Loss of Function of FATTY ACID DESATURASE7 in Tomato Enhances Basal Aphid Resistance in a Salicylate-Dependent Manner
Loss of Function of FATTY ACID DESATURASE7 in Tomato Enhances Basal Aphid Resistance in a Salicylate-Dependent Manner
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DOI：
10.1104/pp.111.191262
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发表时间：
2012-04-01
期刊：
影响因子：
7.4
通讯作者：
Goggin, Fiona L.
中科院分区：
文献类型：
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作者：
Avila, Carlos A.;Arevalo-Soliz, Lirio M.;Goggin, Fiona L.
我们在这里报告说，ω-3脂肪酸去饱和酶7（FAD 7）功能的破坏增强了植物对蚜虫的防御。番茄（Solanum lycopersicum）中的前系统蛋白介导的应答2（spr 2）突变的抑制子消除了FAD 7的功能，降低了马铃薯蚜虫（Macrosiphum euphorphium）的沉降行为、存活和繁殖力。同样，野生型番茄植物中LeFAD 7表达的反义抑制减少了蚜虫侵染。在spr 2突变体中的蚜虫抗性与水杨酸（SA）和编码病程相关蛋白P4的mRNA水平的提高有关。引入萘/水杨酸羟化酶转基因，抑制SA积累，恢复野生型蚜虫对spr 2的敏感性。当我们利用病毒诱导的基因沉默来抑制致病相关蛋白1（NPR 1）的表达时，spr 2中的抗性也会丧失，NPR 1是许多SA依赖性防御的正调节因子。这些结果表明，FAD 7抑制通过SA和NPR 1介导的针对蚜虫的防御。虽然FAD 7功能的丧失也抑制茉莉酸（JA）的合成，这种去饱和酶对蚜虫抗性的影响不依赖于JA; JA合成（acx 1）或感知（jai 1 -1）受损的其他突变体显示野生型水平的蚜虫易感性，和spr 2保留蚜虫抗性时，茉莉酸甲酯处理。因此，FAD 7可能通过独立影响JA合成和SA信号传导来影响JA依赖的对咀嚼昆虫的防御和SA依赖的对蚜虫的防御。与野生型对照相比，拟南芥突变体Atfad 7 -2和Atfad 7 - 1fad 8也显示出对绿色桃蚜（Myzus persicae）增强的抗性，表明FAD 7影响至少两个植物家族中的植物-蚜虫相互作用。
We report here that disruption of function of the omega-3 FATTY ACID DESATURASE7 (FAD7) enhances plant defenses against aphids. The suppressor of prosystemin-mediated responses2 (spr2) mutation in tomato (Solanum lycopersicum), which eliminates the function of FAD7, reduces the settling behavior, survival, and fecundity of the potato aphid (Macrosiphum euphorbiae). Likewise, the antisense suppression of LeFAD7 expression in wild-type tomato plants reduces aphid infestations. Aphid resistance in the spr2 mutant is associated with enhanced levels of salicylic acid (SA) and mRNA encoding the pathogenesis-related protein P4. Introduction of the Naphthalene/salicylate hydroxylase transgene, which suppresses SA accumulation, restores wild-type levels of aphid susceptibility to spr2. Resistance in spr2 is also lost when we utilize virus-induced gene silencing to suppress the expression of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1), a positive regulator of many SA-dependent defenses. These results indicate that FAD7 suppresses defenses against aphids that are mediated through SA and NPR1. Although loss of function of FAD7 also inhibits the synthesis of jasmonate (JA), the effects of this desaturase on aphid resistance are not dependent on JA; other mutants impaired in JA synthesis (acx1) or perception (jai1-1) show wild-type levels of aphid susceptibility, and spr2 retains aphid resistance when treated with methyl jasmonate. Thus, FAD7 may influence JA-dependent defenses against chewing insects and SA-dependent defenses against aphids through independent effects on JA synthesis and SA signaling. The Arabidopsis (Arabidopsis thaliana) mutants Atfad7-2 and Atfad7-1fad8 also show enhanced resistance to the green peach aphid (Myzus persicae) compared with wild-type controls, indicating that FAD7 influences plant-aphid interactions in at least two plant families.