AUTHOR=Wang Fang , Wang Chen , Yan Yan , Jia Haihong , Guo Xingqi 

TITLE=Overexpression of Cotton GhMPK11 Decreases Disease Resistance through the Gibberellin Signaling Pathway in Transgenic Nicotiana benthamiana

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.00689

DOI=10.3389/fpls.2016.00689

ISSN=1664-462X

ABSTRACT=<p>Many changes in development, growth, hormone activity and environmental stimuli responses are mediated by mitogen-activated protein kinase (MAPK) cascades. However, in plants, studies on MAPKs have mainly focused on <italic>MPK3</italic>, <italic>MPK4</italic> and <italic>MPK6</italic>. Here, a novel group B MAPK gene, <italic>GhMPK11</italic>, was isolated from cotton (<italic>Gossypium hirsutum</italic> L.) and characterized. Both promoter and expression pattern analyses revealed that <italic>GhMPK11</italic> is involved in defense responses and signaling pathways. <italic>GhMPK11</italic> overexpression in <italic>Nicotiana benthamiana</italic> plants could increase gibberellin 3 (GA<sub>3</sub>) content through the regulation of GA-related genes. Interestingly, either <italic>GhMPK11</italic> overexpression or exogenous GA<sub>3</sub> treatment in <italic>N. benthamiana</italic> plants could enhance the susceptibility of these plants to the infectious pathogens <italic>Ralstonia solanacearum</italic> and <italic>Rhizoctonia solani</italic>. Moreover, reactive oxygen species (ROS) accumulation was increased after pathogen infiltration due to the increased expression of ROS-related gene respiratory burst oxidative homologs (<italic>RbohB</italic>) and the decreased expression or activity of ROS detoxification enzymes regulated by GA<sub>3</sub>, such as superoxide dismutases (SODs), peroxidases (PODs), catalase (CAT) and glutathione <italic>S</italic>-transferase (GST). Taken together, these results suggest that <italic>GhMPK11</italic> overexpression could enhance the susceptibility of tobacco to pathogen infection through the GA<sub>3</sub> signaling pathway via down-regulation of ROS detoxification enzymes.</p>