Lipid Peroxidation and Chlorophyll Fluorescence of Photosystem II Performance during Drought and Heat Stress is Associated with the Antioxidant Capacities of C3 Sunflower and C4 Maize Varieties

Abstract

<jats:p>Agricultural production is predicted to be adversely affected by an increase in drought and heatwaves. Drought and heat damage cellular membranes, such as the thylakoid membranes where photosystem II occurs (PSII). We investigated the chlorophyll fluorescence (ChlF) of PSII, photosynthetic pigments, membrane damage, and the activity of protective antioxidants in drought-tolerant and -sensitive varieties of C3 sunflower and C4 maize grown at 20/25 and 30/35 °C. Drought-tolerant varieties retained PSII electron transport at lower levels of water availability at both temperatures. Drought and heat stress, in combination and isolation, had a more pronounced effect on the ChlF of the C3 species. For phenotyping, the maximum fluorescence was the most effective ChlF measure in characterizing varietal variation in the response of both species to drought and heat. The drought-tolerant sunflower and maize showed lower lipid peroxidation under drought and heat stress. The greater retention of PSII function in the drought-tolerant sunflower and maize at higher temperatures was associated with an increase in the activities of antioxidants (glutathione reductase, superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase), whereas antioxidant activity declined in the drought-sensitive varieties. Antioxidant activity should play a key role in the development of drought- and heat-tolerant crops for future food security.</jats:p>

Eco‐physiological responses of Calamagrostis epigejos L (Roth) and Solidago gigantea Aition to complex environmental stresses in coal‐mine spoil heaps

“…Therefore, malondialdehyde (MDA) a product of polyunsaturated lipids degradation, is a widely used marker of oxidative lipid injury caused by environmental stress. Several studies confirmed the increase of MDA content in plant leaves under different stress conditions (Jbir‐Koubaa et al, 2015; Jin et al, 2010; Killi et al, 2020).…”

Maize Responses Challenged by Drought, Elevated Daytime Temperature and Arthropod Herbivory Stresses: A Physiological, Biochemical and Molecular View

“…suppressing photorespiration (Killi et al, 2017(Killi et al, , 2020. Water scarcity is known to affect the electron transport chain through inhibition of D1 synthesis and damages to the oxygen-evolving complex in the PSII and in the reaction centers of both PSII and PSI (Dalal and Tripathy, 2018;Wang et al, 2018).…”

“…Under thermal stress, photosynthesis in C4 plants shows a greater tolerance than in plants with C3 metabolism, associated with the accumulation of oxaloacetic acid within the bundle sheath cells. This process effectively concentrates CO 2 at the carboxylation site of Rubisco, suppressing photorespiration ( Killi et al, 2017 , 2020 ). Water scarcity is known to affect the electron transport chain through inhibition of D1 synthesis and damages to the oxygen-evolving complex in the PSII and in the reaction centers of both PSII and PSI ( Dalal and Tripathy, 2018 ; Wang et al, 2018 ).…”

“…These responses may also be associated with the disturbance of the integrity and fluidity of thylakoid membranes, and inhibition of electron transfer due to oxidative stress damage in the plant ( Tian et al, 2013 ; Mathur et al, 2014 ; Talaat, 2020 ). Chlorophyll a fluorescence (an indicator of PSII performance) has been used as a quantitative measure of the impact of drought and heat on the functionality of thylakoid membranes in crops ( Sehgal et al, 2017 ; Killi et al, 2020 ).…”

Differential Modulation of Heat-Inducible Genes Across Diverse Genotypes and Molecular Cloning of a sHSP From Pearl Millet [Pennisetum glaucum (L.) R. Br.]

“…Similarly, Usman et al (2018) reported the role of HSP70 in membrane stability in chili pepper. Also, the accumulation of ROS upon heat stress leads to the accumulation of thiobarbituric acid derivatives leading to membrane lipid damages, and subsequently the electrolyte leakage (Killi et al, 2020). The extent of differences observed in HSP70 expression, membrane stability, and lipid peroxidation can be used to improve the thermotolerance capacity of the genotypes.…”