Kernel Transcriptome Profiles of Susceptible Wheat Genotypes in Response to Wheat Dwarf Bunt

Wheat dwarf bunt is caused by Tilletia controversa J. G. Kühn (TCK), which is a serious fungal diseases affecting kernels of wheat. In order to identify candidate genes involved in the abnormal development of kernels in wheat, we used RNA sequencing technology to analyze the transcriptome of the abnormal and healthy kernels of a susceptible variety (Yili053) at the mid-filling stage, late-filling stage, and maturity stage, respectively. The differentially expressed genes (DEGs) were analyzed, and there were 3930 DEGs, 28,422 DEGs, and 20,874 DEGs found at the mid-filling stage, late-filling stage, and maturity stage in Yili053, respectively. A total of 1592 DEGs (506 DEGs up-regulated) showed continuously differential expression in the three stages. Gene ontology analysis showed that these DEGs were related to biological regulation, metabolic processes, and the response to stimulus. Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that these DEGs play major roles in pathways including photosynthesis, carbon metabolism, carbon fixation in photosynthetic organisms, and glyoxylate and dicarboxylate metabolism. Moreover, we predicted that 13 MADS-MIKC transcription factors, which were continuously up-regulated, were crucial for regulating the maturation and senescence of eukaryotes. Some 21 genes related to the plant hormone signaling transduction pathway and 61 genes related to the response to stimulus were analyzed. A total of 26 of them were successful validated with a qPCR analysis. These genes were thought to be involved in the abnormal development of kernels infected by TCK. A transcriptomics analysis of wheat kernels in response to TCK will contribute to understanding the interaction of TCK and wheat, and may provide a basis for knowledge of molecular events in the abnormal development of kernels, which will be helpful for more efficient TCK management.