Affiliation:
1. Rice Research Institute Yunnan Agricultural University Kunming China
2. College of Biological Resource and Food Engineering Qujing Normal University Qujing China
3. State Key Laboratory for Conservation and Utilization of Bio‐Resources in Yunnan Yunnan Agricultural University Kunming China
4. The Key Laboratory for Crop Production and Smart Agriculture of Yunnan Province Yunnan Agricultural University Kunming China
5. College of Agronomy and Biotechnology Yunnan Agricultural University Kunming China
6. Kunming University Kunming China
Abstract
AbstractChloroplasts play a vital role in plant growth and development, which are the main sites of photosynthesis and the production of hormones and metabolites. Despite their significance, the regulatory mechanisms governing chloroplast development remain unclear. In our investigation, we identified a rice mutant with defective chloroplasts in rice (Oryza sativa L.), named albino lethal 13 (osal13), which displayed a distinct albino phenotype in leaves, ultimately resulting in seedling lethality. Molecular cloning revealed that OsAL13 encodes a novel rice protein with no homologous gene or known conserved domain. This gene was located in the chloroplast and exhibited constitutive expression in various tissues, particularly in green tissues and regions of active cell growth. Our study's findings reveal that RNAi‐mediated knockdown of OsAL13 led to a pronounced albino phenotype, reduced chlorophyll and carotenoid contents, a vesicle chloroplast structure, and a decrease in the expression of chloroplast‐associated genes. Consequently, the pollen fertility and seed setting rate were lower compared with the wild type. In contrast, the overexpression of OsAL13 resulted in an increased photosynthetic rate, a higher total grain number per panicle, and enhanced levels of indole‐3‐acetic acid (IAA) in the roots and gibberellin A3 (GA3) in the shoot. These outcomes provide new insights on the role of OsAL13 in regulating chloroplast development in rice.