Developmental and stimulus-induced expression patterns of Arabidopsis calmodulin-like genes CML37, CML38 and CML39.
Various aspects of plant development and stress physiology are mediated by Ca(2+) signaling. Ca(2+) sensors, such as calmodulin, detect these signals and direct downstream signaling pathways by binding and activating diverse targets. Plants possess many unique, putative Ca(2+) sensors, including a large family (50 in Arabidopsis) of calmodulin-like proteins termed CMLs. Some of these CMLs have been implicated in Ca(2+)-based stress response but most remain unstudied. We generated transgenic plants expressing CML::GUS reporter genes for members of a subfamily of CMLs (CML37, CML38 and CML39) which allowed us to investigate their expression patterns in detail. We found that CML::GUS genes displayed unique tissue, cell-type, and temporal patterns of expression throughout normal development, particularly in the flower, and in response to a variety of stimuli, including biotic and abiotic stress, hormone and chemical treatments. Our findings are supported by semiquantitative reverse-transcription PCR as well as analyses of microarray databases. Analysis of purified, recombinant CMLs demonstrated their ability to bind Ca(2+) in vitro. Collectively, our data suggest that these CMLs likely play important roles as sensors in Ca(2+)-mediated developmental and stress response pathways and provide a framework of spatial and temporal expression to direct future studies aimed at elucidating their physiological roles.
Vanderbeld
Barbara
B
Department of Biology, Queen's University, Kingston, ON, Canada, K7L 3N6.
Snedden
Wayne A
WA
D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000096:biosynthesis / Q000235:genetics*; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000737:chemistry; D002147:Calmodulin / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000737:chemistry; D020411:Oligonucleotide Array Sequence Analysis; D030821:Plants, Genetically Modified / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
D029681:Arabidopsis Proteins; C522735:CML37 protein, Arabidopsis; C522736:CML38 protein, Arabidopsis; C522737:CML39 protein, Arabidopsis; D002135:Calcium-Binding Proteins; D002147:Calmodulin; D018076:DNA, Complementary; D011994:Recombinant Proteins; D006861:Hydrogen Peroxide; D002118:Calcium