Abstract |
Mitogen-activated protein kinase (MAPK) cascades are involved in plant development, stress responses and hormonal signal transduction. MAPK kinases ( MAPKKs), as the key nodes in these cascades, link MAPKs and MAPKK kinases ( MAPKKKs). In this study, GhMKK4, a novel group C MAPKK gene from cotton (Gossypium hirsutum), was isolated and identified. Its expression can be induced by various stresses and signalling molecules. The overexpression of GhMKK4 in Nicotiana benthamiana enhanced its susceptibility to bacterial and fungal pathogens, but had no significant effects on salt or drought tolerance. Notably, the overexpressing plants showed increased sensitivity to abscisic acid (ABA) and gibberellin A3 (GA3), and ABA and gibberellin (GA) signalling were affected on infection with Ralstonia solanacearum bacteria. Furthermore, the overexpressing plants showed more reactive oxygen species (ROS) accumulation and stronger inhibition of catalase (CAT), a ROS-scavenging enzyme, than control plants after salicylic acid (SA) treatment. Interestingly, two genes encoding ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC), the key enzymes in polyamine synthesis, exhibited reduced R. solanacearum-induced expression in overexpressing plants. These findings broaden our knowledge about the functions of MAPKKs in diverse signalling pathways and the negative regulation of disease resistance in the cotton crop.
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Authors | Yuzhen Li, Liang Zhang, Wenjing Lu, Xiuling Wang, Chang-Ai Wu, Xingqi Guo |
Journal | Molecular plant pathology
(Mol Plant Pathol)
Vol. 15
Issue 1
Pg. 94-108
(Jan 2014)
ISSN: 1364-3703 [Electronic] England |
PMID | 23980654
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | © 2013 BSPP AND JOHN WILEY & SONS LTD. |
Chemical References |
- Gibberellins
- Plant Proteins
- RNA, Messenger
- Reactive Oxygen Species
- Sodium Chloride
- Abscisic Acid
- Hydrogen Peroxide
- gibberellic acid
- Salicylic Acid
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Topics |
- Abscisic Acid
(metabolism)
- Adaptation, Physiological
(drug effects, genetics)
- Amino Acid Sequence
- Disease Resistance
- Disease Susceptibility
- Droughts
- Gene Expression Profiling
- Gene Expression Regulation, Plant
(drug effects)
- Gibberellins
(metabolism)
- Gossypium
(metabolism)
- Hydrogen Peroxide
(metabolism)
- Molecular Sequence Data
- Plant Diseases
(genetics, microbiology)
- Plant Proteins
(chemistry, metabolism)
- Plants, Genetically Modified
- RNA, Messenger
(genetics, metabolism)
- Ralstonia solanacearum
(drug effects, physiology)
- Reactive Oxygen Species
(metabolism)
- Rhizoctonia
(drug effects, physiology)
- Salicylic Acid
(pharmacology)
- Sequence Analysis, Protein
- Signal Transduction
(drug effects, genetics)
- Sodium Chloride
(pharmacology)
- Stress, Physiological
(drug effects, genetics)
- Tobacco
(drug effects, genetics, metabolism, microbiology)
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