Delayed senescence of apple leaves by exogenous melatonin treatment: toward regulating the ascorbate–glutathione cycle
Year: 2011
Type: article
Abstract: The objectives of this study were to test the effects of exogenous melatonin on apple (Malus domestica Borkh. cv. Golden Delicious) leaves and investigate its possible physiological role in delaying leaf senescence. Detached leaves treated with 10 mm melatonin solutions clearly showed a slowing in their process of dark-induced senescence, as evidenced by both biochemical and molecular parameters. Melatonin delayed the normal reduction in chlorophyll content and maximum potential photosystem II efficiency (F(v) /F(m) ). It also suppressed the transcript levels of a key chlorophyll degradation gene, pheide a oxygenase (PAO), and the senescence-associated gene 12 (SAG12). This outcome was thought to be because of the enhanced antioxidant capabilities of melatonin. Indeed, H(2) O(2) accumulation was inhibited by exogenous melatonin, which might have resulted from direct reactive oxygen species scavenging by melatonin and a great enhancement of ascorbate peroxidase (APX; EC 1.11.1.11), which acted on both mRNA and protein activity levels. Melatonin treatment led to the maintenance of higher contents of ascorbic acid (AsA) and glutathione (GSH) but less dehydroascorbate (DHA) and oxidized glutathione (GSSG) compared with the control, possibly through its regulation of the AsA-GSH cycle.
Source: Journal of Pineal Research
Authors: Ping Wang, Lihua Yin, Dong Liang, Chao Li, Fengwang Ma, Zhiyong Yue
Institution: Northwest A&F University
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W1845459243