Glycinebetaine improves salt tolerance in vinal (Prosopis ruscifolia Griesbach) seedlings

Abstract

Glycinebetaine (GB) is a very important organic osmolyte that accumulates in a number of diverse groups of plants in response to environmental stress. In some plants, increased resistance to drought, salinity and low temperature has been achieved through exogenous application of GB. In this study, the effect of exogenously applied GB (8 mM) on the ability of vinal (Prosopis ruscifolia G.) plants to withstand NaCl stress was investigated. The dry biomass of vinal showed a decrease under salt stress, but in GBtreated plants exposed to the same stress, this reduction was mitigated. Sodium accumulated in the leaves of plants grown under saline conditions, but the addition of GB to salt-grown plants reduced Na + content by 40%. Salinity significantly reduced the K + concentration in leaves to 65% that of non-salinized controls. In the presence of GB, leaf K + was comparatively higher, reaching as much as 90% of the control concentration. The sodium: potassium ratio in leaves was significantly higher in salt-stressed plants, but this ratio was lowered significantly by the addition of GB. When compared to control plants, NaCl stress increased malondialdehyde (MDA) concentrations by 95%, but GB application reduced the MDA concentration in these same NaCl-treated plants. In comparison to control plants, the activity of superoxide dismutase (SOD) increased by 52% in salt-stressed plants. The addition of GB to salttreated plants stimulated SOD activity twice that of the non-salizined control. These results suggest that, in addition to protecting membranes, GB-enhanced salinity tolerance in vinal may involve an antioxidant mechanism involving enhanced SOD activity and improving the ion homeostasis under conditions of high salinity.Key words: lipid peroxidation, salt stress, superoxide dismutase. resUMo glycinabetaine incrementa a tolerância a estresse salino em plântulas de vinal (Prosopis ruscifolia griesbach): Glycinabetaína (GB) é um dos osmólitos orgânicos mais importantes que se acumulam em diversas plantas em resposta a estresses ambientais. Em algumas espécies, o aumento a resistência à seca, salinidade ou baixa temperatura foram conseguidos pela aplicação exógena da GB. Neste estudo foi investigado o efeito de GB aplicado exogenamente (8 mM) na habilidade do vinal (Prosopis ruscifolia Griesbach) para suportar o estresse salino induzido por NaCl. A biomassa seca das plantas diminuiu por efeito do tratamento salino, mas aumentou em plantas tratadas com GB. O Sódio (Na + ) acumulou-se nas folhas das plantas crescidas sob estresse salino, mas a adição do GB às plantas tratadas com NaCl provocou uma diminuição de 40% no conteúdo de Na + . Em comparação às plantas controle, nas plantas tratadas com NaCl observou-se uma redução de 65% no conteúdo de potássio (K + ). Na presença do GB, a concentração de K + nas plantas sob estresse salino foi maior que nas plantas não tratadas com GB. A relação sódio: potássio aumentou significativamente Braz. J. Plant Physiol., 21(3): 233-241, 2009 234 DIEGO A. MELONI and CARLOS A....

Effect of sodium carbonate-induced salinity–alkalinity on some key osmoprotectants, protein profile, antioxidant enzymes, and lipid peroxidation in two mulberry (Morus alba L.) cultivars

“…Salvadora persica (Ramoliya et al 2004), Olea europea (Chartzoulakis et al 2002), and Simmondsia chinesis (Roussos et al 2006). However, growth inhibition in a plant due to salt or alkali stress could occur due to regulation of a multitude of physiological and biochemical processes such as water relations (Munns 2002;Meloni & Martinez 2009;Ahmad et al 2012b), ion transport and accumulation (Hasegawa et al 2000), photosynthesis (Dubey 2005;Ashraf et al 2008), accumulation of osmoprotectants (Ashraf & Foolad 2007;Koyro et al 2012;Katare et al 2012), synthesis of antioxidant enzymatic and nonenzymatic molecules (Mittler 2002;Patade et al 2011;Bano et al 2013;Kaya et al 2013;Rasool et al 2013), synthesis of plant growth regulators (Ashraf et al 2010), mineral nutrient metabolism (Marschner 1995), and many others. One of the most important biochemical responses of plants to abiotic stresses is overproduction of different types of compatible solutes such as proline, glycine betaine, sugars, soluble proteins, amino acids, etc.…”

Exogenous Glycine Betaine Ameliorates the Adverse Effect of Salt Stress on Perennial Ryegrass

“…Exogenous GB alleviated the inhibitory effect of salt stress, whereas it inhibited the plant vertical growth under non-salinity conditions. It seems that addition of GB alone slightly affects the growth and the protective effect of GB is apparent only under conditions of salt stress (Meloni and Martínez, 2009). Water status is highly sensitive to salinity and therefore is dominant in determining the plant responses to stress (Stepien and Klobus, 2006).…”

“…These results suggested that GB alleviated lipid peroxidation and facilitated the maintenance of membrane functions under salinity conditions. This facilitation could be attributed to the GB-induced antioxidant responses that protect the plant from oxidative damage (Hoque et al, 2007;Meloni and Martínez, 2009).…”

Coordinate induction of antioxidant defense and glyoxalase system by exogenous proline and glycinebetaine is correlated with salt tolerance in mung bean

“…Apart from their osmoprotective roles, both proline and betaine contribute to scavenging free radicals and buffering cellular redox potential and stabilize many functional units such as the complex II electron transport, membranes and proteins under stressful conditions (McNeil et al, 2001;Molinari et al, 2004). Higher antioxidative enzyme activities in stress conditions either by in vivo proline or betaine synthesis or by exogenous application have also been shown to improve salt stress tolerance (Hoque et al, 2007;Raza et al, 2007;Huang et al, 2009;Ahmad et al, 2010b;Meloni and Martinez, 2010). To our knowledge, there is currently no information available on the possible beneficial effects of exogenous proline or betaine in AsA-GSH cycle in mung bean seedlings grown under salinity conditions.…”