Molecular characterization of biotic and abiotic stress-responsive MAP kinase genes, IbMPK3 and IbMPK6, in sweetpotato

作者：Kim Ho Soo; Park Sung Chul; Ji Chang Yoon; Park Seyeon; Jeong Jae Cheol; Lee Haeng Soon; Kwak Sang Soo^*

来源：Plant Physiology and Biochemistry, 2016, 108: 37-48.

DOI：10.1016/j.plaphy.2016.06.036

• Abiotic and biotic stress
• IbMPK3
• IbMPK6
• Sweetpotato
• Transient expression assay

Plants are continually exposed to numerous environmental stresses. To decrease damage caused by these potentially detrimental factors, various stress-related signaling cascades are activated in plants. One such stress-responsive signaling pathway, the mitogen-activated protein kinase (MAPK) module, plays a critical role in diverse plant stress responses. Here, we functionally characterized biotic and abiotic stress-responsive MAPK genes, IbMPK3 and IbMPK6, from sweetpotato. IbMPK3/6 contain totally 11 MAPK conserved subdomains and the phosphorylating motif TEY. Bacterially expressed IbMPK3/6 could be autophosphorylated in vitro, and these proteins phosphorylated universal kinase substrate, such as myelin basic protein. IbMPK3/6 transcripts were expressed in leaf, stem, and root of sweetpotato cultivars with storage roots of various colors. IbMPK3 and IbMPK6 were induced by various biotic/abiotic stress treatments. Furthermore, the kinase activity of IbMPK3/6 was induced during early NaCl, SA, H2O2, and ABA treatment. IbMPK3/6 were predominantly localized to the nucleus. To determine the biological functions of IbMPK3/6, we transiently expressed the IbMPK genes in tobacco (Nicotiana benthamiana) leaves, which resulted in enhanced tolerance to bacterial pathogen and increased expression of pathogenesis-related (PR) genes. These data demonstrate that IbMPK3 and IbMPK6 play significant roles in plant responses to environmental stress.

• 出版日期2016-11