GM tomato gives 45-day shelf life

Genetic marriage

But how soon is soon? That is the bad news: You have to wait for at least a year before you get to taste of the luminous lumpy citrous fruit that will give the same taste and colour to dishes in which they are used.

Tinkering two genes found in perishable fruits and vegetables, scientists at the National Institute of Plant Genome Research here have come out with a genetically modified tomato that retains its texture and firmness for up to 45 days. The findings have been reported on Monday in the Proceedings of the National Academy of Sciences.  

Though it is GM tomato, there may not be fodder for the anti-GM brigade as “it does not have any foreign gene and uses a safe promoter,” team leader and professor of eminence at NIPGR Asis Datta told Deccan Herald.

Datta and his colleagues have identified and cloned two genes – alpha Man and beta Hex – which accumulate in tomatoes at critical stages during the fruit's ripening. Both genes are associated with softening of the fruit leading to post-harvest loss.

The post-harvest loss in India – the world’s second highest producer of fruits and vegetables – accounts for 35-40 per cent of horticulture produce. The softening that accompanies ripening of fruits exacerbates damage during shipping and handling processes.

It plays a key role in determining the cost, because it has a direct impact on palatability, consumer acceptability and shelf life.

The NIPGR scientists used genetic engineering to “silence” the enzymes in tomatoes. The GM tomatoes lacking alpha-Man were approximately 2.5 times firmer than conventional tomatoes and those lacking beta-Hex were two times firmer. Both types of GM tomatoes retained their texture and firmness for up to 45 days, compared with conventional tomatoes, which started shrinking and losing texture after 15 days.

The transgenic tomato plants grew normally and produced typical amounts of vegetation and fruit, which matured at the typical rate.  Datta’s tomato remains stable for a period far longer than GM tomato developed by crop scientists at Indian Agriculture Research Institute here.

Exploiting a different approach, IARI researchers delayed tomato’s ripening by 12-15 days. “That much of delay is good enough for farmers to transport the tomato crop to other markets to avoid glut in one state,” said K C Bansal, the IARI team leader.

Both teams are in the process of approaching the Review Committee on Genetic Manipulation (RCGM) under the department of biotechnology seeking permission for limited field trials.

Once the RCGM approves it, the GM tomato has to be cleared by country’s apex regulatory body – Genetic Engineering Approval Committee under the union environment ministry – before it is commercialised. The entire process can take 3-5 years.

Datta said manipulating the same two enzymes can help increase the shelf life of banana and papaya as well. “But transforming banana and papaya are more technically complicated,” argued Bansal.