【作者】 范玲玲；

【导师】 戴绍军； 孙国荣；

【作者基本信息】 东北林业大学 ， 细胞生物学， 2010， 硕士

【摘要】 星星草(Puccinellia tenuiflora)属禾本科碱茅属多年生草本植物,具有很强的耐盐碱能力,可在pH10以上的碱斑地上生长。为了能够在亚细胞、细胞、组织,以及个体水平揭示星星草抗盐碱的离子平衡和渗透调节作用,我们采用4种胁迫(Na2CO3、NaHC03、NaCl和PEG)10种处理方法(①0.4%Na2C03、0.277%NaCl和9.82%PEG的低浓度等渗溶液；②1.0%Na2C03、0.781%NaCl和19.721%PEG的高浓度等渗溶液；③0.4%Na2C03、0.184%NaCl和0.448%NaHCO3的低浓度等离子溶液；④1.0% Na2C03、0.395% NaCl和1.054%NaHCO3高浓度等离子溶液),将碱性盐这—复合胁迫分解为单一胁迫,这将有利于研究星星草耐胁迫的生理生态学机制。在生理水平,我们测定了各种胁迫条件下的星星草根渗透势、电解质外渗率、根表面Na、K元素含量及根内Na+、K+浓度。结果表明,与对照比,等离子及等渗低浓度胁迫下,星星草根表面Na、K元素含量,以及根内的Na+、K+浓度的变化趋势表现一致。渗透势都降低,但幅度不大,电解质外渗率升高,但不显著。这说明低浓度等离子与等渗溶液胁迫下星星草可以利用其自身调控机制调节胞内的离子平衡,抵抗盐碱胁迫。在高浓度等离子及等渗溶液胁迫下星星草根表面Na、K元素含量及根内的Na+、K+浓度变化趋势则不一致,渗透势大幅度降低,电解质外渗率大幅度升高。这表明高浓度盐碱胁迫条件下,pH胁迫发挥主要的作用,渗透胁迫与离子胁迫次之。同时,我们利用焦锑酸盐沉淀技术和磷酸铅沉淀技术分别对盐碱胁迫条件下星星草根Ca2+与Ca2+-ATPase进行超微细胞化学定位研究,旨在进一步探讨Ca2+在盐碱胁迫诱导胞内信号转导过程中的作用,以及Ca2+-ATPase活性定位变化与盐碱胁迫下星星草抗盐碱能力的关系。结果表明,在正常状态下,根毛区细胞质内Ca2+较少,Ca2+主要位于质膜附近和液泡中,Ca2+-ATPase主要定位于质膜和液泡膜上,有一定活性。在低浓度等离子与等渗溶液胁迫下,根毛区细胞质中Ca2+增多,液泡中Ca2+减少,且主要集中于液泡膜附近,质膜和液泡膜Ca2+-ATPase活性明显升高。高浓度等离子与等渗溶液胁迫下,细胞质中分布的Ca2+增多,而液泡中Ca2+极少,Ca2+-ATPase活性也降低。由此说明,Ca2+亚细胞定位与Ca2+-ATPase活性变化在星星草响应盐碱胁迫的信号传递过程中具有重要作用。更多还原

【Abstract】 Being a species of Puccinellia, Puccinellia tenuiflora is gramineous, perennial, and herbaceous. It can grow in the soil of pH10 owing to its salt-resistant ability.In order to reveal the function of ion balance and osmotic regulation in Rtenuiflora at sub-cellular, cellular, tissue and individual level, four stress (Na2CO3,NaHCO3,NaCl, PEG) with ten concentrations were carried out to seedlings of P.tenuiflora,respectively. The detailed treatment method were as follows:(1)the low-concentration iso osmotic solutions of 0.4%Na2CO3,0.277%NaCl, and 9.82%PEG; (2) the high-concentration iso osmotic solutions of 1.0% Na2CO3,0.781% NaCl, and 19.721%PEG with the equal osmotic pressure;(3)the low-concentration iso-natrium ionic solutions of 0.4%Na2CO3,0.184%NaCl, and 0.448%NaHCO3;(4) the high-concentration iso-natrium ionic solutions of 1.0% Na2CO3,0.395% NaCl, and 1.054%NaHCO3.Thus, the complexed saline-alkali stress was divided into various single factors, and it is better to analyze the ecophysiological mechisms in Puccinellia tenuiflora to cope with stress.At the physiological level, we determined the osmotic potential, electrolyte leakage rate, the content of Na, and K at the surface of root, and the concentration of Na+ and K+ within the root of P. tenuiflora under various stress conditions. The results showed that, compared with the control,under the low-concentration iso-natrium ionic and iso-osmotic stress,the content of Na, K on the surface of root, and the concent of Na+, K+ appeared the similar changes. Osmotic potential decreased not obviously, and electrolyte leakage rate increased not significantly. This showed that P. tenuiflora can use its own control mechanism regulating the intracellular ion balance of at the lower concentration saline-alkali stress.However, the changes of the content of Na, K on the surface of root and the concents of Na+, K+are inconsistent. The osmotic potential significantly reduced, and electrolyte leakage rate increased under the high concentration of saline-alkali stress.This noted that under the high concentration of alkali-salt stress, pH stress is more primary than osmotic and ion stress.Furthermore, to investigate the relationships between the localization of calcium and Ca2+-ATPase, and the capacity of P.tenuiflora resistance to saline-alkali stress, an experiment for ultracytochemical localization of calcium and Ca2+-ATPase in the root of P. tenuiflora under the stress of saline-alkali stress were carried out using a potassium pyroantimonate precipitation and a lead phosphate precipitation technique, respectively.Our results showed that, in normal condition, the deposits of calcium antimonite was less precipitation in the cytoplasm, and it is mainly concentrated within the plasma membrane and vacuoles in the zone of root hair. Ca2+-ATPase had a certain activity and mainly localized in the plasma membrane and tonoplast. Moreover, under the low concentrations stress of iso-natrium ionic and iso- osmotic, the distribution of Ca2+ precipitation particles increased in the cytoplasm, decrease in the vacuole, and mainly concentrated in the vicinity of tonoplast. Meanwhile, the activity of Ca2+ -ATPase was significantly increased in plasma membrane and tonoplast.Furthermore, under the high stress of iso-natrium ionic and iso-osmotic, the distribution of Ca2+ precipitation particles was continued to increase in the cytoplasm, but absent in the vacuole.The activity of Ca2+-ATPase also reduced. All these results highlight that the changes of Ca2+ localization and Ca2+-ATPase activity plays important roles in P. tenuiflora resistance to saline-alkali stress.更多还原