title: Cotton GhMKK1 induces the tolerance of salt and drought stress, and mediates defence responses to pathogen infection in transgenic Nicotiana benthamiana.
abstract: Mitogen-activated protein kinase kinases (MAPKK) mediate a variety of stress responses in plants. So far little is known on the functional role of MAPKKs in cotton. In the present study, Gossypium hirsutum MKK1 (GhMKK1) function was investigated. GhMKK1 protein may activate its specific targets in both the nucleus and cytoplasm. Treatments with salt, drought, and H2O2 induced the expression of GhMKK1 and increased the activity of GhMKK1, while overexpression of GhMKK1 in Nicotiana benthamiana enhanced its tolerance to salt and drought stresses as determined by many physiological data. Additionally, GhMKK1 activity was found to up-regulate pathogen-associated biotic stress, and overexpression of GhMKK1 increased the susceptibility of the transgenic plants to the pathogen Ralstonia solanacearum by reducing the expression of PR genes. Moreover, GhMKK1-overexpressing plants also exhibited an enhanced reactive oxygen species scavenging capability and markedly elevated activities of several antioxidant enzymes. These results indicate that GhMKK1 is involved in plants defence responses and provide new data to further analyze the function of plant MAPK pathways.
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Lu
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Chu
authors.forename: Yuzhen
authors.initials: Y
authors.lastname: Li
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Xingqi
authors.initials: X
authors.lastname: Guo
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D060467:Disease Resistance / Q000235:genetics / Q000276:immunology; D055864:Droughts; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D003368:Gossypium / Q000235:genetics*; D042541:Intracellular Space / Q000378:metabolism; D048369:MAP Kinase Kinase 1 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics; D018384:Oxidative Stress / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D030821:Plants, Genetically Modified; D021381:Protein Transport; D017382:Reactive Oxygen Species / Q000378:metabolism; D055049:Salt Tolerance / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological / Q000235:genetics* / Q000276:immunology; D014026:Nicotiana / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D048369:MAP Kinase Kinase 1