Wheat drought-responsive grain proteome analysis by linear and nonlinear 2-DE and MALDI-TOF mass spectrometry.

Shan-Shan Jiang,Xin Li,Dong-Wen Lv,Wu-Jun Ma,Xiao-Hui Li,Yue-Ming Yan,Shun-Li Wang,Chao-Ying Ma,Xiao-Na Liang

doi:10.3390/ijms131216065

Abstract

A comparative proteomic analysis of drought-responsive proteins during grain development of two wheat varieties Kauz (strong resistance to drought stress) and Janz (sensitive to drought stress) was performed by using linear and nonlinear 2-DE and MALDI-TOF mass spectrometry technologies. Results revealed that the nonlinear 2-DE had much higher resolution than the linear 2-DE. A total of 153 differentially expressed protein spots were detected by both 2-DE maps, of which 122 protein spots were identified by MALDI-TOF and MALDI-TOF/TOF mass spectrometry. The identified differential proteins were mainly involved in carbohydrate metabolism (26%), detoxification and defense (23%), and storage proteins (17%). Some key proteins demonstrated significantly different expression patterns between the two varieties. In particular, catalase isozyme 1, WD40 repeat protein, LEA and alpha-amylase inhibitors displayed an upregulated expression pattern in Kauz, whereas they were downregulated or unchanged in Janz. Small and large subunit ADP glucose pyrophosphorylase, ascorbate peroxidase and G beta-like protein were all downregulated under drought stress in Janz, but had no expression changes in Kauz. Sucrose synthase and triticin precursor showed an upregulated expression pattern under water deficits in both varieties, but their upregulation levels were much higher in Kauz than in Janz. These differentially expressed proteins could be related to the biochemical pathways for stronger drought resistance of Kauz.

Highlights

Drought stress is one of the major abiotic stresses in the world, which causes significant alterations in both yield and quality in many crop species during grain filling
The numbered protein spots were identified by MALDI-TOF mass spectrometry and MALDI-TOF/TOF mass spectrometry
We described the dynamic changes of wheat drought-responsive proteins during grain development and conducted a comparative proteomics analysis between two varieties that differ widely in drought tolerance by using linear and nonlinear 2-DE and MALDI-TOF MS

Summary

Introduction

Drought stress is one of the major abiotic stresses in the world, which causes significant alterations in both yield and quality in many crop species during grain filling. It has been shown that drought stress during the crop flowering stage disrupts photosynthesis and transfer of stored carbohydrates into grains, which is the reason for the reduced grain number and weight [1]. The albumin and globulin proteins accumulate during the early stage of grain development, from flowering to 20 days after flowering (DAF), after which the content of those proteins remains stable. From flowering to 10–15 DAF, these proteins consist of mainly metabolic and structural proteins; but from 10–15 DAF onwards, the albumins and globulins start their accumulation in the developing starchy endosperm, consisting mainly of α,β-amylase/trypsin inhibitors and triticins [5,6,7]. The role of albumins and globulins for the formation of flour quality is not as well defined as that of prolamins

Results

Discussion

Conclusion