Pinot Meunier, a variety of grape used in champagne production, could see enhanced production after the discovery of a new gene by Australian scientists.
According to a report in the journal Nature, scientists Paul Ross and Mark Thomas of the CSRIO Plant Industry in Adelaide, have discovered a mutant gene for Pinot Meunier which could make the plant more productive.
Thomas and colleagues were comparing the genetics of two grapes, Pinot Meunier, now used to make over a third of all champagne, and Pinot noir, which sprouted a branch of Pinot Meunier more than 400 years ago.
They found that Pinot Meunier is actually a hybrid of Pinot noir and another plant. This other vine produces abundant fruit, little foliage and "its grapes taste alright", Thomas said.
According to the Nature report, the thousands of varieties of grapevines are similar genetically, because vines have until now been propagated from cuttings. Usually wine growers make improvements by selecting branches with desirable characteristics caused by genetic mutations. Pinot Meunier was developed from Pinot noir in this way.
However the scientists grew their new vine using cells from the outer, 'L1' layer of a Pinot Meunier shoot. Plants they grew from cells in the inner, L2 layer apparently look just like Pinot noir.
Thomas said that there is great interest in developing fruitful vines that don't produce too many shoots and leaves, although grapevine geneticist Jean-Michel Boursiquot of ENTAV, the French viticulture agency, urged caution. He said that a plant that produces too much fruit "becomes weaker and weaker each year".
Russell Johnstone, a viticulturist at Orlando Wyndham, producer of Australia's Jacob's Creek wines, told Nature that a better understanding of flowering and fruit development "may allow us to manipulate grapevine performance".
The characteristics of the fertile L1 plant can be explained by a mutation in a gene called GAI2. GAI is involved in the plant's response to the hormone gibberellic acid. Surprisingly for the researchers, in vines gibberellic acid seems to limit flower and therefore fruit production. In wheat, rice and thale cress it does the opposite.
This is why the LI plants, with their mutated GAI gene and disrupted gibberellic acid system, produce a seemingly limitless number of healthy grape bunches.
While producing lots of grapes will spark interest among growers, a vine that continually produces fruit could cause problems as not all of the grapes would be ready at the same time.
If the L1 champagne proves itself in terms of taste, and the plants turn out to be suitable for making wine on a large scale, the public may get to sample it in 10-15 years.