Activity of Stress‐related Antioxidative Enzymes in the Invasive Plant Crofton Weed (Eupatorium adenophorum)

Abstract

Crofton weed is an invasive weed in southwestern China. The activities of several antioxidative enzymes involved in plant protection against oxidative stress were assayed to determine physiological aspects of the crofton weed that might render the plant vulnerable to environmental stress. Stresses imposed on crofton weed were heat (progressively increasing temperatures: 25 °C, 30 °C, 35 °C, 38 °C and 42 °C at 24 h intervals), cold (progressively decreasing temperatures: 25 °C, 20 °C, 15 °C, 10 °C and 5 °C at 24 h intervals), and drought (without watering up to 4 days). The three stresses induced oxidative damage as evidenced by an increase in lipid peroxidation. The effect varied with the stress imposed and the length of exposure. The activity of superoxide dismutase (SOD) increased in response to all stresses but was not significantly different from the controls (P < 0.05) when exposed to cold stress. Catalase (CAT) activity decreased in response to heat and drought stress but increased when exposed to cold conditions. Guaiacol peroxidase (POD) and glutathione reductase (GR) activities increased in response to cold and drought but decreased in response to heat stress. The activity of ascorbate peroxidase (APX) responded differently to all three stresses. Monodehydroascorbate reductase (MDHAR) activity decreased in response to heat and drought, and slightly increased in response to the cold stress but was not significantly different from the controls (P < 0.05). The activity of dehydroascorbate reductase (DHAR) increased in response to all three stresses. Taken together, the co‐ordinate increase of the oxygen‐detoxifying enzymes might be more effective to protect crofton weed from the accumulation of oxygen radicals at low temperatures rather than at high temperatures.

Effect of chilling on photosynthesis and antioxidant enzymes in Hevea brasiliensis Muell. Arg.

“…We hypothesize that the augmentation of the APX, GR, and DHAR activities may not be enough to protect membranes from ROS damages, as the production of MDA and electrolyte leakage were maximal at 96 h. Besides enzyme activity measurements, transcript accumulation was monitored for several isoforms. Difference between enzyme activities and mRNA levels was observed, indicating that the control of the expression of plant antioxidant defenses is complex and operates at several levels (Lu et al 2007). A significant increase in transcript accumulation was observed after 24 h of chilling for APX and GPX, both genes being involved in ROS reduction.…”

Abiotic Stress Tolerance and Sustainable Agriculture: A Functional Genomics Perspective

“…Compared to the parent, drought-exposed hybrid P. densata plants showed a higher activity of MDHAR, elevated AsA, and downregulated DHA content (Gao et al 2009 ). Drought stress-mediated modulation of GR (Lu et al 2007 ) and GPX (Mohammadkhani and Heidari 2007 ;Shehab et al 2010 ) activity has also been reported.…”

“…In "Valenciano," O 3 stress increased DHAR activity, whereas in "Nikita" and "Alisacraig," the same stress did not increase DHAR activity (Marco et al 2008 ). Crofton weed subjected to cold and drought stress showed higher GR activity, and under heat stress, it showed lower GR activity (Lu et al 2007 ). Transgenic Gossypium hirsutum plant overexpressing GR showed chilling stress tolerance and photoprotection (Kornyeyev et al 2003 ).…”

Antioxidant potential of ragweeds: Ambrosia artemisiifolia, A. trifida and Iva xanthifolia

“…(Halliwell and Gutteridge, 2007). Some authors (Davis and Swanson, 2001;Lu et al, 2007) proposed that monitoring antioxidant system of weeds could provide an innovative approach to control their spread by overcoming its inherent resistence to environmental stresses. Identifying the genes that regulate some of the enzymes involved in regulating oxidative stress and finding ways to interfere with gene regulation may prove to be an economically viable way to control persistent perennial weeds in inaccessible locations or along waterways where the use of herbicides is undesirable (Davis and Swanson, 2001).…”