Project description:The pistillody mutant wheat (Triticum aestivum L.) plant HTS-1 exhibits homeotic transformation of stamens into pistils or pistil-like structures. Unlike common wheat varieties, HTS-1 produces three to six pistils per floret, potentially increasing the yield. Thus, HTS-1 is highly valuable in the study of floral development in wheat. In this study, we conducted RNA sequencing of the transcriptomes of the pistillody stamen (PS) and the pistil (P) from HTS-1 plants, and the stamen (S) from the non-pistillody control variety Chinese Spring TP to gain insights into pistil and stamen development in wheat.
Project description:Very recently, the genome of the modern durum wheat cv. Svevo was fully sequenced, and its assembly is publicly available. So, we exploited the opportunity to carry out an in-depth study for the systematic characterization of the γ-gliadin gene family in the cv. Svevo by combining a bioinformatic approach with transcript and protein analysis. We found that the γ-gliadin family consists of nine genes that include seven functional genes and two pseudogenes. Three genes, Gli-γ1a, Gli-γ3a and Gli-γ4a, and the pseudogene Gli-γ2a* mapped on the A genome, whereas the remaining four genes, Gli-γ1b, Gli-γ2b, Gli-γ3b and Gli-γ5b, and the pseudogene Gli-γ4b* mapped on the B genome. The functional γ-gliadins presented all six domains and eight-cysteine residues typical of γ-gliadins. The Gli-γ1b also presented an additional cysteine that could possibly have a role in the formation of the gluten network through binding to HMW glutenins. The γ-gliadins from the A and B genome differed in their celiac disease (CD) epitope content and composition, with the γ-gliadins from the B genome showing the highest frequency of CD epitopes. In all the cases, almost all the CD epitopes clustered in the central region of the γ-gliadin proteins. Transcript analysis during seed development revealed that all the functional γ-gliadin genes were expressed with a similar pattern, although significant differences in the transcript levels were observed among individual genes that were sometimes more than 60-fold. A progressive accumulation of the γ-gliadin fraction was observed in the ripening seeds that reached 34% of the total gliadin fraction at harvest maturity. We believe that the insights generated in the present study could aid further studies on gliadin protein functions and future breeding programs aimed at the selection of new healthier durum wheat genotypes.
Project description:A high-Mr subunit was prepared from durum wheat (Triticum durum). Viscometric analysis showed that the molecule is rod-shaped, with molecular dimensions of about 50 nm x 1.75 nm (500 A x 17.5 A) in 0.05 M-acetic acid/0.01 M-glycine and 49 nm x 1.79 nm (490 A x 17.9 A) in aq. 50% (v/v) propan-1-ol (+/- 0.01 M-glycine) at 30 degrees C. C.d. spectroscopy in the same solvents indicated the presence of beta-turns, but little alpha-helix [7% in 50% (v/v) propan-1-ol] and no beta-sheet. However, when dissolved in trifluoroethanol the protein contains about 30% alpha-helix, and viscometric analysis gives dimensions of about 62 nm x 1.53 nm (620 A x 15.3 A). It is proposed, on the basis of these studies and previously published structural prediction, that the repetitive central domain of the high-Mr subunit forms a loose spiral based on repetitive beta-turns, whereas the shorter non-repetitive N- and C-terminal domains are alpha-helical in trifluoroethanol, but random coil in other solvents. The Mr of the high-Mr subunit determined from the intrinsic viscosity in 6.0 M-guanidinium chloride was 65,000, compared with 84,000 determined in 5.0 M-guanidinium thiocyanate. The latter value is consistent with the Mr values for related proteins whose complete amino acid sequences are known, and it was concluded that the protein is incompletely denatured in the former solvent. This was confirmed by c.d. spectroscopy in increasing concentrations (1-6 M) of guanidinium chloride.