Differential Effects of Cold Stress on the Antioxidant Response of Mycorrhizal and Non-Mycorrhizal Jatropha curcas (L.) Plants

Abstract

Our main objective was to analyze the protection provided by Mycorrhiza (Rhizophagus intraradices) to Jatropha curcas plants under cold stress, through the analysis of physiological and oxidative stress parameters. Mycorrhizal (AM) and non-mycorrhizal (nonAM) plants were exposed to cold stress 4±1 ºC temperature for 72 h. The control plant grow at 25 ±1 ºC. Under cold stress, the stomata conductance decreased both AM and nonAM plants and photosynthetic efficiency only in non AM plants. The CAT activity increased in AM plants independently of stress conditions. GR activity shows a typical rise to cold stress in nonAM plants and decreased in AM ones. With cold stress, the APX activity was reduced in all treatments and SOD activity was not affected in all treatment The MDA content increased in nonAM plants while in AM plants it was unaffected by low temperature. This study reported on the regulation of antioxidant compounds, their relationship to the AM symbiosis and cold stress in Jatropha curcas L.

Cold stress in soybean (Glycine max L.) roots: Exogenous gallic acid promotes water status and increases antioxidant activities

“…In addition to CAT and POX, the AsA-GSH cycle--including APX, DHAR, MDHAR and GR--is part of the first line of defense against the harmful effects of H 2 O 2 (Keunen et al 2013). As shown in Jatropha curcas by Pedranzani et al (2015), APX activity in the current study was rapidly lost under cold stress, which might be due to the low concentration of AsA. It is known that MDHAR and GR are responsible for AsA regeneration and for the reduction of GSSG to GSH using NADPH, respectively.…”

Unraveling the Initial Plant Hormone Signaling, Metabolic Mechanisms and Plant Defense Triggering the Endomycorrhizal Symbiosis Behavior

“…Jasmonate and its derivatives belong to a diverse class of lipid metabolites known as oxylipins (Wasternack, 2007; Mosblech et al, 2009) and are mainly involved in plant responses to biotic and abiotic stresses (Creelman and Mullet, 1997; Wasternack and Hause, 2002). JA is part of a signal transduction pathway activated by plant interaction with microorganisms (Pozo et al, 2004), leaf wounding (Schilmiller and Howe, 2005), and generally by abiotic stress conditions (Pedranzani et al, 2015). JA mediates higher transport rates of photosynthates to the roots (Babst et al, 2005; Schwachtje and Baldwin, 2008; Kaplan, 2012), and this might explain some of the positive effects on AM fungal colonization described below.…”

“…Exogenous application of JA has been shown to enhance AM fungal colonization (Regvar et al, 1996; Tejeda-Sartorius et al, 2008; Kiers et al, 2010; León-Morcillo et al, 2012) or to reduce it (Ludwig-Müller et al, 2002; Vierheilig, 2004; Herrera-Medina et al, 2008; Gutjahr et al, 2015). Repeated wounding or various abiotic stresses induce endogenous JA accumulation, and this was associated with higher AM fungal development (Landgraf et al, 2012; Pedranzani et al, 2015). Tests with various JA concentrations under contrasting P showed a strong dose dependence of the AM fungal response: mycorrhizal colonization is enhanced preferentially at 0.5 mM JA under high P (75 kg P Ha -1 year -1 ) but decreased at 5 mM JA under low P (25 kg P Ha -1 year -1 ; Kiers et al, 2010).…”

Physiological Beneficial Effect of Rhizophagus intraradices Inoculation on Tomato Plant Yield under Water Deficit Conditions

“…AMF, which are obligate biotrophs, receive carbon compounds from the host plant [17], in return they provide water and low mobile nutrients (i.e., phosphorus) to the plant, extending its root depletion zone with their extra-radical hyphae [18,19]. Increased tolerance to abiotic stress (drought, salinity, nutrient deficiency, heavy metals and adverse soil pH) in mycorrhizal plants has been widely described in literature [20][21][22][23][24][25] and some of the underlying mechanisms have been recently investigated [26,27]. In particular, under water-deficient environment, modifications in root architecture induced by AMF (root length, density, diameter and number of lateral roots) [28] are responsible for a more efficient root system both in tree and vegetable crops [29,30].…”