Jasmonic acid is a key regulator of spider mite-induced volatile terpenoid and methyl salicylate emission in tomato
Jasmonic acid is a key regulator of spider mite-induced volatile terpenoid and methyl salicylate emission in tomato
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DOI：
10.1104/pp.104.048694
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发表时间：
2004-08-01
期刊：
影响因子：
7.4
通讯作者：
Schuurink, RC
中科院分区：
文献类型：
--
作者：
Ament, K;Kant, MR;Schuurink, RC
以番茄（Lycopersicon esculentum）突变体def-1为材料，研究了茉莉酸（jasmonic acid， JA）在伤害或草食过程中诱导积累不足的作用，以及茉莉酸在对荨麻叶螨（Tetranychus urticae）的直接和间接防御反应中的作用。与先前的报道相反，尽管def-1缺乏蛋白酶抑制剂的诱导活性，但蜘蛛螨在def-1上产卵的数量和造成的伤害与野生型植物一样多。然而，在def-1上的卵的孵化率明显更高，这表明依赖于ja的直接防御增加了卵的死亡率或增加了胚胎发育所需的时间。在基因表达方面，感染1 d后，def-1的ja相关转录本水平降低，水杨酸（SA）相关转录本水平升高。此外，由于没有诱导5种典型的蜘蛛螨诱导的番茄挥发物（水杨酸甲酯[MeSA]、4,8,12-三甲基三烯-1,3,7,11-四烯[TMTT]、芳樟醇、反式神经樟醇和反式- β -八烯），因此在def-1中不存在间接防御反应，并且掠食性螨（Phytoseiulus persimilis）不像对野生型番茄那样区分被侵染和未侵染的def-1番茄。同样，MeSA生物合成基因salicylic acid rnethyltransferase （SAMT）在野生型中被蜘蛛螨诱导表达，而在def-1中没有表达。外源施用JA对def-1诱导SAMT和推测的香叶基二磷酸合成酶转录物的积累，恢复草食时MeSA-和tmtt的释放。因此，JA是诱导SA转化为MeSA的必要条件。结果表明，茉莉酸是建立蜘蛛螨诱导的番茄间接防御反应的必要条件。
The tomato (Lycopersicon esculentum) mutant def-1, which is deficient in induced jasmonic acid (JA) accumulation upon wounding or herbivory, was used to study the role of JA in the direct and indirect defense responses to phytophagous mites (Tetranychus urticae). In contrast to earlier reports, spider mites laid as many eggs and caused as much damage on def-1 as on wild-type plants, even though def-1 lacked induction of proteinase inhibitor activity. However, the hatching-rate of eggs on def-1 was significantly higher, suggesting that JA-dependent direct defenses enhanced egg mortality or increased the time needed for embryonic development. As to gene expression, def-1 had lower levels of JA-related transcripts but higher levels of salicylic acid (SA) related transcripts after 1 d of spider mite infestation. Furthermore, the indirect defense response was absent in def-1, since the five typical spider mite-induced tomato-volatiles (methyl salicylate [MeSA], 4,8,12-trimethyltrideca-1,3,7,11-tetraene [TMTT], linalool, trans-nerolidol, and trans-beta-ocimene) were not induced and the predatory mite Phytoseiulus persimilis did not discriminate between infested and uninfested def-1 tomatoes as it did with wild-type tomatoes. Similarly, the expression of the MeSA biosynthetic gene salicylic acid rnethyltransferase (SAMT) was induced by spider mites in wild type but not in def-1. Exogenous application of JA to def-1 induced the accumulation of SAMT and putative geranylgeranyl diphosphate synthase transcripts and restored MeSA- and TMTT-emission upon herbivory. JA is therefore necessary to induce the enzymatic conversion of SA into MeSA. We conclude that JA is essential for establishing the spider mite-induced indirect defense response in tomato.