Overexpression of MtCAS31 enhances drought tolerance in transgenic Arabidopsis by reducing stomatal density

• Published in: The New phytologist Vol. 195; no. 1; pp. 124 - 135
• Main Authors: Xie, Can, Zhang, Rongxue, Qu, Yueting, Miao, Zhenyan, Zhang, Yunqin, Shen, Xiaoye, Wang, Tao, Dong, Jiangli
• Format: Journal Article
• Language: English
• Published: Oxford, UK New Phytologist Trust 01.07.2012; Blackwell Publishing Ltd; Wiley Subscription Services, Inc
• Subjects: abiotic stress; Abscisic Acid - pharmacology; Arabidopsis; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; dehydrin (DHN); Drought; Drought resistance; Drought tolerance; Droughts; Fluorescence; Gene Expression Regulation, Plant; Genes; Medicago truncatula; Medicago truncatula - genetics; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Stomata - physiology; Plants; Plants, Genetically Modified; Proteins; Sodium Chloride - pharmacology; Stomata; stomatal density; Stress, Physiological; transcription factor; Transcription Factors - genetics; Transcription Factors - metabolism; Transgenic plants; Yeasts
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2012.04136.x

Dehydrins are a type of late embryogenesis abundant protein. Some dehydrins are involved in the response to various abiotic stresses. Accumulation of dehydrins enhances the drought, cold and salt tolerances of transgenic plants, although the underlying mechanism is unclear. MtCAS31 (Medicago Truncatula cold-acclimation specific protein 31) is a Y2K4-type dehydrinthat was isolated from Medicago truncatula. We analyzed the subcellular and histochemical localization of MtCAS31, and the expression patterns of MtCAS31 under different stresses. Transgenic Arabidopsis that overexpressed MtCAS31 was used to determine the function of MtCAS31. A yeast two-hybrid assay was used to screen potential proteins that could interact with MtCAS31. The interaction was confirmed by bimolecular fluorescence complementation (BiFC) assay. After a 3-h drought treatment, the expression of MtCAS31 significantly increased 600-fold. MtCAS31 overexpression dramatically reduced stomatal density and markedly enhanced the drought tolerance of transgenic Arabidopsis. MtCAS31 could interact with AtICE1 (inducer of CBF expression 1) and the AtICE1 homologous protein Mt7g083900.1, which was identified from Medicago truncatula both in vitro and in vivo. Our findings demonstrate that a dehydrin induces decreased stomatal density. Most importantly, the interaction of MtCAS31 with AtICE1 plays a role in stomatal development. We hypothesize that the interaction of MtCAS31 and AtICE1 caused the decrease in stomatal density to enhance the drought resistance of transgenic Arabidopsis.