Does exogenous glycinebetaine affect antioxidative system of rice seedlings under NaCl treatment?

Up-regulation of antioxidant and glyoxalase systems by exogenous glycinebetaine and proline in mung bean confer tolerance to cadmium stress

“…Our results are also supported by the results of Xu et al (2009) and Islam et al (2010). Similar effects of proline and betaine on CAT activity were also observed in response to various stresses (Demiral and Türkan 2004;Khedr et al 2003).…”

“…However, proline-and betaine-supplemented Cd-stressed seedlings maintained significantly lower H 2 O 2 and MDA levels as compared to the seedlings treated with Cd alone (Fig. 5a & b), suggesting that both proline and betaine protect against Cd-dependent oxidative damage by enhancing antioxidant defense and MG detoxification systems (Demiral and Türkan 2004;Okuma et al 2004;Park et al 2006;Huang et al 2009;Hossain and Fujita 2010). Similar findings have been reported by other researchers demonstrating higher Cd tolerance by in vivo betaine or proline synthesis in plants (Siripornadulsil et al 2002;Shao et al 2008).…”

“…However, proline-and betainesupplemented Cd-stressed seedlings showed a sharp increase in APX activity as compared to control as well as Cd-treated seedlings. Similar effects of proline and betaine on APX activity were also observed in plants in response to various stresses (Ma et al 2006;Demiral and Türkan 2004). These results suggest that both exogenous proline and betaine could contribute in detoxification of H 2 O 2 by enhancing APX activity under Cd stress.…”

Proline and Glycinebetaine Ameliorated NaCl Stress via Scavenging of Hydrogen Peroxide and Methylglyoxal but Not Superoxide or Nitric Oxide in Tobacco Cultured Cells

“…[4][5][6][7] Moreover, proline and betaine provide protection against stress by maintaining redox homeostasis. 8) Under salt stress, exogenous application of proline or betaine upregulates stressprotective proteins, 9) and reduces lipid peroxidation [10][11][12] and protein oxidation. 8) Environmental stress, including salinity, induces the production of hydrogen peroxide (H 2 O 2 ), the superoxide radical (O 2 À ), and nitric oxide (NO) in plant cells.…”

“…18) There is increasing evidence that both proline and betaine increase antioxidant defense mechanisms and improve stress tolerance in plants as well as in cultured cells. 9,10,18,[25][26][27] We have found that exogenous application of both proline and betaine increases intracellular proline and betaine contents, 11) which leads to the suppression of cell death and improvement of salt tolerance in tobacco Bright Yellow-2 (BY-2) cells via increments in the antioxidant defense and MG detoxification systems, 8,12,28,29) but protective mechanisms of proline and betaine in plant responses to salt stress remain to be clarified. The present study was therefore conducted to investigate the effects of exogenous proline and betaine on intracellular H 2 O 2 , O 2 À , NO, and MG levels and the mRNA levels of glutathione peroxidase (GPX) and glyoxalase I genes in tobacco BY-2 cells exposed to salt stress.…”