|Luth, Diane - IOWA STATE UNIVERSITY|
|Brummer, E - IOWA STATE UNIVERSITY|
Submitted to: Plant Molecular Biology International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 25, 2000
Publication Date: N/A
Technical Abstract: Alfalfa plants characterized as fall dormant react to changes in day length and temperature during the onset of autumn-like conditions. The premature dormancy results in reduced yields due to growth reduction in late summer and early fall. Fall dormant plants are also slower to resume shoot growth in the spring following harvest in summer. Therefore, breeding alfalfa cultivars with less fall dormancy would be desirable. Dormancy is regulated by the interactions of environmental factors including photoperiod and temperature, the physiological status of the plant, and the plant genotype. The mechanisms controlling dormancy in alfalfa are not well understood, nor are the ensuing effects on winter survival. We have undertaken an RNA profiling approach to study dormancy related gene expression focusing on photoperiod. cDNA libraries were constructed from dormant and nondormant genotypes of Medicago sativa subsp. sativa and falcata grown under dormancy inducing and noninducing photoperiod regimes at a constant temperature. Microarrays will be made from the isolated cDNAs and used to analyze photoperiod induced gene expression in alfalfa genotypes differing in dormancy response. The mRNA populations used to measure transcript abundance include genotypes grown under both natural field and controlled (photoperiod and temperature) conditions. Expression will be determined for different tissue types in the plants. The differentially expressed genes will be mapped and the information from alfalfa used to investigate synteny among photoperiod and dormancy associated genes in soybean and Arabidopsis.