title: Overexpression of two R2R3-MYB genes from Scutellaria baicalensis induces phenylpropanoid accumulation and enhances oxidative stress resistance in transgenic tobacco.
abstract: MYB proteins are involved in many significant physiological and biochemical processes, including regulation of primary and secondary metabolism, flavonoid biosynthesis, response to various biotic and abiotic stresses, hormone synthesis and signal transduction. The functions of R2R3-MYB proteins in Scutellaria baicalensis Georgi under abiotic stress, however, has not been elucidated. To study the molecular mechanism by which MYB2 and MYB7 respond to abiotic stress in S. baicalensis, we analyzed the phenylpropanoid content, growth phenotype, antioxidant enzyme activity and flavonoid synthesis-associated gene expression in SbMYB2 or SbMYB7-overexpressing transgenic tobacco plants after treatment with NaCl, mannitol and abscisic acid (ABA). The transgenic tobacco showed a higher fresh weight than did the wild type (WT) tobacco. In contrast, antioxidant enzyme activity and flavonoid synthesis-related gene expression were markedly higher in WT tobacco after treatment with NaCl, mannitol and ABA, as compared to transgenic plants, This is likely because increased phenylpropanoid accumulation in transgenic tobacco plants played a central role in abiotic stress resistance. These results indicate that overexpression of SbMYB2 or SbMYB7 increased phenylpropanoid accumulation and enhanced NaCl, mannitol and ABA stresses tolerance in transgenic tobacco.
authors.affiliation: Wuhan Polytechnic University, Wuhan, 430023, China. Electronic address: qlj0810139@163.com.
authors.forename: Linjie
authors.initials: L
authors.lastname: Qi
authors.affiliation: National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: yangchem2012@163.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.affiliation: National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: y_yuan@163.com.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: huangluqi01@126.com.
authors.forename: Luqi
authors.initials: L
authors.lastname: Huang
authors.affiliation: Wuhan Polytechnic University, Wuhan, 430023, China. Electronic address: chenpingvip24@163.com.
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
mesh_terms: D018384:Oxidative Stress; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D031364:Scutellaria baicalensis / Q000235:genetics* / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors
keywords: Abiotic stress; Enzyme activity; Gene expression; MYB transcription factor