Temperature extremes represent an important limiting factor to plant growth and productivity. Low concentration of hydrogen sulfide （H2S） has been proven to function in physiological responses to various stresses. T...Temperature extremes represent an important limiting factor to plant growth and productivity. Low concentration of hydrogen sulfide （H2S） has been proven to function in physiological responses to various stresses. The present study evaluated the effect of foliar application of wheat seedlings with a H2S donor, sodium hydrosulfide （NariS）, on the response to acute heat stress. The results showed that pretreatment with NariS could promote heat tolerance of wheat seedlings in a dose-depen- dent manner. Again, it was verified that H2S, rather than other sulfur-containing components or sodion derived from NariS solution, should contribute to the positive role in promoting wheat seedlings against heat stress. To further study antioxidant mechanisms of NariS-induced heat tolerance, superoxide dismutase （SOD, EC 1.15.1.1 ）, catalase （CAT, EC 1.11.1.6） and ascorbate peroxidase （APX, EC 1.11.1.11 ） activities, and HzS, hydrogen peroxide （H2O2）, malonaldehyde （MDA）, and soluble sugar contents in wheat seedlings were determined. The results showed that, under heat stress, the activities of SOD, CAT, and APX, H2S, H2O2, MDA, and soluble sugar contents in NaHS-pretreated seedlings and its control all increased. Meanwhile, NaHS-pretreated seedlings showed higher antioxidant enzymes activities and gene expression levels as well as the H2S and soluble sugar levels, and lower H2O2, MDA contents induced by heat stress. While little effect was detected in antioxidant enzymes activities and soluble substances contents in pretreated wheat seedlings compared with its control under normal culture conditions （data not shown）. All of our results suggested that exogenous NariS could alleviate oxidative damage and improve heat tolerance by regulating the antioxidant system in wheat seedlings under heat stress.展开更多
The surface species transformation of oxidized carrollite processing with NaHS and KBX was investigated.Flotation and contact angle tests indicate that the combination of NaHS and KBX takes a better flotation performa...The surface species transformation of oxidized carrollite processing with NaHS and KBX was investigated.Flotation and contact angle tests indicate that the combination of NaHS and KBX takes a better flotation performance than adding NaHS or KBX alone.Thermodynamic analysis,X-ray photoelectron spectroscopy(XPS) and Fourier transform infrared(FTIR) results confirm the stronger chemisorption of KBX occurs on the oxidized carrollite surface with NaHS,which is beneficial to remove the cobalt oxides,thus contributing to the superior floatability.Interestingly,less elemental sulfur was observed on the carrollite surface as the interaction of NaHS and KBX than adding NaHS alone.It suggests that elemental sulfur is not the main contributor to the restored floatability of oxidized carrollite through sulfidisation.This study provided a new perspective to correlate the surface species with xanthate adsorption and oxidized carrollite flotation through determining the various intermediate products.展开更多
基金supported by the Special Fund for Agro-scientific Research in the Public Interest of China (201203029)
文摘Temperature extremes represent an important limiting factor to plant growth and productivity. Low concentration of hydrogen sulfide （H2S） has been proven to function in physiological responses to various stresses. The present study evaluated the effect of foliar application of wheat seedlings with a H2S donor, sodium hydrosulfide （NariS）, on the response to acute heat stress. The results showed that pretreatment with NariS could promote heat tolerance of wheat seedlings in a dose-depen- dent manner. Again, it was verified that H2S, rather than other sulfur-containing components or sodion derived from NariS solution, should contribute to the positive role in promoting wheat seedlings against heat stress. To further study antioxidant mechanisms of NariS-induced heat tolerance, superoxide dismutase （SOD, EC 1.15.1.1 ）, catalase （CAT, EC 1.11.1.6） and ascorbate peroxidase （APX, EC 1.11.1.11 ） activities, and HzS, hydrogen peroxide （H2O2）, malonaldehyde （MDA）, and soluble sugar contents in wheat seedlings were determined. The results showed that, under heat stress, the activities of SOD, CAT, and APX, H2S, H2O2, MDA, and soluble sugar contents in NaHS-pretreated seedlings and its control all increased. Meanwhile, NaHS-pretreated seedlings showed higher antioxidant enzymes activities and gene expression levels as well as the H2S and soluble sugar levels, and lower H2O2, MDA contents induced by heat stress. While little effect was detected in antioxidant enzymes activities and soluble substances contents in pretreated wheat seedlings compared with its control under normal culture conditions （data not shown）. All of our results suggested that exogenous NariS could alleviate oxidative damage and improve heat tolerance by regulating the antioxidant system in wheat seedlings under heat stress.
基金supported by the Innovation Academy for Green Manufacture, Chinese Academy of Sciences (IAGM-2019A08)。
文摘The surface species transformation of oxidized carrollite processing with NaHS and KBX was investigated.Flotation and contact angle tests indicate that the combination of NaHS and KBX takes a better flotation performance than adding NaHS or KBX alone.Thermodynamic analysis,X-ray photoelectron spectroscopy(XPS) and Fourier transform infrared(FTIR) results confirm the stronger chemisorption of KBX occurs on the oxidized carrollite surface with NaHS,which is beneficial to remove the cobalt oxides,thus contributing to the superior floatability.Interestingly,less elemental sulfur was observed on the carrollite surface as the interaction of NaHS and KBX than adding NaHS alone.It suggests that elemental sulfur is not the main contributor to the restored floatability of oxidized carrollite through sulfidisation.This study provided a new perspective to correlate the surface species with xanthate adsorption and oxidized carrollite flotation through determining the various intermediate products.
