|DE LOS REYES, BENILDO|
|VARMA, T S N|
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2003
Publication Date: 10/1/2003
Citation: DE LOS REYES, B.G., MORSY, M., GIBBONS, J., VARMA, T., ANTOINE, W., MCGRATH, J.M., HALGREN, R., REDUS, M.A. A SNAPSHOT OF THE LOW TEMPERATURE STRESS TRANSCRIPTOME OF DEVELOPING RICE SEEDLINGS (ORYZA SATIVA L.) VIA ESTS FROM SUBTRACTED CDNA LIBRARY. THEORETICAL AND APPLIED GENETICS. 2003. v. 107(6). p. 1071-1082.
Interpretive Summary: Rice is sensitive to chilling temperatures during germination and crop establishment. Chilling temperatures during crop establishment result in severe injury, poor seedling vigor, and crop failure, limiting growth of the crop to warm regions. Genetic variation exists for chilling tolerance within the subspecies japonica, however the basis for chilling tolerance is not known. Using one chilling tolerant rice cultivar, seeds were germinated and seedlings were grown at chilling temperatures and compared with those grown at non-chilling temperatures. Analyses of gene expression demonstrated a host of biological responses to chilling stress in this tropical grass species, some of which mimic cold temperature responses of temperate crops. This information will lead to a better scientific understanding of biological mechanisms of how crop plants can ameliorate low temperature injury, and provides additional tools in the form of Expressed Sequence Tags by which scientists can unravel the complex responses of crop plants to environmental changes.
Technical Abstract: Rice (Oryza sativa L.) is sensitive to chilling particularly during early seedling development. Given the biochemical complexity of tolerance mechanisms, genetic potential for this trait depends on highly coordinated expression of many genes. We used a simple cDNA subtraction strategy to develop ESTs that represent an important subset of cold stress-upregulated genes. The 3,084 subtracted cDNA clones represent a total of 1,967 unigenes from 1,354 singletons and 613 contigs. As expected in developing seedlings, genes involved in basic cellular processes, i.e., metabolism, growth and development, protein synthesis, folding and destination, cellular transport, cell division and DNA replication were widely represented. Genes with stress-related and regulatory functions comprised 23.17% of the total ESTs. These categories included proteins with known function in cellular defenses against abiotic (drought cold, and salinity) and biotic (pathogen) stresseses and proteins involved in developmental and stress response signaling and transcription. Based on the types of genes represented, tolerance mechanisms rely on precise integration of developmental processes with stress-related responses. A large fraction of the ESTs (38.7%) represents unknown proteins. This EST library is a rich source of cold stress-related genes and supplements other publicly available libraries for comprehensive analysis of the stress response transcriptome.