摘 要

1. NaCl灌根造成盐胁迫使得植物膜系统受到破坏，而ACC预处理对于盐胁迫缓解效应不明显，AOA和ACC SHAM则加剧盐胁迫损伤，而ACC AA和AOA AA预处理却可显著缓解盐胁迫。乙烯抗盐信号下游可能有AOX的介导作用。
2. 相比单独盐胁迫，ACC和ACC SHAM预处理加剧植物体内ACC积累，但ACC单独预处理效果更显著；AOA和ACC AA预处理则无显著效果；另外，AOA AA预处理反而减少ACC积累。因此AOX除了介导乙烯抗盐的下游途径，可能还存在其他诱导的上游信号，与乙烯信号互补形成杨树的抗盐体系。
3. 相比对照，ACO3在AOA NaCl和AOA AA NaCl预处理后含量基本不变；在NaCl和NaCl ACC AA和NaCl ACC SHAM预处理后含量明显上升；在NaCl ACC预处理后含量达到最大。可能是ACC增加后促进ACO催化活性，进一步产生更多乙烯。
4. 盐胁迫导致CAS C1和AOX1b表达显著上升。相比单独盐胁迫，AOA预处理降低了CAS C1和AOX1b的表达。但SHAM在抑制AOX1b的同时却诱导了CAS C1表达强烈上调，AA诱导AOX1b的同时抑制CAS C1表达。
5. NaCl处理导致Cys的含量明显升高。在NaCl的基础上存在着ACC时，Cys的含量明显下降。然而，存在着AOA时，Cys的含量达到一个最高值。与此同时，在它的基础上还存在着AA时，则Cys的含量明显下降。

关键词：‘南林895’杨；乙烯；交替呼吸氧化酶；氰丙氨酸合酶；抗盐

Regulatory mechanism of cyanoalanine synthase and mitochondrial alternative oxidase in salt tolerance response of‘ 895’ poplar ethylene

Abstract：Poplar is one of the most adaptable and widely distributed tree species in the world, and it is an important afforestation and industrial timber tree species in China. This topic selected south forest‘895’poplar as the material to conduct salt stress research. By monitoring the expression of cyanoalanine synthase, alternating oxidase and ethylene-related genes in leaves of‘895’poplar, measuring the content of cysteine and measuring the physiological indicators of stress, the regulation mechanism of cyanoalanine synthase and alternating oxidase in ethylene salt tolerance response of ‘895’poplar was discussed, which provided theoretical basis for poplar resistance molecular breeding. The results are as follows:
1. salt stress caused by NaCl irrigation damaged the plant membrane system, but ACC pretreatment had no obvious mitigation effect on salt stress, AOA and ACC sham aggravated salt stress damage, while ACC aa and AOA aa pretreatment could significantly mitigate salt stress. The downstream of ethylene salt resistance signal may be mediated by AOX.
2. compared with salt stress alone, ACC and ACC sham pretreatment aggravated ACC accumulation in plants, but ACC pretreatment alone was more significant. Aoa and ACC aa pretreatment had no significant effect. In addition, AOA aa pretreatment can reduce ACC accumulation instead. Therefore, AOX not only mediates the downstream route of ethylene salt resistance, but also may have other induced upstream signals, which complement with ethylene signals to form poplar salt resistance system.
3. compared with the control, the content of AC O3 after AOA NaCl and AOA aa NaCl pretreatment is basically unchanged. After NaCl and NaCl ACC aa and NaCl ACC sham pretreatment, the content increased significantly. The content reached the maximum after NaCl ACC pretreatment. It may be that ACC increases the catalytic activity of ACO and further generates more ethylene.
4. salt stress led to a significant increase in cas C1 and aox1b expression. Compared with salt stress alone, AOA pretreatment decreased the expression of cas C1 and aox1b. However, while inhibiting aox1b, sham induced a strong up-regulation of cas C1 expression, while aa induced aox1b and inhibited cas C1 expression.
5. NaCl treatment led to a significant increase in Cys content. When ACC exists on the basis of NaCl, the content of Cys obviously decreases. However, when AOA exists, the content of Cys reaches a highest value. At the same time, when aa still exists on its basis, the content of Cys obviously decreases.

Key words: Poplar,Ethylene,Cyaninoninesynthase, Alternative oxidase,Salt resistance

目 录

前言 - 1 -

1文献综述 - 2 -

1.1实验背景 - 2 -

1.1.1杨树的形态特征和研究价值 - 2 -

1.1.2研究植物耐盐性的意义 - 2 -

1.2目前研究进展 - 3 -

1.2.1植物盐胁迫影响的研究方向 - 3 -

1.2.2植物耐盐性的研究进展及成果 - 3 -

1.3实验研究方法 - 4 -

1.3.1植物RNA的提取方法 - 4 -

1.3.2实时荧光定量PCR技术 - 4 -

1.4此次实验研究的目的和意义 - 4 -

2材料与方法 - 6 -

2.1实验材料 - 6 -

2.2实验方法 - 6 -

2.2.1植株培养条件和处理 - 6 -

2.2.2 ACC含量测定 - 6 -

2.2.3电介质渗透率和丙二醛含量测定 - 7 -

2.2.4 RNA提取和实时定量PCR - 8 -

2.2.5 半胱氨酸含量测定 - 8 -

3结果与分析 - 8 -

3.1盐胁迫下杨树叶片氨基环丙烷羧酸含量的变化 - 9 -

3.2化学预处理对盐胁迫下杨树叶片电解质渗漏和丙二醛（MDA）含量的影响 - 9 -

3.3化学预处理对盐胁迫下杨树叶片氨基环丙烷羧酸含量的影响 - 11 -

3.4化学预处理对盐胁迫下杨树叶片基因转录水平的影响 - 12 -

3.5化学预处理对盐胁迫下杨树叶片半胱氨酸和脯氨酸含量影响 - 14 -

4结论与展望 - 16 -

4.1结论 - 16 -

4.2本研究的不足之处 - 16 -

4.3展望 - 17 -

致谢 - 18 -

参考文献 - 19 -

前言

杨树是被子植物门（Angiosperms），双子叶植物纲（Dicots）杨柳科（Salicaceae）杨属（Populus）的落叶乔木。我国西北、华北、东北和沿海地区分布许多盐碱土，而江苏省苏北地处黄海之滨，也拥有大量盐碱土。通常土壤含盐量在0.2%-0.5%时即不利于生长，而盐碱土高达0.6%-10%时，严重伤害植物，危害农林业生产，因此对植物抗盐害的研究十分必要。

‘南林895’杨为美洲黑杨杂种无性系后代，因此具有美洲黑杨的形态特征：高大乔木，主干通直发达，整个生长期为250多天。无性繁殖能力较强，具有相对稳定的遗传特性，喜水、喜肥、喜光，在光照充足、水肥充足的情况下，其生长十分迅速。对溃疡病及褐斑病抗性较强，较耐干旱脊薄，在内陆沿海地区盐碱地上生长良好。