The genetic method can deliver crops that are nutrient-rich, climate-resilient, soil-friendly and resistant to disease and pests
Imagine a variety of rice that’s high in iron, zinc and protein, has a low glycaemic index (safe for diabetics), is pest-resistant and doesn’t need as much water as regular paddy to grow.
Such a ‘super crop’ is currently being created in a laboratory by a team at the Tata Institute for Genetics and Society (TIGS). Called KMP175 (or Daksha) variety of rice, when it is planted in the field a few months from now, it will require 50% less water than regular paddy. Its long root system will provide nourishment from groundwater. At a later stage, it will be fortified with various kinds of nutrients as well.
With climate change and a growing population, food security and nutrition are global concerns today. “We want to reduce the losses farmers face,” says VS Sresty Tavva, principal scientist with the TIGS crop improvement team. “One way is to increase agricultural production by improving yield. Another is to control the diseases and pests affecting the plant. Crop losses can be minimised by developing an inherent resistance mechanism within the plant.”
At a time of dwindling natural resources, finding a variety of rice that needs less water is also important (paddy typically grows in a field submerged in freshwater).
KMP175 has been made possible by genome editing. This involves making specific changes to a plant’s DNA by slightly altering its genetic makeup. This gives the plant the desired properties of a high-yield, low-maintenance crop.
KMP175 — and another ‘mega variety’ that the team is working on — is not entirely lab grown. The crop improvement team works closely with plant breeders who are already cross-fertilising various lines to come up with the hardiest breeds. TIGS takes the best of these and works on them.
“Plant breeders have their standard experiments, which are more sustainable than what we do with this technology,” says Mr Tavva. “The lines we select already have some of the properties we want: one line may have tolerance to drought conditions and another may attract fewer insects. We then combine these lines to create one which has the best of both.”
Save for commercially-cultivated cotton, genetically modified (GM) crops are not used in India. TIGS’s experiments, though they involve genetic modification, are slightly different. “There are millions of nucleotides [basic building blocks] in the DNA of the plant,” says scientist Kamal K Malkuni. “When we do genome editing, we are changing only two-to-five of these. So five nucleotides out of millions means it’s still the same plant; we are not adding any foreign materials, as happens with GM crops.”
“The process starts like GM but the final product will be more like breeding material,” says Mr Tavva. It’s just a normal plant with a small change in its genetic makeup. It’s as good as regular breeding.” But trying to create the desired variety just through breeding may take years and generations of paddy cultivation. Tweaks in the lab accelerate the process.
Another reason for working with breeders is the growing process itself: a plant that seems perfectly healthy in the lab may not survive in the field. That’s why it’s safer to use lines that can be cultivated and harvested, like regular paddy.
The Indian government’s recently-released guidelines will enable the crop improvement team to take their lines to the field by early 2024. If the field tests are successful, the team will approach farmers to convince them to try the new lines. A year or two after that — and subject to government approval — this new paddy can be readied for the market.
The first batch of mega variety and KMP175 will be tested for drought resilience. Subsequent batches will try to be made pest and disease resistant, so that there is no need to spray them with pesticides or even herbicides, making them safer for consumption.
Rice may be the country’s staple, but in its current form it’s far from healthy. “We are giving people starch and sugars,” says Mr Malkuni, who is working on the nutrition enhancement of rice through mutation breeding. “We need to improve the nutrient components, make it more balanced with protein, fibres, etc. This will be especially useful for people who subsist on a bowl of rice a day.”
The idea is to, in the first few rounds of fortification, increase the iron, zinc and protein content and reduce glycaemia. This is a little trickier than genome editing for climate resilience. If you know the genes that endow these properties to the plant, it would be easier to manipulate them. But there are no studies on this, so it’s back to trial and error.
The TIGS team uses a process called mutagenesis, by which hundreds of different varieties of paddy seeds are run through gamma radiation till their genetic makeup is forcibly altered. Since these mutations occur randomly, scientists have to screen a huge number of lines in the seeds to see if any of the changes have resulted in better nutrition composition.
“The lines where we can identify the genes for enhanced nutrient content are the ones we isolate and start working with to enhance these properties,” says Mr Malkuni. A combination of mutations, it is hoped, will lead to a desired trait.
Mutagenesis has yielded 1,500 possible lines of seed that will be screened individually for higher nutritional values. If found, seeds from that line will be planted and replanted many times to see if the preferred traits persist over generations. “Once we get those pure lines we will go in for field tests,” adds Mr Malkuni.
Mutation breeding is the only option for the team at the moment, given that it has not found any existing lines with better nutrition values. But the team is using Sona Masuri, a mega variety rice breed with a low glycaemic index, as their base plant for fortification. “We’re already up one good trait; now we’re trying to add others,” says Mr Tavva.
What ultimately matters, though, is acceptance by farmers and consumers. If the rice looks or tastes even slightly different from the regular fare, consumers will reject it, no matter how many health-related explanations are provided.
“I don’t see any problem with this since we work with breeders who are farmers, and they know what we’re trying to do,” says Mr Tavva. “Also, we are not adding any foreign material to the plant; we are simply making some minor changes to its DNA. It is the same plant with enhanced properties.” The crop improvement team has also started working with millets and certain varieties of pulses and legumes that will improve nitrogen content in soil.
Before being released into the market, TIGS’s crop lines will be submitted for national trials and the central government’s Indian Council of Agricultural Research will check these on parameters such as taste, cooking quality and grain composition.
“The mutations we are working on happen in nature anyway through evolution, but over a long time period,” adds Mr Malkuni. TIGS is merely speeding up the process — and bringing a healthier option to our tables faster.