Genome-Wide Identification And Analysis Of Grape Aldehyde Dehydrogenase (ALDH) And Jasmonate Zim-Domain (JAZ) Gene Families

Grapevine (Vitis vinifera) is economically the most important perennial fruit cropworldwide. The completion of the grape genome sequencing has paved the way for novelgene discovery and functional analysis. Aldehyde dehydrogenases (ALDHs) comprise genesuperfamily encoding NAD (P)+-dependent enzymes that catalyze the irreversible oxidationof a wide range of endogenous and exogenous aromatic and aliphatic aldehydes. JA sigalingplays a central role in controlling a wide range of important plant developmental anddefense-related processes. Acting as the negative regulators in JA signaling pathway, JAZproteins restrain the activity of positive transcription factors involved in the expression ofearly response genes. These two gene families are very important for plant stress tolerance.Although ALDHs and JAZs have been systematically investigated in model plant Arabidopsis,little attention has been paid to these genes in other plants. In present study, all ALDH andJAZ genes were identified in grape genome by Bioinformatics approaches. Phylogenetic andsynteny analysis were used to investigate the evolution of these two familes. We furtheranalyzed the expression profiles of grape ALDH and JAZ genes under various abiotic andbiotic stresses as well as in responses to different phytohormone treatments through miningpublicly available microarray datasets and quantitative real-time RT-PCR. The major resutswere as following:1. Genome-wide identification and annotation of ALDH and JAZ gene families in grape Atotal of23ALDH genes and11JAZ genes were identified in the grape genome. The identifiedgrape ALDH proteins were annotated using the criteria established by the ALDH GeneNomenclature Committee (AGNC). The23ALDH genes were grouped into ten familiesaccording to the criteria. Currently, there is no unified nomenclature for JAZ genes, so theidentified JAZ genes were names based on their genome location.2. Tandem and segmental duplications contribute to the expansion of grape ALDH and JAZgene families By checking the physical locations in individual grape chromosomes andsyentey analysis, we found the majoreity of grape ALDH and JAZ genes were associated witheither tandem or segmental duplications, indicating that segmental and tandem duplicationshave played important roles in the expansion of grape ALDH and JAZ genes. 3. Most grape and Arabidopsis ALDH and JAZ genes are syntenic orthlogs The analysis ofthe comparative synteny map between grape and Arabidopsis genomes identified large-scalesyntenies containing orthologs of ALDH and JAZ genes in both grape and Arabidopsisgenomes. These synetenic orthlogs share a common ancestor, thus we could confidently inferthe functions of grape ALDHs and JAZs based on their Arabidopsis homologues.4. Grape ALDH genes may play important roles in grape pathogen resistance and stresstolerance Through mining publicly available grape microarray datasets, we idenfied a largenumber of grape ALDH genes that were highly responsive to certain types of abiotic andbiotic stresses. Especially, the expression of VvALDH8could be induced by nearly alltreatments and in its promoter region several pathogen-responsive elements Box-W1wereidentified, suggesting its important role in plant pathogen resistance and stress tolerance.5. Expression levels of most grape JAZ genes were not responsive to biotrophic pathogens orvirus infection We investigated the response of grape JAZ genes to various pathogens andvirus infection, and found the expression of most grape JAZ genes was not responsive tobiotrophic pathogens or virus infection, indicating grape JAZ genes were not involved ingrape biotrophic pathogen and virus resistance.6. Grape JAZ genes were responsive to several abiotic stresses All tested grape JAZ geneswere regulated by at least one abiotic stress (dourght, salinity and cold), indicating thesegenes are likely to be involved in plant abiotic stress tolerance.7. Grape JAZ genes are regulated by JA and ABA, but not by SA and ET Grape JAZ geneswere significantly up-regulated by JA or MeJA treatment. The expression of several JAZgenes was also responsive to ABA. In contrast, the expression of no JAZ genes wassignificantly altered by SA or ET treatment. Therefore, JAZ genes were mediated by JA andABA but not by ET and SA.