Polypeptide signaling for plant defensive genes exhibits analogies to defense signaling in animals
Polypeptide signaling for plant defensive genes exhibits analogies to defense signaling in animals
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DOI：
10.1073/pnas.93.22.12053
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发表时间：
1996-10-29
影响因子：
11.1
通讯作者：
Ryan, CA
中科院分区：
文献类型：
--
作者：
Bergey, DR;Howe, GA;Ryan, CA
番茄叶片中植物防御基因的激活是由一种可移动的18个氨基酸的多肽信号系统素介导的，该信号被称为系统素，系统素来源于一个更大的200个氨基酸的前体系统素，类似于动物中的多肽激素和可溶性生长因子。Systemin激活基于脂质的信号级联，也类似于动物的信号系统。在植物中，亚麻酸从膜中释放出来，并通过类十八烷途径转化为氧化脂类植物二烯酸和茉莉酸。植物氧化脂素是动物前列腺素的结构类似物，是由花生四烯酸在多种信号（包括多肽因子）的作用下产生的。转基因番茄植物中原系统素基因的组成性过表达导致原系统素的过量产生和系统素的异常释放，从而导致几种系统性损伤反应蛋白（SWRPs）的组成性过量产生。这些数据表明，系统蛋白是防御食草动物攻击的主要信号。叶片细胞在受到病原体攻击时产生的低聚糖激发子，也会合成由伤害诱导的相同防御蛋白。类十八烷途径的抑制剂和中断该途径的突变，阻断了伤害、系统蛋白和低聚糖激发子对SWRPs的诱导。这表明，在所有这些信号激活防御基因的过程中，类十八烷途径是必不可少的。缺乏类十八烷途径的番茄突变系极易受到雌雄小蛾幼虫的攻击。番茄叶片的防御信号通路与动物巨噬细胞和肥大细胞的防御信号通路之间的相似性表明，植物和动物的防御信号通路可能来自一个共同的祖先起源。
The activation of plant defensive genes in leaves of tomato plants in response to herbivore damage or mechanical wounding is mediated by a mobile 18-amino acid polypeptide signal called systemin, Systemin is derived from a larger, 200-amino acid precursor called prosystemin, similar to polypeptide hormones and soluble growth factors in animals. Systemin activates a lipid-based signaling cascade, also analogous to signaling systems found in animals, In plants, linolenic acid is released from membranes and is converted to the oxylipins phytodienoic acid and jasmonic acid through the octadecanoid pathway. Plant oxylipins are structural analogs of animal prostaglandins which are derived from arachidonic acid in response to various signals, including polypeptide factors, Constitutive overexpression of the prosystemin gene in transgenic tomato plants resulted in the overproduction of prosystemin and the abnormal release of systemin, conferring a constitutive overproduction of several systemic wound-response proteins (SWRPs). The data indicate that systemin is a master signal for defense against attacking herbivores, The same defensive proteins induced by wounding are synthesized in response to oligosaccharide elicitors that are generated in leaf cells in response to pathogen attacks, Inhibitors of the octadecanoid pathway, and a mutation that interrupts this pathway, block the induction of SWRPs by wounding, systemin, and oligosaccharide elicitors, indicating that the octadecanoid pathway is essential for the activation of defense genes by all of these signals, The tomato mutant line that is functionally deficient in the octadecanoid pathway is highly susceptible to attacks by Manduca sexta larvae. The similarities between the defense signaling pathway in tomato leaves and those of the defense signaling pathways of macrophages and mast cells of animals suggests that both the plant and animal pathways may have evolved from a common ancestral origin.