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In order to identify QTLs for 1000-grain weight and its main component traits in wheat, a high-density genetic link map was constructed using a F8:9 recombined inbred line (RIL) population as material and exploiting the single nucleotide polymorphism (SNP) as well as PCR-based molecular markers, and to go a step further, QTL mapping for 1000-grain weight, grain length, and grain width in wheat was conducted. The linkage map was composed of 1257 loci formed by the 3916 markers, including 143 SSR markers and 3773 SNP markers, which were distributed on 22 chromosomes (2A chromosome formed a break point) with the total length of 2291.6 cM and the average genetic distance between loci of 1.82 cM. A total of 41 qualitative trait loci (QTLs) on 19 chromosomes were detected, with contributions to phenotypic variance ranged from 3.59–58.49% for each QTL. Among these QTLs, two were detected in four environments, six in three environments, and 14 in two environments. Fifteen important loci with multi-effect were mapped on 9 chromosomes 1B, 2B, 3A, 4B, 5A, 5B, 6A, 7A, and 7B, involving 37 QTLs that accounted for 90.2% of total numbers of QTLs detected. Of these 15 loci, including one on chromosome 7A flanked by the markers Tdurum_contig77759_5 and BS00062425_51, which consisted of QTLs controlling TGW, GL, and GW and explained 4.2 to 58.49% of the phenotypic variation in these traits. Thus, the chromosome intervals of the 15 loci were important areas controlling the expression of 1000-grain weight and its main component traits in wheat.

Expression of TaRUB1 gene in Arabidopsis thaliana elevates the level of disease-related genes in response to pathogen invasion through the accumulation of callose, necrotic cells, and the outbreak of ROS. Ubiquitin (Ub) and ubiquitin-like proteins are highly conserved in sequence and can covalently bind and modify many intracellular proteins which can be recognized and degraded by 26S proteasome. Post-translational modification of proteins has become a hot research spot today. In the previous study, a cDNA of related-to-ubiquitin protein belonged to ubiquitin-like proteins, whose spatial structure comprised Ub and NEDD8, was obtained from wheat SN6306 by suppression-subtractive hybridization and was named TaRUB1. TaRUB1 is induced by wheat powdery mildew and significantly upregulated in resistant wheat SN6306. In this study, heterologous expression of TaRUB1 in A. thaliana was used to study the function of this gene in response to pathogen Pseudomonas syringae pv. Tomato DC3000 (Pst DC3000). Transgenic A. thaliana showed relatively fewer disease symptoms, accompanied by common inhibition of living body parasitic defense responses, accumulation of more callose and reactive oxygen species (ROS), and concentrated cell death, simultaneously antioxidant enzyme activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase were higher than those in wild-type (WT) plant after infection with Pst DC3000. Meanwhile, hypersensitive cell death, which was possibly ROS burst, was also observed in transgenic A. thaliana. By quantitative reverse transcription-polymerase chain reaction analysis, some marker genes for hypersensitive response showed significantly higher transcriptional expression level in transgenic A. thaliana, which activates system-acquired resistance, than that of WT plants. Heterologous expression of TaRUB1 can significantly enhance resistance to Pst DC3000 in A. thaliana, suggesting that TaRUB1 is related to plant disease resistance.