Cotton GhMPK6a negatively regulates osmotic tolerance and bacterial infection in transgenic Nicotiana benthamiana, and plays a pivotal role in development. (5th September 2013)

• Record Type: Journal Article
• Authors: Li, Yuzhen; Zhang, Liang; Wang, Xiuling; Zhang, Wei; Hao, Lili; Chu, Xiaoqian; Guo, Xingqi
• Is Part Of: FEBS journal. Volume 280:Number 20(2013)
• Page Start: 5128
• Page End: 5144
• Publication Date: 2013-09-05
• Subjects: Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.12488
• Languages: English
• ISSNs: 1742-464X

Abstract

<abstract abstract-type="main" id="febs12488-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="febs12488-sec-0102" sec-type="section"> <p>Mitogen‐activated protein kinase (MAPK) cascades play important roles in the perception of external signals and the generation of suitable responses. Cotton (<italic>Gossypium hirsutum</italic>) 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 <italic>G. hirsutum</italic> (Gh)MPK6a was identified and characterized. <italic>GhMPK6a</italic> expression can be induced through multiple defence‐related signal molecules and abiotic and biotic stresses. The ectopic expression of <italic>GhMPK6a</italic> in <italic>Nicotiana benthamiana</italic> 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 <italic>GhMPK6a</italic> were sensitive to the bacterial pathogen <italic>Ralstonia solanacearum</italic>. Histochemical analysis of β‐glucuronidase activity revealed that <italic>GhMPK6a</italic> 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 <italic>GhMPK6a</italic> 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.</p> </sec> <sec id="febs12488-sec-0112" sec-type="section"> <title>Structured digital abstract</title> <sec id="febs12488-sec-0103" sec-type="section"> <p> <list id="febs12488-list-0001" list-type="bullet"> <list-item> <p>GhMPK6a physically interacts with GhMPK4 by two hybrid (View interaction)</p> </list-item> <list-item> <p>GhMPK6a and GhMPK4 physically interact by bimolecular fluorescence complementation (View interaction)</p> </list-item> </list> </p> </sec> </sec> </abstract>