Evidence supporting a role of jasmonic acid in Arabidopsis leaf senescence
Evidence supporting a role of jasmonic acid in Arabidopsis leaf senescence
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DOI：
10.1104/pp.010843
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发表时间：
2002-03-01
期刊：
影响因子：
7.4
通讯作者：
Gan, SS
中科院分区：
文献类型：
--
作者：
He, YH;Fukushige, H;Gan, SS
在这项工作中，茉莉酸（JA）在叶片衰老的作用进行了研究。外源JA的施用导致野生型拟南芥的附着和离体叶片的早衰，但未能诱导JA不敏感突变体卷曲植物的早衰，这表明JA信号通路是促进叶片衰老所必需的。衰老叶片中的JA含量是非衰老叶片的4倍。与衰老叶片中JA水平的增加同时，编码催化JA生物合成途径的大部分反应的酶的基因在拟南芥叶片衰老期间被差异激活，除了丙二烯氧化物合酶，其在整个叶片发育过程中组成型和高度表达。拟南芥脂氧合酶1（细胞质）的表达大大增加，但脂氧合酶2（质体）的表达急剧减少叶片衰老。类似地，AOC 1（丙二烯氧化物环化酶1）、AOC 2和AOC 3都上调，而AOC 4随着叶片衰老的进展而下调。12-氧代-PDA还原酶1和12-氧代-PDA还原酶3的转录水平也在衰老的叶片中增加，PED 1（编码用于β-氧化的3-酮基-酰基-硫解酶）也是如此。据我们所知，这是第一次报道，在叶片衰老过程中，JA水平和氧化脂素基因的表达增加，并表明JA可能在衰老过程中发挥作用。
In this work, the role of jasmonic acid (JA) in leaf senescence is examined. Exogenous application of JA caused premature senescence in attached and detached leaves in wild-type Arabidopsis but failed to induce precocious senescence of JA-insensitive mutant coil plants, suggesting that the JA-signaling pathway is required for JA to promote leaf senescence. JA levels in senescing leaves are 4-fold hi-her than in non-senescing ones. Concurrent with the increase in JA level in senescing leaves, genes encoding the enzymes that catalyze most of the reactions of the JA biosynthetic pathway are differentially activated during leaf senescence in Arabidopsis, except for allene oxide synthase, which is constitutively and highly expressed throughout leaf development. Arabidopsis lipoxygenase 1 (cytoplasmic) expression is greatly increased but lipoxygenase 2 (plastidial) expression is sharply reduced during leaf senescence. Similarly, AOC1 (allene oxide cyclase 1), AOC2, and AOC3 are all up-regulated, whereas AOC4 is down-regulated with the progression of leaf senescence. The transcript levels of 12-oxo-PDA reductase 1 and 12-oxo-PDA reductase 3 also increase in senescing leaves, as does PED1 (encoding a 3-keto-acyl-thiolase for beta-oxidation). This represents the first report, to our knowledge, of an increase in JA levels and expression of oxylipin genes during leaf senescence, and indicates that JA may play a role in the senescence program.