硫化氢和一氧化氮对平邑甜茶镉胁迫及根系离子流的影响

发布时间：2018-06-22 22:37

本文选题：镉 + 硫化氢　；参考：《山东农业大学》2017年硕士论文

【摘要】：镉是毒性强、污染较普遍的重金属,在土壤难以分解,但极易被根系吸收和积累,并可向果实和籽粒等产品器官迁移。一氧化氮和硫化氢对植物生长发育及其环境适应性有调节作用。离子流动是其被根系吸收和积累的前提,本文以平邑甜茶幼苗为试材,在探讨硫化氢和一氧化氮缓解镉胁迫的基础上,分析硫化氢和一氧化氮对镉离子流的影响,主要结果如下:1.向营养液中添加H_2S供体NaHS(0.35mmol/L NaHS)可以提高平邑甜茶根系呼吸速率,降低膜质过氧化产物丙二醛(MDA)含量,抑制叶绿素降解的速率,提高叶片光合性能,并在一定程度上促进平邑甜茶根系对镉离子的外排作用,抑制平邑甜茶根系对镉离子的吸收速率,从而降低根系中镉离子含量。综合分析表明,适当浓度的硫化氢可通过减少根系对镉离子的吸收,缓解重金属镉对平邑甜茶幼苗的毒害作用。2.向营养液中添加NO供体SNP(50μmol/L)可以提高平邑甜茶根系呼吸速率,降低膜质过氧化产物丙二醛(MDA)含量,抑制叶绿素降解的速率,提高叶片光合性能,并在一定程度上促进平邑甜茶根系对镉离子的外排作用,抑制平邑甜茶根系对镉离子的吸收速率,从而降低根系中镉离子含量。综合分析表明,适当浓度的一氧化氮可通过减少根系对镉离子的吸收,缓解重金属镉对平邑甜茶幼苗的毒害作用。3.向营养液中添加NO供体SNP和H_2S供体NaHS,使营养液中含有50μmol/L的SNP和0.35mmol/L NaHS,可以减轻镉离子对幼苗的离子毒害作用,促进镉胁迫下平邑甜茶幼苗的生长。但其共同处理效果并达不到分别处理的加和作用,有意思的是适当浓度的cPTIO可抑制他们处理的缓解作用。综合分析表明,适当浓度的一氧化氮和硫化氢可通过减少根系对镉离子的吸收,缓解重金属镉对平邑甜茶幼苗的毒害作用,而一氧化氮抑制剂能抑制这一作用。4.硫化氢和一氧化氮对平邑甜茶盐胁迫下Na~+、K~+离子吸收的流速变化,利用非损伤微测技术测定盐胁迫下平邑甜茶幼苗根系对Na~+、K~+离子吸收流速变化,结果表明,盐胁迫会促进根系对Na~+离子的吸收,K~+离子的外排,添加NaHS和SNP会促进Na~+离子的外排和K~+离子的吸收,减少Na~+离子的吸收和K~+离子的外排作用,促进Na~+、K~+离子平衡,从而更好的维护植株生长。
[Abstract]:Cadmium is a highly toxic and polluted heavy metal, which is difficult to decompose in soil, but it is easily absorbed and accumulated by roots, and can migrate to fruit and grain. Nitric oxide and hydrogen sulfide regulate plant growth and environmental adaptability. Ion flow is the premise of absorption and accumulation by roots. In this paper, the effects of hydrogen sulfide and nitric oxide on cadmium ion flow were analyzed on the basis of hydrogen sulfide and nitric oxide. The main results are as follows: 1. Adding H2S donor NaHS (0.35 mmol / L NaHS) to the nutrient solution could increase the root respiration rate, decrease the content of MDA, inhibit the rate of chlorophyll degradation, and improve the photosynthetic performance of leaves. To a certain extent, it can promote the efflux of cadmium ions in the roots of sweet tea of Pingyi, inhibit the absorption rate of cadmium ions in the roots of sweet tea of Pingyi, and thus reduce the content of cadmium ions in the roots. The comprehensive analysis shows that the proper concentration of hydrogen sulfide can reduce the absorption of cadmium ion by roots and alleviate the toxic effect of heavy metal cadmium on the seedlings of sweet tea of Pingyi. Adding no donor SNP (50 渭 mol / L) to the nutrient solution could increase the root respiration rate, decrease the content of MDA, inhibit the rate of chlorophyll degradation, and improve the photosynthetic performance of leaves. To a certain extent, it can promote the efflux of cadmium ions in the roots of sweet tea of Pingyi, inhibit the absorption rate of cadmium ions in the roots of sweet tea of Pingyi, and thus reduce the content of cadmium ions in the roots. The comprehensive analysis showed that the proper concentration of nitric oxide could reduce the absorption of cadmium ion by roots and alleviate the toxic effect of heavy metal cadmium on the seedlings of sweet tea. Adding no donor SNP and H2S donor NaHS to the nutrient solution, the nutrient solution contained 50 渭 mol / L SNP and 0.35 mmol / L NaHS, which could reduce the ion toxicity of cadmium ion to seedlings and promote the growth of Pingyi sweet tea seedling under cadmium stress. However, the effect of co-treatment is not equal to the additive effect of separate treatment. It is interesting that the appropriate concentration of cPTIO can inhibit the mitigation of their treatment. The comprehensive analysis showed that the proper concentration of nitric oxide and hydrogen sulfide could reduce the absorption of cadmium ion by roots, and alleviate the toxic effect of heavy metal cadmium on the seedlings of sweet tea of Pingyi, but the inhibitor of nitric oxide could inhibit this action. The changes of velocity of absorption of Na ~ + K ~ + by hydrogen sulfide and nitric oxide under salt stress in Pingyi sweet tea seedlings were determined by using non-damage micrometer technique. The results showed that the absorption velocity of Na ~ (2 +) K ~ + in roots of sweet tea seedlings under salt stress was higher than that of control group (P < 0.05). Salt stress can promote the absorption of Na ~ + by roots, and the addition of NaHS and SNP can promote the efflux of Na ~ + and K ~ +, reduce the absorption of Na ~ + and efflux of K ~ +, and promote the equilibrium of Na ~ +. In order to better maintain plant growth.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S661.1

【参考文献】