Date of Award
Doctor of Philosophy (PhD)
Biotechnology Science and Engineering
Botrytis cinerea., Pathogenic fungi., Tomatoes., Gene expression.
Botrytis cinerea is a severe plant pathogen that destroys more than 200 crop species worldwide. During early infection, B. cinerea secretes a large store of proteins onto the host surface, many of which cause acute necrosis, senescence, and the loss of cell wall integrity. Recently, cerato-platanin (CP) family member BCSNOD1 was found among fungal secretory products. A subsequent expression profile of B. cinerea-infected strawberry showed the early induction of BCSNOD1 and the CP homologue BCSNOD2. The function of CPs is poorly understood, although evidence suggests a role in plant-pathogen interactions. To characterize CP during B. cinerea infection, the interactions of BCSNOD1 and BCSNOD2 were studied in vitro. The primary objectives were to (a) isolate cerato-platanins in soluble form, (b) assess protein activity on the B. cinerea host Solanum lycopersicum cv Moneymaker (heirloom tomato), and (c) analyze the transcriptome of the BCSNOD-treated tissues. A bacterial expression system was utilized for the isolation, purification, and solubilization of BCSNOD1 and BCSNOD2. Detergent-induced extraction yielded 110-150 mg/L of BCSNOD1 and BCSNOD2, respectively. Application of 50-200 nmol of purified proteins to tomato leaves resulted in severe necrosis within 7 days. For transcription profiling of treated tissues, RNA transcripts were analyzed via next generation sequencing. Both BCSNOD1 and BCSNOD2 show significant regulation of hormonally-induced genes associated with growth, ripening, and defense response. Most notably, BCSNOD2 suppresses the wound-responsive abscisic acid (ABA) signaling genes, while BCSNOD1 is involved with DNA synthesis and transcriptional regulation. These findings demonstrate a significant role for cerato-platanins in B. cinerea pathogenicity.
Caudle, Talitha, "Comprehensive investigation of the transcription profiles of solanum lycopersicum treated with two cerato-platanins from botrytis cinerea" (2013). Dissertations. 3.