Silencing of a Wheat Ortholog of Glucan Synthase-Like Gene Reduced Resistance to Blumeria graminis f. sp. tritici

Integrated VIS/NIR Spectrum and Genome-Wide Association Study for Genetic Dissection of Cellulose Crystallinity in Wheat Stems

Cellulose crystallinity is a crucial factor influencing stem strength and, consequently, wheat lodging. However, the genetic dissection of cellulose crystallinity is less reported due to the difficulty of its measurement. In this study, VIS/NIR spectra and cellulose crystallinity were measured for a wheat accession panel with diverse genetic backgrounds. We developed a reliable VIS/NIR model for cellulose crystallinity with a high determination coefficient (R2) (0.95) and residual prediction deviation (RPD) (4.04), enabling the rapid screening of wheat samples. A GWAS of the cellulose crystallinity in 326 wheat accessions revealed 14 significant SNPs and 13 QTLs. Two candidate genes, TraesCS4B03G0029800 and TraesCS5B03G1085500, were identified. In summary, this study establishes an efficient method for the measurement of cellulose crystallinity in wheat stems and provides a genetic basis for enhancing lodging resistance in wheat.

Genome-wide analysis and characterization of the TaTLP gene family in wheat and functional characterization of the TaTLP44 in response to Rhizoctonia cerealis

Wheat sharp eyespot is a soil-borne disease caused by Rhizoctonia cerealis, which occurs in many countries worldwide and significantly reduces the yield. Thaumatin-like protein (TLP), also known as PR5, is a member of the pathogen response protein family and plays an essential role in plant resistance to pathogen infection. In this study, 131 TaTLP genes were identified from the wheat genome, of which 38 TaTLPs were newly discovered. The TaTLP gene family contains many tandem duplications and fragment duplications, which is a major pathway for gene amplification. Besides, we also analyzed the physicochemical properties, gene structure and promoter cis-acting regulatory elements of all the TaTLP genes. In addition, the expression patterns of nine TaTLPs in response to R. cerealis were analyzed by RT-qPCR. Six TaTLP proteins expressed in vitro had no significant inhibitory effect on R. cerealis, suggesting that these TaTLP proteins may function in other ways. Finally, we performed gene silencing of TaTLP44 in wheat, which increased the expression of some defense-associated genes and improved resistance to R. cerealis. In summary, we systematically analyzed TaTLP family members and demonstrated that TaTLP44 negatively regulates the resistance to R. cerealis by controlling expression of defense-associated genes. These results provide new insights into the functional mechanism of TaTLP proteins.