Root nodule senescence
noun phrasePronunciation: /ˈruːt ˈnɒdjuːl ˌsɛˈnɛsəns/
The programmed degeneration and loss of nitrogen-fixing function in legume root nodules, occurring under stress conditions such as drought, salinity, or nutrient deficiency. This process reduces nodule symbiotic efficiency and nitrogen fixation capacity, directly impacting plant nitrogen nutrition.
Plain English
The aging and death of nitrogen-fixing structures on legume roots, reducing the plant's ability to fix nitrogen from air.
Etymology & History
Usage
"Root nodule senescence in chickpea under drought stress reduced symbiotic nitrogen fixation by 70% within two weeks."
Style guide notes: Specify legume species and stress type causing senescence, as responses vary significantly between species.
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Contrasted with
Related Terms
Frequently Asked Questions
What environmental factors trigger root nodule senescence?
Drought, salinity, low phosphorus, waterlogging, and extreme temperatures all accelerate nodule senescence and functional decline.
Can legumes recover nodule function after senescence?
Limited recovery occurs; new nodules can form under improved conditions, but previously senescent nodules do not regain function.
Why Test Candidates on This?
Relevant for assessing sustainable agriculture impacts and understanding legume productivity under multi-stress field conditions.
Required skill level: Senior