CSIRO PLANT INDUSTRY From little things, big things grow Genes are one of the major factors that control grain quality and development traits such as seed size, vigour and quality. Working to control genes, however, is other biological ‘machinery’ that may help to determine very precisely when genes, particularly important regulatory genes, turn on. Researchers at CSIRO Plant Industry are looking at some of this biological machinery, namely ‘micro RNAs’, to determine just what role they play in grain development in cereals. Grain traits Cereal grain quality determines the price of the grain the grower receives and the grain’s end use. It includes the composition of the grain (for example, how much protein it contains), seed size and vigour – all key traits that breeders try and improve in new varieties. Dr Chris Helliwell and his team at CSIRO Plant Industry are leading the way into understanding how micro RNAs influence grain development traits in rice. Grain quality starts when the grain is forming. It is at this point that certain genes Micro RNAs activate to work together to develop the grain and its characteristics. RNA is a close cousin of DNA, but it is a single strand rather than DNA’s well Environmental and external factors, recognised double helix ladder. Micro such as rain and nutrient availability, RNAs are tiny pieces of RNA, will influence the grain quality, but it equivalent to 21-23 rungs on the DNA is the genes that are the underlying double helix ladder. They have been influence that dictate the potential of shown to be precise controllers of the grain quality that can then be where and when important regulatory realised in ideal environmental genes are turned on. conditions. Dr Chris Helliwell and his team of CSIRO Plant Industry scientists will hunt for new micro RNAs in rice then look to see whether they, and other previously identified micro RNAs, are active during grain development. They will then investigate how the Working with rice Produced by CSIRO Plant Industry Communication Group 2007 active micro RNAs in rice grains are acting in grain development – in Rice is the only cereal crop that has particular whether they are controlling had its genome fully sequenced. This any known grain development genes. makes it a really easy crop to do genetic research in, such as hunting It is likely that some of the micro for micro RNAs. RNAs active during grain development are linked to other undiscovered grain The added advantage is that because development genes, so the micro rice is related to other cereal crops RNAs could be a pointer to new genes knowledge gained from research done involved in grain development. in rice will be much more easily transferred across to other cereal crops like wheat. Improved understanding of the role of micro RNAs in grain development in rice could lead to the development of new cereal crops with improved grain quality traits. Understanding the role of micro RNAs in grain development in rice (above) could lead to new cereal varieties, like wheat (below), with improved grain quality traits. For further information contact: CSIRO Enquiries Bag 10 Clayton South VIC 3169 Phone: 1300 363 400 (National local call) +61 3 95452176 (International phone) Fax: +61 3 9545 2175 Email: firstname.lastname@example.org Disclaimer CSIRO gives no warranty and makes no representation that the information contained in this document is suitable for any purpose or is free from error. CSIRO and its officers, employees and agents accept no responsibility for any person acting or relying upon the information contained in this document, and disclaim all liability for any loss, damage, cost or expense incurred by reason of any person using or relying on the information contained in this document or by reason of any error, omission, defect, or mis-statement contained therein.