Systematic Analysis of the Maize OSCA Genes Revealing ZmOSCA Family Members Involved in Osmotic Stress and ZmOSCA2.4 Confers Enhanced Drought Tolerance in Transgenic Arabidopsis.

Liru Cao,Li Wei,Qianjin Zhang,Tongchao Wang,Guorui Wang,Xin Wei,Xin Zhang,Zhenhua Wang,Fujian Mei,Pengyu Zhang,Xiaomin Lu

doi:10.3390/ijms21010351

Abstract

OSCAs are hyperosmolality-gated calcium-permeable channel proteins. In this study, two co-expression modules, which are strongly associated with maize proline content, were screened by weighted correlation network analysis, including three ZmOSCA family members. Phylogenetic and protein domain analyses revealed that 12 ZmOSCA members were classified into four classes, which all contained DUF221 domain. The promoter region contained multiple core elements responsive to abiotic stresses and hormones. Colinear analysis revealed that ZmOSCAs had diversified prior to maize divergence. Most ZmOSCAs responded positively to ABA, PEG, and NaCl treatments. ZmOSCA2.3 and ZmOSCA2.4 were up-regulated by more than 200-fold under the three stresses, and showed significant positive correlations with proline content. Yeast two-hybrid and bimolecular fluorescence complementation indicated that ZmOSCA2.3 and ZmOSCA2.4 proteins interacted with ZmEREB198. Over-expression of ZmOSCA2.4 in Arabidopsis remarkably improved drought resistance. Moreover, over-expression of ZmOSCA2.4 enhanced the expression of drought tolerance-associated genes and reduced the expression of senescence-associated genes. We also found that perhaps ZmOSCA2.4 was regulated by miR5054.The results provide a high-quality molecular resource for selecting resistant breeding, and lay a foundation for elucidating regulatory mechanism of ZmOSCA under abiotic stresses.

Highlights

Studies have shown that salt stress can cause osmotic stress and ionic stress on plants, and when stress is severe, it will cause extravasation of plant tissue, resulting in physiological drought [1]
We found that perhaps ZmOSCA2.4 was regulated by miR5054
The present results suggested that ZmOSCA2.3 and ZmOSCA2.4 interact with ZmEREB198 to alleviate cellular damage in plants subjected to osmotic stress

Summary

Introduction

Studies have shown that salt stress can cause osmotic stress and ionic stress on plants, and when stress is severe, it will cause extravasation of plant tissue, resulting in physiological drought [1]. High osmotic stress caused by salt and drought stress is the key environmental stress factor affecting maize growth and yield. The plants are exposed to external osmotic stress, and sudden changes in the concentration of solute around the cell. They broke the plants’ osmotic potential, and caused damage to their cell membrane. Plants open the membrane channel by osmotic adjustment, and the permeate extracts water from the cells, thereby restoring normal cell volume [3,4]. These permeates include betaine, glycine, proline, etc. These permeates include betaine, glycine, proline, etc. [5,6]

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Results

Conclusion