Researchers Come Out With Drought Resistant Tobacco Plants

Source from:  New York (PTI) 11/29/2007

Researchers have created drought-resistant tobacco plants, which can withstand prolonged dry periods and thrive on 70 per cent less water than ordinary tobacco plants, a media report said on Wednesday. The finding holds importance in context of agricultural countries like India with uncertain monsoon patterns. It could be important for creating other drought-resistant crops, Jeffrey Leung, a plant biologist, at France's National Centre for Scientific Research in Gif-sur-Yvette, was quoted as saying by Nature. While so far, researchers led by plant biologist Eduardo Blumwald of the University of California, Davis, have focused on the easier to genetically manipulate, tobacco, Nature said, they are now trying the same approach in rice, tomatoes and wheat. Drought is the major culprit behind crop losses worldwide, and water shortages are expected to become still more important as climate change alters rainfall patterns and increases the proportion of arid land in some key agricultural regions, the report noted. In many parts of the world, water is already as expensive as fertilizer, Blumwald was quoted as saying. Water-starved plants, Nature said, often cope with the stress by wilting and shedding their leaves. That's believed to be a key part of their survival strategy --they sacrifice older leaves to stay alive just long enough to make seeds. That approach may boost long-term survival in the wild, but it can be devastating to crop yields, says Blumwald. "Crops adopt the same strategy that those plants in the wild use," he says. "If things go wrong, they put out some seeds and die. But we do not grow crops for that." Blumwald, says the report, suspected that the drought-induced leaf shedding was genetically programmed, and reasoned that one way to circumvent that programming would be to boost a plant hormone called cytokinin. Cytokinins promote cell division and are found in actively growing plant tissues. Dying tissues, on the other hand, do not make the hormone. So Blumwald and his colleagues created transgenic tobacco plants that produce a protein that makes cytokinin in stressed tissues. Although ordinary tobacco plants shed their leaves and died if not watered for two weeks, the transgenic plants kept their foliage and revived when watering resumed. The transgenic plants, the report says, also suffered only a 12 per cent reduction in yield when watered with 70 per cent less water than normally used. The findings are published this week in Proceedings of the National Academy of Sciences of the USA. Enditem