RESUMO
MicroRNAs (miRNAs) are endogenous, non-coding RNAs, which are functional in a variety of biological processes through post-transcriptional regulation of gene expression. However, the role of miRNAs in the interaction between Bacillus thuringiensis and insects remains unclear. In this study, small RNA libraries were constructed for B. thuringiensis-infected (Bt) and uninfected (CK) Spodoptera exigua larvae (treated with double-distilled water) using Illumina sequencing. Utilising the miRDeep2 and Randfold, a total of 233 known and 726 novel miRNAs were identified, among which 16 up-regulated and 34 down-regulated differentially expressed (DE) miRNAs were identified compared to the CK. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that potential target genes of DE miRNAs were associated with ABC transporters, fatty acid metabolism and MAPK signalling pathway which are related to the development, reproduction and immunity. Moreover, two miRNA core genes, SeDicer1 and SeAgo1 were identified. The phylogenetic tree showed that lepidopteran Dicer1 clustered into one branch, with SeDicer1 in the position closest to Spodoptera litura Dicer1. A similar phylogenetic relationship was observed in the Ago1 protein. Expression of SeDicer1 increased at 72 h post infection (hpi) with B. thuringiensis; however, expression of SeDicer1 and SeAgo1 decreased at 96 hpi. The RNAi results showed that the knockdown of SeDicer1 directly caused the down-regulation of miRNAs and promoted the mortality of S. exigua infected by B. thuringiensis GS57. In conclusion, our study is crucial to understand the relationship between miRNAs and various biological processes caused by B. thuringiensis infection, and develop an integrated pest management strategy for S. exigua via miRNAs.
Assuntos
Bacillus thuringiensis , MicroRNAs , Spodoptera , Animais , Spodoptera/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Bacillus thuringiensis/genética , Larva/genética , Perfilação da Expressão GênicaRESUMO
YABBY family is a plant specific transcription factor family, with the typical N-terminal C2C2 type zinc finger domain and the C-terminal YABBY conservative structure domain, which plays important biological roles in plant growth, development and morphogenesis. In this study, a total of 17 YABBY genes were identified in the soybean genome. The results of this research showed that 17 soybean YABBY genes were located on 11 chromosomes. Analysis of putative cis-acting elements showed that soybean YABBY genes contained lots of MYB and MYC elements. Quantitative Real-time PCR (qRT-PCR) showed that the expressions of GmYABBY3, GmYABBY10 and GmYABBY16 were more highly sensitive in drought, NaCl and ABA stresses. And the transient expression in Arabidopsis protoplasts showed that GmYABBY3 protein distributed uniformly the whole cells, while GmYABBY10 protein was mainly localized in the membranes and cytoplasm and GmYABBY16 protein was localized the nucleus and membranes. To further identify the function of GmYABBY10, we obtained the transgenic Arabidopsis overexpression GmYABBY10. Based on germination and seedling root arrays in transgenic Arabidopsis, we found that the rates of wild type seeds was a litter higher than that of GmYABBY10 transgenic seeds under both PEG and NaCl treatment. While the root length and root surface of wild type seedlings were bigger than those of GmYABBY10 transgenic seedlings. When seedlings were grown in soil, the survival rates of wild type were higher than those of transgenic plants under both PEG and NaCl treatment, which indicated that GmYABBY10 may be a negatively regulator in plant resistances to drought and salt stresses. This study provided valuable information regarding the classification and functions of YABBY genes in soybean.