Rice epigenetics project could yield hardier crops

Rice is recognised as the world's most important staple crop, as it is a major source of sustenance for some 1.6bn people, the majority of which is grown in China, Japan, Australia, the Philippines, Thailand, Indonesia and Burma. More than 600m people are thought to get more than half of their calories from rice. Given its global importance, rice is a key subject for researchers seeking to ensure food security in the light of threats like changes in climate and growing conditions and pests. The researchers at the University of Delaware, who have received a US$5.3m grant from the National Science Foundation, believe the new technology will help spur this. Their aim is to figure out "where, why and how certain genes are switched on or off in rice". In particular, the team will be looking for chemical modifications in chromatin, from which chromosomes are made, which consists of DNA and proteins that interact with it. They want to know how it is configured, and how changes can affect plant development. Lead researcher Blake Meyers, associate professor of plant and soil sciences, explained that epigenetics refers to a heritable change that is not a result of a change in DNA sequence, but of a chemical modification of nucleotides in the DNA or associated proteins. "That means these changes can be reversible, and it's easier to switch them on or off," he said. The project, which uses technology developed by Solexa, was born out of Meyer's previous work in the same field, and ongoing investigations into the role of short lengths of ribonucleic acids known as small RNAs, which act as gene regulators. Small RNAs are one of the key control switches directing the chemical modifications, Meyers said. Earlier this year researchers from Australia drew attention to the importance of plant genetics and genetic modification for securing the food supply for the future. Professor Mark Tester, a plant genomics researcher at the University of Adelaide's Australian Centre for Plant Functional Genomics and fellow of the Australian Research Council Federation, is working on identifying genes that make some plants more tolerant to hostile environments like drought, salinity and frost. The aim is to use these genes in plants that are suitable for commercial production, using both genetic modification and conventional breeding techniques. So far, laboratory tests "suggest great promise" for the rapid development of crops with increased salt tolerance, Tester reported.