2025年7月29日出版的《遗传学报》杂志发表了科学家的一项最新研究成果。来自广东省农业科学院水稻研究所的赵均良团队提出了OsLT9调控水稻叶片厚度的功能研究。

在这项研究中，该课题组利用全基因组关联研究（Pan-GWAS）对302份来自中国南方的不同水稻材料进行分析，鉴定出49个与叶片厚度相关的数量性状位点（QTLs）。最重要的位点qLT9被精确定位到9号染色体上79kb的区域。转录组学和基因组序列分析发现，LOC_Os09g33480编码多细胞器RNA编辑因子（MORF）家族的一个蛋白，是关键的候选基因。过表达和互补转基因实验证实LOC_Os09g33480（OsLT9）是qLT9的功能基因，其启动子上有一个24bp的Indel与表达水平和叶片厚度相关。

值得注意的是，OsLT9过表达系不仅叶片变厚，而且光合效率和籽粒产量也显著提高，从而建立了叶片厚度调节与产量提高之间的联系。群体基因组分析表明，在驯化和育种过程中，OsLT9有很强的选择性，现代栽培品种倾向于OsLT9的厚叶单倍型。本研究确立了OsLT9作为水稻叶片厚度的关键调控因子，并通过优化植株结构为高产水稻分子育种提供了有价值的遗传抗性。

据了解，水稻叶片厚度对光合效率和产量有重要影响，但其遗传基础尚不清楚，以前很少有功能基因被发现。

附：英文原文

Title: Functional characterization of OsLT9 in regulating rice leaf thickness

Author: Xinqiao Zhou, Chuanguang Liu, Junliang Zhao

Issue&Volume: 2025/07/29

Abstract: Leaf thickness in rice critically influences photosynthetic efficiency and yield, yet its genetic basis remains poorly understood, with few functional genes previously characterized. In this study, we employ a pangenome-wide association study (Pan-GWAS) on 302 diverse rice accessions from southern China, identifying 49 quantitative trait loci (QTLs) associated with leaf thickness. The most significant locus, qLT9, is fine-mapped to a 79 kb region on chromosome 9. Transcriptomic and genomic sequence analyses identify LOC_Os09g33480, which encodes a protein belonging to Multiple Organellar RNA Editing Factor (MORF) family, as the key candidate gene. Overexpression and complementation transgenic experiments confirm LOC_Os09g33480 (OsLT9) as the functional gene underlying qLT9, demonstrating a 24-bp Indel in its promoter correlates with the expression levels and leaf thickness. Notably, OsLT9 overexpression lines show not only thicker leaf, but also significantly enhanced photosynthetic efficiency and grain yield, establishing a link between leaf thickness modulation and yield enhancement. Population genomic analyses indicate strong selection for OsLT9 during domestication and breeding, with modern cultivars favoring thick leaf haplotype of OsLT9. This study establishes OsLT9 as a key regulator controlling leaf thickness in rice, and provides a valuable genetic resource for molecular breeding of high-yielding rice through optimization of plant architecture.

DOI: 10.1016/j.jgg.2025.07.010

Source: https://www.sciencedirect.com/science/article/abs/pii/S1673852725002073