Boron toxicity is alleviated by hydrogen sulfide in cucumber (Cucumis sativus L.) seedlings

Abstract

Boron (B) is an essential micronutrient for plants, which when occurs in excess in the growth medium, becomes toxic to plants. Rapid inhibition of root elongation is one of the most distinct symptoms of B toxicity. Hydrogen sulfide (H(2)S) is emerging as a potential messenger molecule involved in modulation of physiological processes in plants. In the present study, we investigated the role of H(2)S in B toxicity in cucumber (Cucumis sativus) seedlings. Root elongation was significantly inhibited by exposure of cucumber seedlings to solutions containing 5 mM B. The inhibitory effect of B on root elongation was substantially alleviated by treatment with H(2)S donor sodium hydrosulfide (NaHS). There was an increase in the activity of pectin methylesterase (PME) and up-regulated expression of genes encoding PME (CsPME) and expansin (CsExp) on exposure to high B concentration. The increase in PME activity and up-regulation of expression of CsPME and CsExp induced by high B concentration were markedly reduced in the presence of H(2)S donor. There was a rapid increase in soluble B concentrations in roots on exposure to high concentration B solutions. Treatment with H(2)S donor led to a transient reduction in soluble B concentration in roots such that no differences in soluble B concentrations in roots in the absence and presence of NaHS were found after 8 h exposure to the high concentration B solutions. These findings suggest that increases in activities of PME and expansin may underlie the inhibition of root elongation by toxic B, and that H(2)S plays an ameliorative role in protection of plants from B toxicity by counteracting B-induced up-regulation of cell wall-associated proteins of PME and expansins.

Hydrogen sulfide is involved in the chilling stress response in Vitis vinifera L.

“…Recent studies in plants revealed that H 2 S plays multiple roles in the modulation of various physiological processes [3], such as copper, cadmium, drought, salinity and heat et al [6][7][8][9][10]. In addition, our results indicate that the content of H 2 S was rapidly increased by low temperature.…”

“…Many data indicate that most of the endogenously synthesized H 2 S occurred via L-cysteine desulfhydrase (LCD, EC4.4.1.1) and D-cysteine desulfhydrase (DCD, EC4.4.1.15) in high plants [2][3][4][5]. Recent studies show that H 2 S is involved not only in plant responses to drought and copper stresses but also in tolerance to salinity, heat, cadmium, boron and chromium stresses [6][7][8][9][10]. It is reported that exogenous H 2 S can enhance the resistance of plants to drought stress [11][12][13][14] and copper stress [15,16] by improving the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD).…”

Effect of pretreatment with hydrogen sulfide donor sodium hydrosulfide on heat tolerance in relation to antioxidant system in maize (Zea mays) seedlings

“…In cucumber (Cucumis sativus) seedlings, root elongation was significantly inhibited by exposure of cucumber seedlings to solutions containing 5 mM boron (B), but this inhibitory effect was substantially alleviated by treatment with NaHS, a hydrogen sulfide donor (Wang et al 2010). In addition, under chromium (Cr) stress, the percentage of germination of wheat seeds decreased, but this decrease could be alleviated by pretreatment with NaHS in a dose-dependent manner (Zhang et al 2010a).…”

Signaling in the plant cytosol: cysteine or sulfide?

“…In plants, numerous studies have shown that sulfide increases tolerance/resistance against stress conditions, such as metal stress (Zhang et al 2008 ;Dawood et al 2012 ;Wang et al 2010 ;Sun et al 2013 ;, drought (Jin et al 2011 ), hypoxia (Cheng et al 2013 ), salinity (Christou et al 2013 ;Wang et al 2012 ), and heat . Moreover, sulfide has been also demonstrated to regulate many essential plant processes, like photosynthesis (Chen et al 2011 ), stomatal movement (Garcia-Mata and Lamattina 2010 ;Lisjak et al 2010 ), flower senescence (Zhang et al 2011 ), and postharvest life of fruits (Hu et al 2012 ).…”