Seed vigour is an important trait for direct seeding in rice. In this study, indole‐3‐acetate beta‐glucosyltransferase OsIAGLU was cloned in rice, and its roles on seed vigour were mainly investigated. Disruption of OsIAGLU resulted in low seed vigour in rice. Quantitative RT‐PCR analysis showed that the expressions of OsIAGLU were relatively higher in the late developing and the early germinating seeds and were significantly induced by indole‐3‐acetic acid (IAA) and abscisic acid (ABA). Transcriptome analysis revealed that the IAA‐ and ABA‐related genes were involved in the OsIAGLU regulation of seed vigour in rice. The higher levels of free IAA and ABA were identified in germinating seeds of osiaglu mutants compared to wild‐type (WT) plants. When treated with exogenous IAA and ABA, the osiaglu mutants and WT plants showed sensitivity to ABA while not IAA, but the exogenous IAA amplified ABA‐induced reduction of seed vigour in rice. The continuously higher expressions of ABA‐INSENSITIVE 3 (OsABI3 ) and OsABI5 occurred in germinating seeds of osiaglu mutants compared to WT plants. The regulation of seed vigour by OsIAGLU might be through modulating IAA and ABA levels to alert OsABIs expression in germinating seeds in rice. Based on analysis of single‐nucleotide polymorphism data of rice accessions, two haplotypes of OsIAGLU that positively correlated with seed vigour were identified in indica accessions. This study provides important insights into the roles of OsIAGLU on seed vigour and facilitates the practical use of OsIAGLU in rice breeding.

中文翻译：

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3-乙酸吲哚β-葡萄糖基转移酶OsIAGLU通过介导水稻中生长素和脱落酸之间的串扰来调节种子活力。

种子活力是直接播种水稻的重要特征。在这项研究中，在水稻中克隆了吲哚-3-乙酸β-葡萄糖基转移酶OsIAGLU，并主要研究了其对种子活力的作用。OsIAGLU的破坏导致水稻种子活力低下。RT-PCR定量分析显示，OsIAGLU在发育后期和早期发芽种子中的表达相对较高，并被吲哚-3-乙酸（IAA）和脱落酸（ABA）明显诱导。转录组分析显示，IAA和ABA相关基因参与了OsIAGLU对水稻种子活力的调节。在osiaglu的发芽种子中鉴定出较高水平的游离IAA和ABA突变体与野生型（WT）植物相比。当用外源IAA和ABA处理时，osiaglu突变体和野生型植物对ABA表现出敏感性，而对IAA则不敏感，但是外源IAA放大了ABA诱导的水稻种子活力降低。与野生型植物相比，osiaglu突变体的发芽种子中ABA-INSENSITIVE 3（OsABI3）和OsABI5的表达持续升高。OsIAGLU对种子活力的调节可能是通过调节IAA和ABA水平来提醒OsABIs在水稻发芽种子中的表达。基于水稻种质的单核苷酸多态性数据分析，OsIAGLU的两个单倍型与在被确定活力种子正相关籼稻种质。这项研究为OsIAGLU在种子活力中的作用提供了重要的见识，并促进了OsIAGLU在水稻育种中的实际应用。