Expression Profile Responsed To Drought Stress And Identification Of Aldehyde Dehydrogenase Gene Family Of Foxtail Millet

Foxtail millet (Setaria italica L.),an elite drought-tolerant poaceae crop, grown in arid and semi-arid regions.it is a C4ponicoid crop with a comparatively small genome and short life cycle and The completion of the foxtail millet genome sequencing in2011. These traits were beneficial to clone excellent stress resistance gene from foxtail millet and study the plant stress-tolerant molecular mechanisms. However, system study of foxtail millet expression profiles responsed to drought stress was little. Aldehyde dehydrogenases(ALDHs) contain a group of enzymes involved in the NAD(P)+-dependent conversion of various aldehydes to their corresponding carboxylic acids.The ALDH gene family play an key role in adaption of plant stress tolerant. Hence,in this study,we carried out RNA-seq to analysis the expression profiles responsed to drought stress of foxtail millet.we found numerous ALDH gene families from RNA-seq results, and hoped to screen out excellent stress-tolerant genes. The major results were as following:1. From expression profile responsed to drought,3777genes were up-regulated,3316genes were down-regulated and the majority of genes had been annotated by GO and Pathway.2. Genome-wide identification and annotation of ALDH genes in foxtail millet:20ALDH genes were identified in foxtail millet and annotated by the criteria established by the ALDH Gene Nomenclature Committee(AGCN). the20ALDH genes were divided into ten different families.3. distribution of foxtail millet ALDH gene in foxtail millet chromosome and syentey analysis revealed that parts of foxtail millet ALDH genes were associated with either tandem or the whole genome duplications, indicating that tandem and the whole genome duolications have played important roles in the expansion of foxtail millet ALDH gene families.4. The majority of foxtail millet and rice ALDH genes are syntenic orthlogs:the analysis of the comparative syntenty map between foxtail millet and rice genomes identified orthologs of ALDH genes in both foxtail millet and rice genome,indicating that ALDH genes from foxtail millet and rice have a common ancestor,so we could infer the functions of foxtail millet ALDH genes based on their rice homologues.5. Real-time PCR revealed that expression level of a large number of foxtail millet ALDH genes were responsive to certain types of abiotic stresses,such as SiALDH2C-3、SiALDH3H-1.6. The functional analysis of foxtail millet ALDH genes in E.coli (Rosetta) demonstrated that SiALDH2B-1, SiALDH10A-1, SiALDH5F-1, SiALDH22A-1, and SiALDH3E-1could improve the salt tolerance of E.coli(Rosetta). Maybe these ALDH genes contributed to the plant stress tolerance.