RESUMO
BACKGROUND: Golden 2-Like (G2-like) transcription factors play an important role in plant development. However, the roles of these G2-like regulatory genes in response to abiotic stresses in tomato are not well understood. RESULTS: In this study, we identified 66 putative G2-like genes in tomato (Solanum lycopersicum) and classified them into 5 groups (I to V) according to gene structure, motif composition and phylogenetic analysis. The G2-like genes were unevenly distributed across all 12 chromosomes. There were nine pairs of duplicated gene segments and four tandem duplicated SlGlk genes. Analysis of the cis-regulatory elements (CREs) showed that the promoter regions of SlGlks contain many kinds of stress- and hormone-related CREs. Based on RNA-seq, SlGlks were expressed in response to three abiotic stresses. Thirty-six differentially expressed SlGlks were identified; these genes have multiple functions according to Gene Ontology (GO) analysis and are enriched mainly in the zeatin biosynthesis pathway. Further studies exhibited that silencing SlGlk16 in tomato would reduce drought stress tolerance by earlier wilted, lower superoxide dismutase (SOD), peroxidase (POD) activities, less Pro contents and more MDA contents. CONCLUSIONS: Overall, the results of this study provide comprehensive information on G2-like transcription factors and G2-like genes that may be expressed in response to abiotic stresses.
Assuntos
Proteínas de Plantas/genética , Solanum lycopersicum/genética , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Mapeamento Cromossômico , Secas , Duplicação Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Estudo de Associação Genômica Ampla , Solanum lycopersicum/efeitos dos fármacos , Solanum lycopersicum/metabolismo , Malondialdeído/metabolismo , Filogenia , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Prolina/metabolismo , Sequências Reguladoras de Ácido Nucleico , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Fatores de Transcrição/químicaRESUMO
Cf-12 is an effective gene for resisting tomato leaf mold disease caused by Cladosporium fulvum (C. fulvum). Unlike many other Cf genes such as Cf-2, Cf-4, Cf-5, and Cf-9, no physiological races of C. fulvum that are virulent to Cf-12 carrying plant lines have been identified. In order to better understand the molecular mechanism of Cf-12 gene resistance response, RNA-Seq was used to analyze the transcriptome changes at three different stages of C. fulvum infection (0, 4, and 8 days post infection [dpi]). A total of 9100 differentially expressed genes (DEGs) between 4 and 0 dpi, 8643 DEGs between 8 and 0 dpi and 2547 DEGs between 8 and 4 dpi were identified. In addition, we found that 736 DEGs shared among the above three groups, suggesting the presence of a common core of DEGs in response to C. fulvum infection. These DEGs were significantly enriched in defense-signaling pathways such as the calcium dependent protein kinases pathway and the jasmonic acid signaling pathway. Additionally, we found that many transcription factor genes were among the DEGs, indicating that transcription factors play an important role in C. fulvum defense response. Our study provides new insight on the molecular mechanism of Cf resistance to C. fulvum, especially the unique features of Cf-12 in responding to C. fulvum infection.
