The world's no. 1 food crop is now completely sequenced

World agriculture gets a major boost with the completion of the rice genome sequence. A detailed analysis of the high-quality sequence of the rice genome is featured in the August 11 issue of the journalNature 436: 793-800. The paper provides an overview of the structure and function of the genes that defines the rice plant, and provides clues on how the sequence can be useful to accelerate the improvement of rice.

Rice is the most important food source for half the world's population. It is the first crop plant to be sequenced and will therefore have a great impact in agriculture. The accurate, map based sequence has already led to the identification of genes responsible for agronomically important traits such as genes that affect growth habit to promote yield and photoperiod genes to extend the range of elite cultivars. This could probably provide the key in improving yield to feed an expanding world population at a time of increasing restraints on agriculture.

The genome sequence identifies 37,544 genes many of which are represented by 2 or more copies. About 71% of these genes are similar to genes found in Arabidopsis, a model experimental dicot plant which has been completely sequenced in 2000. A total of 2,859 rice genes however could not be found in Arabidopsis and may represent genes which differentiate the two major groups of flowering plants, monocot and dicot.

The information on the gene models referred in Nature publication are electronically accessible from our website (

This is one of the most accurate and complete sequences from a higher organism. The sequence was obtained through the clone-by-clone sequencing strategy. The accuracy of the sequence data is maintained at 99.99% corresponding to less than one error per 10,000 bases so that the reliability of identified genes is also high. Previously published draft sequences of rice are shown to lack the coverage and accuracy required to identify important genes.

The genetic information of rice will be useful in understanding the genome of other crops in the grass family including corn, wheat, barley, rye and sorghum, all of which share a common ancestor with rice. As a consequence, the arrangement of genes is similar among these crops. However although rice has a genome of about 390 million bases, corn and wheat genomes contain 2 billion and 16 billion bases, respectively. Therefore the genome information of rice could be used in elucidating the genome structure and finding target genes in these larger genomes.

The sequencing was accomplished by a consortium of publicly funded laboratories from10 countries and regions, which comprise the International Rice Genome Sequencing Project (IRGSP). Japan through the Rice Genome Research Program (RGP), a joint collaboration of the National Institute of Agrobiological Sciences (NIAS) and the Institute of the Society for Techno-innovation of Agriculture, Forestry and Fisheries (STAFF), is in-charge of sequencing chromosomes 1, 2, 6, 7, 8 and 9, which correspond to almost half of the genome. The US groups, which comprise of the ACWW Consortium representing the University of Arizona, Cold Spring Harbor Laboratory, Washington University and the University of Wisconsin-Madison, The Institute for Genome Research (TIGR) and Plant Genome Center at Rutgers (PGIR), are in-charge of sequencing chromosomes 3, 10 and 11. China through the National Center for Gene Research of the Chinese Academy of Sciences is in-charge of chromosome 4. Taiwan is in-charge of chromosome 5 through the Academia Sinica Plant Genome Center. France through Genoscope is in-charge of chromosome 12 and a duplicated region in chromosome 11. Other participating groups include the Korea Rice Genome Research Program (KRGRP), the Indian Initiative for Rice Genome Sequencing (IIRGS), the National Center for Genetic Engineering and Biotechnology (BIOTEC) in Thailand, the Brazilian Rice Genome Initiative (BRIGI) and the John Innes Center in UK. These groups are involved in sequencing specific regions in chromosomes 1, 2, 9 and 11. Originally planned as a 10-year project, the sequence was completed in six years based on the principles of sharing materials, data, and technology. The contribution of two private companies namely, Monsanto and Syngenta also facilitates the early completion of the sequence.

Press release from IRGSP members

Brookhaven National Laboratory



Science. 2005 Aug 12;309(5737):997.
EL COLOMBIANO (pdf)) (Spanish)

last updated 2005.8.31 
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