Effect of growth regulators on photosynthetic metabolites in cotton under water stress

The contents of several photosynthetic metabolites-3-phosphoglyceric acid (3-PGA), pyruvate, nicotinamide adenine dinucleotide phosphate (NADP) and adenosine triphosphate (ATP)-were determined in leaves of cotton plants (Gossypium hirsutum L. cv. H-777) subjected to waterlogging at vegetative stage, and/or drought at the reproductive stage. In controls. soil moisture contents was kept at field capacity. One day prior to stress, the plant shoots were sprayed with 5 muM aqueous solution of indole-3-acetic acid (IAA), gibberellic acid (GA(3)) benzylaminopurine (BAP), abscisic acid. and ethrel. In control plants, various growth regulators reduced contents of 3-PGA and ATP while increased contents of NADP and pyruvate. During waterlogging IAA promoted 3-PGA content, and BAP enhanced pyruvate content. During drought, GA(3) enhanced ATP and 3-PGA contents, while IAA enhanced pyruvate content.