Mutation of the Arabidopsis Calmodulin-Like Protein CML37 Deregulates the Jasmonate Pathway and Enhances Susceptibility to Herbivory  

作　　者：Sandra S. Scholz Jyothilakshmi Vadassery Monika Heyer Michael Reichelt Kyle W. Bender Wayne A. Snedden Wilhelm Boland Axel Mithofer 

机构地区：[1]Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Hans-Knoll-StraBe 8, 07745 Jena, Germany [2]Department of Biochemistry, Max Planck Institute for Chemica Eco ogy, Hans-Knoll-StraBe 8, 07745 Jena, Germany [3]Department of Plant Biology, University of Illinois, Urbana, IL 61801, USA [4]Department of Biology, Queen's University, Kingston, Ontario, Canada, Canada, K7L 3N6

出　　处：《Molecular Plant》2014年第12期1712-1726,共15页分子植物（英文版）

摘　　要：Throughout their life, plants are challenged by various abiotic and biotic stress factors. Among those are attacks from herbivorous insects. The molecular mechanisms underlying the detection of herbivores and the subsequent signal transduction are not well understood. As a second messenger, fluxes in intracellular Ca2＋ levels play a key role in mediating stress response pathways. Ca2＋ signals are decoded by Ca2＋ sensor proteins such as calmodulin-like proteins （CMLs）. Here, we demonstrate that recombinant CML37 behaves like a Ca2＋ sensor in vitro and, in Arabidopsis, AtCML37 is induced by mechanical wounding as well as by infestation with larvae of the generalist lepidopteran herbivore Spodoptera littoralis. Loss of function of CML37 led to a better feeding performance of larvae suggesting that CML37 is a positive defense regulator. No herbivory-induced changes in secondary metabolites such as glucosinolates or flavonoids were detected in cml37 plants, although a significant reduction in the accumulation of jasmonates was observed, due to reduced expression of JAR1 mRNA and cellular enzyme activity. Consequently, the expression of jasmonate-responsive genes was reduced as well. Summarizing, our results suggest that the Ca2＋ sensor protein, CML37, functions as a positive regulator in Ca2＋ signaling during herbivory, connecting Ca2＋ and jasmonate signaling.Throughout their life, plants are challenged by various abiotic and biotic stress factors. Among those are attacks from herbivorous insects. The molecular mechanisms underlying the detection of herbivores and the subsequent signal transduction are not well understood. As a second messenger, fluxes in intracellular Ca2＋ levels play a key role in mediating stress response pathways. Ca2＋ signals are decoded by Ca2＋ sensor proteins such as calmodulin-like proteins （CMLs）. Here, we demonstrate that recombinant CML37 behaves like a Ca2＋ sensor in vitro and, in Arabidopsis, AtCML37 is induced by mechanical wounding as well as by infestation with larvae of the generalist lepidopteran herbivore Spodoptera littoralis. Loss of function of CML37 led to a better feeding performance of larvae suggesting that CML37 is a positive defense regulator. No herbivory-induced changes in secondary metabolites such as glucosinolates or flavonoids were detected in cml37 plants, although a significant reduction in the accumulation of jasmonates was observed, due to reduced expression of JAR1 mRNA and cellular enzyme activity. Consequently, the expression of jasmonate-responsive genes was reduced as well. Summarizing, our results suggest that the Ca2＋ sensor protein, CML37, functions as a positive regulator in Ca2＋ signaling during herbivory, connecting Ca2＋ and jasmonate signaling.

关 键 词：HERBIVORY oral secretion JASMONATES cytosolic calcium calmodulin-like proteins. 

分 类 号：Q51[生物学—生物化学] S661.1[农业科学—果树学]