Cu Stress-Induced Transcriptome Alterations in Sorghum and Expression Analysis of the Transcription Factor-Encoding Gene SbWRKY24.

Sorghum is not only an important bio-energy crop but also a vital raw material for brewing. Exogenous copper affects the growth and metabolism of crops in specific ways. This study identified 8475 differentially expressed genes (DEGs) by high-throughput transcriptome sequencing in the sorghum cultivar 'Jinnuoliang 2' after 24 h of treatment with 10 mM CuSO. Using GO analysis, 476 genes were functionally annotated, which were mainly related to catabolism and biosynthetic processes. Additionally, 90 pathways were annotated by employing the KEGG analysis. Among them, glutathione metabolism and peroxisome were induced, while photosynthesis, photosynthesis-antenna protein, and carbon sequestration of photosynthetic organisms were inhibited. Of the DEGs, 399 were identified to encode transcription factors belonging to 49 families. This study also identified a WRKY transcription factor-encoding gene SbWRKY24 from the transcriptome data. For studying its function, the relative expression levels of SbWRKY24 in roots and leaves post-treatment with different growth hormones and exposure to a variety of abiotic stresses were detected by RT-qPCR. SbWRKY24 showed treatment-and tissue-specific expression patterns, indicating its unique role in stress tolerance. This study lays a theoretical basis for the functional exploration of SbWRKY24 , elucidating the mechanism of copper resistance, and elaborating on the stress responses in sorghum. It also guides the exploration of the molecular mechanism of copper ions inducing intracellular signal transduction pathways. [ABSTRACT FROM AUTHOR]