Water deficit mechanisms in perennial shrubs leaves revealed by physiological and proteomic analyses.

BACKGROUND

Drought (Water deficit, WD) poses a serious threat to extensively economic losses of trees throughout the world. Chinese dwarf cherry () is a good perennial plant for studying the physiological and sophisticated molecular network under WD. The aim of this study is to identify the effect of WD on through physiological and global proteomics analysis and improve understanding of the WD resistance of plants.

METHODS

Currently, physiological parameters were applied to investigate response to WD. Moreover, we used two-dimensional gel electrophoresis (2DE) to identify differentially expressed proteins in leaves subjected to WD (24 d). Furthermore, we also examined the correlation between protein and transcript levels.

RESULTS

Several physiological parameters, including relative water content and Pn were reduced by WD. In addition, the malondialdehyde (MDA), relative electrolyte leakage (REL), total soluble sugar, and proline were increased in WD-treated . Comparative proteomic analysis revealed 46 protein spots (representing 43 unique proteins) differentially expressed in leaves under WD. These proteins were mainly involved in photosynthesis, ROS scavenging, carbohydrate metabolism, transcription, protein synthesis, protein processing, and nitrogen and amino acid metabolisms, respectively.

CONCLUSIONS

WD promoted the CO assimilation by increase light reaction and Calvin cycle, leading to the reprogramming of carbon metabolism. Moreover, the accumulation of osmolytes (i.e., proline and total soluble sugar) and enhancement of ascorbate-glutathione cycle and glutathione peroxidase/glutathione s-transferase pathway in leaves could minimize oxidative damage of membrane and other molecules under WD. Importantly, the regulation role of carbohydrate metabolisms (e. g. glycolysis, pentose phosphate pathways, and TCA) was enhanced. These findings provide key candidate proteins for genetic improvement of perennial plants metabolism under WD.