TOMATOES genetically modified to stay fresh for 30 days longer have been developed by scientists. The breakthrough could apply to other fruit - including bananas - after the chemicals that make it go soft were identified. By suppressing the two enzymes, known as A-Man and B-Hex, which accumulate at critical stages during ripening the researchers were able to extend shelf-life by a month. The phenomenon could be a big boost for farmers everywhere who can lose almost half their harvest because of excessive softening which makes their fruit shrivel up and go rotten before they can get it to the shops. Dr Asis Datta and colleagues used genetic engineering to 'silence the enzymes in tomatoes and showed those lacking A-Man were about two-and-a-half times firmer than conventional counterparts. Ones without B-Hex were twice as hard. Both types of transgenic tomatoes retained their texture and firmness for up to forty-five days compared with conventional ones which started shrinking and softening after fifteen days. The researchers whose findings are published in Proceedings of the National Academy of Sciences said the GM plants grew normally and produced typical amounts of vegetation and fruit which matured at the usual rate. Dr Datta, of the National Institute of Plant Genome Research in New Delhi, said: 'Overall the results demonstrate a substantial improvement in fruit shelf-life. DM Previous efforts have been made to combat the problem by blocking proteins that damage fruit cells but these have met with 'very limited success. Dr Datta said: 'Manipulating the enzymes that alter the speed and duration of ripening may help enhance the shelf-life of tomatoes and, potentially, other fruit. 'In a globalised economy the control of fruit ripening is of strategic importance because excessive softening limits shelf-life. 'Our strategy allows the achievement of desired texture/firmness and enhancement of fruit shelf-life by judicious manipulation without any ill effects. 'The high levels of A-Man and B-Hex activities in the fruits such as papaya, banana, and mango also suggest their potential involvement in the softening of other fruits. 'In conclusion the engineering of plants provides a strategy for crop improvement that can be extended to other important fruit crops. -Daily Mail