Abstract：
Rice leaf width (RLW) is a crucial determinant of photosynthetic area. Despite the discovery of several genes controlling RLW, the underlying genetic architecture remains unclear. In order to better understand RLW, this study conducted a genome-wide association study (GWAS) on 351 accessions from the rice diversity population II (RDP-II). The results revealed 12 loci associated with leaf width (LALW). In LALW4, we identified one gene, Narrow Leaf 22 (NAL22), whose polymorphisms and expression levels were associated with RLW variation. Knocking out this gene in Zhonghua11, using CRISPR/Cas9 gene editing technology, resulted in a short and narrow leaf phenotype. However, seed width remained unchanged. Additionally, we discovered that the vein width and expression levels of genes associated with cell division were suppressed in nal22 mutants. Gibberellin (GA) was also found to negatively regulate NAL22 expression and impact RLW. In summary, we dissected the genetic architecture of RLW and identified a gene, NAL22, which provides new loci for further RLW studies and a target gene for leaf shape design in modern rice breeding.
摘要：
水稻叶宽(RLW)是决定光合面积的关键因素。尽管发现了几个控制RLW的基因，潜在的遗传结构仍不清楚.为了更好地理解RLW,这项研究对来自水稻多样性种群II（RDP-II）的351个种质进行了全基因组关联研究（GWAS）。结果揭示了与叶宽(LALW)相关的12个位点。在LALW4中，我们发现了一个基因，窄叶22(NAL22),其多态性和表达水平与RLW变异相关。利用CRISPR/Cas9基因编辑技术，在中华11敲出这个基因，导致短而窄的叶片表型。然而,种子宽度保持不变。此外,我们发现，在nal22突变体中，与细胞分裂相关的基因的静脉宽度和表达水平受到抑制。还发现赤霉素(GA)负调节NAL22表达并影响RLW。总之,我们解剖了RLW的遗传结构并鉴定了一个基因，NAL22，为进一步的RLW研究提供了新的基因座，并为现代水稻育种中的叶形设计提供了目标基因。
