A SBP-Box Gene VpSBP5 from Chinese Wild Vitis Species Responds to Erysiphe necator and Defense Signaling Molecules

Abstract

A novel SQUAMOSA PROMOTER BINDING PROTEIN (SBP)-box gene, designated as VpSBP5, was isolated from Chinese wild Vitis pseudoreticulata clone “Baihe-35-1” infected by Erysiphe necator under natural field conditions. The full-length cDNA sequence of VpSBP5 comprised 3,811 bp and encoded a polypeptide of 1,030 amino acids which contained a highly conserved SBP domain bearing two zinc-binding sites of the C2HCH type and a nuclear localization signal. The deduced amino acid sequence of VpSBP5 was identical to that of VvSBP5 and grouped into the same clade (group 1) with AtSPL1, AtSPL12, AtSPL14, VvSBP7, and VvSBP17. We further confirmed that VpSBP5 gene is indeed targeted to the nucleus and possesses transcriptional activation activity. The expression of VpSBP5 as determined by reverse transcription PCR, was induced by E. necator in the E. necator-resistant V. pseudoreticulata clone Baihe-35-1 and the susceptible clone “Hunan-1,” and exhibited a quicker response in Baihe-35-1. Moreover, the expression of VpSBP5 was induced by salicylic acid (SA) and methyl jasmonate (MeJA) in Baihe-35-1. Together, our results indicate that VpSBP5 is likely to participate in the regulation of the resistance to E. necator by inducing SA and MeJA molecular signals in grape, and the degree of disease resistance of the grapevine genotypes may correlate with the time of the peak appearing.