Dataset Information

Grapevine DMR6-1 Is a Candidate Gene for Susceptibility to Downy Mildew.

ABSTRACT: Grapevine (Vitis vinifera) is a valuable crop in Europe for both economical and cultural reasons, but highly susceptible to Downy mildew (DM). The generation of resistant vines is of critical importance for a sustainable viticulture and can be achieved either by introgression of resistance genes in susceptible varieties or by mutation of Susceptibility (S) genes, e.g., by gene editing. This second approach offers several advantages: it maintains the genetic identity of cultivars otherwise disrupted by crossing and generally results in a broad-spectrum and durable resistance, but it is hindered by the poor knowledge about S genes in grapevines. Candidate S genes are Downy mildew Resistance 6 (DMR6) and DMR6-Like Oxygenases (DLOs), whose mutations confer resistance to DM in Arabidopsis. In this work, we show that grapevine VviDMR6-1 complements the Arabidopsis dmr6-1 resistant mutant. We studied the expression of grapevine VviDMR6 and VviDLO genes in different organs and in response to the DM causative agent Plasmopara viticola. Through an automated evaluation of causal relationships among genes, we show that VviDMR6-1, VviDMR6-2, and VviDLO1 group into different co-regulatory networks, suggesting distinct functions, and that mostly VviDMR6-1 is connected with pathogenesis-responsive genes. Therefore, VviDMR6-1 represents a good candidate to produce resistant cultivars with a gene-editing approach.

SUBMITTER: Pirrello C

PROVIDER: S-EPMC8961545 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Grapevine <i>DMR6-1</i> Is a Candidate Gene for Susceptibility to Downy Mildew.

Pirrello Carlotta C Malacarne Giulia G Moretto Marco M Lenzi Luisa L Perazzolli Michele M Zeilmaker Tieme T Van den Ackerveken Guido G Pilati Stefania S Moser Claudio C Giacomelli Lisa L

Biomolecules 20220122 2

Grapevine (<i>Vitis vinifera</i>) is a valuable crop in Europe for both economical and cultural reasons, but highly susceptible to Downy mildew (DM). The generation of resistant vines is of critical importance for a sustainable viticulture and can be achieved either by introgression of resistance genes in susceptible varieties or by mutation of Susceptibility (S) genes, e.g., by gene editing. This second approach offers several advantages: it maintains the genetic identity of cultivars otherwise ...[more]

PMID: 35204683

Similar Datasets

Project description:Sweet basil (Ocimum basilicum) is an economically important allotetraploid (2n = 4x = 48) herb whose global production is threatened by downy mildew disease caused by the obligate biotrophic oomycete, Peronospora belbahrii. Generation of disease resistant cultivars by mutagenesis of susceptibility (S) genes via CRISPR/Cas9 is currently one of the most promising strategies to maintain favored traits while improving disease resistance. Previous studies have identified Arabidopsis DMR6 (Downy Mildew Resistance 6) as an S gene required for pathogenesis of the downy mildew-causing oomycete pathogen Hyaloperonospora arabidopsidis. In this study, a sweet basil homolog of DMR6, designated ObDMR6, was identified in the popular sweet basil cultivar Genoveser and found to exist with a high copy number in the genome with polymorphisms among the variants. Two CRISPR/Cas9 constructs expressing one or two single guide RNAs (sgRNAs) targeting the conserved regions of ObDMR6 variants were generated and used to transform Genoveser via Agrobacterium-mediated transformation. 56 T0 lines were generated, and mutations of ObDMR6 were detected by analyzing the Sanger sequencing chromatograms of an ObDMR6 fragment using the Interference of CRISPR Edits (ICE) software. Among 54 lines containing mutations in the targeted sites, 13 had an indel percentage greater than 96% suggesting a near-complete knockout (KO) of ObDMR6. Three representative transgene-free lines with near-complete KO of ObDMR6 determined by ICE were identified in the T1 segregating populations derived from three independent T0 lines. The mutations were further confirmed using amplicon deep sequencing. Disease assays conducted on T2 seedlings of the above T1 lines showed a reduction in production of sporangia by 61-68% compared to the wild-type plants and 69-93% reduction in relative pathogen biomass determined by quantitative PCR (qPCR). This study not only has generated transgene-free sweet basil varieties with improved downy mildew resistance, but also contributed to our understanding of the molecular interactions of sweet basil-P. belbahrii.

Project description:BackgroundTo limit the impact of the downy mildew disease of grapevine and reduce the need to recur to chemical treatments, an effective strategy might be recovering adaptive resistance traits in both cultivated and wild V. vinifera germplasm. Considering that stilbenes represent the most important class of phytoalexins in the Vitaceae, the constitutive expression and transcriptional activation of all the functional members of the stilbene synthase gene family were analysed in a group of nine grapevine genotypes following artificial infection with the oomycete Plasmopara viticola, the causal agent of the disease. In addition, in the same genotypes we analyzed the expression of genes encoding for two transcription factors involved in the transcriptional regulation of the stilbene synthase genes, namely VvMYB14 and VvMYB15, and of genes encoding for chalcone synthases.ResultsDowny mildew incidence and severity ranged from nihil to high in the grapevine genotypes considered, being low to moderate in a subgroup of V. vinifera genotypes. The constitutive expression of the stilbene synthase genes as well as the extent of their transcriptional activation following P. viticola inoculation appeared to be inversely related to the proneness to develop disease symptoms upon infection. In a specular manner, following P. viticola inoculation all the chalcone synthase genes were up-regulated in the susceptible grapevine genotypes and down-regulated in the resistant ones. The infection brought by P. viticola appeared to elicit a co-ordinated and sequential transcriptional activation of distinct stilbene synthase genes subsets, each of which may be regulated by a distinct and specific MYB transcription factor.ConclusionsThe present results suggest that the induction of stilbene biosynthesis may contribute to the basal immunity against the downy mildew of grapevine, thus representing an adaptive resistance trait to recover, in both cultivated and wild V. vinifera germplasm. During the early stages of P. viticola infection, an antagonistic interaction between flavonol and stilbene biosynthesis might occur, whose outcome might determine the subsequent extent of disease symptoms. Further studies are needed to decipher the possible regulatory mechanisms involved in the antagonistic crosstalk between these two metabolic pathways in resistant and susceptible genotypes in response to P. viticola.

Dataset Information

Grapevine DMR6-1 Is a Candidate Gene for Susceptibility to Downy Mildew.

Publications

Grapevine <i>DMR6-1</i> Is a Candidate Gene for Susceptibility to Downy Mildew.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets