Low Temperature Induced Signaling and Molecular Responses in Tomato

151 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1999.Overnight exposure to chilling in nature can have a long term detrimental effect on chilling-sensitive plants, such as tomato, including a direct effect on photosynthesis. However, plants can regain their photosynthetic efficiency during a recovery period at warm temperature, low light and high humidity. The mechanism by which plants sense the signal of temperature change and eventually show a response remains unknown. A putative model for the temperature signal transduction pathway is proposed, based on the finding of a highly phosphorylated protein (pp34) and two sequentially activated serine/threonine protein kinases during the initial stage of rewarming. By using rubisco activase as a model gene, my study shows that chilling may interfere with the normal expression of photosynthetic genes, by disrupting phosphorylation/dephosphorylation regulatory steps involved in transcription and translation. A diurnal and circadian regulated protein (p35) was purified and its full length cDNA sequence (named dcr) was cloned. Chilling treatment delays the endogenous rhythm of dcr transcripts and that may also associate with interfering specific protein phosphorylation states.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD