title: Coupling calcium/calmodulin-mediated signaling and herbivore-induced plant response through calmodulin-binding transcription factor AtSR1/CAMTA3.
abstract: Calcium/calmodulin (Ca(2+)/CaM) has long been considered a crucial component in wound signaling pathway. However, very few Ca(2+)/CaM-binding proteins have been identified which regulate plant responses to herbivore attack/wounding stress. We have reported earlier that a family of Ca(2+)/CaM-binding transcription factors designated as AtSRs (also known as AtCAMTAs) can respond differentially to wounding stress. Further studies revealed that AtSR1/CAMTA3 is a negative regulator of plant defense, and Ca(2+)/CaM-binding to AtSR1 is indispensable for the suppression of salicylic acid (SA) accumulation and disease resistance. Here we report that Ca(2+)/CaM-binding is also critical for AtSR1-mediated herbivore-induced wound response. Interestingly, atsr1 mutant plants are more susceptible to herbivore attack than wild-type plants. Complementation of atsr1 mutant plants by overexpressing wild-type AtSR1 protein can effectively restore plant resistance to herbivore attack. However, when mutants of AtSR1 with impaired CaM-binding ability were overexpressed in atsr1 mutant plants, plant resistance to herbivore attack was not restored, suggesting a key role for Ca(2+)/CaM-binding in wound signaling. Furthermore, it was observed that elevated SA levels in atsr1 mutant plants have a negative impact on both basal and induced biosynthesis of jasmonates (JA). These results revealed that Ca(2+)/CaM-mediated signaling regulates plant response to herbivore attack/wounding by modulating the SA-JA crosstalk through AtSR1.
authors.affiliation: Molecular Plant Science, Department of Horticulture, Washington State University, Pullman, WA 99164-6414, USA.
authors.forename: Yongjian
authors.initials: Y
authors.lastname: Qiu
authors.forename: Jing
authors.initials: J
authors.lastname: Xi
authors.forename: Liqun
authors.initials: L
authors.lastname: Du
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Suttle
authors.forename: B W
authors.initials: BW
authors.lastname: Poovaiah
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000187:drug effects / Q000276:immunology* / Q000469:parasitology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D002147:Calmodulin / Q000378:metabolism*; D003517:Cyclopentanes / Q000494:pharmacology; D060434:Herbivory / Q000187:drug effects / Q000502:physiology*; D007313:Insecta / Q000187:drug effects / Q000502:physiology; D007814:Larva / Q000187:drug effects / Q000502:physiology; D009154:Mutation / Q000235:genetics; D054883:Oxylipins / Q000494:pharmacology; D010935:Plant Diseases / Q000469:parasitology; D011485:Protein Binding / Q000187:drug effects; D020156:Salicylic Acid / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: C572689:AT2G22300 protein, Arabidopsis; D029681:Arabidopsis Proteins; D002147:Calmodulin; D003517:Cyclopentanes; D054883:Oxylipins; D014157:Transcription Factors; C572690:AT5G37780 protein, Arabidopsis; C011006:jasmonic acid; D020156:Salicylic Acid