【作者】 乔江方；

【导师】 赵全志；

【作者基本信息】 河南农业大学 ， 作物栽培学与耕作学， 2008， 硕士

【摘要】 为揭示水稻根系与叶片光合生理特性之间的联系,本研究以生产上大面积推广的水稻品种籼稻两优培九、粳稻豫粳六号和陆稻品种旱稻738为试验材料,在水培条件下,通过短时（30 min和150 min）水分胁迫处理及根系调节措施,从水稻的光合特性响应、气体交换、叶绿素荧光诱导动力学参数、光合机构关键酶活性、叶绿体类囊体膜蛋白表达、根叶渗透调节物质含量变化、根系呼吸代谢关键酶活性、根叶中激素（ABA、CTK、IAA、GA3）含量变化、H2O2含量变化、抗氧化酶活性变化等方面,研究短时水分胁迫条件下水稻光合荧光特性的响应机制;根系和叶片中渗透调节物质的调控效应;根系呼吸代谢对光合特性的影响;根系和叶片中激素含量变化对光合的调控及互作效应;根系和叶片之间的ABA化学信号传递及转导。试验结果如下:1.30 min短时水分胁迫下,光合特性变化幅度较小,净光合速率、蒸腾速率、羧化效率基本上在15 min后开始有下降趋势,气孔导度下降开始的较早在5-10 min便开始下降,水分利用效率变化幅度较小或基本不变,气孔限制值保持稳步上升的趋势;荧光诱导动力学参数短时间内变化较明显,Fo对干旱胁迫较敏感,不同基因型品种均有上升。150 min处理光合荧光特性指标下降更加明显,下降幅度更大,净光合速率和蒸腾速率表现出三段式的变化趋势,30 min内下降幅度较大,30-90 min下降趋势较平缓,90 min后下降幅度又较大,气孔导度下降幅度最大的时间在30-60 min;胞间CO2浓度在0-90 min基本表现下降的变化趋势,90 min后开始有所上升;水分利用效率在30-60 min表现出上升的变化过程;气孔限制值在120 min胁迫处理后期表现出下降的变化趋势。2.短时水分胁迫处理后,叶片水势变化明显,特别是在30%严重胁迫条件下;根系和叶片中细胞膜透性受到严重的影响,膜的选择质膜透性发生改变;短时水分胁迫过程中根系和叶片中渗透调节物质的改变,结果表明脯氨酸、可溶性糖含量短时间内变化较大,一般都是在20 min后上升幅度较大;比较根系和叶片中渗透调节物质的改变,发现根系中脯氨酸的改变的绝对量和上升幅度要大于叶片,而叶片中可溶性糖含量改变的绝对量和上升幅度要大于根系。3.不同的根系处理方式（全根、半根、剪去半根）对干旱胁迫后叶片的光合特性影响的结果表明,净光合速率、蒸腾速率、胞间CO₂浓度、羧化效率、水分利用效率在短时间内都有下降趋势,气孔限制值则表现为上升趋势,特别是在20 min以后变化更加明显,半根处理可以降低叶片光合特性变化的幅度。如果在处理20 min后剪去半根,明显看出,叶片的光合特性发生很快的改变,特别是气孔导度的变化最为敏感,上述指标都表现为不变或者开始有回升的趋势。不同根系处理方式叶片水势的试验也同样表明,剪去抑制半根处理可以降低叶片水势降低的幅度,甚至可以使叶片水势有上升的趋势。4.根系和叶片中CTR、IAA、GA3在短时间内都有下降的趋势,而ABA则表现出明显的上升趋势。同样,半根胁迫处理降低了这种改变的幅度,通过20 min剪去半根处理,发现可以明显改变叶片中激素含量的变化。通过试验设计全根、半根、20 min剪去半根处理,可以计算出不同根系胁迫处理在处理30 min后叶片中ABA和Zr的变化,30 min内根系ABA、Zr向叶片中输送ABA和Zr的平均速率分别为7.5 ng/g. FW.min-1、0.034 ng/g. FW.min-1。根系和叶片中ZR/ ABA、IAA/ABA、GA3 / ABA、（ZR+GA3） / ABA比值在干旱处理过程中都表现出下降的趋势。全根处理比值变化的幅度最大,剪去半根处理降低了这种变化的幅度。全根条件下（ZR+GA3） / ABA比值的变化幅度较大,这是水稻植株生长变缓的标志,是水稻对水分胁迫的一种保护性生理机制。5.通过抑制剂处理的方法研究根系呼吸代谢对叶片光合特性的影响,结果表明,正常条件下呼吸代谢抑制剂处理,叶片的光合特性在短时间内发生了一定程度的改变,特别是HgCl2处理后对光合特性影响最大,在30 min内光合速率就下降了35.8%;在光合各个指标中气孔导度下降的幅度最大,HgCl2处理后在30 min内就下降了75.1%;DNP处理后光合特性也有不同程度的下降;Na₃PO₄处理后,除了胞间CO₂有明显的下降趋势外,其它指标均变化不明显。短时干旱胁迫条件下对根系呼吸代谢不同途径关键酶活性也存在明显影响,结果表明,不同水分梯度都可以明显降低根系中ATP合酶、细胞色素氧化酶、琥珀酸脱氢酶的活性;不同处理间存在明显差异,且酶活性的降低一般都出现在胁迫处理10 min以后。6.不同基因型水稻胁迫处理后RuBP羧化酶活性有不同程度的下降,90 min后下降较明显。不同基因型品种间存在明显差异,两优培九在处理前期具有较高的RuBP羧化酶活性,处理后期下降幅度较大。通过SDS聚丙烯酰胺垂直板电泳方法,分析胁迫处理后叶片叶绿体类囊提膜蛋白的差异表达,结果表明胁迫处理150 min后,两优培九、738品种处理前后存在差异蛋白条带,不同品种间也存在差异蛋白条带;豫粳六号在处理前后没有出现差异。7.加入ABA合成抑制剂可以明显的改变半根胁迫中的光合特性,特别是气孔导度的改变;抑制剂处理后根系和叶片中ABA含量都有一定程度的下降,叶片中表现更加明显;ABA合成抑制剂也同时影响了根系和叶片中H₂O₂含量的变化,特别是叶片中的改变;通过运用剪去半根的方法,运用ABA运输速率的计算方法,计算根系中H₂O₂向叶片中运输的速率为0.051μmol.g-1.FW.min-1,结果说明根系向叶片中运输的H₂O₂还是非常少的,叶片中自身产生的H2O2是叶片中H₂O₂含量变化的主要原因。更多还原

【Abstract】 In order to promulgate between the root system and the leaf photosynthesis characteristic contacts. In the present study, we use the rice varieties of Liangyoupeijiu, the japonica Rice Variety of Yujingliuhao and upland rice variety of 738 as test materials which be planted in large scale. Response of photosynthesis characteristics, gas exchange, chlorophyll fluorescence parameter, key enzymes activities of photosynthetic apparatus, chloroplast thylakoid membrane proteins expression, content of osmoregulation substance in roots and leaves, key enzymes activities of root respiratory metabolism, changes of hormone content（ABA、CTK、IAA、GA3）, changes of H2O2 content, changes of anti-oxygen protective enzyme were detected as the main indexes when rice varieties were subjected to short water stress（30min and 150min）. Study on response mechanism of photosynthesis characteristics, regulating effect of osmoregulation substance, the efforts of root respiratory metabolism on photosynthesis characteristics, regulating and interaction effect of changes of hormone content on photosynthesis characteristics, ABA chemical signals transfer and transduction between roots and leaves under short water stress. The main results of this study were as followings.1. The change range of changes of photosynthesis characteristics is smaller in 30min short water stress, and the net photosynthetic rate, transpiration Rate and carboxylation efficiency begin to reduce after 15min stress treatment, while the stomatal conductance begin to reduce more early at about 5-10min stress treatment, and water use efficiency have less change or kept steady, and stomatal limitation value keep steady rising. The results of photosynthetic fluorescence characteristics after 150min water stress showed that index of which reduced more significantly and larger. The net photosynthetic rate and transpiration rate showed changing in three steps: changes larger in the first 30min and maintained stable during 30-90min and with larger reduced amplitude after 90min, while the changes larger amplitude of stomata conductance was from 30 to 60min. At the same time, intercellular CO₂ concentration reduced during 0-90min and begins to increase after 90min treatment, and water use efficiency showed raised during 30-60min, and the stomata limitation value exhibits a decreased trend at the late stress treatment.2. The Responses of Leaf Water Potential changed obviously after the short water stress, especially in serious stress. Cell membrane permeability in roots and leaves has been affected seriously, and membrane permeability will change. The result that changes of osmoregulation substance in roots and leaves during the short water stress showed the content of proline and soluble sugar change faster in short time, especially since 20min. Compared with the changes of osmoregulation substance in roots and leaves, the absolute value and change range of proline in roots are all greater than those in leaves, while the absolute value and change range of soluble sugar in leaves are all greater than those in roots.3.The result that the efforts of different roots treatment method （whole root, half-root, wipe out half-root） on photosynthetic characteristics after water stress showed that net photosynthetic rate, transpiration Rate, intercellular CO2 concentration, carboxylation efficiency and water use efficiency all showed a trend of decrease, while the stomatal limitation value also showed an ascending trend, and more significantly especially after 20min. Half-root treatment can reduced the range of leaf photosynthetic characteristics changes. Photosynthetic characteristics of leaf changes obviously especially the change of stomatal conductance if the half-root of stress treatment be wiped after 20min treated and other indexes all showed unchanged or some degree of improvement.The experiment of different roots treatment method on leaf water potential also showed that the treatment of wipe out half-root can reduced the range of leaf water potential changes, and even some degree of improvement.4. The content of CTR, IAA and GA3 in roots and leaves decreased in short times, and the content of ABA increased obviously. The half-root treatment can reduced the range of changes, and the content of hormone in leaves decreased obviously by wiping the half-root after 20min treatment. Designing the treatment of whole root, half-root and wipe out half-root, we can calculate the changes of content of ABA and Zr in leaves after 30min different roots treatment, and then calculate out the average rate of ABA and Zr which respectively reach 7.5 ng/g.W.min-1 and 0.034 ng/g.W.min-1 that transport from roots to leaves within the 30 min. Ratios of ZR/ ABA, IAA/ABA, GA3 / ABA and （ZR+GA3） / ABA in roots and leaves exhibit a downward trend during the drought process. The change of the ratio of whole root is the largest, and the wipe out half-root treatment reduced the range of this change. The change of the ratio of （ZR+GA3） / ABA is also bigger, and maybe it is a sign that growth of rice becomes very slow, and it also a protective physiological mechanism.5. The result that the effects of Inhibitor of root respiratory metabolism treatment on leaves photosynthetic characteristics showed that the photosynthetic characteristics of leaves will change by different Inhibitors in normal conditions, especially the treatment of HgCl2, of which the change of net photosynthetic rate reached 35.8%. The change of stomatal conductance is largest in the indexes of photosynthetic characteristics, which reduced by 75.1% within 30min under HgCl2 treatment. DNP treatment also has different degree of variation, however, the photosynthetic characteristics indexes of Na3PO4 treatment basically has no change except intercellular CO2 concentration。The results indicate that the short water stress have significant influence on key enzyme of root respiratory metabolism. Different water gradient can reduce the ATP synthase, cytochrome oxida and sesuccinate dehydrogenises of root, and existing obvious difference between those treatments, and the enzyme activity decrease occurred since 10min drought stress generally.6. The enzyme activity has different degree while in all different rice varieties, especially since 90min later. There are difference existing different rice varieties, for example, Liangyoupeijiu has high enzyme activity of RuBP carboxylase, however, it decreased with large range in the later treatment. Using the method of SDS polyacrylamide vertical slab electrophoresis, the results of difference of chloroplast thylakoid membrane proteins expression under water stress indicate that Liangyoupeijiu and 738 all have a new difference protein band, and different rice varieties also have various protein band, and Yujingliuhao have no protein variation during the drought process.7. Synthesis inhibitor of ABA can change the photosynthetic characteristics of half-root water stress, especially for the change of stomatal conductance. After the synthesis inhibitor of ABA treatment, the content of ABA have somewhat decrease, especially for the change in leaves. The content of H2O2 in root and leaves can also be affected by the synthesis inhibitor of ABA, particularly for the change of content of H2O2 in leaves. Using the method of wiping out half-root, we can also calculate out the average rate of H2O2 which reach 0.051μmol.g-1.FW.min-1 that transport from roots to leaves. It is reveals that it is little content of H2O2 which transport from roots to leaves, and the chief result of the change of H2O2 content in leaves should be the self produced H2O2.更多还原