Open AccessOverexpression of GmCaM4 in soybean enhances resistance to pathogens and tolerance to salt stress
Author(s) -
Rao Suryadevara S.,
ElHabbak Mohamed H.,
Havens Wendy M.,
Singh Ajay,
Zheng Danman,
Vaughn Laura,
Haudenshield James S.,
Hartman Glen L.,
Korban Schuyler S.,
Ghabrial Said A.
Publication year - 2014
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/mpp.12075
Subject(s) - biology , gene silencing , jasmonic acid , bimolecular fluorescence complementation , microbiology and biotechnology , rna interference , gene , gene expression , abiotic stress , transcription factor , transgene , genetics , rna
Summary Plant diseases inflict heavy losses on soybean yield, necessitating an understanding of the molecular mechanisms underlying biotic/abiotic stress responses. Ca 2 + is an important universal messenger, and protein sensors, prominently calmodulins ( CaM s), recognize cellular changes in Ca 2 + in response to diverse signals. Because the development of stable transgenic soybeans is laborious and time consuming, we used the Bean pod mottle virus ( BPMV )‐based vector for rapid and efficient protein expression and gene silencing. The present study focuses on the functional roles of the gene encoding the soybean CaM isoform GmCaM4 . Overexpression of GmCaM4 in soybean resulted in enhanced resistance to three plant pathogens and increased tolerance to high salt conditions. To gain an understanding of the underlying mechanisms, we examined the potential defence pathways involved. Our studies revealed activation/increased expression levels of pathogenesis‐related ( PR ) genes in GmCaM4 ‐overexpressing plants and the accumulation of jasmonic acid ( JA ). Silencing of GmCaM4 , however, markedly repressed the expression of PR genes. We confirmed the in vivo interaction between GmCaM4 and the CaM binding transcription factor M yb2, which regulates the expression of salt‐responsive genes, using the yeast two‐hybrid ( Y2H ) system and bimolecular fluorescence complementation assays. GmCaM4 and G lycine max CaM binding receptor‐like kinase ( GmCBRLK ) did not interact in the Y2H assays, but the interaction between GmCaM2 and GmCBRLK was confirmed. Thus, a GmCaM2 – GmCBRLK ‐mediated salt tolerance mechanism, similar to that reported in G lycine soja , may also be functional in soybean. Confocal microscopy showed subcellular localization of the green fluorescent protein ( GFP )‐ GmCaM4 fusion protein in the nucleus and cytoplasm.