Wheat stripe rust and powdery mildew are important worldwide diseases of wheat (Triticum aestivum). The wheat cultivar Xingmin318 (XM318) is resistant to both wheat stripe rust and powdery mildew, which are caused by Puccinia striiformis f. sp. tritici (Pst) and Blumeria graminis f. sp. tritici (Bgt), respectively. To explore the difference between wheat defense response against Pst and Bgt, quantitative proteomic analyses of XM318 inoculated with either Pst or Bgt were performed using tandem mass tags technology. A total of 741 proteins were identified as differentially accumulated proteins (DAPs). Bioinformatics analyses indicated that some functional categories, including antioxidant activity and immune system process, exhibited obvious differences between Pst and Bgt infections. Intriguingly, only 42 DAPs responded to both Pst and Bgt infections. Twelve DAPs were randomly selected for reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis, and the mRNA expression levels of 11 were consistent with their protein expression. Furthermore, gene silencing using the virus-induced gene silencing system indicated that glutathione S-transferase (TaGSTU6) has an important role in resistance to Bgt but not to Pst. TaGSTU6 interacted with the cystathionine beta-synthase (CBS) domain-containing protein (TaCBSX3) in both Pst and Bgt infections. Knockdown of TaCBSX3 expression only reduced wheat resistance to Bgt infection. Overexpression of TaGSTU6 and TaCBSX3 in Arabidopsis (Arabidopsis thaliana) promoted plant resistance to Pseudomonas syringae pv. Tomato DC3000. Our results indicate that TaGSTU6 interaction with TaCBSX3 only confers wheat resistance to Bgt, suggesting that wheat has different response mechanisms to Pst and Bgt stress.

Background: Squamous promoter binding protein-like (SPL) proteins are a class of transcription factors that play essential roles in plant growth and development, signal transduction, and responses to biotic and abiotic stresses. The rapid development of whole genome sequencing has enabled the identification and characterization of SPL gene families in many plant species, but to date this has not been performed in quinoa (Chenopodium quinoa). Results: This study identified 23 SPL genes in quinoa, which were unevenly distributed on 18 quinoa chromosomes. Quinoa SPL genes were then classified into eight subfamilies based on homology to Arabidopsis thaliana SPL genes. We selected three dicotyledonous and monocotyledonous representative species, each associated with C. quinoa, for comparative sympatric mapping to better understand the evolution of the developmental mechanisms of the CqSPL family. Furthermore, we also used 15 representative genes from eight subfamilies to characterize CqSPLs gene expression in different tissues and at different fruit developmental stages under six different abiotic stress conditions. Conclusions: This study, the first to identify and characterize SPL genes in quinoa, reported that CqSPL genes, especially CqSPL1, play a critical role in quinoa development and in its response to various abiotic stresses.

Background: Heat shock factor (HSF), a typical class of transcription factors in plants, has played an essential role in plant growth and developmental stages, signal transduction, and response to biotic and abiotic stresses. The HSF genes families has been identified and characterized in many species through leveraging whole genome sequencing (WGS). However, the identification and systematic analysis of HSF family genes in Rye is limited. Results: In this study, 31 HSF genes were identified in Rye, which were unevenly distributed on seven chromosomes. Based on the homology of A. thaliana, we analyzed the number of conserved domains and gene structures of ScHSF genes that were classified into seven subfamilies. To better understand the developmental mechanisms of ScHSF family during evolution, we selected one monocotyledon (Arabidopsis thaliana) and five (Triticum aestivum L., Hordeum vulgare L., Oryza sativa L., Zea mays L., and Aegilops tauschii Coss.) specific representative dicotyledons associated with Rye for comparative homology mapping. The results showed that fragment replication events modulated the expansion of the ScHSF genes family. In addition, interactions between ScHSF proteins and promoters containing hormone- and stress-responsive cis-acting elements suggest that the regulation of ScHSF expression was complex. A total of 15 representative genes were targeted from seven subfamilies to characterize their gene expression responses in different tissues, fruit developmental stages, three hormones, and six different abiotic stresses. Conclusions: This study demonstrated that ScHSF genes, especially ScHSF1 and ScHSF3, played a key role in Rye development and its response to various hormones and abiotic stresses. These results provided new insights into the evolution of HSF genes in Rye, which could help the success of molecular breeding in Rye.

Stripe rust, caused by the biotrophic fungus Puccinia striiformis f. sp. tritici (Pst), is one of the most widespread and destructive wheat diseases worldwide. Growing resistant cultivars is an effective approach for controlling this disease. However, because host resistance genes were easily overcome by new virulent Pst races, there is a continuous demand for identifying new effective wheat stripe rust resistance genes and develop closely linked markers for marker-assisted selection (MAS). Baidatou, an old Chinese wheat landrace, has been grown for several decades in Longnan region, Gansu Province, where stripe rust epidemics are frequent and severe. In our previous study, a single dominant gene YrBai in Baidatou was identified to control the adult-plant resistance (APR) to Chinese prevalent Pst race CYR33. And the gene was located on wheat chromosome 6DS by four polymorphic simple sequence repeat (SSR) and two sequence-related amplified polymorphism (SRAP) markers, with the genetic distances of two closely linked markers 3.6 and 5.4 cM, respectively. To further confirm the APR gene in Baidatou and construct the high-density map for the resistance gene, adult plants of F₁, F₂, F₃, and F_5:6 populations derived from the cross Mingxian169/Baidatou and two parents were inoculated with CYR33 at Yangling field, Shaanxi Province during 2014–2015, 2015–2016, and 2016–2017 crop seasons, respectively. The field evaluation results indicated that a single dominant gene confers the APR to Pst race CYR33 in Baidatou. 92 F₃ lines and parents were sequenced using DArTseq technology based on wheat GBS1.0 platform, and 31 genetic maps consisted of 2,131 polymorphic SilicoDArT and 952 SNP markers spanning 4,293.94 cM were constructed. Using polymorphic SilicoDArT, SNP markers and infection types (ITs) data of F₃ lines, the gene YrBai was further located in 0.8 cM region on wheat chromosome 6D. These closely linked markers developed in this study should be useful for MAS for Baidatou in crop improvement and map-based clone this gene.