Alleviation of salt stress in wheat seedlings by mammalian sex hormones

BACKGROUND: Salinity is one of the most serious constraints facing agriculture today. Some mechanical, chemical and biological approaches are being pursued to cope with soil salinity. Although exogenously treated mammalian sex hormones (MSHs), progesterone, β‐estradiol and androsterone, activate significant effects in various biological aspects in plants growing under normal conditions, there is no report investigating their effects on plants growing under salt stress. The present study aimed to investigate whether MSHs could alleviate the destructive effect of salt stress on wheat seedlings and thereby increase their salt tolerance. Wheat leaves were sprayed with 10^?6, 10^?8 and 10^?10 mol L^?1 concentrations of MSH on the ninth day after sowing. MSH‐treated seedlings (10‐day‐old seedlings) were subjected to salt stress for 5 days (between days 10 and 15). RESULTS: At all the concentrations tested, MSH treatment provided a significant protection against to detrimental effects of salt stress in wheat seedlings. It improved dry weight, sugar, proline, protein, chlorophyll and glutathione contents in comparison to salinity alone. Similarly, superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and nitrate reductase activities also were augmented by MSH treatment. On the other hand, increases in lipid peroxidation level, superoxide production and hydrogen peroxide content arising from salt treatment were reduced by MSH treatment. The highest salt tolerance was obtained at the concentrations of 10^?6 mol L^?1 for progesterone and 10^?8 mol L^?1 for β‐estradiol and for androsterone. CONCLUSION: MSHs could be used effectively to protect wheat seedlings from the destructive effects of salt stress by stimulating both enzymatic and non‐enzymatic antioxidant mechanism and by promoting levels of osmotic protectants such as proline and sugars resulting in osmotic adjustment, carbon storage and radical scavenging in plants. Copyright © 2011 Society of Chemical Industry     

添加食盐对鸡骨汤中营养物质的迁移影响及微纳米颗粒的稳定性和抗氧化活性研究

目的 研究食盐添加方式对鸡骨汤中营养物质的迁移以及熬煮时间对微纳米颗粒（micro-nano particles,MNPs）的稳定性及其抗氧化活性的影响。方法 通过紫外分光光度计测定鸡骨汤中的蛋白质含量、总糖含量、总脂含量和游离氨基酸含量;利用显微镜观察MNPs的形态变化;采用纳米粒度电位仪测定MNPs的平均粒径、ζ-电位及多分散系数（polydipersity index,PDI）;通过体外自由基清除能力及总还原力评价抗氧化活性。结果 在0 min时添加3%的食盐,鸡骨汤中蛋白质、总糖、总脂和游离氨基酸的含量最高,MNPs在0~240 min内呈现先融合成大颗粒后分离成小颗粒形态变化,且在熬煮时间为240 min时鸡骨汤中MNPs的平均粒径、ζ-电位绝对值及PDI最小,随着熬煮时间的延长鸡骨汤的抗氧化活性增强。结论 添加食盐对鸡骨汤中蛋白质等营养物质的迁移具有促进作用,在0 min添加3%的食盐的鸡骨汤营养价值好,且随着熬煮时间的延长,鸡骨汤中的MNPs形成了相对稳定的体系,并具有较强的抗氧化活性。     

Effect of salt stress on phenolic compounds,glucosinolates, myrosinase and antioxidant activity in radish sprouts

The germination, growth, total phenolics, glucosinolate, myrosinase and antioxidant activity of radish sprouts germinated under 0 (control), 10, 50 and 100 mM of NaCl were investigated. The glucoraphasatin (4-methylthio-3-butenyl-glucosinolate), total glucosinolate and total phenolic contents of 5- and 7-day-old sprouts treated with 10 and 50 mM of NaCl were significantly decreased. However, the antioxidant activity of sprouts treated with 10 and 50 mM of NaCl was not affected. The glucoraphasatin and total glucosinolate contents of 5- and 7-day-old sprouts, total phenolic contents of 3- and 5-day-old sprouts were significantly increased and myrosinase activities of 3- and 5-day-old sprouts were inhibited, although the germination was dramatically inhibited by 100 mM of NaCl treatment. These results indicated that salt stress (100 mM of NaCl treatment) could improve the nutritional value of radish sprouts, and germination of sprouts under adequate salt stress could be one useful way to enhance health-promoting compounds of plant food.     

外源抗氧化剂对高温胁迫下红地球葡萄果皮组织CAT、APX和SOD酶活性的影响

以红地球葡萄为试材,喷施抗坏血酸(Vc)、苯甲酸钠(SBN)、水杨酸(SA)、柠檬酸(CA)、氯化钙(CaCl2)等5种抗氧化剂,研究不同外源抗氧化剂对高温胁迫下果皮组织中过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、超氧化物歧化酶(SOD)活性的影响。结果表明:喷施外源抗氧化剂均能显著提高果皮组织内CAT、APX和SOD的活性。综合分析:以Vc 10 mmol/L,SA 0.05 mmol/L,CA 10 mmol/L,Vc 10 mmol/L+CaCl21000 mg/L,Vc 10 mmol+SBN 10 mmol/L为极显著。