Faculty of Bioresource Sciences, Department of Biological Production, Akita Prefectural University, Akita 010-0195, Japan.
Department of Applied Chemistry, National Defense Academy of Japan, Yokosuka 239-8686, Japan.
Int J Mol Sci. 2017 Oct 17;18(10):2165. doi: 10.3390/ijms18102165.
Leaf senescence is an important physiological process involving the degradation of a number of metabolites and their remobilization to new reproductive and storage organs. NAC (NAM, ATAF, and CUC) transcription factors are reported as important regulators of the senescence process. Here, we describe the identification and functional characterization of the NAC transcription factor gene, (Oryza sativa Yellow37, ONAC011) obtained from cv. , and . We created transgenic plants expressing the gene under the control of a strong and constitutive CaMV35S promoter. The resulting transgenic plants overexpressing gene showed early heading and precocious senescence phenotype of flag leaves compared with wild-type plants. By contrast, blocking the function of this gene via RNAi (RNA interference) and CRES-T (Chimeric Repressor Silencing Technology) technology, delayed both heading time and leaf senescence. Furthermore, knockdown of expression caused dwarfism and high accumulation of chlorophyll during the vegetative phase. Irrespective of early or delayed senescence, transgenic plants showed reduced grain yields. Our results indicate that acts as a positive regulator of heading and senescence during the reproductive phase in rice. In addition, may be involved in plant development and grain yield.
叶片衰老是一个重要的生理过程，涉及到许多代谢物的降解及其向新的生殖和贮藏器官的再转移。NAC（NAM、ATAF 和 CUC）转录因子被报道为衰老过程的重要调节因子。在这里，我们描述了从 cv. 和 中获得的 NAC 转录因子基因 （Oryza sativa Yellow37，ONAC011）的鉴定和功能特征。我们创建了在强而组成型的 CaMV35S 启动子控制下表达 基因的转基因植物。与野生型植物相比，过表达 基因的转基因植物表现出早期抽穗和旗叶早衰的表型。相比之下，通过 RNAi（RNA 干扰）和 CRES-T（嵌合阻遏物沉默技术）技术阻断该基因的功能，会延迟抽穗时间和叶片衰老。此外， 表达的敲低导致营养生长阶段矮化和叶绿素大量积累。无论是早期还是延迟衰老，转基因植物的产量都降低。我们的结果表明， 在水稻生殖阶段作为抽穗和衰老的正调控因子发挥作用。此外， 可能参与植物发育和籽粒产量。
