Proteome characterization of developing grains in bread wheat cultivars (Triticum aestivum L.).

Guangfang Guo,Xing Yan,Saminathan Subburaj,Dongwen Lv,Yingkao Hu,Xiaohui Li,Pei Ge,Yueming Yan

doi:10.1186/1471-2229-12-147

Abstract

BackgroundThe analyses of protein synthesis, accumulation and regulation during grain development in wheat are more complex because of its larger genome size compared to model plants such as Arabidopsis and rice. In this study, grains from two wheat cultivars Jimai 20 and Zhoumai 16 with different gluten quality properties were harvested at five development stages, and were used to displayed variable expression patterns of grain proteins.ResultsProteome characterization during grain development in Chinese bread wheat cultivars Jimai 20 and Zhoumai 16 with different quality properties was investigated by 2-DE and tandem MALDI-TOF/TOF-MS. Identification of 117 differentially accumulated protein spots representing 82 unique proteins and five main expression patterns enabled a chronological description of wheat grain formation. Significant proteome expression differences between the two cultivars were found; these included 14 protein spots that accumulated in both cultivars but with different patterns and 27 cultivar-different spots. Among the cultivar-different protein spots, 14 accumulated in higher abundance in Jimai 20 than in Zhoumai 16, and included NAD-dependent isocitrate dehydrogenase, triticin precursor, LMW-s glutenin subunit and replication factor C-like protein. These proteins are likely to be associated with superior gluten quality. In addition, some proteins such as class II chitinase and peroxidase 1 with isoforms in developing grains were shown to be phosphorylated by Pro-Q Diamond staining and phosphorprotein site prediction. Phosphorylation could have important roles in wheat grain development. qRT-PCR analysis demonstrated that transcriptional and translational expression patterns of many genes were significantly different.ConclusionsWheat grain proteins displayed variable expression patterns at different developmental stages and a considerable number of protein spots showed differential accumulation between two cultivars. Differences in seed storage proteins were considered to be related to different quality performance of the flour from these wheat cultivars. Some proteins with isoforms were phosphorylated, and this may reflect their importance in grain development. Our results provide new insights into proteome characterization during grain development in different wheat genotypes.

Highlights

The analyses of protein synthesis, accumulation and regulation during grain development in wheat are more complex because of its larger genome size compared to model plants such as Arabidopsis and rice
That the accumulated amounts of a large proportion of proteins are often poorly correlated with their corresponding mRNAs in expression profiles [5,6,7] and direct proteome approaches can be more valuable in monitoring developmental profiles
We used proteomic approaches to characterize protein accumulation during grain development in Chinese bread wheat cultivars Jimai 20 and Zhoumai 16, which differ in gluten quality

Summary

Introduction

The analyses of protein synthesis, accumulation and regulation during grain development in wheat are more complex because of its larger genome size compared to model plants such as Arabidopsis and rice. Transcriptomic and metabolomic approaches have been used to investigate the impacts of nitrogen (N) and sulphur (S) deficiency on N and S remobilization during grain filling in winter wheat [4] It has been noted, that the accumulated amounts of a large proportion of proteins are often poorly correlated with their corresponding mRNAs in expression profiles [5,6,7] and direct proteome approaches can be more valuable in monitoring developmental profiles. Falcon [24], four developmental stages in two spring wheat varieties Ningchun 4 and Chinese Spring under drought stress [25] These studies provided valuable information, the biochemical processes important for wheat grain development still require research because this species has a much larger genome and a more complex proteome than model plants such as Arabidopsis and rice

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