Biology subjects

Salvagnin, U.

Publications and source records attributed to Salvagnin, U..

4 recordsLinked to original sources

bioRxiv2022

Vitis vinifera plants edited in DMR6 genes show improved resistance to downy mildew.

The production and cultivation of vines (Vitis vinifera) tolerant or resistant to diseases such as downy mildew (DM) is a promising strategy to reduce fungicides and help viticulture sustainability. In many crops, generation of knock-out mutants in host genes controlling susceptibility to DM, such as Downy Mildew Resistant 6 (DMR6) is a strategy of proven success to obtain resistant plants, while the effect of mutations in DMR6 genes has yet to be demonstrated in grapevine. In addition, small mutations in genes governing important traits can be obtained by gene-editing while maintaining the genetic background of commercially important clones. Moreover, very recent advances in the technology of gene-editing allowed to produce non-transgenic grapevine mutants, by regeneration of protoplasts previously edited with the CRISPR-Cas9 ribonucleoprotein. This approach may revolutionize the production of new grapevine varieties and clones, but it requires knowledge on the targets, and an extensive evaluation of the impact of their mutation on plant phenotype and fitness. In this work we generated single and double knock-out mutants in DMR6 susceptibility (S) genes in multiple grapevine cultivars with improved resistance to DM.

plant biology↗

bioRxiv2021

Regeneration of Plants from DNA-free Edited Grapevine Protoplasts

CRISPR-Cas technology has widely extended the application fields of genome editing in plant breeding, making possible specific and minimal mutations within a genetic pool. With respect to standard genome editing technologies, CRISPR-Cas machinery can be introduced in the form of ribonucleoproteins (RNPs), thus avoiding the introduction of exogenous DNA into cells. The interest on the application of DNA-free delivery into plant cells is constantly increasing, especially in the case of valuable woody plants elite varieties where CRISPR-Cas9 technology would preserve their genotype, while still resulting into targeted genetic modifications. The use of single cells fits well the requirements of New Breeding Technologies, by ensuring both the CRISPR-Cas DNA-free delivery as RNPs and, since every plant will be regenerated from a single edited cell, the absence of chimerism. However, the use of protoplasts cell culture from woody plants is generally hampered by low editing efficiencies and an unsuccessful regenerative process. We here describe a successful DNA-free methodology to obtain fully edited grapevine plants, regenerated from protoplasts obtained from V. vinifera cv. Crimson seedless L. embryogenic callus. The transfected protoplasts were edited on the Downy Mildew susceptibility gene VvDMR6-2. The regenerated edited plants exhibited homozygous deletions of 1bp or 2bp, and homozygous insertion of 1bp.

plant biology↗

bioRxiv2021

The Arabidopsis pattern recognition receptor EFR enhances fire blight resistance in apple

Fire blight disease, caused by the bacterium Erwinia amylovora (E. amylovora), is responsible for substantial losses in cultivated apple worldwide. An important mechanism of plant immunity is based on the recognition of conserved microbial molecules, named pathogen- or microbe-associated molecular patterns (PAMPs or MAMPs), through pattern recognition receptors (PRRs), leading to pattern-triggered immunity (PTI). The interspecies transfer of PRRs represents a promising strategy to engineer broad spectrum and durable disease resistance in crops. EFR, the Arabidopsis thaliana PRR for the PAMP elf18 derived from the elongation factor thermal unstable (EF-Tu) proved to be effective in improving bacterial resistance when expressed into Solanaceae and other plant species. In this study, we tested whether EFR can affect the interaction of apple with E. amylovora by its ectopic expression in the susceptible apple rootstock M.26. Stable EFR expression led to the activation of PAMP-triggered immune response in apple leaves upon treatment with supernatant of E. amylovora, as measured by production of reactive oxygen species and the induction of known defense genes. The amount of tissue necrosis associated with E. amylovora infection was significantly reduced in the EFR transgenic rootstock compared to the wild-type. Our results show that the expression of EFR in apple rootstock may be a valuable biotechnology strategy to improve the resistance of apple to fire blight.

plant biology↗

bioRxiv2017

The Peach RGF/GLV Signalling Peptide pCTG134 Is Involved In A Regulatory Circuit That Sustains Auxin And Ethylene Actions

Peach is a climacteric species whose ripening is regulated by the plant hormone ethylene. A crosstalk mechanism with auxin is necessary to support climacteric ethylene synthesis. The homeostasis control of auxin is regulated also by the activity of peptide hormones (PHs), acting both as short and long distant ligands. In this work, we investigated the role of CTG134, a peach gene encoding a GOLVEN-like PH isolated in mesocarp at the onset of ripening.\n\nIn peach fruit, CTG134 was expressed during the climacteric transition and its mRNA level was induced by auxin and 1-methylcyclopropene (1-MCP) treatments, whereas it was minimally affected by ethylene. To better elucidate its function, CTG134 was overexpressed in Arabidopsis and tobacco, which showed abnormal root hair growth, similar to wild-type plants treated with a synthetic form of the peptide. Molecular surveys demonstrated an impaired hormonal crosstalk, resulting in a re-modulated expression of a set of genes involved in both ethylene and auxin domains. In addition, the promoter of pCTG134 fused with GUS reporter highlighted gene activity in plant organs in which the auxin-ethylene interplay is known to occur. These data support the role of pCTG134 as mediator in an auxin-ethylene regulatory circuit.\n\nHighlightThe role of the peach RGF/GLV peptide during root hair formation in Arabidopsis and tobacco supports its involvement in a cross-hormonal auxin-ethylene regulatory circuit.

plant biology↗