ARS | Publication request: DOES HIGH TEMPERATURE REDUCE SEED MASS AND VIGOR IN SOYBEAN BY REPRESSING GENE EXPRESSION FOR SUCROSE BINDING PROTEIN?

Submitted to: Cellular and Molecular Biology of Soybean Biennial Conference
Publication Type: Abstract Only
Publication Acceptance Date: August 11, 2006
Publication Date: N/A

Technical Abstract: Sucrose is the major carbon source that is transported from soybean photosynthetic tissues into developing seed for synthesis of storage reserves, such as protein and oil. Accumulating storage reserves in developing seed determines seed mass and vigor. Sucrose binding protein (SBP) is a vehicle for sucrose transport across plasma membranes. Soybean plants grown in our laboratory under high temperature (37/30°C, day/night) produced mature seed of smaller mass and reduced vigor, relative to mature seeds from soybean plants grown under control temperature conditions (27/18ºC). Proteomic analysis of the mature soybean seed revealed that seed from the high-temperature growth condition exhibited decreased SBP levels. We hypothesize that high temperature represses SBP gene expression and restricts sucrose transport into developing seeds, resulting in mature seed with less mass and reduced seed vigor. To test our hypothesis, we are conducting real time RT-PCR to compare SBP gene expressions in seeds developed on soybean plants grown under control or high temperature conditions. Comparisons include examinations of seed in developing stages (R5-early R8) and mature seed (R8). Varied sucrose concentrations of water-based solutions will test whether seeds impaired by high temperature can have their vigor restored when imbibed in an exogenous sucrose source.