Mahyco develops new GM crops

India’s Hybrid Seeds Company (Mahyco) is seeking regulatory approvals for field trials in genetically modified (GM) rice and cotton lines that can grow under water-stressed and saline environments, besides requiring less nitrogen fertilisers.

The 700-crore company has developed these new plants using proprietary genes belonging to Arcadia Biosciences, a privately-held agri-biotech firm headquartered in Davis, California.

This is a departure from the past when Mahyco relied on the US life sciences giant Monsanto – which holds 26 per cent in it – for either GM technology or genes.

Mahyco-Monsanto Biotech, a 50:50 joint venture between the two companies, is currently the Indian licensee for Bt cotton incorporating Monsanto’s Bollgard and Bollgard II technology events.

Even in Bt brinjal, where the ‘event’ per se – the process of integrating the foreign gene, including developing protocols and identifying the specific location in the host plant’s genome where the insertion is to happen – was that of Mahyco, the specific ‘cry1Ac’ gene was sourced from Monsanto.

Mahyco has used Monsanto’s cry1Ac gene – isolated from a soil bacteria, Bacillus thuringiensis or Bt – to also develop its own Bt rice and okra.

The cry1Ac gene confers resistance to American bollworm in cotton, fruit-and-shoot borer in brinjal, fruit borer in okra, and yellow stem borer in rice by producing proteins toxic to these insect pests.

Beyond Monsanto

Obtaining genes from multiple sources is part of the company’s efforts to move up the technology value chain, Dr Usha Barwale Zehr, Mahyco’s Chief Technology Officer, told Business Line.

Thus, while being a licensee for Bollgard was the first step, Bt brinjal was the second, and accessing genes from other than Monsanto the third. The next step after that would be to develop the company’s own genes in-house.Mahyco has obtained three genes from Arcadia Biosciences.

The first one is an ‘iso-pentenyl-transferace’ gene derived from Agrobacterium tumefaciens – yet another soil bacterium – which stimulates production of proteins that delay drought-induced senescence or aging of plants. Plants incorporating the gene are able to tolerate water stress and stay green.

“If the normal yield for a cotton hybrid is 10 quintals/acre, which may drop to 4-5 quintals due to poor rains, this technology can help produce 7-8 quintals. We have introduced the gene to develop both drought-resistant rice and cotton lines,” said Dr Zehr.

The second is a ‘sodium proton exchanger’ gene from rice that suppresses flow of salts from the roots to the shoots of plants. This has been used to create ‘cisgenic’ rice – a GM plant where the gene inserted through recombinant DNA technology is from the same species – that can grow even in saline soils.

The third is an ‘alanine-aminotransferace’ gene from barley that can enhance nitrogen uptake and utilisation by plants. Since crops typically absorb barely half of the nitrogen in fertilisers that farmers apply, this gene – Mahyco has incorporated it in cotton lines – could enable them to use less number of bags.

Trial hurdles

“We have conducted greenhouse trials in the lines containing all the three genes. The results are promising, but need replication under field conditions. We have applied to the Genetic Engineering Appraisal Committee for event selection field trials”, informed Dr Zehr.

Event selection tests are carried out in one or two locations to identify candidate lines that can be further tested out in bio-safety research level-1 and 2 (BRL I/BRL II) field trials.

BRL I trials are usually done in one-acre plots at a minimum of two locations/region for two years. This is accompanied by animal feeding and other studies to evaluate toxicity of the GM crops. The BRL II trials that follow are in larger 2.5-acre fields over one growing season.

The Government has currently stopped giving clearances for any field trials, including for event selection.

While Mahyco’s Bt brinjal did not get commercialisation approvals even after completing all field trials and bio-safety studies, its Bt rice and okra haven’t progressed beyond BLR I stage.