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

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.

Analysis of gluten proteins composition during grain filling in two durum wheat cultivars submitted to two water regimes

“…In this region both in Ciccio and in Svevo several spots, specific for milk stage, resulted more concentrated in the gel zone near pH 3, while at physiological stage the specific spots appeared in the basic zone of the gel (Figure 1) making us assume a possible change in the protein isoelectric point (pI) during grain filling. According to our results also Guo et al (2012) reported the presence of proteins near the acid zone of the gel in the early developmental stage, with the number of basic proteins increasing at maturity. Moreover in both cultivars there was one spot that seems to be a master spot at the beginning of a spot train.…”

“…To better investigate the effects of environment on proteins and genes that may be involved in determining yield and quality, proteomic and transcriptomic approaches result useful (Altenbach, 2012). However, also due to the various post-translational modifications of proteins that occur as grain develops, the accumulated amounts of a large proportion of proteins are often poorly correlated with their corresponding mRNAs in expression profiles; for this reason a proteomic approach can be more valuable in monitoring developmental profiles (Guo et al, 2012).…”

Albumin content in bread wheat (Triticum aestivum L.) and durum wheat (Triticum durum Desf.) as affected by the environment

“…None of the examined genotypes of durum wheat can be recommended for the simultaneous selection of genotypes with high content of albumins and good stability, because genotypes with high mean albumins content had unsatisfactory stability. The albumins content in bread wheat grains is not as stable across environments as that of the storage proteins according to Guo et al (2012). The inclusion of all climatic variables to the factorial regression led to the model (mt3, wmr, mnt2, mnt1) for bread wheat and to the model (pr2, sh1, mxt3, wmr) for durum wheat, which were obtained at the level of significance (P < 0.01) ( Table 3).…”

Signal transduction during wheat grain development

“…In a study by Guo et al (2012), several main groups of grain proteins were identified according to their functions, of which 3.4 % was involved in signal transduction including NDPK. NDPK might play an important role in signal regulation for grain development in wheat, because it was gradually down-regulated during grain development .…”