Institute of Crops and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Genes (Basel). 2024 Sep 27;15(10):1267. doi: 10.3390/genes15101267.
The proper development of grana and stroma within chloroplasts is critical for plant vitality and crop yield in rice and other cereals. While the molecular mechanisms underpinning these processes are known, the genetic networks governing them require further exploration. In this study, we characterize a novel rice mutant termed (), which presents with yellow, lesion-like leaves and a dwarf growth habit. The mutant shows reduced photosynthetic activity, lower chlorophyll content, and abnormal chloroplast structure. Transmission electron microscopy (TEM) analysis revealed defective grana stacking in chloroplasts. Additionally, plants accumulate high levels of hydrogen peroxide (HO) and exhibit an up-regulation of senescence-associated genes, leading to accelerated cell death. Map-based cloning identified a C-to-T mutation in the LOC_Os07g33660 gene, encoding the YLD7 protein, which is a novel ankyrin domain-containing protein localized to the chloroplast. Immunoblot analysis of four LHCI proteins indicated that the YLD7 protein plays an important role in the normal biogenesis of chloroplast stroma and grana, directly affecting leaf senescence and overall plant stature. This study emphasizes the significance of in the intricate molecular mechanisms that regulate the structural integrity of chloroplasts and the senescence of leaves, thus providing valuable implications for the enhancement of rice breeding strategies and cultivation.
叶绿体中类囊体和基质的正常发育对于水稻和其他谷类作物的植物活力和作物产量至关重要。虽然这些过程的分子机制已经为人所知，但调控它们的遗传网络仍需要进一步探索。在本研究中，我们对一个新的水稻突变体进行了表征，该突变体被命名为 （），其表现为黄色、斑状叶片和矮小的生长习性。突变体显示出降低的光合作用活性、较低的叶绿素含量和异常的叶绿体结构。透射电子显微镜（TEM）分析显示突变体的类囊体堆叠有缺陷。此外， 植株积累高水平的过氧化氢（HO），并表现出衰老相关基因的上调，导致细胞死亡加速。基于图谱的克隆鉴定出 LOC_Os07g33660 基因中的一个 C 到 T 突变，该基因编码 YLD7 蛋白，这是一种新型的锚蛋白域包含蛋白，定位于叶绿体。对四种 LHCI 蛋白的免疫印迹分析表明，YLD7 蛋白在叶绿体基质和类囊体的正常生物发生中发挥重要作用，直接影响叶片衰老和整体植物株高。本研究强调了 在调控叶绿体结构完整性和叶片衰老的复杂分子机制中的重要性，从而为增强水稻育种策略和栽培提供了有价值的启示。
