硫化氢在植物中抵御非生物胁迫机制的研究进展

植物在生长发育过程中不可避免地受到各种生物或非生物胁迫。硫化氢(H2S)作为一种细胞信号分子，在植物体抵御冷热、重金属、盐、干旱等各种非生物逆境胁迫及与其他信号物质的互作等方面发挥重要作用。综述了H2S在植物体中通过基因调控、改变酶活性和蛋白质的表达、硫巯基化修饰、减轻氧化应激、与信号物质的互作等抵御非生物胁迫的作用机制，并展望了H2S在植物体中抵御非生物胁迫的作用机制。     

Enhancement of sulfide auto-oxidation by metal ion in artificial seawater and a seawater which is a possible source of aoshio

SUMMARY: Aoshio is hypoxic milky blue-green seawater observed in some eutrophic bays. Previous studies have shown that colloidal sulfur causes the coloration and that the source of aoshio water is attributed to coastal anoxic bottom water. Occurrences of aoshio have been reported in limited areas of coastal seawater, although hypoxic transparent water seems rather universal. Promotion in auto-oxidation of sulfide by metal ions in seawater was investigated to explain the occurrences of aoshio. Artificial seawater containing 10 μM metal ion was assayed for the sulfide oxidation rate. The velocity constant which represents the oxidation rate within the initial 30 min and the amount of reacted sulfide in 2 h were determined by oxygen monitoring and sulfide quantification, respectively. Fe²⁺ and Cu²⁺ enhanced the initial 30 min reaction. Fe²⁺, Fe³⁺ and Ni²⁺ increased the amount of reacted sulfide in 2 h, forming whitish turbid water. Seawater from a suspected source of aoshio water was also assayed for the auto-oxidation rate of sulfide. The oxidation rate in water from 12 m depth was 13–19 times higher than the artificial seawater without an addition of heavy metal ions. More than 15% of the oxidation rate in 12 m deep seawater was explained by dissolved iron in the seawater.     

保定市工业废水农灌的研究

本文论述了保定市工业废水经农灌土地处理,对土壤、地下水和农作物品质的影响。结果表明:以造纸、食品、轻纺和化工为主的工业废水在重金属常年不超出农灌标准下,宜于在非盐化土壤灌溉;废水中硫化物超标,通过土壤生物区系,能降低毒性;废水中常规有机物,农灌后利大于害;只要在土壤容量允许内,可具有二级污水处理工艺不能完成的效果。     

Effect of GYY4137 on cytosolic lipid decomposition in mouse primary hepatocytes

AIM: To evaluate the effect of GYY4137, a novel hydrogen sulfide (H₂S) donor, on cytosolic lipid decomposition in mouse primary steatosis hepatocytes. METHODS: Oleic acid (OA) was used to induce hepatic steatosis model in vitro. The C57BL/6 mouse primary hepatocytes isolated and cultured by 2-step in situ perfusion were divided into 4 groups:the cells in control group were incubated with normal medium for 54 h; the cells in model group were incubated with OA at 1.2 mmol/L for 48 h followed by serum-free phenol red-free RPMI-1640 for 6 h; the cells in H₂S group or DL-propar-gylglycine (PAG; an inhibitor of cystathione γ-lysase, inhibiting H₂S synthesis) group were incubated with OA at 1.2 mmol/L for 48 h followed by serum-free phenol red-free RPMI-1640 which contained 1 mmol/L GYY4137 or 200 μmol/L PAG for 6 h. The glycerin release and the protein expression of hormone-sensitive lipase (HSL) in the cells were mea-sured. RESULTS: Compared with model group, the glycerin release and the protein expression of phosphorylated HSL (p-HSL) in H₂S group decreased significantly, while those increased significantly in PAG group. CONCLUSION: In steatosis hepatocytes, exogenous H₂S possibly decreases cytosolic lipid decomposition by decreasing the protein level of p-HSL.     

Effect of exogenous hydrogen sulfide on lipophagy in mouse primary hepatocytes

AIM: To evaluate the effect of exogenous hydrogen sulfide (H₂S) from GYY4137 on lipophagy in mouse primary hepatocytes. METHODS: The C57BL/6 mouse primary hepatocytes isolated and cultured by 2-step in situ perfusion method were divided into 4 groups: the cells in control group were incubated with normal medium; the cells in model group were incubated with 1.2 mmol/L oleic acid (OA) for 48 h; the cells in H₂S group or propargylglycine (PAG) group were incubated with 1.2 mmol/L OA for 48 h followed by serum-free phenol red-free RPMI-1640 medium which contained 1 mmol/L GYY4137 or 200 μmol/L PAG for 6 h. The cells were collected to conduct immunofluorescence staining of LC3 and photography under fluorescence microscope, phase-contrast microscope or transmission electron microscope. The protein expression of LC3-Ⅰ/Ⅱ in the hepatocytes was determined by Western blot. RESULTS: In contrast with the model group, the fluorescent particles of LC3, the protein expression of LC3, the number of autophagic lysosome and vacuoles in hepatocytes in H₂S group increased. CONCLUSION: In steatosis hepatocytes, exogenous H₂S promotes the lipophagy.     

Effect of hydrogen sulfide on myocardial fibrosis and PPARγ and NF-κB expression in rat model of diabetes

AIM: To explore the effects of hydrogen sulfide (H₂S) on the myocardial fibrosis in a rat model of diabetes and its mechanism.METHODS: Single intraperitoneal injection of streptozotocin (STZ) was utilized to establish a rat model of diabetes. Sodium hydrosulfide was used as an exogenous donor of hydrogen sulfide. Male SD rats were randomly divided into control group, STZ group, STZ+H₂S group and H₂S group. Eight weeks later, HE and VG staining methods were used to observe the collagen distribution and collagen volume fraction was measured by image analysis. The expression levels of type I collagen, PPARγ and NF-κB in the cardiac tissues were determined by Western blotting.RESULTS: Compared with control group, collagen distribution and the expression levels of type I collagen and NF-κB in the cardiac tissues were markedly increased (P<0.05), while PPARγ was significantly decreased in STZ group (P<0.05), but these indexes were reversed significantly in STZ+H₂S group (P<0.05). The expression levels of type I collagen, PPARγ and NF-κB had no significant difference between H₂S group and control group.CONCLUSION: Hydrogen sulfide attenuates cardiac fibrosis in diabetic rats, and its mechanism may be related to PPARγ-NF-κB signaling pathway.     

Observations on the bismuth sulfide colorimetric procedure for sulfate analysis in soil

Abstract

The bismuth sulfide and methylene blue colorimetric finishes for soil sulfate determination by the Johnson‐Nishita distillation method were examined and compared. Both procedures gave comparable results when applied to soils and soil extracts, but the bismuth method was more rapid and more reliable. Nitrogen flow rate over the range 100–500 ml/min was not critical for the bismuth method, provided appropriate distillation times were employed. However, the release and transfer of hydrogen sulfide in the bismuth method was effected in one‐third of the time required for the méthylène blue finish, largely due to the elimination of a gas‐washing step. Predrying of soil extract samples increased recovery of hydrogen sulfide with the bismuth procedure arid could be used to increase sensitivity. Nitrate interference was observed with the bismuth procedure but attributed to interference during the reduction step. The bismuth procedure can readily be adapted for microdetermination in the 0–40 ppm sulfate‐S range.     

大鹏澳网箱养殖区底质硫化物分布、变化和污染分析

为进一步了解粤东海水网箱渔场硫化物污染特征,研究了大鹏澳网箱养殖海域底质硫化物的空间分布、季节变化和污染状况。结果表明,底质硫化物含量(mg·kg~(-1),干重)在网箱区内(为344～949,平均624)远高于网箱区外(为142～278,平均212),春夏季(平均694)显著高于秋冬季(平均554)(P<0.02)。研究海域底质硫化物含量与有机质含量正相关(r+0.704,P<0.05),其中夏季相关最显著(r=0.818,P<0.02)。硫化物平均污染指数1.57,老化风险级别为4级,说明沉积环境已达到重污染,已面临很大的老化风险。     

Hydrogen sulfide inhibits inflammatory responses induced by acute myocardial ischemia in isolated rat hearts

AIM：To investigate whether hydrogen sulfide (H2S) protects the hearts against inflammatory responses induced by acute myocardial ischemia in isolated rat hearts. METHODS：Rat acute myocardial ischemia injury was induced by ligation of the left anterior descending coronary artery for 4 h, and the normal perfusate was replaced with NaHS (5 μmol/L, 10 μmol/L and 20 μmol/L) perfusate accordingly in NaHS groups 2 h after ischemia. The changes of cardiac function in the myocardial ischemic injury rats were observed. The mRNA expression of TNF-α, IL-1β, IL-6, IL-10 and ICAM-1 was detected by real-time PCR. The protein level of nuclear factor-κB (NF-κB) in the myocardial tissues was detected by Western blotting. RESULTS：The cardiac function in ischemia group was lower than that in sham group (P<0.01). Compared with ischemia group, perfusion of NaHS resulted in the improvement of the cardiac function (P<0.05 or P<0.01). Compared with sham group, the mRNA expression of TNF-α, IL-1β, IL-6 and ICAM-1 in the cardiac tissues was significantly increased, and the mRNA expression of IL-10 in the cardiac tissues was significantly decreased in ischemia group (P<0.01). Compared with ischemia group, the perfusion of NaHS significantly decreased the mRNA expression of TNF-α, IL-1β, IL-6 and ICAM-1 (P<0.05 or P<0.01). The perfusion of NaHS at concentrations of 10 μmol/L and 20 μmol/L significantly increased the mRNA expression of IL-10 (P<0.01). The protein level of NF-κB in ischemia group was markedly higher than that in sham group (P<0.01). Compared with ischemia group, the perfusion of NaHS at concentrations of 10 μmol/L and 20 μmol/L significantly decreased the expression of NF-κB (P<0.05 or P<0.01). CONCLUSION：H2S protects the hearts against acute ischemia injury through inhibition of NF-κB activation and subsequent down-regulation of NF-κB-dependent inflammatory gene expression.