DataSheet1_Impact of Pre-Anthesis Drought Stress on Physiology, Yield-Related Traits, and Drought-Responsive Genes in Green Super Rice.xlsx

Optimum soil water availability is vital for maximum yield production in rice which is challenged by increasing spells of drought. The reproductive stage drought is among the main limiting factors leading to the drastic reduction in grain yield. The objective of this study was to investigate the molecular and morphophysiological responses of pre-anthesis stage drought stress in green super rice. The study assessed the performance of 26 rice lines under irrigated and drought conditions. Irrigated treatment was allowed to grow normally, while drought stress was imposed for 30 days at the pre-anthesis stage. Three important physiological traits including pollen fertility percentage (PFP), cell membrane stability (CMS), and normalized difference vegetative index (NDVI) were recorded at anthesis stage during the last week of drought stress. Agronomic traits of economic importance including grain yield were recorded at maturity stage. The analysis of variance demonstrated significant variation among the genotypes for most of the studied traits. Correlation and principal component analyses demonstrated highly significant associations of particular agronomic traits with grain yield, and genetic diversity among genotypes, respectively. Our study demonstrated a higher drought tolerance potential of GSR lines compared with local cultivars, mainly by higher pollen viability, plant biomass, CMS, and harvest index under drought. In addition, the molecular basis of drought tolerance in GSR lines was related to upregulation of certain drought-responsive genes including OsSADRI, OsDSM1, OsDT11, but not the DREB genes. Our study identified novel drought-responsive genes (LOC_Os11g36190, LOC_Os12g04500, LOC_Os12g26290, and LOC_Os02g11960) that could be further characterized using reverse genetics to be utilized in molecular breeding for drought tolerance.

优化土壤水分的有效供应对于实现水稻产量最大化至关重要，而干旱期频发则为这一目标带来了挑战。繁殖阶段的干旱是导致谷物产量急剧下降的主要限制因素之一。本研究旨在探究绿超水稻（GSR）抽穗前干旱胁迫的分子及形态生理反应。研究评估了26个水稻品种在灌溉和干旱条件下的表现。灌溉处理允许正常生长，而干旱胁迫则在抽穗前持续施加30天。在干旱胁迫的最后一周，记录了三个重要的生理特征，包括花粉育性百分比（PFP）、细胞膜稳定性（CMS）和归一化植被指数（NDVI）。在成熟阶段，记录了具有经济意义农艺特性，包括谷物产量。方差分析显示，大部分研究性状在不同基因型之间存在显著差异。相关性分析和主成分分析表明，特定的农艺特性与谷物产量之间存在高度显著的关联，以及基因型间的遗传多样性。本研究证明了GSR品种相较于地方品种具有更高的耐旱潜力，这主要归因于花粉活力、植物生物量、CMS和收获指数在干旱条件下的提升。此外，GSR品种耐旱性的分子基础与特定干旱响应基因（如OsSADRI、OsDSM1、OsDT11）的上调有关，而非DREB基因。本研究鉴定出新的干旱响应基因（LOC_Os11g36190、LOC_Os12g04500、LOC_Os12g26290和LOC_Os02g11960），这些基因可以通过反向遗传学进一步研究，以用于耐旱性的分子育种。