Removal of DELLA repression promotes leaf senescence in Arabidopsis
Removal of DELLA repression promotes leaf senescence in Arabidopsis
复制标题
去除 DELLA 抑制促进拟南芥叶片衰老
DOI：
10.1016/j.plantsci.2013.11.016
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发表时间：
2014-04-01
期刊：
影响因子：
5.2
通讯作者：
Jiang, Lixi
中科院分区：
文献类型：
--
作者：
Chen, Mingxun;Maodzeka, Antony;Jiang, Lixi
叶片衰老是叶片细胞对发育年龄及各种内部和环境信号的综合反应。然而，赤霉素(GA)在叶片衰老中的作用尚不清楚。在本研究中，我们研究了Della对叶片衰老的影响。与野生型(WT)相比，突变体Gal-3 GAI-T6 RGA-T2 rgl1-1 rgl2-1(简称Q-DELIalga13)的叶片衰老早于野生型，而GA生物合成受阻且Della蛋白积累异常的突变体Gal-3叶片衰老较慢。在叶片衰老过程中，SAG12和SAG29在Q-Delia/GAL-3中上调，在GAL-3中下调。Q-DELLAIga-3衰老叶片含糖量高于GAL-3和WT，而叶绿素和脂肪酸含量低于GAL-3和WT。Q-DellaIga1-3衰老叶片中C18：3的绝对含量和相对含量均低于WT和GAL-3叶片。Q-DELLAIga-3中调控FAβ氧化的基因Km、IACS6、IACS7、AGO、ACX2和MAP2显著上调。Della抑制基因的去除高度上调了不同激素途径上的某些基因，表明GA信号作用于茉莉酸、水杨酸和乙烯途径的上游，调节叶片衰老。(C)2014爱思唯尔爱尔兰有限公司。保留所有权利。
Leaf senescence is an integrated response of leaf cells to developmental age and various internal and environmental signals. However, the role of gibberellins (GA) in leaf senescence is not clear. In the current study, we investigated the effect of DELLA on leaf senescence. Compared with the wild type (WT), leaf senescence occurred earlier in the mutant gal-3 gai-t6 rga-t2 rgl1-1 rgl2-1 (abbreviated as Q-DELIAlga13) whose DELLA repression was removed, whereas leaf senescence was retarded in the mutant gal-3 whose GA biosynthesis was blocked and whose DELLA proteins accumulated abnormally. During leaf senescence, SAG12 and SAG29 were upregulated in Q-DELIA/gal-3 and downregulated in gal-3 plants. The Q-DELLAIgal-3 senescent leaves contained more sugar but less chlorophyll and fatty acids (FAs) than those of gal-3 and WT. Both absolute and relative contents of C18:3 in Q-DELLAIga1-3 senescent leaves were lower compared with those of the WT and gal-3 leaves. The genes regulating FA beta-oxidation in Q-DELLAIgal-3, such as KM, IACS6, IACS7, AGO, ACX2 and MAP2, were significantly upregulated. The removal of DELLA repression highly upregulated certain genes on various hormone pathways, suggesting that GA signaling acts upstream of the jasmonic acid, salicylic acid, and ethylene pathways in regulating leaf senescence. (c) 2014 Elsevier Ireland Ltd. All rights reserved.