Abstract

Biotic and abiotic stresses adversely affect plant growth and improvement. In order to discover new stress-tolerance genes in rice (Oryza sativa L.), we analyzed a global genome expression profiling of the indica cultivar Pei’ai 64S, using Affymetrix rice expression chip, subjected to cold, drought or heat stress. A large number of genes highly up regulated or down regulated were identified under the stresses. One of these genes, O. sativa L. protein phosphatase2C-l (OsPP2C1), was highly induced in leaf and panicle at the heading and flowering stages, in response to all stresses. The expression profile of OsPP2C1 obtained by the microarray analysis was confirmed by quantitative real-time PCR (qRT-PCR). The two sets of data matched very well, suggesting that OsPP2C1 is a multiple stresses responsive gene in rice. In order to study its function in stress tolerance, the cDNA of the gene was cloned by reverse transcription (RT-PCR). Sequence analysis showed that there is 3bp discrepancy between the cDNA of japonica and indica group. Deduced protein from OsPP2C1 cDNA has molecular weight about 37.6 kD and isoelectric points about 6.16. Analysis of the putative promoter regions showed that there were about 10 kinds of stress induced by cis-acting elements. Based on the mentioned analyses and results obtained, we propose that OsPP2C1 is a novel candidate gene involved in stress tolerance in rice. 

Key words: Rice, stress, microarray, real-time PCR, analysis function.