Rice leaf angle, a major determinant of plant architecture and yield potential, is tightly regulated by brassinosteroid (BR) signaling. Although the core BR pathway is well characterized, how BR responses are precisely controlled in space and time remains unclear. Here, we identify OsvWA36, a novel regulator required to fine-tune BR signaling. The osvwa36 mutant exhibits typical BR-deficient phenotypes, including decreased leaf angle and reduced BR responsiveness, whereas ubiquitin promoter-driven expression of OsvWA36 confers BR hypersensitivity. We further show that the OsvWA36 protein undergoes intrinsically disordered region (IDR)-driven liquid-liquid phase separation to form dynamic condensates associated with the endoplasmic reticulum. These condensates facilitate a direct interaction between the OsvWA36 protein and the KNOX transcription factor OSH1. Genetic analyses indicate that OsvWA36 is necessary for full activation of the OSH1-regulated transcriptional program, including induction of BR catabolic genes (e.g., CYP734A2/4/6). In parallel, OsvWA36 broadly influences the expression of key activators of BR signaling and biosynthesis. Collectively, OsvWA36 integrates both positive and negative regulatory branches of the BR network to optimize leaf angle. These findings reveal a phase separation-based mechanism underlying hormone signaling and suggest that OsvWA36 is a promising target for the engineering of plant architecture.

Grain length is a crucial determinant of rice yield and quality. Although von Willebrand factor type A (VWA) domain proteins have recently emerged as regulators of plant architecture in cereals, their roles in controlling rice grain length remain largely unexplored. Here, we report the functional characterization of OsvWA36, a VWA-domain protein selected from a TMT-based quantitative proteomic screen of indica rice varieties differing in grain length. Loss-of-function OsvWA36 mutants exhibited significantly reduced grain length and thousand-grain weight, while complementation and overexpression assays confirmed its positive regulatory role in these traits. Cytological analysis revealed that the shortened grain phenotype was due to suppressed longitudinal elongation of hull epidermal cells, which was accompanied by aberrantly enhanced lignin deposition. Transcriptomic profiling and Gene Ontology (GO) enrichment analysis demonstrated that OsvWA36 is essential for the expression of a comprehensive suite of cell wall biosynthesis and modification genes, including those involved in cellulose, pectin, and lignin metabolism. Furthermore, OsvWA36 localizes to punctate structures on the endoplasmic reticulum (ER). Our study establishes OsvWA36 as a novel VWA-domain protein that positively regulates grain length by orchestrating cell wall remodeling programs, thereby bridging VWA protein function with the transcriptional regulation of cell wall dynamics in rice. This work not only identifies a promising genetic target for molecular breeding but also provides a new molecular framework for understanding grain size regulation in cereal crops.

A total of 4006 tropical and subtropical rice germplasms were screened for brown planthopper resistance, and the resistance mechanisms of 63 highly resistant accessions were characterized. This led to the designation of three novel resistance QTLs: Bph47, Bph48, and Bph49. The brown planthopper (BPH) is a significant piercing-sucking pest of rice plants that causes widespread destruction globally. Discovering new germplasms and genes for BPH resistance is essential for enhancing genetic diversity in rice breeding. In this study, 4006 rice accessions from tropical and subtropical regions were screened for BPH resistance at the seedling stage, and 63 accessions with high-resistant were identified. Of these, 59 accessions exhibited high resistance to BPH at the adult stage. The 63 accessions displayed widespread variation in key agronomic traits, though most were generally unsatisfactory. Assessments of antixenosis, antibiosis, and tolerance indicated diverse resistance mechanisms in the 63 accessions, with the majority (39/63) demonstrating both antixenosis and antibiosis. Microscopic observations and physiological assessments revealed significant differences in vascular bundle structure, fiber content, and activity of defense-related enzymes between the 63 high-resistance and 27 susceptible ones. Furthermore, correlation analysis highlighted a substantial positive relationship between BPH resistance and parameters such as rice trypsin inhibitor (RTI) levels and width of the sclerenchyma layer (WSL). Genetic analysis of F2:3 segregating populations from four resistant accessions crossed with the susceptible rice variety 9311 identified three novel major-effect quantitative-trait loci (QTLs) located on chromosome 1L (690 kb and 1.84 Mb) and 5S (295 kb). This study significantly enriched the BPH-resistant germplasm sources and genes, highlighting the varied resistance mechanisms of rice against BPH.

Grain length is a critical agronomic trait that directly determines rice yield. In this study, we identified OsvWA36, a von Willebrand factor A (VWA) domain protein containing intrinsically disordered regions (IDRs). We showed that it is a novel positive regulator of grain length and that its function is achieved through liquid-liquid phase separation (LLPS) and subsequent modulation of cell wall remodeling.OsvWA36 was discovered through proteomic screening, and its abundance was positively correlated with grain length. It preferentially accumulated in developing panicles and formed liquid-like condensates via IDR-mediated LLPS, as indicated by in vitro/in vivo assays and fluorescence recovery after photobleaching analysis. CRISPR-Cas9-generated osvwa36 mutants developed shorter grains due to reductions in glume cell length and the aberrant accumulation of lignin. Transcriptomic and qRT-PCR analyses revealed that deficiency in OsvWA36 suppressed the expression of genes associated with cell wall dynamics, including those involved in cellulose synthesis ( OsCESA4, OsCESA7 , and OsCSLE1 ), pectin metabolism ( OsPME68, OsPME1 ), and lignin modification ( OsCAD2, OsMYB58 , and OsExo70H3 ). Genetic complementation restored the wild-type phenotype, whereas overexpression of OsvWA36 further elongated grains. Deletion of the IDR domain abolished LLPS and resulted in short grains, phenocopying the osvwa36 mutants and underscoring the functional necessity of phase separation. Furthermore, haplotype analysis revealed that natural variation in OsvWA36 was correlated with grain length diversity in rice cultivars.In conclusion, our findings indicate that OsvWA36 regulates grain length by orchestrating cell wall remodeling through IDR-mediated LLPS and could be a useful target for molecular breeding strategies aimed at improving yield.

Rice blast disease, caused by Magnaporthe oryzae (M. oryzae), poses a major threat to global rice production annually. The Pi1 gene is a key determinant of resistance to this pathogen. However, the proteomic responses of rice to M. oryzae infection in both Pi1-containing and Pi1-deficient backgrounds remain poorly understood. This study investigated Pi1-mediated protein responses in rice using quantitative proteomics to compare the susceptible line MeiB and its Pi1-introgression line 96B. Comparative analysis of 4-day post-infection samples versus untreated controls identified 121 differentially expressed proteins (DEPs) in 96B and 126 in MeiB. Functional classification showed that DEPs related to cellular processes, metabolic processesprocesses, and responses to stimuli were significantly enriched in Gene Ontology (GO) analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed enrichment in metabolic pathways, secondary metabolite biosynthesis, and phenylpropanoid biosynthesis in both lines. Notably, Pi1 modulated proteins associated with apoptosis and purine metabolism during M. oryzae infection in 96B. Network analysis revealed 44 DEPs, including the pathogenesis-related protein PR10a, forming protein–protein interaction networks in 96B, compared to only 22 DEPs in MeiB. The key findings include the specific regulation of biotic stress-related proteins such as Gnk2-homologous domain-containing protein and AT-hook motif nuclear-localized protein in 96B; apoptosis and purine metabolism pathways being unique to DEPs from 96B; and the presence of pathogenesis-related protein 10a and stress-responsive proteins (e.g., Bet_v_1 domain-containing and Gnk2-homologous domain-containing proteins) in the 96B interaction network. Therefore, these results suggest that Pi1 contributes to rice blast resistance by modulating apoptosis/purine metabolism pathways and protein–protein interaction networks.

[目的]筛选出同时响应褐飞虱和稻瘿蚊取食的基因,揭示水稻幼苗应对2种害虫时基因表达层面的差异,为后续挖掘广谱抗虫基因和解析水稻抗虫机制打下理论基础.[方法]以水稻品种9311为供试植物,分别对15日龄的水稻幼苗进行褐飞虱和稻瘿蚊接虫处理,观测幼苗表型,并通过转录组测序技术分别对褐飞虱接入后24 h和稻瘿蚊接入后7 d的水稻幼苗进行转录组测序.以水稻日本晴基因组作为参考基因组进行对比,利用FPKM法计算基因表达量,设定参数(|log2 FC|>1且P<0.05)筛选差异表达基因.结合基因差异表达分析和功能富集分析,研究水稻响应2种害虫的机制异同点.[结果]鉴定出响应褐飞虱取食的差异表达基因3963个,响应稻瘿蚊取食的差异表达基因1206个,有251个差异表达基因同时响应2种害虫,其中108个具有相同表达模式,143个具有相反表达模式.GO功能注释分析表明,褐飞虱取食显著影响植物体内细胞壁合成和缺水响应,而稻瘿蚊取食则对植物光合作用的影响更显著,具有相同表达模式的差异表达基因主要富集在光合作用、水杨酸合成、茉莉酸信号转导和伤害响应等生物学功能,而具有相反表达模式的差异表达基因仅富集在乙醛酸循环.KEGG信号通路富集分析表明,褐飞虱和稻瘿蚊取食均显著影响植物体内次生代谢物的合成,相同表达模式的差异表达基因富集到MAPK信号通路、植物激素信号转导通路及光合作用等6个通路,而相反表达模式的差异表达基因没有富集的通路.[结论]水稻应对褐飞虱和稻瘿蚊的基因表达调控存在相同点和不同之处,共响应2种害虫的调控通路可能在水稻抗虫过程中发挥重要作用.

Abstract Background The rice gall midge (RGM, Orseolia oryzae, Wood-Mason), an important stem-feeding pest worldwide, has caused serious production losses over the past decades. Rice production practices indicate that the most reliable method for managing RGM is the deployment of cultivars that incorporate host resistance. However, the conventional phenotypic screening method of rice resistance to RGM suggested by the International Rice Research Institute (IRRI) has been used for approximately 30 years, and only 12 rice varieties/lines (including controls) can be evaluated in one tray. It is not suitable for high-throughput phenotyping of rice germplasm. Moreover, a suitable method to prepare samples for molecular biological studies of rice resistance against RGM is imperative with the rapid development of modern molecular techniques. Results The proper density of seedlings/RGM was determined for four seeding arrangements. A high-throughput phenotyping method (HTPM) for 60 lines/varieties infested with 36 female RGM adults in one tray, as described by method 4–3 (seeded 60 lines/varieties), was developed and verified using mutant screening. Furthermore, one RGM resistance gene flanked by markers 12RM28346 and 12RM28739 on chromosome 12 was simultaneously detected using method 2–2 (seeded 30 lines/varieties in one tray) treated with 24 RGM and analyzed using conventional and simplified grading systems. Genetic analysis of the RGM resistance gene was confirmed using a method identical to that suggested by IRRI. Finally, one bucket with 24 seedlings treated with at least five female RGM adults was efficacious and could offer adequate samples for insect development observation or molecular biological studies. Conclusion A highly efficient and reliable procedure for evaluation of resistance in rice to RGM was developed and improved, and was verified through mutant screening, gene mapping, genetic analysis, and insect growth and development observations.

[目的]研究白背飞虱取食后苗期水稻内源激素含量变化规律及其合成途经相关基因的差异表达,为进一步解析内源激素调控水稻白背飞虱抗性机理提供参考.[方法]利用UPLC-MS方法测定了白背飞虱敏感材料9311与抗性近等基因系(NIL)在白背飞虱取食0、24和48 h后植株水杨酸(SA)、脱落酸(ABA)、茉莉酸(JA)和生长素(IAA)4种激素含量的变化;qRT-PCR分析5个与激素合成途径相关基因在抗、感植株中表达水平的差异.[结果]激素含量测定结果表明,白背飞虱取食的48 h内,NIL中SA含量先升后降,而在9311中先降后升;ABA的含量在NIL中波动较小,而在9311中先升后降;IAA和JA在抗、感植株中均持续上升.激素合成途径相关基因OsPAL06、OsZEP、OsLOX和OsYUCCA1在接虫后24 h的表达量差异在抗、感植株中均达到显著或极显著水平,而在0 h和48 h差异不显著.OsICS1则在接虫后48 h的表达量差异在抗、感植株达到显著水平,而接虫0和24 h后差异不显著.[结论]在接虫或者对照处理中,JA和ABA含量在抗性植株中均高于感虫植株,可能与抗性基因有较大关系;而SA含量和OsPAL06、OsICS1基因表达水平均表明抗性植株对白背飞虱的取食响应更迅速,在抗虫过程中能够起到明显的调控作用.