Japanese and Colombian scientists have engineered drought-resistant transgenic rice, which is good news in this warming, increasingly crowded world.
The rice strains that were modified with a gene from the Arabidopsis – a common mustard plant – produced more rice than natural strains did when subjected to drought stress, the researchers report in Plant Biotechnology Journal.
Geneticists love working with Arabidopsis, which is small, simple and was the first plant to have its DNA fully sequenced. It has become the go-to model and benchmark for researching plant biology.
In nature, drought conditions lead plants to produce osmoprotectants – molecules that help it retain water. One osmoprotectant in rice is called galactinol, which the plant makes using an enzyme called galactinol synthase.
Japanese scientists had previously demonstrated that when drought-stressed, Arabidopsis produces more of the galactinol synthase enzyme. The scientists then took the gene for galactinol synthase and stuck it into several lines of Brazilian and African rice, creating variants that overexpress this gene. And yes, testing in greenhouses and in the ground showed the plant’s resistance to drought improved.
“This is one of the best model cases in which basic research knowledge has been successfully applied toward researching a resolution to a food-related problem,” stated the team.
In greenhouse conditions, the scientists showed that their engineered Brazilian and African rice variants indeed sported higher levels of galactinol than the unmodified control rice.
The next stage of testing was to grow rice seedlings in earth with artificially created drought-like conditions. “After three weeks, the modified strains had grown taller and showed less leaf-rolling, a common response to drought stress,” wrote the researchers.
Drought tolerance was then confirmed in a series of tests in Colombia, at different locations and during different seasons. The transgenic lines produced greater yields and greater biomass with less leaf-rolling, and sported better fertility than the unmodified rice. Ta da.
A three-year test period in different natural environments again supported the concept: Several if not all of the engineered rice strains produced higher grain yields under mild and severe natural drought, said the team.
Scientists in general, and companies too, have been racing to develop hardier crop plants that will survive in a weather-crazed world. Israel’s Agricultural Research Organization, better known as the Volcani Institute, has been working for well over a decade on developing crops that will not only survive but thrive in hotter conditions. Last year scientists there identified a genetic mechanism that controls temperature sensitivity in the apricot, which they hope to migrate to other species to improve their heat tolerance.
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