【作者】 杨春雪；

【导师】 卓丽环； 柳参奎；

【作者基本信息】 东北林业大学 ， 园林植物与观赏园艺， 2008， 博士

【摘要】 盐胁迫是影响全世界作物产量的主要非生物胁迫之一,如何提高作物耐盐性、有效利用盐碱土资源已经成为亟待解决的重大课题。星星草是一种广泛分布于我国北方的天然耐盐植物,在含高Na⁺和高pH值的土壤中能够生长良好,其优良的耐盐碱特性使其成为植物耐盐碱胁迫研究的理想材料。与NaCl胁迫相比,具有高pH值的NaHCO₃胁迫对植物的影响更加复杂。本文以星星草为研究对象,以水稻品种“日本晴”为对照,利用显微、超微观察、双向电泳等研究方法和手段,不但对NaHCO₃胁迫下星星草种子萌发、幼苗生长特点、气孔特性、叶片及根的表皮结构特征进行了观察,还对星星草体内钾、钠、钙三种重要离子组分的吸收与运输特点,以及星星草根部蛋白质图谱的变化进行了系统的研究,从微观形态、离子分布及蛋白表达三个不同层面揭示了盐生植物星星草的耐盐基础。研究结果对进一步了解星星草的耐盐特性具有很实际的指导意义,而且,蛋白质水平的研究还为了解星星草对NaHCO₃胁迫的响应提供了新的线索,为我们用遗传手段进一步研究这些基因的功能奠定了重要基础。上述研究的主要结论如下:1.总体讲,星星草种子发芽率与NaHCO₃浓度成反比,NaHCO₃胁迫对星星草幼苗株高及干物重影响不明显,对水稻幼苗株高和干物重有一定的抑制作用。2.星星草叶表气孔长度在短时间低浓度NaHCO₃胁迫下增加,高浓度下减小;高浓度和长时间的NaHCO₃胁迫均促进气孔宽度增加,两者的作用有叠加效应;低浓度NaHCO₃胁迫即可引起水稻叶表皮的气孔长度、宽度明显下降;无盐胁迫时,星星草叶表的气孔密度是水稻的7倍多。3.星星草与水稻的叶表都有蜡质层存在。NaHCO₃胁迫浓度增大及胁迫天数增多均能促进蜡质层密度增加,从增加的幅度比较,星星草＞水稻;星星草叶表有分泌物质存在,分泌物质随NaHCO₃胁迫浓度增大及胁迫天数增多而增加,高浓度下,星星草叶表还有盐结晶析出,水稻叶表无盐结晶或其它分泌物质出现;星星草与水稻根的表皮上都具有侧根和分泌物质,从侧根的数量比较,星星草＞水稻,长时间高浓度胁迫下侧根明显收缩变细;随胁迫浓度增大或胁迫时间增长,星星草分泌物质的量增多。水稻分泌物质的量则没有表现出任何规律性的变化。4.对盐胁迫后星星草幼苗根部及地上部Na⁺、K⁺及Ca²⁺含量进行测定的结果表明,星星草体内两种K⁺吸收系统对K⁺的吸收能力及星星草根部K⁺/Na⁺均明显高于水稻;随Na⁺浓度增加,星星草相比于水稻表现出了较强的吸收与运输Ca²⁺的能力。5.以蒸馏水作对照,对150mmol/L NaHCO₃和NaCl胁迫5天的星星草根部全蛋白图谱进行了分析和比较,以期从蛋白质水平上找出NaHCO₃与NaCl逆境对星星草危害不同的原因。结果表明,在约400个可重复的蛋白质点中,有13个受NaHCO₃胁迫诱导而丰度上调,3个只在NaHCO₃胁迫下出现,经质谱鉴定得到了F3H、CYP450和果糖-1,6-二磷酸醛缩酶3个与抗逆性相关的蛋白。更多还原

【Abstract】 Soil salinity is one of the main abiotic stresses that restrict the development of agriculture worldwide.How to improve crop salt tolerance and make good use of salinity-alkalinity soil has become a significant thesis urgent to be solved.Puccinellia tenuiflora is a natural salt tolerant plant widely distributed in the north of China,and it can grow well in the soil with high Na⁺ concentration and high pH.The excellelant salt and alkali tolerance of P.tenuiflora made it become the perfect material of the research on salt and alkali tolerance.Compared with NaC1 stress,the impact of NaHCO₃ stress with high pH on plant is more complex.In this paper,we choose P tenuiflora as experimental material and rice cultivar Nipponbare（Oryza sativa L.） as comparison.Using methods of micro and ultra-structure observation,2-D electrophoresis ect,not only seed germination,seedling growth character, stoma as well as leaf and root epidermis Character of P.tenuiflora were observed,but also the absorption and transportation Character of three important ion component K⁺,Na^<sup> and Ca²⁺ in P.tenuiflora,and the changes of protein expression of its root were studied in detail.The purpose is to reveal the salt tolerant base of P tenuiflora from three different aspects of microstructure,ion distribution and protein expression.The result has practically instructional significance on the understanding of salt tolerant character of P.tenuiflora.Moreover,study on protein level provides new clew to the understanding on response of P.tenuiflora to NaHCO₃, and it also lays vital foundation to the further study of these genes by genetic measures.Main results of the above research are as follows:1.Generally speaking,with the increasing of NaHCO₃ concentrate,the seed germination rates of P.tenuiflora decline.Although seedling height and dry weight of P.tenuiflora were not obviously affected by NaHCO₃ stress,those of Rice were restrained under the same stress.2.Length of P.tenuiflora stoma increase under short time of low concentrate NaHCO₃ stress,while it decrease under high concentrate of NaHCO₃;Width of P.tenuiflora stoma increase under high concentrate or long time of NaHCO₃ stress,and the effects of the two factors can be combined with each other.Length and width of rice stoma decrease obviously under low concentrate of NaHCO₃ stress;Density of stoma on P.tenuiflora leaf epidermis is 7 times that of Rice.3.There are wax layers on both P.tenuiflora and rice.Density of wax layers enhances with the increasing of NaHCO₃ concentrate and stress time length,the increasing extent follows the order of P.tenuiflora＞rice;There are secretion on P tenuiflora leaf epidermis, and the amount of secretion increased with the increasing of NaHCO₃ concentrate and stress time length.Salt crystal can be excluded by P.tenuiflora leaf epidermis under high concentrate of NaHCO₃ stress,while no salt crystal of secretion can be found on the leaf epidermis of rice. Lateral roots and secretion can be found on both P.tenuiflora and rice root epidermis,and the numbers of lateral roots follows the order of P.tenuiflora＞rice;Lateral roots become thinner after long time of high concentrate NaHCO₃ stress.With the increasing of NaHCO₃ concentrate and stress time length,the amount of secretion on P.tenuiflora root epidermis increases,while that of rice doesnot show any changes.4.Na⁺,K⁺ and Ca²⁺ content in roots and shoots of P.tenuiflora seedlings were determined after NaHCO₃ stress.The result shows that the ability of two kind of K⁺ absorption system of P.tenuiflora is both higher than rice,so does the K⁺/Na⁺ of P.tenuiflora roots;With the increasing of Na⁺ concentrate,P.tenuiflora shows higher Ca²⁺ absorption and transportation ability than rice.5.Roots protein of P.tenuiflora plates under 150mmol/L concentrate of NaHCO₃ and NaC1 stress was compared with distilled water in order to find the reason why NaHCO₃ and NaC1 stress showed different harm effect on plant.The results are as follows,among about 400 protein spots,there are 13 spots increased in abundance after NaHCO₃ stress,3 spots only appear under NaHCO₃ stress.3 stress correlative proteins were obtained by MS analysis,they are F3H、CYP450 and fructose-bisphosphate aldolase.更多还原