RESUMO
BACKGROUND: Glutathione S-transferases (GSTs) are the ubiquitous enzymes that play a key role in cellular detoxification. Although several GSTs have been identified and characterized in various plant species, the knowledge about their role in developmental processes and response to various stimuli is still very limited. In this study, we report genome-wide identification, characterization and comprehensive expression analysis of members of GST gene family in crop plant rice, to reveal their function(s). RESULTS: A systematic analysis revealed the presence of at least 79 GST genes in the rice genome. Phylogenetic analysis grouped GST proteins into seven classes. Sequence analysis together with the organization of putative motifs indicated the potential diverse functions of GST gene family members in rice. The tandem gene duplications have contributed a major role in expansion of this gene family. Microarray data analysis revealed tissue-/organ- and developmental stage-specific expression patterns of several rice GST genes. At least 31 GST genes showed response to plant hormones auxin and cytokinin. Furthermore, expression analysis showed the differential expression of quite a large number of GST genes during various abiotic stress (20), arsenate stress (32) and biotic stress (48) conditions. Many of the GST genes were commonly regulated by developmental processes, hormones, abiotic and biotic stresses. CONCLUSION: The transcript profiling suggests overlapping and specific role(s) of GSTs during various stages of development in rice. Further, the study provides evidence for the role of GSTs in mediating crosstalk between various stress and hormone response pathways and represents a very useful resource for functional analysis of selected members of this family in rice.
Assuntos
Perfilação da Expressão Gênica , Glutationa Transferase/metabolismo , Oryza/genética , Proteínas de Plantas/metabolismo , Citocininas/metabolismo , DNA de Plantas/genética , Duplicação Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Genoma de Planta , Glutationa Transferase/genética , Ácidos Indolacéticos/metabolismo , Família Multigênica , Análise de Sequência com Séries de Oligonucleotídeos , Oryza/enzimologia , Oryza/crescimento & desenvolvimento , Filogenia , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Análise de Sequência de DNA , Estresse FisiológicoRESUMO
Although the phytohormone auxin has been implicated primarily in developmental processes, some recent studies suggest its involvement in stress/defense responses as well. Recently, we identified auxin-responsive genes and reported their comprehensive transcript profiling during various stages of development and abiotic stress responses in crop plant rice. The analysis revealed tissue-specific and overlapping expression profiles of auxin-responsive genes during various stages of reproductive development. In addition, a large number of auxin-responsive genes were also found to be differentially expressed under various abiotic stress conditions. Here, we further analyze the expression profiles of auxin-responsive genes during various biotic stress conditions. Several auxin-responsive genes showed response to biotic stress as well. Our analysis provides evidence for role of auxin in plant defense responses and suggests cross-talk between auxin, abiotic stress and biotic stress signaling pathways.
