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.

Download the abstract

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…

Exploring the mechanisms of grapevine single berry development and ripening

The strategy of single berry phenotyping is a recently rediscovered research tool that has gained great attention. The latest studies have indicated that previous physiological models based on pooling asynchronous populations of berries provided biased or blurred information on berry development key players. The possibility of monitoring and sampling single synchronized berries to study their development sequentially has opened new lines of research aimed at unraveling the genes that regulate grapevine fruit development. This study aimed to decipher the gene pathways responsible for the activation/deactivation of physiological processes involved in the green phase of growth, the onset of ripening, and the second growth phase.

Read More

Optimization of in vitro establishment of grapevine varieties for fast micropropagation 

Micropropagation is an important alternative to conventional methods of plant propagation. The objective of this study was to optimize a protocol for in vitro micropropagation of selected grapevine hybrids (H19 and H20) that are included in our breeding program. For the sprouting initiation experiment, nodal cuttings with only one axillary bud from two hybrids were separated, disinfected, and cultivated in 50% Murashige Skoog nutrient medium (½ MS) and Woody Plant Medium (WPM), adding 4.4 µM benzyladenine (BA) in both mediums.

Read More

Influence of the type of flavonol and the presence of mannoproteins in the copigmentation with malvidin 3-O-glucoside

To study the copigmentation between different wine flavonols (myricetin, quercetin, kaempferol, isorhamnetin and syringetin 3-O-glucosides) and malvidin

Read More

The influence of tertiary and quaternary deposits on the viticultural potential of the terroirs to be found in Geneva, Switzerland

The 1365 ha of the Genevese vineyard are located at the south-western corner of the Swiss plateau, between 395m and 505 m altitude.

Read More

Soils, climate, nutritive status and production of cv “Palomino fino” in the superior quality area of the Jerez-Xérès-Sherry zone

The Registered Appellation of Origin Mark (RAOM) « Jerez-Xérès-Sherry and Manzanilla Sanlucar de Barrameda » is one of the oldest and more important zone in wine history and production. «Albarizas» unit (white calcareous marls with sea-fossils) is the most representative geological material of the RAOM (75%) and even more in the central-NW area of the RAOM, known as «Jerez Superior» area (Superior Quality Sherry Area). « Albarizas » form undulated hillocks (3-10% slope) and hills (>10% slope), the litologic unit has E-W and S-W direction, and Regosols and Leptosols are the principal soils.

Read More