Plant, Animal & Microbe Genomes X Conference Plant, Animal & Microbe Genomes X ConferenceJanuary 12-16, 2002
Town & Country Convention Center
San Diego, CA
Workshop: Abiotic Stress
The NSF-supported project on Functional genomics of plant stress tolerance will be reviewed. Abiotic stresses primarily affect plant water relations and may affect ion homeostasis of cells and plants. This requires adjustments in photosynthesis, changes in resource allocation, and stress defense reactions predominantly for the purpose of radical oxygen scavenging. We are tracing plant responses to drought and salinity stresses in three categories. First, we monitor transcripts in cDNA libraries from stressed plants through global expression profiles, which indicate which functional categories are abundantly transcribed after a particular stress and how these profiles change during development. Second, microarray analyses utilizing several halophytic and glycophytic models, from yeast to higher plants (A. thaliana, M. crystallinum, Z. mays, O. sativa and H. vulgare), provides clues as to which transcripts are regulated. In addition, using Arabidopsis as the model, we generate and find mutants that show altered responses to salinity/drought compared to wild type plants. Expression profiles from more than 20 cDNA libraries indicate the complexity and diversity of stress responses in tissues, cells and different developmental stages. Microarray experiments demonstrate that approximately 12-15% of all transcripts in plant species change during a stress episode (stress exerted as a shock, i.e., without any adaptation period). The comparable value for yeast (S. cerevisiae) and other fungi being ~8% of all transcripts Examples for the temporal sequence of salinity and drought stress responses, and either successful adaptation or terminal decline, will be provided for yeast, rice and barley with microarrays that include up to 2000 functionally partially known cDNAs.