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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: Identification and Manipulation of Postharvest Physiological and Molecular Processes Controlling Potato Nutritional and Market Quality

Location: Sugarbeet and Potato Research

Project Number: 5442-21430-006-00
Project Type: Appropriated

Start Date: Jul 02, 2010
End Date: Jul 01, 2015

Objective:
To determine the normal and molecular processes that control the initiation, maintenance and termination of potato bud dormancy and regulate early sprout growth and tuber wound healing. The specific objectives are as follows: Objective 1: Determine role and metabolic control of cytokinin content and activity during dormancy progression and wound-healing. Sub-Objective 1-1: Clone and characterize genes encoding cytokinin dehydrogenase/oxidase in potato tubers and determine changes in transcript abundances during tuber dormancy. Sub-Objective 1-2: Determine changes in cytokinin content during wound-healing of potato tubers in relation to wound-induced cell division. Objective 2: Determine role of polyamines in tuber dormancy and wound-healing. Sub-Objective 2.1: Quantify changes in free polyamine content and polyamine biosynthetic gene abundances in tuber meristems during dormancy progression and determine physiological significance of these changes in dormancy exit. Sub-Objective 2.2: Quantify changes in polyamine content in tuber parenchyma tissues during wound-healing and determine the role of endogenous polyamines in tuber wound-healing. Objective 3: Determine the effects of heat-sprouting on endogenous hormone levels in tuber meristems. Sub-Objective 3.1: Quantify changes in ABA content and expression of genes encoding key ABA metabolic enzymes in tuber meristems during heat-induced sprouting. Sub-Objective 3.2: Determine changes in gibberellin (GA) content and transcription of GA biosynthetic genes during heat-induced sprouting. Objective 4: Determine effects of pink-eye syndrome on tuber wound-healing and endogenous contents of wound-related hormones. Sub-Objective 4.1: Quantify formation of wound-induced suberin components in tubers developing pink-eye and those that are fully afflicted in relation to non-afflicted tubers. Sub-Objective 4.2: Quantify tuber ABA and JA content in the periderm and cortical parenchyma of tubers developing the pink-eye syndrome in relation to non-afflicted tubers. Sub-objective 4.3: Develop a greenhouse/growth chamber protocol to artificially induce the PE syndrome in a susceptible potato genotype.

Approach:
Identify physiological/biochemical mechanisms that control potato tuber dormancy/sprout growth and wound-healing/skin set. Determine the roles of endogenous hormones in tuber dormancy progression and identify the biochemical and molecular mechanisms governing hormone homeostasis in tubers as related to dormancy. Identify and characterize genes controlling tuber dormancy/sprout growth and wound-healing/skin set. Identify hormones and endogenous elicitor systems initiating and regulating wound-healing in harvest-damaged and cut-seed tubers. Identify physiological processes and discorders adversely affecting tuber wound healing. Project has been classified as "Exempt" by the rating Institutional Biosafety Committee, ltr dated 5-26-2010.

Last Modified: 7/31/2014
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