Comparative transcriptomic analysis reveals that multiple hormone signal transduction and carbohydrate metabolic pathways are affected by Bacillus cereus in Nicotiana tabacum

• Published in: Genomics (San Diego, Calif.) Vol. 112; no. 6; pp. 4254 - 4267
• Main Authors: Li, Yueyue, Zhao, Min, Chen, Wenwen, Du, Hongyi, Xie, Xiaodong, Wang, Daibin, Dai, Ya, Xia, Qingyou, Wang, Genhong
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-11-2020
• Subjects: Bacillus cereus; Bacillus cereus - physiology; Carbohydrate metabolism; Carbohydrate Metabolism - genetics; Gluconeogenesis - genetics; Glycolysis - genetics; Host Microbial Interactions - genetics; Metabolic Networks and Pathways - genetics; Nicotiana - genetics; Nicotiana - metabolism; Nicotiana - microbiology; Nicotiana tabacum; Nucleic Acids - metabolism; Oxidative Stress - genetics; Plant Growth Regulators - physiology; Plant Leaves - genetics; Plant Leaves - metabolism; Plant Leaves - microbiology; Plant-microbial interaction; Real-Time Polymerase Chain Reaction; RNA-Seq; Signal Transduction; Starch - metabolism; Transcriptomics; Carbohydrate metabolism; Bacillus cereus; Nicotiana tabacum; Transcriptomics; Plant-microbial interaction
• ISSN: 0888-7543; 1089-8646
• DOI: 10.1016/j.ygeno.2020.07.022

Bacillus cereus is thought to be a beneficial bacterium for plants in several aspects, such as promoting plant growth and inducing plant disease resistance. However, there is no detailed report on the effect of Bacillus cereus acting on Nicotiana tabacum. In the present study, RNA-based sequencing (RNA-seq) was used to identify the molecular mechanisms of the interaction between B. cereus CGMCC 5977 and N. tabacum. A total of 7345 and 5604 differentially expressed genes (DEGs) were identified from leaves inoculated with Bacillus cereus at 6 and 24 hpi, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that the most DEGs could be significantly enriched in hormone signal transduction, the MAPK signaling pathway, photosynthesis, oxidative stress, and amino sugar, and nucleotide sugar metabolism. Furthermore, glycolysis/gluconeogenesis was severely affected by inoculation with Bacillus cereus. In the hormone signal pathway, multiple DEGs were involved in plant defense-related major hormones, including activation of jasmonic acid (JA), salicylic acid (SA), and ethylene (Eth). Further analyses showed that other hormone-related genes involved in abscisic acid (ABA), gibberellin (GA), auxin (AUX), and cytokinin (CK) also showed changes. Notably, a large number of genes associated with glycolysis/gluconeogenesis, catabolism of starch and oxidative stress were induced. In addition, the majority of DEGs related to nucleic acid sugar metabolism were also significantly upregulated. Biochemical assays showed that the starch content of B. cereus-treated leaves was reduced to 2.51 mg/g and 2.38 mg/g at 6 and 24 hpi, respectively, while that of the control sample was 5.42 mg/g. Overall, our results demonstrated that multiple hormone signal transduction and carbohydrate metabolic pathways are involved in the interaction of tobacco and B. cereus.
•Transcriptome sequencing of N. tabacum in response to B. cereus.•7345 and 5604 differentially expressed genes (DEGs) identified from leaves inoculated with B. cereus at 6 and 24 hpi, respectively.•Hormone signal transduction, the MAPK signaling pathway, photosynthesis, oxidative stress, amino sugar and nucleotide sugar metabolism, glycolysis/gluconeogenesis and catabolism of starch were affected by B. cereus.•Multiple genes associated with oxidative stress induced by B. cereus.•Starch content of B. cereus-treated leaves reduced dramaticly.