|Klein, Robert - Bob|
Submitted to: Plant Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/2005
Publication Date: 8/1/2005
Citation: Buchanan, C.D., Lim, S., Salzman, R.A., Kagiampakis, I., Klein, R.R., Pratt, L.H., Cordonnier-Pratt, M.M., Klein, P.E., Mullet, J.E. 2005. Transcriptome analysis of genes induced by ABA high salt, and osmotic stress in Sorghum bicolor. Plant Molecular Biology. 58:690-720. Interpretive Summary: Major advancements in science hinge on the development of new tools including gene microarrays. Microarrays are small glass slides onto which portions of thousands of genes can be spotted. Genes are tiny packets of genetic blueprint material that are found inside the cells of all plants and animals and control all of the physical characteristics of these organisms. Our work focuses on improving major grain crops, and with an understanding how all genes are regulated, the genetic blueprint will be visible and this information can make improving the plants more efficient. This study details the expression of thousands of plant genes and reveals which genes respond to defend plants against biological and environmental stresses. The simultaneous examination of the expression of thousands of genes will permit more efficient identification of defense-response genes, and will improve our understanding of how all genes are regulated in an orchestrated manner. Information will be primarily used by fellow scientists but the work should ultimately result in better adapted, higher producing crop varieties available to American farmers.
Technical Abstract: Genome wide changes in gene expression were monitored in Sorghum bicolor seedlings following exposure to high salinity, osmotic stress or abscisic acid. A sorghum cDNA microarray containing sequences from 12,982 unique gene clusters was used to examine gene expression in roots and shoots at 3 and 27 hours post treatment. Expression of 2,200 genes were altered by abscisisc acid, high salinity or osmotic stress. The modulated genes included novel gene discoveries as well as genes involved in stress signal transduction, transcription/translation, growth/cell walls/cytoskeleton functions, membrane/protein turnover/repair, metabolic/transport functions, dehydration protection, reactive oxygen scavenging, and plant defense mechanisms. Quantitative real time PCR was used to quantify changes in relative mRNA abundance for 337 genes whose expression was responsive to ABA, high salinity or osmotic stress. Analysis of response profiles and the identification of regulons by cluster analysis demonstrated the existence of a complex gene regulatory network that differentially modulates gene expression in a tissue specific manner. Expression of 22 transcription factors were modulated in a complex manner contributing to overlapping and distinct responses of sorghum to abscisic acid, high salinity, and osmotic stress.