Genetic improvement of grapevine: WHY ?

Melané A VivierInstitute for Wine Biotechnology

Stellenbosch University

Why am I here trying to answer this question?

Because we, together with a large international community, supported by numerous industries

and other funding agencies, are trying to ask and answer scientific questions regarding the most important fruit crop of the world, namely Vitis

vinifera (grapevine)

We focus on understanding the genetic potential of the species, using molecular and cellular biology tools

We have developed (bio)technologies that can lead to genetically improved grapevines, aligned with industry

needs

We have applied for an experimental field trial with transgenic grapes, which sparked much debate

Media reports

GM Grapes earn wrath of growers (Sunday Times)

SA Scientists seek go-ahead for field trials of GM grapes (Cape Times)

Wingerdinstituut se GM proef sal ‘n eerste wees (Die Burger)

GM grape trials could affect SA wine sales

(Farmer’s Weekly, letter)Frankenfoods’ from a

madman’s lab. Gene grapes no barrel of fun (Son)

GM wingerdplante ontlok

reaksie (Landbou Burger)

No to GMO in the wine industry (WOSA)

Protests at Stellenbosch transgenic grapevine experiment (Grape news)

Genetically modified wine on the cards

(Cape Times)

So, are we interested in “contaminating” the environment, creating “weedy” grapevines

or causing harm to wine-drinking customers, or the wine-industry in general?

Aims of the programme • To know more about grapevine and how it

“works”……• To find solutions to support environmentally

friendly production…..less pesticides • To find solutions to the impact of the changing

climate…..stress-tolerance • To find novel ways to improve quality and

wholesomeness

Towards environmentally friendly production and stress tolerance…..

A grape gene (Vvpgip), present in multiple copies protects against fungal pathogens

A grape gene (VvNCED), protects against water stress

The process involved to generate a transgenic grapevine and the evaluations

needed

Photographs obtained from the work of Dr. Khrishnan Vasanth, IWBT

Somatic embrogenesis

Cryopreservation

Genetic transformation

Regeneration

(a)

Grapevine flower

Isolation of anther

filaments

Embryogeniccallus line

Globular

Heart stage

Torpedo

Cotyledonary

Induction of somatic embryogensis

Somatic embryos : target material for grapevine transformation/regeneration

(b)

Agrobacterium-mediated or biolistic bombardment of somatic embryo cultures

Selection of transformants

Regeneration of putative transgenic plantlets

Hardening-off of plantlets

(c)

Confirmation of transformations (PCR, Southern, Northern analysis)

Evaluation of stable expression

Greenhouse trials

Fieldtrials

Evaluation for stable expression, phenotype, ampelography, viticultural analysis, analysis of fruit and/or wine produced

depending of industry targeted.

1-2 Years

1-2 Years

5-8 Years

GRAPEVINE TISSUE CULTUREGRAPEVINE TISSUE CULTURE

GRAPEVINE TRANSFORMATIONGRAPEVINE TRANSFORMATION

EVALUATION OF TRANSGENICSEVALUATION OF TRANSGENICS

The p

roce

ss a

nd

evalu

ati

ons

The specifics about the contained experimental vineyard

• Why did we apply?– To obtain a mature, fruit-bearing GMO vineyard for scientific

purposes

• What would it contain and where will it be?– Grapevine plants with inserted reporter and antibiotic genes (the

latter as selectable marker) alongside non-transgenic grapevines

– The transgenic material will be grafted on non-transgenic rootstocks on the Welgevallen experimental farm of Stellenbosch University

• Objectives?– To assess the reporter gene activity over several seasons and to

assess the agronomical performance of the transgenic material alongside conventional grapevines

• On Welgevallen experimental farm• 930 m2, fenced, restricted admission

• 238 US Vit 8-7 (NON-TRANSGENIC) Rootstocks planted – 100 used for first trial

• Virus-free (molecular analyses)

• Trellis and irrigation systems for Chardonnay and Sultana established

• Structure for super fine netting to cover trial

• Normal viticultural practices

The experimental vineyard

Transgenic grapevine plants

• 100 plants in first round trial– 6 Lines Chardonnay, 6 lines

Sultana, 4 controls of each– 5 plants of each line

• Random block design• Monitoring: at least five

seasons• Management plan included

Public notification• Public notification with details of proposed field trial:

– IWBT and DVO staff and students– SU Research Development

• SU management• Ethical committee

– IWBT Website– SU Bulletin– Winetech and DFPT – to industry role players– Local media:

• Eikestadnuus• Die Burger• Cape Argus

• The wording of the notification was not optimal…..

Reaction to public notification

• 2 Official objections within allowed period (Biowatch and African Centre for Biosafety); 1 Subsequent objection from Biowatch

• Several email messages from the public• Replies to all official objections, a further press

release in collaboration with SA Wine Industry and significant e-mail correspondence

• Interviews with the media:– Newspapers– Electronic journals / newsletters– Magazines– Radio stations (SABC)

Not factual reporting in all cases!

General concerns

General aspects:1. General anti-GMO2. Environmental contamination / Biosafety3. Antibiotic Resistance Genes: nptII

Wine-industry specific aspects:1. Activities done without support of SA wine

industry2. Impact of the possible commercialisation of GM

grapevine and wine

Understanding the specifics about Vitis

will clarify many misconceptions • Grapevines are not

indigenous to South Africa– The first Vitis

species arrived with the settlers!

• Grapevines have no close relatives in South Africa, meaning that there is no plant species with which it could interbreed

Misconceptions………Pollen flow and seed dispersal

• Domesticated grapevine flowers are functionally bisexual and largely self-pollinated

• Grapevine is not planted from seed; it is vegetatively propagated– In SA certified plant

material is strictly controlled in the supply chain

Misconceptions……….Seed dispersal and seedling volunteers

• Grapevines are planted in “manicured” vineyards which are intensively worked

• Seedling volunteers are scarce, very visible and routinely removed through normal viticultural practices

Understanding the specifics about Vitis will clarify many misconceptions

•The concept of “true-to-typeness” (in viticultural terms)……

– In the wine industry, the varietal names and characteristics are important marketing attributes

– The viticultural performance, as well as the varietal characteristics in the vineyard and in the resulting wine are important factors to consider

– This has a direct impact on the prospect of GMO vines and wines and therefore needs to be assessed rigorously

•Scientific advances provides the possibility to also perform genetic and transcriptomic profiles of GMO vines in comparison with non-transgenic vines

Environmental contamination• Possible release of transgenes into the environment

–Pollination of grapevine: largely by self-pollination, no wild relatives of grapevine in SA, no related plant species to hybridise

• Flowers in the trial will be covered with bags

–Seed dispersal: Seedlings do not normally survive in uncultivated habitats; Volunteer seedlings controlled by routine viticultural practices.

• The trial site will be covered with a superfine net and fruit will be bagged

–Soil contamination: The transgenic plants will be grafted on non-transgenic rootstocks, frequency of horizontal gene transfer from plants to microorganisms very low under normal circumstances, transgenes already present in very large amounts in environment, transgenes do not give competitive advantage.

• Rigorous management of fallen leaves and other plant material; Environmental impact monitored

General concerns

Perspectives

The challenge is perhaps to strike a balance between strict control and monitoring of

GMO materials and their release, while not hampering the progress of science

Thank you