Accelerating the Pursuit of Better Rice Plants

Human cultivation of rice dates back more than 7,000 years and rice is now a basic food staple for nearly half the world's population. Around the planet, rice paddies cover more than 10% of all arable land.

Since the 1960s, scientists have been experimenting with ways to boost global production of rice and other cereal grains. Early on, major improvements came from advances in irrigation, chemical fertilization and chemical herbicides and pesticides. The rate of improvement from those efforts has tapered off, however, so the key remaining variable is the plants themselves.

Conventional plant breeding has created some useful hybrids, but it can take 10 or 20 years to assess the impact of cross-breeding, and even then the results are often unpredictable. Biotechnology opens the door to identifying which variations in plant characteristics will allow them to be more productive, nutritious or disease-resistant in various climates and conditions.

Sequencing a model organism

Since 1991, Japan has been a leader in rice genomics. This is a natural role for the nation because rice is both its staple food and its main crop. As part of this effort, Japan's National Institute of Agrobiological Science (NIAS) was created to conduct basic life sciences research on insects, animals and plants (especially rice). As part of Japan's National Rice Genome Project, NIAS participated in the sequencing of the rice genome.

The complete sequence for the subspecies Oryza sativa japonica was published in 2002, making rice the second plant organism to be sequenced. The first was Arabidopsis thaliana, a member of the mustard family that researchers commonly study as a model plant system.

Rice provides another excellent model organism for plant researchers because it has a relatively small genome and a large set of common plant genes. As a member of the grass family, rice is related to corn, wheat, barley, sorghum and sugarcane—the other plants that provide most of the world's food and animal feed. Through this family connection, discoveries made in the rice genome can be potentially applied to other cereal grains.

Providing highly sensitive gene probes

Agilent microarrays are printed on the industry-standard 1" x 3" glass slide format, making them accessible to any lab that has a standard 1" x 3" scanner or the Agilent Microarray Scanner

To help advance this research, Agilent Technologies has worked with NIAS to commercialize the first 60-mer rice oligonucleotide microarray. The Agilent Rice Oligo Microarray includes genetic probes for more than 21,000 genes for Oryza sativa L. ssp japonica (cultivar Nipponbare), a strain cultivated mainly in Japan. This is believed to be about 50 percent of the total rice genome, currently estimated at 40,000 to 50,000 genes.

Researchers can use the rice oligo microarray to study gene activity associated with various plant organ functions, stages of growth, and biotic and abiotic stresses. This will help scientists identify varieties with greater tolerance to drought, salt, cold climate or pests for planting in less arable lands.

Agilent's microarrays are made with 60-mer gene probes that provide industry-leading sensitivity for detecting genes with low expression levels. Validation experiments performed by NIAS showed that microarray results were very clear and reproducibility was very good.

With tools such as the Agilent Rice Oligo Microarray, researchers can accelerate the identification and planting of strains of rice and other cereal plants that will thrive under difficult growing conditions. The possible advances promise to enhance the quality and availability of basic dietary staples for people all around the world.

For more information

To learn more about related solutions from Agilent, please see the Gene Expression and DNA Microarrays & Scanner sections of our website. For additional information about these and other Agilent life sciences products and resources, please visit the Life Sciences/Chemical Analysis main page.