Antisense suppression of phospholipase Dα retards abscisic acid- and ethylene-promoted senescence of postharvest Arabidopsis leaves
Antisense suppression of phospholipase Dα retards abscisic acid- and ethylene-promoted senescence of postharvest Arabidopsis leaves
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DOI：
10.1105/tpc.9.12.2183
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发表时间：
1997-12-01
期刊：
影响因子：
11.6
通讯作者：
Wang, XM
中科院分区：
文献类型：
--
作者：
Fan, L;Zheng, SQ;Wang, XM
磷脂酶D（PLD; EC 3.1.4.4）在植物细胞膜衰老过程中起重要作用。在本研究中，我们研究了磷脂水解酶PLD α在拟南芥细胞膜降解和衰老中的作用，通过将PLD α反义cDNA片段导入拟南芥，抑制PLD α的表达，当用脱落酸和乙烯孵育时，与野生型和转基因对照植物相比，从PLD α缺陷型转基因植物分离的叶子显示出较慢的衰老速率。延迟叶片变黄，较低的离子泄漏，更大的光合活性，和更高的含量的叶绿素和磷脂的PLD α反义叶片比野生型，脱落酸和乙烯刺激PLD α表达的离体叶片的处理，如PLD α mRNA，蛋白质和活性的增加所示，证实了衰老的延迟。然而，在脱落酸和乙烯的情况下，从PLD α缺陷和野生型植物的离体叶显示出相似的衰老速率。此外，PLD α的抑制不会改变天然植物的生长和发育。这些数据表明，PLD α是一个重要的调解人在离体叶片中的植物激素促进衰老，但不是自然衰老的直接启动子。这些研究结果的生理相关性进行了讨论。
Membrane disruption has been proposed to be a key event in plant senescence, and phospholipase D (PLD; EC 3.1.4.4) has been thought to play an important role in membrane deterioration, We recently cloned and biochemically characterized three different PLDs from Arabidopsis. In this study, we investigated the role of the most prevalent phospholipid-hydrolyzing enzyme, PLD alpha, in membrane degradation and senescence in Arabidopsis, The expression of PLD alpha was suppressed by introducing a PLD alpha antisense cDNA fragment into Arabidopsis, When incubated with abscisic acid and ethylene, leaves detached from the PLD alpha-deficient transgenic plants showed a slower rate of senescence than did those from wild-type and transgenic control plants. The retardation of senescence was demonstrated by delayed leaf yellowing, lower ion leakage, greater photosynthetic activity, and higher content of chlorophyll and phospholipids in the PLD alpha antisense leaves than in those of the wild type, Treatment of detached leaves with abscisic acid and ethylene stimulated PLD alpha expression, as indicated by increases in PLD alpha mRNA, protein, and activity. In the absence of abscisic acid and ethylene, however, detached leaves from the PLD alpha-deficient and wild-type plants showed a similar rate of senescence. In addition, the suppression of PLD alpha did not alter natural plant growth and development. These data suggest that PLD alpha is an important mediator in phytohormone-promoted senescence in detached leaves but is not a direct promoter of natural senescence. The physiological relevance of these findings is discussed.