Abstract
The control of senescence has economic importance due to its effects on parameters such as herbal product quality and shelf life. This study is on the control of induced senescence in Triticum aestivum L. 'Gün-91' plants with silver nitrate (AgNO3) treatments. It was observed that some changes that occurred with dark and indole-1-acetic acid (IAA) treatments could be reduced with AgNO3 treatments. After dark-induced senescence, it was observed in plants that seedling length, relative water content (RWC), chlorophyll, β-carotene, xanthophylls, total antioxidant capacity, soluble phenol, total soluble protein, catalase (CAT), total superoxide dismutase (SOD), copper-zinc superoxide dismutase (Cu/Zn-SOD) activities, and expression of genes encoding these enzymes declined. After IAA treatments, seedling length, RWC, chlorophyll, β-carotene, xanthophylls, total antioxidant capacity, soluble phenolics, and soluble protein levels declined, whereas activities of CAT, total SOD, and Cu/Zn-SOD enzymes and expression of Cu/Zn-SOD and CAT genes increased. AgNO3 (200 mg L-1 ) applied by spraying onto leaves led to an increase in seedling length, RWC, chlorophyll, β-carotene, xanthophylls, total antioxidant capacity, soluble phenolics, soluble protein levels, and expression of Cu/Zn-SOD, CAT genes, CAT, SOD, and Cu/Zn-SOD enzyme activities compared to controls. Findings obtained from this study showed that the senescence process was related to changes in the levels of antioxidant compounds and enzymes. It was defined that the role of silver ions in slowing senescence was related to antioxidant defense capacity.
Highlights
Senescence affects many different agriculturally important properties such as seed count, yield and quality, fruit maturation, seed germination time, and postharvest shelf life (Liebsch and Keech, 2016)
Compared to the seedlings grown in the light as the control group, dark caused a considerable decrease in seedling length
Concentrations of 50 and 100 mg L–1 indole-1-acetic acid (IAA) sprayed onto leaves as a senescence inducer caused an increase in seedling length, while 200 mg L–1 AgNO3 did not cause a significant change in seedling length for seedlings grown in light and 200 mg L–1 AgNO3 treatment caused a significant increase in seedling length for seedlings with darkinduced senescence (P ≤ 0.05)
Summary
Senescence affects many different agriculturally important properties such as seed count, yield and quality, fruit maturation, seed germination time, and postharvest shelf life (Liebsch and Keech, 2016). Senescence leads to a 50% decrease in yield of grains (Gan, 2007). Senescence is defined as the transport of nutrients and minerals in aging tissues to developing tissues of the plant. In this process, expression of genes associated with photosynthesis decreases, whereas expression of genes associated with destruction and transportation of macromolecules increases (Buchanan-Wollaston et al, 2003). Senescence is characterized by visibly yellowed leaves. Yellowing of leaves progresses with several biochemical processes such as loss of chlorophyll content, degradation of proteins and RNA, and decreased photosynthetic activity (Lim et al, 2007; Keles, 2009)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
