Lian Jian-Ping, Yuan Chao, Feng Yan-Zhao, Liu Qing, Wang Cong-Ying, Zhou Yan-Fei, Huang Qiao-Juan, Zhu Qing-Feng, Zhang Yu-Chan, Chen Yue-Qin, Yu Yang
Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou 510275, PR China.
Guangdong Key Laboratory of Crop Germplasm Resources Preservation and Utilization, Key Laboratory of South China Modern Biological Seed Industry, Ministry of Agriculture and Rural Affairs, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China.
Plant Physiol. 2024 Mar 29;194(4):2101-2116. doi: 10.1093/plphys/kiad626.
The precise timing of flowering plays a pivotal role in ensuring successful plant reproduction and seed production. This process is intricately governed by complex genetic networks that integrate internal and external signals. This study delved into the regulatory function of microRNA397 (miR397) and its target gene LACCASE-15 (OsLAC15) in modulating flowering traits in rice (Oryza sativa). Overexpression of miR397 led to earlier heading dates, decreased number of leaves on the main stem, and accelerated differentiation of the spikelet meristem. Conversely, overexpression of OsLAC15 resulted in delayed flowering and prolonged vegetative growth. Through biochemical and physiological assays, we uncovered that miR397-OsLAC15 had a profound impact on carbohydrate accumulation and photosynthetic assimilation, consequently enhancing the photosynthetic intensity in miR397-overexpressing rice plants. Notably, we identified that OsLAC15 is at least partially localized within the peroxisome organelle, where it regulates the photorespiration pathway. Moreover, we observed that a high CO2 concentration could rescue the late flowering phenotype in OsLAC15-overexpressing plants. These findings shed valuable insights into the regulatory mechanisms of miR397-OsLAC15 in rice flowering and provided potential strategies for developing crop varieties with early flowering and high-yield traits through genetic breeding.
开花的精确时间在确保植物成功繁殖和种子生产方面起着关键作用。这一过程由整合内部和外部信号的复杂基因网络精细调控。本研究深入探讨了微小RNA397（miR397）及其靶基因漆酶-15（OsLAC15）在调节水稻（Oryza sativa）开花性状中的调控功能。miR397过表达导致抽穗期提前、主茎叶片数量减少以及小穗分生组织分化加速。相反，OsLAC15过表达导致开花延迟和营养生长延长。通过生化和生理分析，我们发现miR397 - OsLAC15对碳水化合物积累和光合同化有深远影响，从而增强了miR397过表达水稻植株的光合强度。值得注意的是，我们确定OsLAC15至少部分定位于过氧化物酶体细胞器内，在那里它调节光呼吸途径。此外，我们观察到高二氧化碳浓度可以挽救OsLAC15过表达植株的晚花表型。这些发现为miR397 - OsLAC15在水稻开花中的调控机制提供了有价值的见解，并为通过遗传育种培育具有早花和高产性状的作物品种提供了潜在策略。
