RESUMO
Various plant genes can be activated or inhibited by phytohormones under conditions of biotic and abiotic stress, especially in response to jasmonic acid (JA) and salicylic acid (SA). Interactions between JA and SA may be synergistic or antagonistic, depending on the stress condition. In this study, we cloned a full-length cDNA (LeWRKY1, GenBank accession No. FJ654265) from Lycopersicon esculentum by rapid amplification of cDNA ends. Sequence analysis showed that this gene is a group II WRKY transcription factor. Analysis of LeWRKY1 mRNA expression in various tissues by qRT-PCR showed that the highest and lowest expression occurred in the leaves and stems, respectively. In addition, LeWRKY1 expression was induced by JA and Botrytis cinerea Pers., but not by SA.
Assuntos
Ciclopentanos/metabolismo , Genes de Plantas/genética , Oxilipinas/metabolismo , Proteínas de Plantas/genética , Ácido Salicílico/metabolismo , Solanum lycopersicum/genética , Botrytis/metabolismo , Clonagem Molecular/métodos , DNA Complementar/genética , Regulação da Expressão Gênica de Plantas/genética , Reguladores de Crescimento de Plantas/genética , Folhas de Planta/genética , Caules de Planta/genética , RNA Mensageiro/genética , Fatores de Transcrição/genéticaRESUMO
MicroRNAs (miRNAs) are a newly discovered class of noncoding small RNAs that regulate gene expression by directing target mRNA cleavage or translational inhibition. A large number of miRNAs have been identified in plants. Increasing evidence has shown that miRNAs play multiple roles in plant biological processes. So far, identification of miRNAs has been limited to a few model plant species, whose genomes have been sequenced. Wheat (Triticum aestivum L.) is one of the most important cereal crops worldwide. To date, only a few conserved miRNAs have been predicted in wheat. Here, we showed the conserved miRNAs identified in wheat by expressed sequence tag (EST) analysis. All previously known miRNAs from Arabidopsis, rice, and other plant species were used in a BLAST search against the wheat EST database to identify novel wheat miRNAs by a series of filtering criteria. By this strategy, we identified 62 conserved miRNAs, belonging to 30 miRNA families, 48 of which were newly discovered in wheat. These newly identified wheat miRNAs may regulate 287 potential targets, which are involved in development, signal transduction, metabolic pathways, disease resistance, ion transportation, and environmental stress response.