Photosynthetic gas exchange, chlorophyll fluorescence, antioxidant enzymes, and growth responses of Jatropha curcas during soil flooding

Abstract

The response of chlorophyll fluorescence, photosynthetic CO 2 assimilation (PN), stomatal conductance (gs), electrolyte leakage, and transpiration (E) was observed in Jatropha curcas seedlings subjected to soil flooding. A strong reduction in growth, leafarea expansion (64%), and stomatal conductance (45%) impaired photosynthetic CO 2 assimilation (66%), which eventually reduced biomass yield. The ratio between variable-to-initial chlorophyll fluorescence (Fv/Fo) and the maximum quantum yield efficiency of the photosystem II (Fv/Fm) was used to explore damage associated with the functioning of the photosynthetic apparatus. A strong, nonlinear correlation between physiological parameters and soil flooding duration was found. Our study primarily revealed consequences of epigenetics, i.e. stagnant soil flooding, which affected growth, development, and performance of Jatropha curcas significantly. The activities of catalase (CAT), ascorbate peroxidase (APx), glutathione reductase (GR), and glutathione peroxidase (GPx) in leaves increased, implying an integrated pathway involving CAT, APx, GR, and GPx for protection against the detrimental effects of reactive oxygen species (ROS) during soil flooding.

Antioxidant enzymes efficiently control leaf and root cell damage in young Euterpe oleracea plants exposed to waterlogging

“…Plants under waterlogging frequently suffer destruction of the cell membrane that increases membrane permeability and consequently results in electrolyte leakage (Aziz and Larher 1998). Similar results were reported by Verma et al (2014) in case of Jatropha curcas subjected to flooding. Very little increases in hydrogen peroxide content in the leaf and the root under waterlogging condition can be explained by the tolerance of the species to waterlogging (Pereira et al 2014).…”

“…Increase in POX activity can be explained by the fact that waterlogging generates oxidative stress (Verma et al 2014) that causes an overproduction of hydrogen peroxide, which is a POX substrate (Gill and Tuteja 2010). Therefore, this enzyme could be used as an indicator of tolerance to waterlogging in this species.…”

Photosynthetic characteristics of red and green leaves in growing seedlings of Jatropha curcas

“…Photosynthesis is particularly sensitive to water-deficit because the stomata close to conserve water due to stomatal dynamics to sustain the hydric status of the plants (Saibo et al, 2009;Guo et al, 2010). Jatropha plantations are found to be prone to waterlogging (Verma et al, 2012(Verma et al, , 2014 and are vulnerable to drought in planting years. Generally, epigenetic responses such as loss in relative humidity (RH), sharp irradiance, and elevated temperatures affect morphophysiological characteristics by lowering plant efficiency linked with impaired chlorophyll fluorescence, stomatal conductance, and CO 2 diffusion into the intrinsic milieu of the cells for enzymatic CO 2 processing/biological CO 2 fixation.…”

Chilling tolerance of Cicer arietinum lines evaluated by photosystem II and antioxidant activities

“…As a result of the overproduction of ROS, oxidative stress responses such as membrane lipid peroxidation, protein denaturation and aggregation, DNA damage, and enzyme inactivation occur in plants. Plants have evolved many protective defense mechanisms including ROS scavenging systems such as enzymatic antioxidants [superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), and glutathione peroxidase (GPX)] and nonenzymatic antioxidants [ascorbic acid (vitamin C), glutathione (GSH), α-tocopherols (vitamin E), carotenoids, and flavonoids] to mitigate the effects of oxidative stress (Gill and Tuteja, 2010;Baloğlu et al, 2012;Gharari et al, 2014;Verma et al, 2014). Cold acclimation, a phenomenon involving exposure to cool, nonchilling temperatures before chilling, reduces chilling injury to chilling-sensitive plants.…”