Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2006
Publication Date: 5/24/2006
Citation: Ren, C., Bilyeu, K.D., Valliyodan, B., Nguyen, H.T., Beuselinck, P.R. 2006. Proteomic studies on soybean seed quality as affected by high temperature [abstract]. Interdisciplinary Plant Group (IPG) 23rd Annual Symposium.
Technical Abstract: Long-term high temperature stresses can occur during soybean seed development through maturity and negatively impact seed quality. We investigated soybean seed quality as affected by high temperature using a proteomic approach. The effects of a prolonged high temperature treatment (37/30ºC day/night) were investigated on mature dry seeds harvested from plants grown in environment-controlled chambers. Seeds that developed under the high temperature regime exhibited decreased quality relative to seeds developed under a control temperature regime (27/18ºC day/night). The high temperature regime resulted in smaller seed, a greater proportion of abnormal seeds, and lower germination. High temperature damaged the integrity of cellular membranes as indicated by increased electrolyte leakage. The total fatty acid of mature dry seeds produced in the high temperature regime had increased palmitic (16:0), stearic (18:0) and oleic (18:1) acids and decreased linolenic (18:2) and linolenic (18:3) acids, relative to seeds developed under the control regime. Sucrose and stachyose levels also decreased, but total protein and phytic acid concentration changes were not significant. Proteomic analysis was performed by two-dimensional fluorescent difference gel (DIGE) electrophoresis, trypsin digestion, MALDI-TOF MS fingerprinting, tandem MS/MS sequencing, and database research. From mature dry seeds 20 protein spots were identified as exhibiting changes in accumulation caused by high temperature. Among them, 14 spots were identified as seven subunits of seed storage proteins glycine or -conglycine and the remaining six proteins were identified as those responding to abiotic stresses (sucrose binding protein [SBP], Class III acidic endochitinase, heat shock protein [HSP22], late embryo abundant protein [EM], Bowman-Birk proteinase inhibitor) or having a function during respiration (formate dehydrogenase [FDH]). SBP is associated with cellular membranes and functions in sucrose transportation through the plasma membrane. During germination and post-germinative growth, sucrose not only acts as a major nutrient supply for seedling growth, but also plays an important role as a signal in regulation of seed germination. The decreased SBP and sucrose levels in mature dry seeds derived from high temperature conditions might be determinants of the smaller seed size and reduced seed vigor. Our continuing research is to further investigate SPB gene expression and its interaction with sucrose during soybean seed germination and seedling vigor.