Table 1.

Examples of oxidative stress in plants under various environmental stresses.

Plant Species	Stress Levels	Oxidative Stress Indicators	Reference
Drought
Lolium perenne L.	Drought stress, withholding irrigation, 45 d	Increased EL.	[171]
		MDA and H2O2 content increased.
Lens culinaris Medik. cv. JL-3	Seedlings were exposed to dry air for 4 h, 3 d	Reduced membrane stability index by 57%. MDA content increased by 36%.	[77]
Arabidopsis thaliana L.	Drought stress (300 mM d-mannitol), 10 d	Accelerated oxidative stress through elevated ROS generation.	[172]
Brassica napus L.	Water deficit (60% FC), 21 d	The LPO product MDA is markedly enhanced.	[173]
		H2O2 contents remained unchanged.
Olea europaea L.	Water deficit condition by withholding water, 20 d	Increased cell membrane permeability.	[174]
Oryza sativa L.	Osmotic stress (15% followed by 20% PEG), 7 d	Higher accumulation of O2•−.	[71]
		Increased LPO as well as TBARS content.
Salinity
Triticum aestivum L.	NaCl (150 mM), 7 d	The H2O2 content increased by 41%, while MDA content increased by 61% in the salt-tolerant cultivar.	[80]
		The H2O2 content increased by 230% and MDA content increased by 90% in the salt-sensitive cultivar.
Zea mays L.	NaCl stress; 75 mM (mild) and 150 mM (severe), 3 weeks	Mild and severe stress resulted in a 1.5- and 3-folds increase in H2O2 in roots.	[79]
		EL and MDA contents also increased similarly.
L. culinaris Medik.	NaCl (100 mM), 3 d	Enhanced H2O2 and MDA and content by 37 and 139%, respectively, compared to control.	[175]
Metals/Metalloids Toxicity
Pisum sativum L.	NiCl2 (100 µM), 3 d	Higher content of MDA by almost 4.5-fold and H2O2 by 7-fold.	[90]
Withania somnifera L.	Cadmium sulphate (5, 10, 20, 50, 100, 150, 200 and 300 μM)	Increased MDA content by 2.4-fold at 10 μM cadmium sulfate.	[176]
		Total ROS, H2O2, O2•− and •OH radicals were maximum at 100 μM dose by about 2.1–3.0 -fold than control.
O. sativa L.	CdCl2 (2.0 mM), 72 h	Higher MDA and H2O2 accumulation by 124 and 19%, respectively.	[177]
		LOX activity increased by 114% while shoot EL was 391% higher.
Morus alba L.	PbCl2 and CdCl2 (100 and 200 μM)	Higher accumulation of H2O2, O2•−, MDA and EL were comparably higher intensity in all these under Cd stress than Pb.	[14]
Cucumis sativus L. cv. Jingyan-4	Cu2+ (80 mM as CuSO4), 14 d	Elevation in O2•−, H2O2, and •OH accumulation with a higher MDA level.	[178]
High Temperature
Gossypium hirsutum L. (84-S and M-503)	30–45 °C, 7 d	MDA content increased by 79% in 84-S and did not change in M-503.	[179]
Portulaca oleracea L.	42 °C, 7 d	Increased O2•−, EL, and MDA contents by 2.4, 3.84-fold, and 23%, respectively.	[102]
C. sativus L.	35 ± 1 °C, 7 d	Increased MDA content (60.6%) and O2•− (79.9%).	[180]
Nicotiana tabacum cv. Bright-Yellow 2	50 °C, 5 min	Increased O2•− by 50%.	[181]
		Increased MDA and H2O2 contents.
Low Temperature
O. sativa cv. Nipponbare and 93–11	2 ± 1 °C, 10, 33, 57 h	H2O2 (brown spots of histochemical analysis of H2O2) increased.	[106]
Calendula officinalis L.	4 °C for 24, 48, 72, 96 and 120 h	Elevated MDA content (16.79%) and EL (11.78%).	[110]
O. sativa cv. Taiwan	15 °C for 4 d	Higher levels of H2O2 along with MDA in roots decreased the growth rate	[111]
Prunus armenica L.	Freezing stress (−3 and −1 °C), 30 min	Increased LPO level, H2O2 content, and ion leakage percentage	[182]
Waterlogging/Flooding
Z. mays L.	Waterlogging, 14 d	Accumulation of MDA, H2O2, O2•− and •OH was increased in WL treatment.	[119]
P.persica L. Batsch	Waterlogging, 72 h	H2O2, O2•− accumulation, and cell death intensity increased compared to control plants.	[183]
G. max L.	Waterlogging, 10 d	Increased H2O2, O2•− and MDA contents.	[184]
P. mahaleb P. pseudocerasus, P. cerasus × P. canescens	Waterlogging, 24 h	Increased MDA, H2O2, and O2•− accumulation. P. mahaleb accumulated much higher MDA, H2O2, and O2•− than the other two.	[185]
		About 2.2, 7.2, and 1.5-fold higher MDA, H2O2, and O2•− contents were noticed in stressed P. mahaleb than control.
C. sativus L.	Waterlogging, 96 h	Increased H2O2 and O2•− accumulation.	[186]
High Light
A. thaliana L.	1000 µmol photons m−2 s−1, 2 d	1O2 and H2O2 increased.	[187]
O. sativa L.	1400–1600 µmol photons m−2 s−1, 1 h	Increase of O2•− and H2O2 in midvein by 1.23 and 1.72-fold, respectively.	[188]
		NADPH/NADP+ ratio (2.19-fold) also found higher in midvein.
Coffea arabica L.	1000 µmol photons m−2 s−1, 12 months	NADPH/NADP+ ratio (0.6-fold) lower in HL than low light (1.1 to 1.2-fold).	[135]
Solanumlycopersicum L.	500, 1000 µmol photons m−2 s−1, 5 d	MDA and H2O2 contents progressively increased by 90 and 83%, respectively.	[189]
UV-Radiation
T. aestivum L.	UV-B radiation of 8.6 kJ m−2 d−1 at 12th and 14th day after emergence	The rate of O2•− generation increased by 127%, and the contents of MDA and H2O2 increased by 64 and 44%, respectively.	[129]
O. europaea L. cv. Galega Vulgar	UV-B radiation of 6.5 kJ m−2 d−1 (UV-B1) and 12.4 kJ m−2 d−1 (UV-B2) for 5 d	Almost similar H2O2 contents with a free radical scavenging capacity—ABTS being higher than the control (UV-B1: 23.5% and UV-B2: 21.7%).	[190]
Elevated Ozone
G. max L.	80 ppb, 6 h d−1 for 5 d	TBARS content was higher in saplings of Tracajá cultivar of soybean than in Sambaíba.	[191]
		Plants of both cultivars showed a 2-fold increase in TBARS content than plants maintained under filtered air.
S.tuberosum L.	70 ppb O3; 3 months	MDA and H2O2 increased by 2-fold and 1.5-fold, respectively, at 60 d after emergence.	[192]
N. tabacum L. G. max L., and Populus tremula L.	96, 74, and 64 ppb	Increase of MDA content by 97.0, 65.3, and 63.4, respectively in tobacco, soybean, and poplar, respectively.	[193]
		Increased O2•− content in poplar (by 18.4%), tobacco (by 18.8%), and soybean (by 45.6%).
		Increased H2O2 content of tobacco and soybean by 26.2 and 82.0%, respectively, whereas had no effect on poplar.
O. sativa L.	70–150 ppb for 10 d	Increased MDA content, compared to control.	[194]
T. aestivum L.	59.6 ppb; 122 d	MDA content increased in HD2967.	[195]
Acidity and Alkalinity
O. sativa L.	Simulated acid rain stress (pH 2.0 or 3.0, 4.0)	The H2O2 content in the root increased with the decrease of the pH (3.0 or 2.0).	[196]
		Decreased antioxidant enzyme activities. Increased cellular damages.
S. lycopersicum L. cv. Micro-Tom	Simulated acid rain stress (pH 2.5 and 5.6), 17 d	Overaccumulation of ROS.	[197]
		Damaged grana lamella of the chloroplast.
		Increase of MDA and H2O2 contents by 63 and 45%, respectively, compared to control.
Medicago sativa L. cv. Gongnong No. 1	Alkaline stress (25 mM Na2CO3, pH 11.2), 48 h	Increased accumulation of ROS as well as increased oxidative damage.	[145]
		Increased cell membrane injury by 463%. Enhanced MDA content by 57%.
Z. mays L.	Alkaline stress (100 mM and 150 mM Na2CO3 solution), 10 d	The H2O2 production increased considerably by 96 and 154% with 100 and 150 mM Na2CO3 treatments, respectively.	[198]
		Amplified LOX activity by 99 and 167%, in both alkaline stresses, respectively.
B. oleracea L. cv ‘Bronco’	Alkaline stress (50 mM NaHCO3: Na2CO3), pH 9, 25 d	Greater contents of MDA and higher LOX activity.	[199]
		Increased level of ROS specially amplified O2•− content.
O. sativa L.	Simulated acid rain (SAR) stress (pH 5.5, 5.0, 4.5, 4.0, 3.5, 3.0 or 2.5), 5 d	Overaccumulation of ROS exceeded the scavenging ability of the antioxidant enzymes.	[200]
		Disrupted membrane permeability.
		Elevated level of H2O2, O2•− and MDA, contents by 107, 155 and 187% respectively, were found under the acid rain stress (pH 2.5) over the control.
Herbicides Toxicity
Hordeum vulgare L.	Glyphosate (6 mM)	Increased lipid peroxidation (MDA; 45% in leaves and 104% in roots) and H2O2 (82% in leaves and 123% in roots), and O2•− generation.	[162]
Salvinia natans L.	Glyphosate (0.006, 0.03, 0.15, 0.3 and 0.45 mM)	Enhanced MDA and H2O2 production.	[201]
S. lycopersicum L.	Glyphosate (2, 4 and 6 mM)	Higher H2O2 (40%), and O2•− (100%) contents in root at maximum concentration.	[6]
B. napus L.	Paraquat (62.5, 125 and 250 mM)	Increased lipid peroxidation (MDA; 24, 71, and 85%), ROS generation (H2O2; 30, 90, and 134% and O2•−; 28, 59, and 82%) and LOX activity (69, 167, and 234%).	[164]
Cucurbita spp.	Paraquat (0.05, 0.1, 0.2, 0.3 and 0.5 mM)	Increased cellular leakage and MDA production.	[202]
N. tabacum cv. oriental	Imazapic (0.03, 0.06 and 0.12 mM)	Increased MDA content.	[203]
Eupatorium adenophorum	Picloram (0.1, 0.2, 0.5, 1.0 and 2.0 mM)	Increased EL (32, 36, 42, 43, and 44%) and MDA content (2.23, 2.27, 2.62, 2.71, and 2.93 times).	[163]