Plant Ageing, a Counteracting Agent to Xenobiotic Stress

Are Myriophyllum alterniflorum biomarker responses to arsenic stress differentially affected by hydrodynamic conditions?

“…This differential effect of As on older parts could be explained by the increased activity of the enzymatic antioxidant system (superoxide dismutase, ascorbate peroxidase, peroxidase) in younger parts, contributing to ROS limitation in order to protect young tissues from ROS degradation, i.e. a phenomenon previously observed in several species in response to various trace elements (da-Silva et al, 2017;Hasanuzzaman et al, 2015;Delmail and Labrousse, 2012). Another aspect could be the preferential As sequestration in old leaves to protect the younger ones.…”

“…Therefore, the As effect on older parts was greater than on younger ones, especially for chlorophylls a and b. The decrease in photosynthetic pigment contents could be due to: (i) lipid peroxidation by ROS and chloroplast membrane degradation (Upadhyay and Panda, 2009), (ii) chlorophyll degradation by chlorophyllase (Sharma and Dubey, 2005), or (iii) acceleration of a tissue aging process called "senescence" resulting in a decrease in pigment content due to resource remobilization (Delmail and Labrousse, 2012). The stability of the carotenoid contents in the younger parts and their increase in the older parts is reflected by the major role these contents play in defending and protecting the other pigments from oxidative degradation (Ferrat et al, 2003).…”

DNA damage protection, antioxidant and free-radical scavenging activities ofMyriophyllum alterniflorumDC (Haloragaceae) vegetative parts

“…They can act either directly on the ROS biosynthesis or on their oxidative mechanisms (e.g. scavenging) (Delmail and Labrousse 2012). Increasing levels of antioxidants through exogenous supports may decrease pathology effects and evolution.…”

Myriophyllum alterniflorum biochemical changes during in vitro Cu/Cd metal stress: Focusing on cell detoxifying enzymes

“…Reactive oxygen species (ROS) production and scavenging processes are common characteristics of cells. These toxic molecules are derived from successive one-electron reductions of molecular oxygen (O2) and comprise a variety of forms, including superoxide radicals (O2• − ), hydrogen peroxide (H2O2), singlet oxygen ( 1 O2), hydroxyl radical (•OH), perhydroxyl radical (HO2•) and alkoxy radicals (RO•) (Bolwell and Wojtaszek, 1997;Gill and Tuteja, 2010;Delmail and Labrousse, 2012;Mullineaux et al, 2018). Despite their significant role in plant growth and development [by virtue of their use as an oxidant for cell wall crosslinking, cell wall-loosening and as a signaling molecule controlling various biological processes (Kärkönen and Kuchitsu, 2015)], ROS also serve as warning signals tied to intracellular degradation processes in plants.…”