title: Cotton GhMPK6a negatively regulates osmotic tolerance and bacterial infection in transgenic Nicotiana benthamiana, and plays a pivotal role in development.
abstract: Mitogen-activated protein kinase (MAPK) cascades play important roles in the perception of external signals and the generation of suitable responses. Cotton (Gossypium hirsutum) is an important fibre-producing and oil-producing crop worldwide. However, few MAPKs and their interaction partners have been functionally characterized in cotton. In the present study, the group A MAPK G. hirsutum (Gh)MPK6a was identified and characterized. GhMPK6a expression can be induced through multiple defence-related signal molecules and abiotic and biotic stresses. The ectopic expression of GhMPK6a in Nicotiana benthamiana reduced drought and salt tolerance, with elevated malondialdehyde content, higher reactive oxygen species content and lower abscisic acid content than in wild-type plants. Moreover, plants overexpressing GhMPK6a were sensitive to the bacterial pathogen Ralstonia solanacearum. Histochemical analysis of β-glucuronidase activity revealed that GhMPK6a showed tissue-specific expression during postgermination development, mixed bud differentiation, and pollination. Most importantly, GhMPK6a interacts with the upstream MAPK kinase GhMKK4, as shown by the use of yeast two-hybrid and bimolecular fluorescence complementation systems, compensating for a deficiency of MAPK interaction partners in cotton crops. Taken together, these results suggest that GhMPK6a negatively regulates osmotic stress and bacterial infection, and plays an important role in developmental processes. These results provide useful information for elucidating the roles of MAPK cascades in cotton crops.
  GhMPK6a physically interacts with GhMPK4 by two hybrid (View interaction) GhMPK6a and GhMPK4 physically interact by bimolecular fluorescence complementation (View interaction).
authors: State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, China.
authors: Yuzhen
authors: Y
authors: Li
authors: Liang
authors: L
authors: Zhang
authors: Xiuling
authors: X
authors: Wang
authors: Wei
authors: W
authors: Zhang
authors: Lili
authors: L
authors: Hao
authors: Xiaoqian
authors: X
authors: Chu
authors: Xingqi
authors: X
authors: Guo
mesh_terms: D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D001419:Bacteria / Q000472:pathogenicity*; D002467:Cell Nucleus / Q000201:enzymology; D003593:Cytoplasm / Q000201:enzymology; D055864:Droughts; D003368:Gossypium / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009995:Osmosis; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D017382:Reactive Oxygen Species; D020928:Mitogen-Activated Protein Kinases
keywords: GhMPK6a; cotton; development; mitogen-activated protein kinase cascade; osmotic stress