Plant, Animal & Microbe Genomes X Conference

January 12-16, 2002
Town & Country Convention Center
San Diego, CA

Poster: Genome Sequencing & ESTs
            

A NON-REDUNDANT COLLECTION OF DEFENSE RESPONSE RICE cDNAS FOR DEVELOPMENT OF MICROARRAYS.

¹ Dept. of Plant Pathology, Kansas State University, Manhattan, KS 66506-5502,USA

² Division of Entomology and Plant Pathology, International Rice Research Institute, DAPO 7777, Metro Manila, The Philippines

Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (Xoo) is an important disease on rice. Rice cultivars IRBB10 and IRBB7 carry Xa10 and Xa7 that confer resistance to Xoo strains with the corresponding avirulence genes respectively. To understand the underlying molecular mechanisms of rice plant responses to Xoo infection, subtractive cDNA libraries for IRBB10 and IRBB7 were constructed by using suppression subtraction hybridization (SSH). Leaves of IRBB10 and IRBB7 were collected for RNA extraction and cDNA synthesis at 4, 8, and 12 hrs after infiltration with Xoo strains carrying the corresponding avirulence genes and control (empty vector). Forward (resistant vs. susceptible) and reverse (susceptible vs. resistance) subtraction of cDNAs were carried out to isolate genes involved in defense responses and disease development. Approximately 350 non-redundant cDNA clones were selected and sequenced. Most of the sequences (90%) have homology with known genes in the public database. These cDNAs include known defense/stress response genes (e.g. rice inducible peroxidase, chitinase), genes involved in signal transduction (e.g. MAP kinase, Pto-like kinase, calcium-dependent protein kinase), gene expression and regulation (e.g. Myb-related protein, EREBP), and rice ESTs. A microarray constructed using the PCR-amplified cDNAs is being evaluated for gene expression profile in rice.