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Author Pudota, Bala Bhaskar
Title Gene silencing based approach to study late blight resistance and cold sweetening in potato
book jacket
Descript 139 p
Note Source: Dissertation Abstracts International, Volume: 71-03, Section: B, page: 1415
Adviser: Jiming Jiang
Thesis (Ph.D.)--The University of Wisconsin - Madison, 2009
RNA Interference (RNAi) is a post-transcriptional gene-silencing phenomenon widely used in plant biotechnology as a precise way to engineer specific reductions in gene expression. I used gene silencing based approach to study the function of several potato genes associated with late blight disease resistance and cold-induced sweetening. (1) Late blight is the most serious potato disease and currently the utilization of late blight resistant varieties is the most cost-effective and environmentally friendly method to control the disease. Previously, transgenic potato lines containing a single RB (Resistance from bulbocastanum) gene showed broad-spectrum resistance to Phytophthora infestans. Several other late blight resistance genes have also been cloned in recent years. However, there is almost no information available about the resistance pathways mediated by any of these genes. In this study, an initial effort has been made to functionally characterize the roles of Rar1 and Sgt1 using RNAi -based silencing. We found that Sgt1, but not Rar1, is essential for RB-mediated resistance. (2) Potato tubers must be stored under low temperatures to prevent sprouting, reduce respiration and minimize disease losses. Unfortunately, cold storage also triggers the accumulation of glucose and fructose; a phenomenon recognized as cold-induced sweetening (CIS). Processing potato chips and fries from tubers that have accumulated high levels of glucose and fructose produce unacceptably brown- to black-pigmented products via a non-enzymatic, Maillard-type reaction. In addition these may have elevated amounts of acrylamide, which can be harmful to human health. There are no commercially acceptable potato varieties available that can be processed directly from cold storage. We have used an RNAi-based approach to control the CIS problem by silencing the potato Vacuolar Invertase (VInv) gene. Tubers harvested from VInv-silenced RNAi lines produced light color potato chips after several months of cold storage and produced chips with low levels of acrylamide
School code: 0262
Host Item Dissertation Abstracts International 71-03B
Subject Agriculture, Plant Culture
0479
Alt Author The University of Wisconsin - Madison
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