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Abstract Background Sucrose non-fermenting-1-related protein kinases (SnRKs) have been implicated in plant growth and stress responses. Although SnRK3.23 is known to be involved in drought stress, the underlying mechanism of resistance differs between Arabidopsis and rice, and little is known about its function in wheat. Results In the current work, TaSnRK3.23B was detected on the cell membrane and in the nucleus. TaSnRK3.23B overexpression in Arabidopsis promoted reactive oxygen species (ROS) scavenging via the accumulation of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and then conferred significant tolerance to drought. The prediction analysis, yeast two-hybrid, and bimolecular fluorescence complementation (BiFC) assays revealed that TaSnRK3.23B interacted with TaCBL2B and TaCBL6B, which are calcineurin B-like (CBL) proteins. The predicted model demonstrated that TaSnRK3 subfamily proteins participate in Ca2+ signaling mediated by TaCBL2B/TaCBL6B and subsequently provide drought stress tolerance by promoting ROS scavenging in wheat. Conclusions Altogether, the obtained findings contribute to a better understanding of the functions of SnRK3.23 in wheat and offer genetic suggestions for improving drought resistance of wheat.

Abstract Background Stripe rust (yellow rust) is a significant disease for bread wheat (Triticum aestivum L.) worldwide. A genome-wide association study was conducted on 240 Chinese wheat cultivars and elite lines genotyped with the wheat 90 K single nucleotide polymorphism (SNP) arrays to decipher the genetic architecture of stripe rust resistance in Chinese germplasm. Results Stripe rust resistance was evaluated at the adult plant stage in Pixian and Xindu in Sichuan province in the 2015–2016 cropping season, and in Wuhan in Hubei province in the 2013–2014, 2016–2017 and 2018–2019 cropping seasons. Twelve stable loci for stripe rust resistance were identified by GWAS using TASSEL and GAPIT software. These loci were distributed on chromosomes 1B, 1D, 2A, 2B, 3A, 3B, 4B (3), 4D, 6D, and 7B and explained 3.6 to 10.3% of the phenotypic variation. Six of the loci corresponded with previously reported genes/QTLs, including Sr2/Yr30/Lr27, while the other six (QYr.hbaas-1BS, QYr.hbaas-2BL, QYr.hbaas-3AL, QYr.hbaas-4BL.3, QYr.hbaas-4DL, and QYr.hbaas-6DS) are probably novel. The results suggest high genetic diversity for stripe rust resistance in this population. The resistance alleles of QYr.hbaas-2AS, QYr.hbaas-3BS, QYr.hbaas-4DL, and QYr.hbaas-7BL were rare in the present panel, indicating their potential use in breeding for stripe rust resistance in China. Eleven penta-primer amplification refractory mutation system (PARMS) markers were developed from SNPs significantly associated with seven mapped QTLs. Twenty-seven genes were predicted for mapped QTLs. Six of them were considered as candidates for their high relative expression levels post-inoculation. Conclusion The resistant germplasm, mapped QTLs, and PARMS markers developed in this study are resources for enhancing stripe rust resistance in wheat breeding.