terclim by ICS banner
IVES 9 IVES Conference Series 9 Functional characterization of grapevine MLO genes to define their roles in Powdery mildew susceptibility by CRISPR/Cas9 genome editing

Functional characterization of grapevine MLO genes to define their roles in Powdery mildew susceptibility by CRISPR/Cas9 genome editing

Abstract

Successful powdery mildew (PM) infection in plants relies on Mildew Resistance Locus O (MLO) genes, which encode susceptibility factors essential for fungal penetration. In Arabidopsis, loss-of-function mutations in three clade-V MLOs, AtMLO2, 6, and 12 confer complete resistance to PM infection. Since then, efforts are on to discover MLO genes contributing to PM susceptibility in many species to introduce mlo-based PM-resistance. Earlier studies in tomato and grapevine, using the RNAi approach, attributed PM susceptibility to SlMLO1, 5, and 8 and VvMLO3, 13, and 17, respectively indicating likely functional redundancy among MLOs. Here, we disrupted the closest grapevine orthologues, VvMLO3, 4, 13, and 17 through CRISPR/Cas9-mediated mutagenesis in the microvine model with the goal of identifying the candidate MLO genes to introduce mlo-based PM resistance. Individual mutants mlo3, mlo4, mlo13 and mlo17 showed 8 to 50% less infection to E. necator, whereas double mutants, mlo3/4, mlo3/13 andmlo13/17 and triple mutant mlo3/13/17 showed 60 to 90% less infection. But the quadruple mlo3/4/13/17 mutant plants showed near complete PM resistance. Considerable differences were observed in the resistance level of clones among the triple and quadruple mutants due to the differences in editing efficiency of individual guide RNAs. Some mutants showed pleiotropic effects in the growth and development, ranging from early senescence and stunted growth to non-flowering phenotypes, which also seemed to depend on the percentage of gene-edited cells in the plant. The overarching goal is to excise the genome-integrated T-DNA cassette from the mutants using CRISPR Ribonucleoproteins for transgene-free PM resistance.

DOI:

Publication date: June 13, 2024

Issue: Open GPB 2024

Type: Article

Authors

Satyanarayana Gouthu1*, Laurent Deluc2,3, Samuel Talbot1

1,2 Department of Horticulture, Oregon State University, Corvallis, OR, USA
3 Oregon Wine Research Institute, Oregon State University, Corvallis, OR, USA

Contact the author*

Keywords

Powdery mildew, Grapevine MLO, mildew-resistance, Gene Editing

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

A comparative analysis of regions worldwide with Pinot noir

This study examines the growing season climates of selected wine regions worldwide that have significant areas under Pinot noir.

Remote sensing and ground techniques, applied to the characterization of a new viticultural region at Pinto Bandeira, Brazil

The region of viticultural production near Pinto Bandeira, Brazil, is being studied to define typical characteristics of wines locally produced.

Legacy of land-cover changes on soil erosion and microbiology in Burgundian vineyards

Soils in vineyards are recognized as complex agrosystems whose characteristics reflect complex interactions between natural factors (lithology, climate, slope, biodiversity) and human activities. To date, most of the unknown lies in an incomplete understanding of soil ecosystems, and specifically in the microbial biodiversity even though soil microbiota is involved in many key functions, such as nutrient cycling and carbon sequestration. Soil biological properties are indicative of soil quality. Therefore, understanding how soil communities are related to soil ecosystem functioning is becoming an essential issue for soil strategy conservation. Here, we propose to assess the importance of land-cover history on the present-day microbiological and physico-chemical properties. The studied area was selected in the Burgundian vineyards (Pernand-Vergelesses, Burgundy, France) where land occupation has been reconstructed over the last 40 years. Soil samples were collected in five areas reflecting various land cover history (forest, vineyards, shifting from forest to vineyards). For each area, physico-chemical parameters (pH, C, N, P, grain size) were measured and DNA was extracted to characterize the abundance and diversity of microbial communities. The obtained results show significant differences in the five areas suggesting that present-day microbial molecular biomass and bacterial taxonomic is partly inherited from past land occupation. Over longer period of time, such study of land-uses legacies may help to better assess ecosystem recovery and the impact of management practices for a better soil quality and vineyards sustainability.

Field evaluation of biofungicides to control powdery mildew and botrytis bunch rot of wine grapes in California

Grapevine powdery mildew caused by Erysiphe necator and Botrytis bunch rot caused by Botrytis cinerea are two of the most important fungal diseases in California grape production.

Comportement de différents clones de Sauvignon blanc dans certains terroirs viticoles du Friuli-Venezia Giulia (Nord-Est de l’Italie)

The worldwide reputation of Sauvignon Blanc has led technicians to ask themselves various questions about the cultivation of this variety: choice of the most suitable localities, the most effective agronomic strategies and the most appropriate wine-growing techniques, to bring out its particular aroma.