No abstract

No abstract

No abstract

No abstract

Cotton (Gossypium hirsutum L.) yield is severely limited by waterlogging in some global production areas. Th e objective was to study physiological and biochemical mechanisms of cotton root recovery aft er waterlogging during diff erent reproductive stages. Cotton plants (cultivar Simian 3) were subjected to waterlogging for 10 d and then permitted to recover for 20 d. Waterlogging signifi cantly reduced root dry matter, root vigor, and net photosynthetic rate (P n ). Aft er the termination of waterlogging, root growth showed a signifi cant recovery. Root dry matter of waterlogged plants increased quickly, but remained 20 to 30% lower than controls. Total N content in waterlogged cotton roots was the same as controls at 20 d aft er waterlogging during the squaring stage, but was signifi cantly lower during the fl owering and boll-forming stage. Th e activities of superoxide dismutase, catalase, and peroxidase in waterlogged plants increased for 10 d aft er waterlogging, then declined slowly. Th e malondialdehyde content in waterlogged roots continued to increase for 5 d aft er waterlogging, then declined to a signifi cantly lower level than the control. Root vigor recovered rapidly aft er waterlogging, and was much higher than the control during the squaring stage, but signifi cantly lower during fl owering and boll-forming stage. P n of waterlogged cotton was suppressed aft er a 10-d recovery period, and remained lower than well-watered controls. Th ese results suggest (i) roots of waterlogged cotton recovered more quickly than shoots, (ii) cotton roots recover better from oxidant damage due to waterlogging during the squaring stage than during the fl owering and boll-forming stage.

An investigation to better understand the molecular mechanism of cotton (Gossypium hirsutum L.) fiber elongation in response to drought stress and recovery was conducted using a comparative proteomics analysis. Cotton plants (cv. NuCOTN 33B) were subjected to water deprivation for 10 days followed by a recovery period (with watering) of 5 days. The temporal changes in total proteins in cotton fibers were examined using 2DE. The results revealed that 163 proteins are significantly drought responsive. MS analysis led to the identification of 132 differentially expressed proteins that include some known as well as some novel drought-responsive proteins. These drought responsive fiber proteins in NuCOTN 33B are associated with a variety of cellular functions, i.e. signal transduction, protein processing, redox homeostasis, cell wall modification, metabolisms of carbon, energy, lipid, lignin, and flavonoid. The results suggest that the enhancement of the perception of drought stress, a new balance of the metabolism of the biosynthesis of cell wall components and cytoskeleton homeostasis plays an important role in the response of cotton fibers to drought stress. Overall, the current study provides an overview of the molecular mechanism of drought response in cotton fiber cells.

No abstract

No abstract