The calmodulin-binding transcription factor SIGNAL RESPONSIVE1 is a novel regulator of glucosinolate metabolism and herbivory tolerance in Arabidopsis.
The Arabidopsis Ca(2+)/calmodulin (CaM)-binding transcription factor SIGNAL RESPONSIVE1 (AtSR1/CAMTA3) was previously identified as a key negative regulator of plant immune responses. Here, we report a new role for AtSR1 as a critical component of plant defense against insect herbivory. Loss of AtSR1 function impairs tolerance to feeding by the generalist herbivore Trichoplusia ni as well as wound-induced jasmonate accumulation. The susceptibility of the atsr1 mutant is associated with decreased total glucosinolate (GS) levels. The two key herbivory deterrents, indol-3-ylmethyl (I3M) and 4-methylsulfinylbutyl (4MSOB), showed the most significant reductions in atsr1 plants. Further, changes in AtSR1 transcript levels led to altered expression of several genes involved in GS metabolism including IQD1, MYB51 and AtST5a. Overall, our results establish AtSR1 as an important component of plant resistance to insect herbivory as well as one of only three described proteins involved in Ca(2+)/CaM-dependent signaling to function in the regulation of GS metabolism, providing a novel avenue for future investigations of plant-insect interactions.
Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.
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K
Laluk
K V S K
KV
Prasad
T
T
Savchenko
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H
Celesnik
K
K
Dehesh
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M
Levy
T
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Mitchell-Olds
A S N
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Reddy
D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020013:Calcium Signaling; D002147:Calmodulin / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D005961:Glucosinolates / Q000378:metabolism*; D060434:Herbivory; D009036:Moths / Q000502:physiology*; D009154:Mutation; D054883:Oxylipins / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology* / Q000469:parasitology; D010937:Plant Growth Regulators / Q000378:metabolism; D030821:Plants, Genetically Modified; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D018749:RNA, Plant / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014947:Wounds and Injuries
D029681:Arabidopsis Proteins; D002147:Calmodulin; D003517:Cyclopentanes; D005961:Glucosinolates; D054883:Oxylipins; D010937:Plant Growth Regulators; D017346:Protein Serine-Threonine Kinases; D018749:RNA, Plant; D014157:Transcription Factors; C011006:jasmonic acid; C490996:At5g01820 protein, Arabidopsis