No abstract

In this study, we aimed to identify differentially accumulated proteins (DAPs) involved in PEG mock osmotic stress, cadmium (Cd2+) stress, and their combined stress responses in Brachypodium distachyon seedling roots. The results showed that combined PEG and Cd2+ stresses had more significant effects on Brachypodium seedling root growth, physiological traits, and ultrastructures when compared with each individual stress. Totally, 106 DAPs were identified that are responsive to individual and combined stresses in roots. These DAPs were mainly involved in energy metabolism, detoxification and stress defense and protein metabolism. Principal component analysis revealed that DAPs from Cd2+ and combined stress treatments were grouped closer than those from osmotic stress treatment, indicating that Cd2+ and combined stresses had more severe influences on the root proteome than osmotic stress alone. Protein–protein interaction analyses highlighted a 14-3-3 centered sub-network that synergistically responded to osmotic and Cd2+ stresses and their combined stresses. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis of 14 key DAP genes revealed that most genes showed consistency between transcriptional and translational expression patterns. A putative pathway of proteome metabolic changes in Brachypodium seedling roots under different stresses was proposed, which revealed a complicated synergetic responsive network of plant roots to adverse environments.

The elasticity of wheat dough is mainly determined by high-molecular-weight glutenin subunits (HMW-GSs) encoded by Glu-1 loci. In this study, we performed the first comprehensive study on the effects of Glu-B1i-encoded 1Bx17 and 1By18 subunits on dough rheological properties and breadmaking quality by using a pair of Glu-B1 near-isogenic lines (NILs) ZM-NIL1 and ZM-NIL2. Comparative analysis of basic quality parameters, rapid visco analyzer (RVA) and farinograph parameters, and C-cell and loaf parameters showed that ZM-NIL2 containing Glu-B1i-encoded 1Bx17 and 1By18 subunits had better dough rheological properties and breadmaking quality than ZM-NIL1 carrying Glu-B1c-encoded 1Bx7 and 1By9 subunits, including significantly increased protein and gluten content, development time and stability, and loaf volume and score. Particularly, 1Bx17 and 1By18 subunits could significantly enhance bread texture, including significant increase in slice brightness, slice area, circumference, cell contrast, cell extension, and cell quantity. These results demonstrate that 1Bx17 and 1By18 subunits have a significant contribution to dough rheological properties and breadmaking quality.

Drought is a widespread abiotic stress that has a detrimental effect on both yield and quality of wheat. Discovery and utilisation of drought-resistant gene resources from wheat-related species may help to mitigate effects of drought and decrease yield loss. In this study, we used a comparative proteome approach to identify potential drought-resistance proteins from a wheat (Triticum aestivum L.)–Haynaldia villosa (L.) Schur 6VS/6AL translocation line. Drought experiments showed that introgression of the H. villosa 6VS chromosome short arm into common wheat cultivar Yangmai 5 through 6VS/6AL translocation led to better drought resistance. Two-dimensional difference gel electrophoresis (2D-DIGE) identified 99 differentially accumulated protein (DAP) spots in the wheat–H. villosa 6VS/6AL translocation line, 42 of which were specifically present or showed a significantly upregulated accumulation. Of these, 20 DAPs representing 19 unique proteins in the wheat–H. villosa 6VS/6AL translocation line were upregulated under drought stress. These proteins were mainly involved in defence–stress, energy metabolism, carbon metabolism, nitrogen metabolism, and protein metabolism or folding. Protein–protein interaction analysis of key DAPs displayed a complex interaction network that synergistically regulated drought response. Dynamic transcriptional expression analysis revealed the differential expression of six key DAP genes involved in drought-stress response in the protein–protein interaction network. Our results indicated that H. villosa may have gene resources for wheat drought-resistance improvement.

2017): Effects of glu-1 and glu-3 allelic variations on wheat glutenin macropolymer (GMP) content as revealed by size-exclusion high performance liquid chromatography vol 49, no. 2,(677)(678)(679)(680)(681)(682)(683)(684)(685)(686)(687)(688)(689)(690)(691) Gluten macropolymers (GMPs), formed by seed storage proteins glutenins and gliadins through intermolecular disulfide bond, confer dough viscoelasticity and wheat processing quality. Glutenins consist of high and low molecular weight glutenin subunits (HMW-GS, LMW-GS) encoded by Glu-1 and Glu-3 loci, respectively. The allelic variations at both loci have important effects on GMP content and breadmaking quality. In this study, GMP extraction and size-exclusion high performance liquid chromatography (SE-HPLC) separation were optimized, and then applied to investigate the effects of Glu-1 and Glu-3 allelic variations on GMP content using different wheat genotypes, chromosome 678 GENETIKA, Vol. 49, No.2, 677-691, 2017 substitution lines and near-isogenic lines (NILs). The results showed that the optimized GMP extraction and SE-HPLC protocol could obtain a reproducible separation and reliable quantitation of GMP content with small samples. The allelic variations at Glu-1 and Glu-3 were closely related to GMP content. Particularly, Glu-D1d encoded 1Dx5+1Dy10 subunits, Glu-A3a and Glu-B3h encoded an abundant LMW-B subunit respectively had positive effects on GMP content and breadmaking quality. The introgress of HMW-GS and LMW-GS into bread wheat from related genomes could significantly increase GMP content, indicating that wheat related species has potential gene resources for breadmaking quality improvement. Our results demonstrated that SE-HPLC could serve as an effective tool for rapid separation and quantitation of GMPs and had potential application for gluten quality screening in the early generations during wheat quality improvement program.