Rice CaM-binding transcription factor (OsCBT) mediates defense signaling via transcriptional reprogramming

• Published in: Plant biotechnology reports 2020, 14(3), , pp.309-321
• Main Authors: Chung, Jung-Sung, Koo, Sung Cheol, Jin, Byung Jun, Baek, Dongwon, Yeom, Seon-In, Chun, Hyun Jin, Choi, Man Soo, Cho, Hyun Min, Lee, Su Hyeon, Jung, Wook-Hun, Choi, Cheol Woo, Chandran, Anil Kumar Nalini, Shim, Sang In, Chung, Jong-Il, Jung, Ki-Hong, Kim, Min Chul
• Format: Article
• Language: English
• Subjects: Agriculture; Binding; Biological activity; Biomedical and Life Sciences; Biotechnology; Calcium-binding protein; Calmodulin; Catalytic activity; Cell Biology; DNA microarrays; Gene expression; Genes; Hypersensitive response; Life Sciences; Mutants; Original Article; Pathogens; Plant Biochemistry; Plant Sciences; Rice; Tiling; 농학
• ISSN: 1863-5466; 1863-5474
• DOI: 10.1007/s11816-020-00603-y

The mutant allele of rice calmodulin-binding transcription activator OsCBT, oscbt-1 , exhibits broad-spectrum resistance against rice pathogens. Previously, we reported that the strong resistance of the oscbt-1 mutant to pathogens was conferred by a constitutive upregulation of defense-related genes even under pathogen-free conditions. We also found strong induction of the hypersensitive response as a reaction to pathogen invasion. The results suggest that OsCBT acts as a negative regulator of basal resistance to pathogen attack. To identify the transcriptional network regulated by OsCBT, we compared global gene expression profiles between wild-type (WT) and oscbt-1 rice plants grown under pathogen-free conditions. The results of a 3′ tiling microarray revealed that in oscbt-1 plants, 81 genes are upregulated and 200 genes are downregulated when compared with the WT. A gene ontology analysis showed that differentially regulated genes in oscbt-1 were very closely associated with “death” GO term in a biological process category, and “catalytic activity” and “binding” GO terms in a molecular function category. A MapMan analysis indicated that the functions of these genes were associated with plant responses to biotic stress. Moreover, the results from quantitative real-time PCR in the oscbt-1 mutant showed a significant effect on the gene expression patterns of the fungal pathogen response. Our results suggested that the OsCBT regulates a rice defense response by modulating the expressions of various defense-related genes.