Shanshan Wen

To understand the molecular changes taking place during the early grain development in common wheat, we profiled transcriptome and proteome of two cultivars, “P271” and “Chinese Spring” (CS) with large and small grains, respectively. More than 85,000 genes and 7500 proteins were identified to express during early grain development in two wheat cultivars. We observed enrichment in the number of genes falling in the functional categories—carbohydrate metabolism, amino acid metabolism, lipid metabolism, and cofactor as well as vitamin metabolism with progression in grain development, which indicates towards the importance of these metabolic pathways during grain maturation. Many genes showed inconsistency between transcription and translation, which suggested a role of post-transcriptional events that determine the fate of nascent transcript/protein, in the early grain development. In silico localization of differentially expressed genes/proteins between CS and P271 to wheat chromosomes, exhibited a biased genomic distribution with chromosomes 1A, 4B, and 5B contributing primarily to it. These results corroborated the earlier findings, where chromosomes 1A, 4B, and 5B were reported to harbor genes/QTLs for yield contributing traits such as grain length and thickness. Collectively, this study reveals the molecular changes taking place during early grain development, through light on the regulation of these processes, and allows identification of the gene candidates contributing to the contrasting grain characteristics of CS and P721. This information has implications in the future wheat breeding for the enhanced grain yield.

The 12-oxo-phytodienoic acid reductases (OPRs), which belong to the old yellow enzyme (OYE) family, are flavin mononucleotide (FMN)-dependent oxidoreductases with critical functions in plants. Despite the clear characteristics of growth and development, as well as the defense responses in Arabidopsis, tomato, rice, and maize, the potential roles of OPRs in wheat are not fully understood. Here, forty-eight putative OPR genes were found and classified into five subfamilies, with 6 in sub. I, 4 in sub. II, 33 in sub. III, 3 in sub. IV, and 2 in sub. V. Similar gene structures and conserved protein motifs of TaOPRs in wheat were identified in the same subfamilies. An analysis of cis-acting elements in promoters revealed that the functions of OPRs in wheat were mostly related to growth, development, hormones, biotic, and abiotic stresses. A total of 14 wheat OPR genes were identified as tandem duplicated genes, while 37 OPR genes were segmentally duplicated genes. The expression patterns of TaOPRs were tissue- and stress-specific, and the expression of TaOPRs could be regulated or induced by phytohormones and various stresses. Therefore, there were multiple wheat OPR genes, classified into five subfamilies, with functional diversification and specific expression patterns, and to our knowledge, this was the first study to systematically investigate the wheat OPR gene family. The findings not only provide a scientific foundation for the comprehensive understanding of the wheat OPR gene family, but could also be helpful for screening more candidate genes and breeding new varieties of wheat, with a high yield and stress resistance.