Narrow Leaf21, encoding ribosomal protein RPS3A, controls leaf development in rice
Narrow Leaf21, encoding ribosomal protein RPS3A, controls leaf development in rice
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Narrow Leaf21，编码核糖体蛋白 RPS3A，控制水稻叶片发育
DOI：
10.1093/plphys/kiab075
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发表时间：
2021-02-16
期刊：
影响因子：
7.4
通讯作者：
Li, Xueyong
中科院分区：
文献类型：
--
作者：
Uzair, Muhammad;Long, Haixin;Li, Xueyong
叶片形态影响光合作用、蒸腾作用，并最终影响作物产量。然而，叶片发育的分子机制尚不完全清楚。本研究鉴定了水稻（Oryza sativa）窄叶21 （nal21）突变体，该突变体的叶宽、叶长和株高均显著降低，分蘖数显著增加。显微观察显示，nal21叶片维管系统出现缺陷，表皮细胞大小和数量减少。基于图谱的克隆显示NAL21编码一个核糖体小亚基蛋白RPS3A。核糖体靶向抗生素耐药试验和核糖体分析显示，nal21突变体中游离40S核糖体亚基显著减少。nal21突变体表现出异常的生长素反应，在其5'-非翻译区含有上游开放阅读框（uorf）的多个生长素反应因子（ARFs）在翻译水平上受到抑制。wuschell相关同源盒3A （OsWOX3A）基因是参与叶片侧向生长的关键转录因子，也受RPS3A的翻译调控。用缺乏uorf的修饰OsARF11、OsARF16和OsWOX3A基因组DNA （gDNA）转化nal21，比用其原生gDNA转化更能挽救窄叶表型，这表明RPS3A可以通过uorf调节arf和WOX3A的翻译。我们的研究结果表明，参与叶片发育的关键因子的适当的翻译调控对于维持正常的叶片形态至关重要。
Leaf morphology influences photosynthesis, transpiration, and ultimately crop yield. However, the molecular mechanism of leaf development is still not fully understood. Here, we identified and characterized the narrow leaf21 (nal21) mutant in rice (Oryza sativa), showing a significant reduction in leaf width, leaf length and plant height, and increased tiller number. Microscopic observation revealed defects in the vascular system and reduced epidermal cell size and number in the nal21 leaf blade. Map-based cloning revealed that NAL21 encodes a ribosomal small subunit protein RPS3A. Ribosome-targeting antibiotics resistance assay and ribosome profiling showed a significant reduction in the free 40S ribosome subunit in the nal21 mutant. The nal21 mutant showed aberrant auxin responses in which multiple auxin response factors (ARFs) harboring upstream open-reading frames (uORFs) in their 5'-untranslated region were repressed at the translational level. The WUSCHEL-related homeobox 3A (OsWOX3A) gene, a key transcription factor involved in leaf blade lateral outgrowth, is also under the translational regulation by RPS3A. Transformation with modified OsARF11, OsARF16, and OsWOX3A genomic DNA (gDNA) lacking uORFs rescued the narrow leaf phenotype of nal21 to a better extent than transformation with their native gDNA, implying that RPS3A could regulate translation of ARFs and WOX3A through uORFs. Our results demonstrate that proper translational regulation of key factors involved in leaf development is essential to maintain normal leaf morphology.