Leaf senescence is an active and genetically controlled process characterised by leaf yellowing. It is essential for the remobilisation of cellular components and nutrient cycling and can occur naturally with developmental age or be induced by stressful abiotic conditions. Prolonged darkness is a particularly strong inducer of leaf senescence and this presents a problem within agriculture as many crops are stored in darkness following harvesting and during transportation. Leaf yellowing in crops degrades their nutritional quality and their cosmetic value, leading to increased waste in the food supply chain. High intensity UV-B irradiation has been previously shown to antagonise dark-induced senescence (DIS) in a UVR8-independent manner, but little work has been carried out to investigate the role of low intensity UV-B in DIS. Here, it has been found that a 4 h pre-harvest treatment with low intensity UV-B is sufficient to antagonise DIS in a UVR8 -dependent manner. This treatment did not increase leaf antioxidant content or reduce electrolyte leakage following dark incubation. UVR8-mediated antagonism of DIS is also not strongly dose dependent. This work indicates it may be possible to use short, low intensity UV-B treatments to antagonise DIS in an agricultural setting in order to reduce losses of harvested crops.
The effects of ultraviolet B radiation on dark-induced foliar senescence in Arabidopsis thaliana.
Sweetman, J. M. (Author). 21 Jan 2021
Student thesis: Master's Thesis › Master of Science by Research (MScR)