Newsletter 2 | Junio 2021

Whole-genome sequencing reveals rare off-target mutations in CRISPR/Cas9-edited grapevine

The CRISPR (clustered regularly interspaced short palindromic repeats)-associated protein 9 (Cas9) system is a powerful tool for targeted genome editing, with applications that include plant biotechnology and functional genomics research. However, the specificity of Cas9 targeting is poorly investigated in many plant species, including fruit trees.

Genetic variation and association analyses identify genes linked to fruit set-related traits in grapevine

Grapevine is one of the most valuable fruit crops in the world. Adverse environmental conditions reduce fruit quality and crop yield, so understanding the genetic and molecular mechanisms determining crop yield components is essential to optimize grape production. The analysis of a diverse collection of grapevine cultivars allowed us to evaluate the relationship between fruit set-related components of yield, including the incidence of reproductive disorders such as coulure and millerandage. The collection displayed a great phenotypic variation that we surveyed in a genetics association study using 15,309 single nucleotide polymorphisms (SNPs) detected in the sequence of 289 candidate genes scattered across the 19 grapevine linkage groups.

Whole genome resequencing and custom genotyping unveil clonal lineages in 'Malbec' grapevines (Vitis vinifera L.)

Grapevine cultivars are clonally propagated to preserve their varietal attributes. However, genetic variations accumulate due to the occurrence of somatic mutations. This process is anthropically influenced through plant transportation, clonal propagation and selection. Malbec is a cultivar that is well-appreciated for the elaboration of red wine. It originated in Southwestern France and was introduced in Argentina during the 1850s. In order to study the clonal genetic diversity of Malbec grapevines, we generated whole-genome resequencing data for four accessions with different clonal propagation records.

Metabolic differences between a wild and a wine strain of Saccharomyces cerevisiae during fermentation unveiled by multi-omic analysis

Saccharomyces cerevisiae, a widespread yeast present both in the wild and in fermentative processes, like winemaking. During the colonization of these human-associated fermentative environments, certain strains of S. cerevisiae acquired differential adaptive traits that enhanced their physiological properties to cope with the challenges imposed by these new ecological niches. The advent of omics technologies allowed unveiling some details of the molecular bases responsible for the peculiar traits of S. cerevisiae wine strains. However, the metabolic diversity within yeasts remained poorly explored, in particular that existing between wine and wild strains of S. cerevisiae.

CRISPAltRations: a validated cloud-based approach for interrogation of double-strand break repair mediated by CRISPR genome editing

CRISPR systems enable targeted genome editing in a wide variety of organisms by introducing single- or double-strand DNA breaks, which are repaired using endogenous molecular pathways. Characterization of on- and off-target editing events from CRISPR proteins can be evaluated using targeted genome resequencing. We characterized DNA repair fingerprints that result from non-homologous end joining (NHEJ) after double-stranded breaks (DSBs) were introduced by Cas9 or Cas12a for >500 paired treatment/control experiments.

Web-Based Base Editing Toolkits: BE-Designer and BE-Analyzer

The CRISPR-Cas system is broadly used for genome editing because of its convenience and relatively low cost. However, the use of CRISPR nucleases to induce specific nucleotide changes in target DNA requires complex procedures and additional donor DNAs. Furthermore, CRISPR nuclease-mediated DNA cleavage at target sites frequently causes large deletions or genomic rearrangements. In contrast, base editors that consist of catalytically dead Cas9 (dCas9) or Cas9 nickase (nCas9) connected to a cytidine or a guanine deaminase can correct point mutations in the absence of additional donor DNA and without generating double-strand breaks (DSBs) in the target region.

CRISPR-ERA: A Webserver for Guide RNA Design of Gene Editing and Regulation

The CRISPR/Cas9 system has been developed as a powerful technology for both targeted genome editing and gene regulation. However, the design of efficient single-guide RNAs (sgRNAs) remains challenging with the consideration of many criteria. In this section, we introduce how to design sgRNA sequences and build genome-wide sgRNA library using CRISPR-ERA, which is one of the state-of-the-art designer webserver tools for sgRNA design based on a set of sgRNA design rules summarized from published reports.

Biocontrol Potential of Grapevine Endophytic and Rhizospheric Fungi Against Trunk Pathogens

Grapevine Trunk Diseases (GTDs) are a major challenge to the grape industry worldwide. GTDs are responsible for considerable loss of quality, production, and vineyard longevity. Seventy-five percent of Chilean vineyards are estimated to be affected by GTDs. GTDs are complex diseases caused by several fungi species, including members of the Botryosphaeriaceae family and Phaeomoniella chlamydospora, considered some of the most important causal agents for these diseases in Chile. In this study, we isolated 169 endophytic and 209 rhizospheric fungi from grapevines grown under organic and conventional farming in Chile.

Encapsulation of fluazinam to extend efficacy duration in controlling Botrytis cinerea on cucumber

Fluazinam is an effective fungicide in controlling gray mold, but has short duration of efficacy. Increasing application dosage may cause phytotoxicity. To overcome this shortage, a controlled-release technology was studied by encapsulating fluazinam. Ethyl cellulose polymer microcapsules were loaded with fluazinam to formulate a fluazinam capsule suspension (FCS). The efficacy for inhibition of B. cinerea and persistency of the FCS were examined by comparing with fluazinam technical concentrate (FTC) and aqueous fluazinam suspension concentrate (FSC) using microscopic observation and high-performance liquid chromatography analysis.

Population genomics reveals molecular determinants of specialization to tomato in the polyphagous fungal pathogen Botrytis cinerea in France

CTIn order to discover novel antifungal agents, three series of simple 2-aminobenzoxazole derivatives were designed, synthesized and evaluated for their antifungal activities against eight phytopathogenic fungi. The in vitro antifungal results showed that most of the target compounds exhibited excellent and broad-spectrum antifungal activities to all the tested fungi.

Dirección de Innovación y Transferencia Tecnológica
Vicerrectoría de Investigación y Doctorado - Universidad Andrés Bello ®