The developing reproductive 'sink' induces oxidative stress to mediate nitrogen mobilization during monocarpic senescence in wheat.
Removal of reproductive 'sink,' i.e., spikelets from wheat, after anthesis delays the rate of flag leaf senescence. Oxidative stress and the oxidative damage to proteins were studied in relation to nitrogen mobilization in wheat plants showing normal and delayed senescence. Wheat plants lacking a reproductive sink showed decreased oxidative stress, lower lipid peroxidation and maintained higher protein, oxidatively damaged proteins, and nitrogen levels as compared to plants with reproductive sink during monocarpic senescence. Oxidative damage to the proteins when not followed by high proteolytic activities led to a slower nitrogen mobilization in wheat plants lacking a reproductive sink. Thus, the influence of the reproductive sink was due to its ability to drive forward the nitrogen mobilization process through high ROS levels which mediated both damage to the proteins and influenced proteolytic activities.
Srivalli
B
B
Stress Physiology Laboratory, Water Technology Centre, Indian Agricultural Research Institute, New Delhi 110 012, India.
Khanna-Chopra
Renu
R
D000375:Aging / Q000502:physiology*; D015227:Lipid Peroxidation; D009584:Nitrogen / Q000378:metabolism*; D018384:Oxidative Stress; D018515:Plant Leaves / Q000502:physiology; D010940:Plant Proteins / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012098:Reproduction / Q000502:physiology*; D014908:Triticum / Q000033:anatomy & histology / Q000502:physiology
D010940:Plant Proteins; D017382:Reactive Oxygen Species; D009584:Nitrogen