Sheng Teng

ERD4 proteins, members of the early responsive-to-dehydration family, act as plasma membrane ion channels that contribute to ion homeostasis and modulate plant response to abiotic stresses. However, the functions of ERD4 homologs in non-vascular species remain largely unexplored. Here, we characterized an ERD4 family homolog in Physcomitrium patens (Hedw.) Mitt., PpCSC1 (Calcium-permeable Stress-responsive Cation Channel 1), and investigated its role in salt stress response. PpCSC1 localized to the plasma membrane and functioned as a non-selective cation channel permeable to Na+, K+, Ca2+, and Mg2+. Under salt treatment, PpCSC1 transcripts were markedly downregulated, whereas overexpression lines exhibited enhanced salt sensitivity. Ion content analysis further revealed reduced K+ accumulation, lowered K+/Na+ ratios, and elevated Mg2+ levels, collectively disrupting ionic homeostasis and impairing salt tolerance. Transcriptional regulation analysis revealed that the C2H2-type zinc finger transcription factor PpSTOP2 directly activated PpCSC1 expression. Notably, PpSTOP2 knockout plants displayed reduced PpCSC1 mRNA accumulation and improved salt tolerance. Together, these findings indicate that PpCSC1 is a plasma membrane-localized cation channel that negatively regulates salt tolerance by disturbing ion balance, and that its regulation by PpSTOP2 integrates upstream signaling with downstream physiological responses. This work provides new insight into how non-selective ion channels shape stress adaptation in early land plants.

Direct-seeding systems in rice require cultivars with enhanced seed vigor to ensure rapid and uniform germination. In this study, a population of 42 chromosome segment substitution lines (CSSLs) derived from aus Kasalath in the japonica Nipponbare background, coupled with whole-genome resequencing data, was analyzed to identify quantitative trait loci (QTLs) associated with early seed germination. Phenotypic traits, including germination percentage (GP), germination rate (GR), and germination index (GI), were measured over two consecutive years to ensure robustness. Six stable QTLs were identified, with qSV-1 on chromosome 1 (30.10–30.94 Mb) emerging as the most consistent across evaluations for GP and GI. Functional annotation and gene expression analyses of the 840-kb qSV-1 interval pinpointed C3H10 and OsOFP3 as the primary candidate genes for further investigation. This study underscores the effectiveness of whole-genome resequencing paired with the CSSL platform for precise QTL identification, thereby providing critical genetic resources for improving seed vigor through marker-assisted breeding and functional genomics.

Glycosylation, a prevalent post‐translational modification in eukaryotic secreted and membrane‐associated proteins, plays a pivotal role in diverse physiological and pathological processes. Although UDP‐N‐acetylglucosamine (UDP‐GlcNAc) is essential for this modification, the specific glycosylation mechanisms during plant leaf senescence and defense responses remain poorly understood. In our research, we identified a novel rice mutant named rbb1 (resistance to blast and bacterial blight1), exhibiting broad‐spectrum disease resistance. This mutant phenotype results from a loss‐of‐function mutation in the gene encoding glucosamine‐6‐phosphate acetyltransferase, an important enzyme in D‐glucosamine 6‐phosphate acetylation. The rbb1 mutant demonstrates enhanced defense responses, evident in increased resistance to rice blast and bacterial blight, along with the upregulation of defense‐response genes. Various biochemical markers indicate an activated defense mechanism in the rbb1 mutant, such as elevated levels of reactive oxygen species and malondialdehyde, reduced enzyme activity and UDP‐GlcNAc content, and decreased expression of N‐glycan and O‐glycan modifying proteins. Moreover, proteome analysis of N‐glycosylation modifications reveals alterations in the N‐glycosylation of several disease‐resistance‐related proteins, with a significant reduction in Prx4 and Prx13 in rbb1‐1. Additionally, the knockout of Prx4 or Prx13 also enhances resistance to Xanthomonas oryzae pv. oryzae (Xoo) and Magnaporthe oryzae (M. oryzae). This study uncovers a novel mechanism of defense response in rice, suggesting potential targets for the development of disease‐resistant varieties.

Improvement of photosynthetic efficiency is a major approach to increase crop yield potential. Previously, we cloned a gene encoding the chloroplast-located putative monooxygenase TCD5, which is essential in plastid development under low temperature in rice (Oryza sativa L.). In this study, the effects of TCD5 on the photosynthesis and the yields were investigated in rice. Two sets of genetic materials with three levels of TCD5 expression, including tcd5 mutant or TCD5 RNAi transgenic lines and TCD5 over-expression transgenic lines in Jiahua1 and Nipponbare backgrounds, were used in the field trails of multi-locations and multi-years. TCD5 positively affected the panicle number and the yield at dosage. Compared with the wild-types, the panicle numbers were 12.4%–14.6% less in tcd5 mutant and 8.3%–38.6% less in TCD5 RNAi lines, but 26.2%–61.8% more in TCD5 over-expression lines. The grain yields per plant were 9.1%–18.4% less in tcd5 mutant and 14.3%–56.7% less in TCD5 RNAi lines, but 6.9%–56.5% more in TCD5 over-expression lines. The measurements of net photosynthetic rate indicated that mutation or knock down of TCD5 decreased the net photosynthetic rate by 10.4% and 15.6%, respectively, while increasing it by 8.9% and 8.7% in the TCD5 over-expression lines in Jiahua1 and Nipponbare backgrounds, respectively. Accordingly, the measurements of chlorophyll fluorescence parameters showed that the electron transport rate and quantum yield decreased in tcd5 mutant or TCD5 RNAi lines but increased in TCD5 over-expression lines, both in Jiahua1 and Nipponbare backgrounds. IP-MS screening revealed that TCD5 interacts with 29 chloroplast proteins involved in chlorophyll synthesis, photo-reactions of the photosynthesis, carbon assimilation and metabolism, energy metabolism, redox balance, protein synthesis and transportation. Two TCD5 interacted proteins, D1 and FBA were effective targets for improving photosynthesis. These results suggest a potentially new strategy for increasing rice yield by enhancing photosynthesis.

The primary considerations in rice (Oryza sativa L.) production evoke improvements in the nutritional quality as well as production. Rice cultivars need to be developed to tackle hunger globally with high yield and better nutrition. The traditional cultivation methods of rice to increase the production by use of non-judicious fertilizers to fulfill the nutritional requirement of the masses. This article provokes nutritional strategies by utilization of available omics techniques to increase the nutritional profiling of rice. Recent scientific advancements in genetic resources provide many approaches for better understanding the molecular mechanisms encircled in a specific trait for its up- or down-regulation for opening new horizons for marker-assisted breeding of new rice varieties. In this perspective, genome-wide association studies, genome selection (GS) and QTL mapping are all genetic analysis that help in precise augmentation of specific nutritional enrichment in rice grain. Implementation of several omics techniques are effective approaches to enhance and regulate the nutritional quality of rice cultivars. Advancements in different types of omics including genomics and pangenomics, transcriptomics, metabolomics, nutrigenomics and proteomics are also relevant to rice development initiatives. This review article compiles genes, locus, mutants and for rice yield and yield attribute enhancement. This knowledge will be useful for now and for the future regarding rice studies.

Nitrogen-use efficiency (NUE) in rice is a complex quantitative trait involved in multiple biological processes and agronomic traits; however, the genetic basis and regulatory network of NUE remain largely unknown. We constructed a high-resolution microarray-based genetic map for 261 recombinant inbred lines derived from twoindicaparents. Using 2,345 bin markers, comprehensive analyses of quantitative trait loci (QTLs) of seven key agronomic traits under two different N levels were performed. A total of 11 non-redundant QTLs for effective panicle number (EPN), 7 for grain number per panicle, 13 for thousand-grain weight, 2 for seed-setting percentage, 15 for plant height, 12 for panicle length, and 6 for grain yield per plant were identified. The QTL regions were as small as 512 kb on average, and more than half spanned an interval smaller than 100 kb. Using this advantage, we identified possible candidate genes of two major EPN-related QTLs. One QTL detected under both N levels possibly encodes a DELLA protein SLR1, which is known to regulate NUE, although the natural variations of this protein have not been reported. The other QTL detected only under a high N level could encode the transcription factor OsbZIP59. We also predicted the possible candidate genes for another three of the NUE-related QTLs. Our results provide a reference for improving NUE-related QTL cloning and promote our understanding of NUE regulation inindicarice.