Identification of disease resistance to soft rot in transgenic potato plants that overexpress the soybean calmodulin-4 gene (GmCaM-4)

Abstract

Calmodulin (CaM) mediates cellular Ca2+signals in the defense responses of plants. We previously reported that GmCaM-4 and 5 are involved in salicylic acidindependent activation of disease resistance responses in soybean (Glycine max). Here, we generated a GmCaM-4 cDNA construct under the control of the cauliflower mosaic virus (CaMV) 35S promoter and transformed this construct into potato (Solanum tuberosum L.). The constitutive over-expression of GmCaM-4 in potato induced high-level expression of pathogenesis-related (PR) genes, such as PR-2, PR-3, PR-5, phenylalanine ammonia-lyase (PAL), and proteinase inhibitorII (pinII). In addition, the transgenic potato plants exhibited enhanced resistance against a bacterial pathogen, Erwinia carotovora ssp. Carotovora (ECC), that causes soft rot disease and showed spontaneous lesion phenotypes on their leaves. These results strongly suggest that a CaM protein in soybean, GmCaM-4, plays an important role in the response of potato plants to pathogen defense signaling. ? 2020 Korean Society of Plant Biotechnology. All rights reserved.