C6-volatiles derived from the lipoxygenase pathway induce a subset of defense-related genes
C6-volatiles derived from the lipoxygenase pathway induce a subset of defense-related genes
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DOI：
10.1046/j.1365-313x.1998.00324.x
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发表时间：
1998-12-01
期刊：
影响因子：
7.2
通讯作者：
Rothstein, SJ
中科院分区：
文献类型：
--
作者：
Bate, NJ;Rothstein, SJ
六碳（C-6-）挥发物，包括醛类反式-2-己烯醛、己醛和顺式-3-己烯醛及其相应的醇，是由受损或受伤的植物组织产生的，是氢过氧化物裂解酶（HPL）酶活性的产物，HPL是脂氧合酶（LOX）途径的一个组成部分。用10 μ M浓度的反式2-己烯醛对拟南芥幼苗进行空中处理，诱导了几种已知参与植物防御反应的基因，包括苯丙素相关基因和LOX途径的基因。然而，编码致病相关蛋白PR-1或PR-2的基因未被诱导。因此，反式2-己烯醛诱导与茉莉酸甲酯（MeJA）诱导的基因组非常相似，茉莉酸甲酯也是一种lox衍生的挥发性物质。然而，与MeJA不同，反式2-己烯醛不会诱导羟甲基戊二酰辅酶A还原酶（HMGR）或硫氨酸2-1。诱导作用似乎仅限于c -6相关挥发物，因为C-8-、C-9-和其他相关挥发物不诱导LOX mRNA水平。正如MeJA所证明的那样，反式-2-己烯醛定量地降低了野生型种子的萌发。反式-2-己烯醛还降低了抗MeJA的拟南芥突变体jar1-1的萌发频率，支持了反式-2-己烯醛和MeJA通过不同机制被识别的观点。此外，与相似浓度的MeJA相比，反式2-己烯醛对根长有中等抑制作用，在诱导拟南芥幼苗花青素积累方面的效果比MeJA低约10倍。这些结果表明，LOX途径的c -6挥发物在植物中作为一种创伤信号，但在生理和分子水平上导致植物对MeJA的反应较弱。
Six-Carbon (C-6-) volatiles, including the aldehydes trans-2-hexenal, hexanal and cis-3-hexenal, as well as their corresponding alcohols, are produced from damaged or wounded plant tissue as a product of the enzymatic activity of hydroperoxide lyase (HPL), a component of the lipoxygenase (LOX) pathway. Aerial treatment of Arabidopsis seedlings with 10 mu M concentrations of trans-2-hexenal induces several genes known to be involved in the plant's defense response, including phenylpropanoid-related genes as well as genes of the LOX pathway. Genes encoding the pathogenesis-related proteins PR-1 or PR-2, however, were not induced. Trans-2-hexenal induction thus closely mimics the group of genes induced by methyl jasmonate (MeJA), also a LOX-derived volatile. However, unlike MeJA, trans-2-hexenal did not induce hydroxymethylglutaryl-coenzyme A reductase (HMGR) or thionin2-1. The inductive effect seemed to be limited to C-6-related volatiles, as C-8-, C-9- and other related volatiles did not induce LOX mRNA levels. As has been demonstrated for MeJA, trans-2-hexenal quantitatively reduced wild-type seed germination. Trans-2-hexenal also reduced the germination frequency of the MeJA resistant Arabidopsis mutant, jar1-1, supporting the notion that trans-2-hexenal and MeJA are recognized via different mechanisms. In addition, trans-2-hexenal had a moderate inhibitory effect on root length relative to similar concentrations of MeJA and was approximately 10-fold less effective than MeJA at inducing anthocyanin accumulation in Arabidopsis seedlings. These results suggest that C-6-volatiles of the LOX pathway act as a wound signal in plants, but result in a moderate plant response relative to MeJA at both the physiological and molecular level.