【作者】 刘志华；

【导师】 赵可夫；

【作者基本信息】 山东师范大学 ， 植物学， 2004， 硕士

【摘要】 植物的耐盐方式多种多样，耐盐机理也很复杂，涉及到植物生理生化方面，所以不同的植物在适应盐渍环境的过程中，形成了自己独特的形态结构。泌盐方式是盐生植物适应盐渍环境的一条重要途径，泌盐盐生植物的叶片和茎部的一些特殊的表皮细胞在发育过程中可分化成盐腺，通过盐腺把吸收到体内的盐分排出体外，以维持体内的低盐水平。本实验对单子叶植物獐毛(Aeluropus sinensis)的耐盐机理进行了研究和探讨，主要结果如下： 1．NaCl处理对獐毛生长状况的影响 (1)随着盐浓度的增加，植株的叶片面积明显减小，以尽量降低蒸腾速率，根系的长度变化较小，以便根系可以从高盐环境中吸收水分，避免造成生理干旱。同时，植株的高度、分蘖数量和根容量也逐渐降低。 (2)盐胁迫下，植株的鲜重、干重和含水量均小于对照，虽然无机干重和有机干重都小于对照，但有机干重所占的比例越来越大。根冠比呈上升趋势，不过，鲜重基础上的根冠比始终大于干重基础上的根冠比。 2．盐处理对獐毛叶片和根细胞汁液渗透势的影响 NaCl处理使獐毛叶片和根细胞汁液渗透势降低，在盐浓度相同的情况下，叶的渗透势大于根。 3．盐处理对獐毛叶片和根质膜透性的影响 NaCl处理使獐毛叶片和根的质膜透性增加，但叶片受到的影响较大，根部受到的影响较小。 4．盐处理对獐毛叶片和根中丙二醛(MDA)含量的影响 随着盐浓度的增加，獐毛叶片和根中丙二醛含量逐渐增加。在盐浓度相同的情况下，叶片中的丙二醛含量大于根中的丙二醛含量。 5．盐处理对獐毛叶绿素含量的影响 盐处理下，叶片中的叶绿素a和叶绿素b的含量呈上升趋势，但叶绿素a／b的比值呈下降趋势。 6．盐处理对獐毛无机离子和有机溶质含量的影响 獐毛叶片和根内的Na~+、K~+、Cl~-含量均随盐处理浓度的升高而增加，200mmol／L盆全茵游带丢对盆基础全理村研穷NaCI时，根内的Na+、K+、CI’含量分别是叶片内的1 .10、143和1.07倍。Na十服+也呈增加趋势，但叶部的Na+/K+比值大于根部的Na十爪+比值。 盐处理后，叶片和根内的有机溶质的总量增加，其中可溶性糖、氨基酸和脯氨酸的含量增加较明显，有机酸含量增加的程度相对较小，另外，蔗糖阿溶性糖的比值也随盐浓度的升高而增加。7.盐腺抑制剂对璋毛生长的影响 分别用loomm。比NaCI和loommol几NaCI+盐腺抑制剂处理材料后，后者虽提高了植物体内的Na+、K+、Cl一含量，但泌Na+率却由82.65%降为35.23%，这是樟毛生长继续受到抑制的主要原因。8.璋毛盐腺的形态与结构 璋毛的盐腺主要分布在叶脉上及其附近。从盐腺的显微结构来看，盐腺只由一个较大的基细胞和一个较小的帽细胞组成，盐腺并不是深深地下陷到表皮层中，而是镶嵌于其中。9.Na+含量的x一ray微区分析 在对照情况下，盐腺细胞的Na十含量与表皮细胞和叶肉细胞几乎相同，但在盐处理下，盐腺细胞的Na+含量明显大于表皮细胞和叶肉细胞，表明樟毛能通过盐腺活动有效降低周围细胞的Na+含量以维持其正常的生理功能;另外，盐腺细胞液泡中的Na+含量大于细胞质中的含量，表明液泡在分泌过程中起着重要作用。 总之，璋毛具有较强的适应盐渍环境的能力和很好的渗透调节能力。在20ommol几NaCI的条件下虽然生长受到抑制，但仍能正常生长，在盐渍环境中，璋毛能通过盐腺活动将体内的Na+、K+和CI.排出体外，从而使璋毛表现出一定的耐盐能力。关键词:璋毛;Nacl;生长;盐腺;盐腺抑制剂;显微结构;x一ray微区分析论文分类号:Q945·78更多还原

【Abstract】 Plants have many different kinds of salt -tolerance ways, and the salt -tolerance mechanisms are very complex relating to many kinds of biochemical events, thus the plants display singular structures during its adaptation to salt stress. Salt secretion is an important way in various halophytic plants adapting to salt stress, some special epidermis cells of leaves and stems of the recretohalophytes can differentiate into salt glands during its development, the salt which was absorbed into the plants can be secreted from these salt glands, thus the plants can keep a low level of salt. In this experiment, the salt tolerence mechanism of Aeluropus sinensis( monocotyledon) is studied. The main results are shown as fllows:1. The effects of salt-treatment on the growth situations of Aeluropus sinensis(1) The area of leaf from plant grown in the increasing salt concentration became smaller, thus its transpivation fell; the longth of roots was minished, but not very obviously, so that roots could absorb water from higher salinity in case of physiological drought. At the same time, the high of plant, the number of tiller and the volume of roots declined gradually.(2) Comparing with control, the fresh weight, dry weight and water content of the whole plant declined with the increase of NaCl concentration in medium. Although the inorganic dry weight and the organic dry weight declined, the ratio of the organic dry weight and the whole dry weight was increasing. In addition, the ratios of roots and shoots of both fresh weight and dry weight also increased with the increase of NaCl concentration in medium, but that of the fresh weight was higher than that of the dry weight.2. The effects of salt-treatment on osmotic potential of Aeluropus sinensisWith the increase of NaCl concentration, osmotic potential in leaves and roots of plants decreased, while osmotic adjustment ability increased gradually, when the concentrations of Na+ were equal, the osmotic potential in leaves were stronger than thatin roots.3. The effects of salt-treatment on the plasmalemma permeability of AeluropussinensisThe plasmalemma permeability of leaves and roots increased gradually with the increase of NaCl concentration in medium, but the leaves were affected greatly, the roots were affected weakly.4. The effects of salt-treatment on the content of Malon dialdehyda(MDA) of Aeluropus sinensisUnder the salt stress, the content of Malon dialdehyda(MDA) of plants increased with the increase of NaCl concentration, the content of Malon dialdehyda(MDA) in leaves increased significantly, which was much higher than that in roots.5. The effects of salt-treatment on the content of chlorophyll of Aeluropus sinensisThe content of of plants increased with the increase of NaCl concentration, the content of Chla and Chlb of leaves increased, but Chla /b declined gradually.6. The effects of salt-treatment on the contents of inorganic ions and soluable organic components of Aeluropus sinensisThe contents of Na+, K+and Cl" in the leaves and roots of plants increased with the increase of NaCl concentration. At 200mmol/L NaCl, the contents of Na+, K+and Cl" in the roots were 1.10, 1.43 and 1.07 times higher than those of in leaves, the ratios of Na+/K+ increased, but the ratios of leaves were higher than those of in roots.After salt treatment, the contents of soluable organic components increased, the contents of proline, amino acids and soluable sugar increased much higher than organic acids. The ratios of sucrose and soluable sugar increased too.7. The effects of the inhibitor on the growth situations of Aeluropus sinensisAfter the plants were treated respectively with 100mmol/L NaCl and 100mmol/L NaCl+inhibitor, the later enhanced the contents of Na+, K+and Cl" in plants, Na+ especially. The quotiety of Na+ recreted by leaves declined from 82.65% to 35.23%, thus the growth of plants were inhibited.8. The shape and structure of salt glands of Aeluropus sinensisThe salt glands of Aeluropus sinensis distributed around the nervations of leaves mostly. A salt gland c更多还原