PDF(Pubmed)
Abstract：
Chromium (Cr) is a toxic heavy metal that contaminates soil and water resources after its discharge from different industries. A pot experiment was conducted to determine the effects of single and/or combined application of sodium nitroprusside (SNP) (250 μM) and sodium hydrogen sulfide (NaHS) (1 mM) on growth, photosynthetic pigments, gas exchange characteristics, oxidative stress biomarkers, antioxidant machinery (enzymatic and non-enzymatic antioxidants), ion uptake, organic acid exudation, and Cr uptake of spinach (Spinacia oleracea L.) exposed to severe Cr stress [Cr: 0 (no Cr), 150, and 300 μM]. Our results depicted that Cr addition to the soil significantly (P < 0.05) decreased plant growth and biomass, gas exchange attributes, and mineral uptake by S. oleracea when compared to the plants grown without the addition of Cr. However, Cr toxicity boosted the production of reactive oxygen species (ROS) by increasing the content of malondialdehyde (MDA), which is the indication of oxidative stress in S. oleracea, and was also manifested by hydrogen peroxide (H2O2) content and electrolyte leakage to the membrane-bound organelles. The results showed that the activities of various antioxidative enzymes, such as superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and the content of non-enzymatic antioxidants, such as phenolic, flavonoid, ascorbic acid, and anthocyanin, initially increased with an increase in the Cr concentration in the soil. The results also revealed that the levels of soluble sugar, reducing sugar, and non-reducing sugar were decreased in plants grown under elevating Cr levels, but the accumulation of the metal in the roots and shoots of S. oleracea, was found to be increased, and the values of bioaccumulation factor were <1 in all the Cr treatments. The negative impacts of Cr injury were reduced by the application of SNP and NaHS (individually or combined), which increased plant growth and biomass, improved photosynthetic apparatus, antioxidant enzymes, and mineral uptake, as well as diminished the exudation of organic acids and oxidative stress indicators in roots of S. oleracea by decreasing Cr toxicity. Here, we conclude that the application of SNP and NaHS under the exposure to Cr stress significantly improved plant growth and biomass, photosynthetic pigments, and gas exchange characteristics; regulated antioxidant defense system and essential nutrient uptake; and balanced organic acid exudation pattern in S. oleracea.
摘要：
铬（Cr）是一种有毒的重金属，从不同行业排放后会污染土壤和水资源。进行盆栽实验以确定硝普钠（SNP）（250μM）和硫化氢钠（NaHS）（1mM）的单一和/或联合应用对生长的影响，光合色素,气体交换特性，氧化应激生物标志物，抗氧化机制（酶促和非酶促抗氧化剂），离子吸收，有机酸渗出，和暴露于严重Cr胁迫的菠菜（SpinaciaoleraceaL.）的Cr吸收[Cr：0（无Cr），150和300μM]。我们的结果表明，土壤中添加Cr显着（P<0.05）降低了植物的生长和生物量，气体交换属性，与不添加Cr的植物相比，甘草对矿物质的吸收。然而,Cr毒性通过增加丙二醛（MDA）的含量来促进活性氧（ROS）的产生，这表明了甘草的氧化应激，并且还表现为过氧化氢（H2O2）含量和电解质泄漏到膜结合的细胞器。结果表明,各种抗氧化酶的活性,如超氧化酶歧化酶（SOD），过氧化物酶(POD),过氧化氢酶(CAT),和抗坏血酸过氧化物酶（APX），和非酶抗氧化剂的含量，如酚醛，类黄酮，抗坏血酸,和花青素,最初随着土壤中Cr浓度的增加而增加。结果还表明，可溶性糖的水平，还原糖,在Cr水平升高的植物中，非还原糖减少，但是金属在甘蓝根和芽中的积累，被发现增加了，所有Cr处理的生物富集因子值均<1。通过应用SNP和NaHS（单独或联合）减少了Cr损伤的负面影响，增加了植物生长和生物量，改良光合装置，抗氧化酶，和矿物质吸收，并通过降低Cr毒性来减少甘蓝根中有机酸的渗出和氧化应激指标。这里,我们的结论是，在暴露于Cr胁迫下，施用SNP和NaHS显着改善了植物的生长和生物量，光合色素,和气体交换特性；调节抗氧化防御系统和必需营养素的吸收；和平衡的有机酸渗出模式。
