increased number of hairy roots, enhanced their growth and subsequently improved the positive rate of transgenic hairy roots. Furthermore, we found that the inoculation with rhizobium at 14 d of induction was able to enhance the contact between the bacteria and the transgenic hairy roots at early growth stages, and thus improved the soybean’s nodulation efficiency. Taken together, we successfully established a simple and efficient method to generate chimeric soybean plants with transgenic hairy roots. This method can be widely used in soybean gene functional studies.

To solve the problem of breeding excellent seedlings of Erythropalum scandens, research has been conducted on the establishment and optimization of tissue culture and rapid propagation systems of E. scandens by taking apical bud-induced aseptic seedlings as the material. Explant sterilization, callus induction, callus differentiation, test-tube rooting and transplanting and domestication were studied. The results are as follows: the best ratio of sterilization was 60 seconds of 75% alcohol+10 minutes of 0.1% HgCl₂, and the success rate was 48.89%. The best formula for callus induction by aseptic seedling leaf was MS+0.5 mg·L^-1 6-BA+1.0 mg·L^-1 2,4-D+1.0 mg·L^-1 IBA, for 30 days, and the induction rate was 71.11%, with compact green and strong differentiation potential. The best formula for callus induction by aseptic seedling shoot was MS+1.0 mg·L^-1 6-BA+0.5 mg·L^-1 2,4-D+1.0 mg·L^-1 IBA, for 30 days, and the induction rate was 70.00%; The most suitable medium for induction of callus propagation and differentiation was MS+2.0 mg·L^-1 6-BA+0.5 mg·L^-1 TDZ+1.0 mg·L^-1 IBA, bud differentiation rate was 98.89%, and coefficient of propagation was 3.33. The most suitable medium for rootage was MS+1.5 mg·L^-1 6-BA+0.5 mg·L^-1 IBA, achieving a 100% rootage rate with 2.2 of the average number. Plantlets were transplanted to small particle peat soil, and 88.89% of rooted plants survived. The research has established the tissue culture and rapid propagation system of E. scandens, which can be applied in production and serve as a foundation for providing seedlings and factory production.

Stress associated proteins (SAPs) are a group of A20/AN1 zinc-finger domain-containing proteins which play regulatory roles in plant response to adverse stresses. Although many studies have elucidated the functions of plant SAPs during these processes, their action mechanisms have not been systematically summarized. In this review, we briefly summarized the structural characteristics and classification of plant SAPs, with a focus on elucidating their action mechanisms. Further, we summarized the research progress on their response to environmental stress, with the aim of enhancing our understanding of plant SAPs and providing a reference for future research.

As plants cannot escape from adversity, they need to evolve highly sensitive and flexible physiological mechanisms to cope with various abiotic stresses in the natural environment. It has been shown that when plants are subjected to abiotic stresses in local tissues or organs, the plant is able to generate systemic responses through intercellular signaling that allows the plant to develop an acclimation to the stress (i.e., systemic acquired acclimation). Currently, a large amount of work has investigated the role of intercellular signaling molecules in systemic acquired acclimation of plants (mainly including reactive oxygen species signals, calcium signals, electrical signals, plant hormones, phosphatidylinositol, and pH signals) receptor-like protein kinases and other protein kinases in systemic signaling. Here, we mainly review the research progress of intercellular signaling in the abiotic stress-induced systemic responses in plants, and analyze the possible relationships among different signals, so as to provide reference for related research.

The secondary metabolites produced by plants provide human beings with a wealth of pharmaceutical, perfume and industrial raw materials. With the rapid development of molecular biology and genomics research, the biosynthetic gene clusters (BGCs) of secondary metabolites of various plants have been analyzed, which opens a new path for us to quickly obtain the biosynthetic pathways of target products and discover novel natural products. This paper focuses on the definition and characteristics of plant secondary metabolite biosynthesis gene clusters, and its basic structural models, evolution and regulatory mechanisms, in order to provide theoretical basis and reference for related research.

Chloroplast is the main place for photosynthesis of green plants, and thylakoid is the key component of the membrane structure in the chloroplast. Various protein complexes and lipids are distributed on the plant thylakoid membrane. About half of the lipid components are glycolipids, mainly including monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol. The proportion of phospholipid in the membrane is very low, and the main phospholipid component is phosphatidylglycerol. Most protein complexes of photosynthesis are embedded in regularly arrranged polar lipids. These membrane lipids are essential for plant photosynthesis and growth. A comprehensive knowledge on the structure and function of the major lipids in thylakoid membranes in prokaryotes or eukaryotes and their biosynthesis will help our further study in understanding of the mechanism of photosynthesis light energy and substance conversion, and provide theoretical basis for the study of membrane lipids in plant thylakoids.