结论:水稻中生长停滞和DNA损伤诱导型45(GADD45)的同源基因在调节植物结构中起作用,粮食产量,和防爆。生长停滞和DNA损伤诱导型45(GADD45)家族蛋白,哺乳动物中成熟的应力传感器和肿瘤抑制剂,作为基因毒性应激反应和肿瘤发生的关键调节剂。相比之下,GADD45在植物中的同源物和作用尚不清楚。在这里,利用正向遗传学,我们确定了一个激活标记突变体AC13表现出矮化特征,这是由于水稻GADD45α同源物的功能丧失所致,表示为OsGADD45a1。osgadd45a1突变体显示降低的植物高度,缩短的圆锥花序长度,与野生型Kitaake相比,谷物产量下降。相反,株高无明显差异,圆锥花序长度,在野生型和OsGADD45a1过表达植物之间观察到谷物产量。OsGADD45a1在发芽的种子和圆锥花序中显示出相对较高的表达,定位在细胞核和细胞质中。RNA测序分析表明,OsGADD45a1在光合作用调节中具有潜在作用,结合伴侣鉴定表明OsGADD45a1与OsRML1相互作用以调节水稻生长。有趣的是,我们的研究揭示了OsGADD45a1在稻瘟病抗性中的新作用,由于osgadd45a1突变体对稻瘟病菌的抗性增强,在稻瘟病菌处理后,OsGADD45a1的表达减少。OsGADD45a1参与稻瘟病菌抗性是一个开创性的发现。总之,我们的研究结果揭示了OsGADD45a1在水稻中的多方面作用,包括生物胁迫反应和几种农业性状的调节,包括植物高度,圆锥花序长度,和谷物产量。
CONCLUSIONS: The homolog gene of the Growth Arrest and DNA Damage-inducible 45 (GADD45) in rice functions in the regulation of plant architecture, grain yield, and blast resistance. The Growth Arrest and DNA Damage-inducible 45 (GADD45) family proteins, well-established stress sensors and tumor suppressors in mammals, serve as pivotal regulators of genotoxic stress responses and tumorigenesis. In contrast, the homolog and role of GADD45 in plants have remained unclear. Herein, using forward genetics, we identified an activation tagging mutant AC13 exhibited dwarf characteristics resulting from the loss-of-function of the rice GADD45α homolog, denoted as OsGADD45a1. osgadd45a1 mutants displayed reduced plant height, shortened panicle length, and decreased grain yield compared to the wild-type Kitaake. Conversely, no obvious differences in plant height, panicle length, or grain yield were observed between wild-type and OsGADD45a1 overexpression plants. OsGADD45a1 displayed relatively high expression in germinated seeds and panicles, with localization in both the nucleus and cytoplasm. RNA-sequencing analysis suggested a potential role for OsGADD45a1 in the regulation of photosynthesis, and binding partner identification indicates OsGADD45a1 interacts with OsRML1 to regulate rice growth. Intriguingly, our study unveiled a novel role for OsGADD45a1 in rice blast resistance, as osgadd45a1 mutant showed enhanced resistance to Magnaporthe oryzae, and the expression of OsGADD45a1 was diminished upon blast fungus treatment. The involvement of OsGADD45a1 in rice blast fungus resistance presents a groundbreaking finding. In summary, our results shed light on the multifaceted role of OsGADD45a1 in rice, encompassing biotic stress response and the modulation of several agricultural traits, including plant height, panicle length, and grain yield.