TITLE:
Effect of 1-MCP on Gas Exchange and Carbohydrate Concentrations of the Cotton Flower and Subtending Leaf under Water-Deficit Stress
AUTHORS:
Dimitra A. Loka, Derrick M. Oosterhuis
KEYWORDS:
Cotton; 1-Methylcyclopropene; Ethylene; Water-Deficit Stress; Carbohydrates; Gas Exchange
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.1,
January
31,
2013
ABSTRACT: Ethylene is an endogenous plant hormone that increases under adverse environmental conditions, resulting in leaf and fruit abscission and ultimately yield reduction. In cotton, however, the effects of water-deficit stress on ethylene production have been uncertain. In this study it was hypothesized that application of an ethylene inhibitor 1-Methylcyclo- propene (1-MCP) would prevent ethylene production and result in alleviation of water-deficit stress consequences on the physiology and metabolism of the cotton flower and subtending leaf. To test this hypothesis, growth chamber experiments were conducted in 2009-2010 with treatments consisting of (C) untreated well-watered control, (C + 1MCP) well-watered plus 1-MCP, (WS) untreated water-stressed control, and (WS + 1MCP) water-stressed plus 1-MCP. The plants were subjected to two consecutive drying cycles during flowering, approximately 8 weeks after planting, and 1-MCP was foliar applied at a rate of 10g. ai/ha at the beginning of each drying cycle. The results showed that 1-MCP application had no significant effect on gas exchange functions and did not prevent reductions from water stress in leaf photosynthesis, respiration and stomatal conductance. However, application of 1-MCP resulted in a decrease in sucrose content of water-stressed pistils compared to the control indicating that 1-MCP has the potential to interfere in carbohydrate metabolism of reproductive units.