Find in Library

Calmodulin-binding transcription activator (CAMTA) is a transcription factor family containing calmodulin (CaM) binding sites and is involved in plant development. Although CAMTAs in Arabidopsis have been extensively investigated, the functions of CAMTAs remain largely unclear in peaches. In this study, we identified five peach CAMTAs which contained conserved CG-1 box, ANK repeats, CaM binding domain (CaMBD) and IQ motifs. Overexpression in tobacco showed that PpCAMTA1/2/3 were located in the nucleus, while PpCAMTA4 and PpCAMTA5 were located in the plasma membrane. Increased expression levels were observed for <i>PpCAMTA1</i> and <i>PpCAMTA3</i> during peach fruit ripening. Expression of <i>PpCAMTA1</i> was induced by cold treatment and was inhibited by ultraviolet B irradiation (UV-B). Driven by <i>AtCAMTA3</i> promoter, <i>PpCAMTA1/2/3</i> were overexpressed in Arabidopsis mutant. Here, we characterized peach <i>PpCAMTA1,</i> representing an ortholog of <i>AtCAMTA3.</i> <i>PpCAMTA1</i> expression in Arabidopsis complements the developmental deficiencies of the <i>camta2,3</i> mutant, and restored the plant size to the wild type level. Moreover, overexpressing <i>PpCAMTA1</i> in <i>camta2,3</i> mutant inhibited salicylic acid (SA) biosynthesis and expression of SA-related genes, resulting in a susceptibility phenotype to <i>Pst</i> DC3000. Taken together, our results provide new insights for <i>CAMTAs</i> in peach fruit and indicate that <i>PpCAMTA1</i> is associated with response to stresses during development.