ALA促进不结球白菜耐盐机理的研究

论文摘要

不结球白菜（Brassica campestris ssp.chinensis var. communis Tsen et Lee）又称小白菜、青菜、油菜,原产中国,为十字花科芸薹属芸薹种白菜亚种中的一个变种,以其嫩叶为产品器官的一、二年生蔬菜作物。由于其适应性强、生长周期短、营养价值高,是我国南方的大众化蔬菜,在“菜篮子”工程中占有重要地位,成为衡量市场供应优劣的主要标志。近年来东南亚、日本、美国及欧洲各国也均有引种栽培,不结球白菜日益成为一种世界性的蔬菜。世界上盐碱地面积不断扩大,而有关不结球白菜耐盐性及其机理方面却鲜有研究,本文研究了盐胁迫下ALA对不结球白菜种子萌发、矿质元素含量、光合特性、抗氧化酶活性及耐盐相关基因的影响。1.不结球白菜种子萌发及幼苗期耐盐性的研究试验发现随着盐胁迫的增强,种子的萌发率、根的长度、根、子叶及胚轴的干、鲜重和呼吸强度均显著下降。在50 mmol 1-1 NaCl低盐胁迫下"Za-1", "Su-1", "Ak-1"及"Ha-1"四个品种的种子萌发率均高于对照,其中"Ai-1”表现的呼吸强度最高、根长最长,“Ak-1”表现出最高的下胚轴鲜重（16.8 mg/p）,而"Ba-1”则表现出最大的子叶鲜重（25 mg/P）2.盐胁迫下ALA对不结球白菜种子萌发的促进效应盐胁迫下种子的萌发率及幼苗的生长随着ALA浓度的增加而显著增加,在200mmol 1"1 NaCl盐胁迫下添加5Omg1-1 ALA, "Lb-1"和“Ai-1”表现出最高的种子萌发率,而"Qi-1”则表现出最高的下胚轴干、鲜重（25mg/p,1.6mg/P）及子叶干、鲜重（30.4mg/P,2.9mg/P）。在添加：20 mg I-1 ALA’情况下,"Lb-1", "Za-1"及“Su-1”的根长最长。在添加20 mmol I-1 ALA抑制剂LA溶液后,幼苗生长受到显著抑制。ALA可能是通过色素物质影响种子萌发及幼苗生长,而后者在线粒体呼吸途径中又具有重要的作用。3.盐胁迫下ALA对不结球白菜矿质含量的影响盐胁迫下,不结球白菜叶片Mg2+、Ca2+和K+的含量下降,而Nz+和Cl-的含量增加。进一步经ALA处理后,叶片Mg2+、Ca2+、K+的含量增加,Na+和Cl-的含量降低。但在"Qd-1”中Na+含量没有降低,而在“Li-1”和“Ai-1”两品种中Na+明显降低。处理后8天“Ai-1”的Ca2+含量最高（36.08 mg/g）；处理后24天,“Li-1”中Mg2+和Cl-含量最高,分别达到4.07 mg/g和7.0 mg/g; "Qd-1"中Na+（47.16 mg/g）和"Ai-1"中K+（43.34 mg/g）的含量在处理24天后达到最高。4.盐胁迫下ALA对不结球白菜色素量、抗氧化酶活性及光合特性的影响试验表明,ALA提高了不结球白菜的光合速率及色素含量,15Ommo11-1 NaCl胁迫下添加100 mg 1-1ALA后,“Qd-1”在1000μmol m-2 s-1光照强度下表现出最大的光合速率15.41μmol m-2 s-1,色素含量也达到最大值,叶绿素a、b及总量分别为1.08 mg g-1FW、0.59 mg/g FW及1.67 mg/g FW,叶绿素a/b为0.54。盐胁迫下耐盐品种“Ai-1”,表现出最大的SOD酶活性（72Ug-1min-1）和POD酶活性（0.08Ug-1min-1）。而"Li-1”中CAT酶活性在50mg 1-1和150mg 1-1盐胁下增加,而添加100mg 1-1ALA后,CAT酶活性分别下降180%和155%。5.盐胁迫下ALA对不结球白菜色素荧光特性的影响盐胁迫下研究了耐盐"Aijiaohuang"、中耐盐’Qingdi"及盐敏感"Lichuandasuo mian"品种的色素荧光特性,结果表明盐胁迫下添加ALA后,中耐盐品种“Qingdi”表现出最高的色素光吸收效率,电子吸收及传递率也有所增加。盐胁迫影响到光合PSⅡ的稳定性,而ALA则显著增加了光合器官的稳定性。6.不结球白菜S44基因的诱导表达特性S44基因有助于增强植株的耐盐性,采用同源克隆的方法,获得了294 bp的S44基因。通过Real-time PCR技术对S44基因的表达研究发现,ALA促进S44基因的表达,其中根的表达量高于叶片中的表达。7.ALA对不结球白菜色素含量、抗氧化酶活性及光合特性的影响非盐胁迫下测定了不同浓度的ALA对不结球白菜色素含量、抗氧化酶活性及光合特性的影响,结果表明250 mg l-1 ALA处理后“Qd-1”叶绿素a含量最高（1.96 mg/g FW）,50mgl-1 ALA处理后“Za-1”叶绿素b含量及色素总量最高,分别达到1.74 mg/g FW和2.32 mg/g FW,150 mg I-1 ALA处理后“Ai-1”有最高的Chla比值250 mg-1 ALA处理后,“Zh-1”表现出最高的POD活性1.23 Ug-1.min-1, "Zy-1"有最高的CAT活性0.93Ug-1.min-1,"Qi-1"有最强的SOD活性（287Ug-1.min-1）。同样处理下"Ba-1”具有最高的净光合速率Pn (14.78 （μmol m-2 s-1）,而“Qi-1”具有最高的胞内CO2浓度（Ci）,50mgl-1 ALA处理“Zh-1"气孔导度(（Gs）最高（0.599μmol m-2 s-1）。250mg I-1 ALA也促使“Za-1”达到最大的蒸腾速率11.2μmol m-2 s-1。

论文目录

• ABSTRACT
• 摘要
• ABBREVIATIONS
• GENERAL INTRODUCTION
• Origins and Distribution
• Plant Habit
• Flowers
• Commercial Production
• Climatic and Soil Requirements
• Seeding and Spacing
• Cultural Practices
• Fertilizer Requirements
• Nutrients for Vegetables
• Importance and Uses
• Uses
• Nutritional Value
• Medicinal Value
• Factors Affecting Pak choi production
• Abiotic Factors
• Biotic Factors
• Environmental Fluctuation
• Plant Responses to Salinity
• Morphological Effects
• Physiological Effects
• Biochemical Effects
• Effects of Salinity on the Enzyme Activities
• 5.Aminolevulinic Acid Application in Plant Growth
• Aims of Thesis
• Literatures Cited
• Chapter 1 Salt Tolerance of Pak choi at Germination and Seedling Growth
• Abstract
• Introduction
• 1 Materials and Methods
• 1.1 Plant Materials
• 1.2 Seed Germination
• 1.3 Seed Respiration
• 1.4 Data Collection and Statistical Analysis
• 2 Results
• 2.1 Different NaCl Treatments on the Seed Germination of Pak choi
• 2.2 NaCl Treatment on the Seed Respiration
• 3 Discussion
• 4. Conclusion
• Literature Cited
• Chapter 2 Promotion by 5-ALA of Seed Germination of Pak choi under Salt Stress
• Abstract
• Introduction
• 1. Materials and Methods
• 1.1 Plant Material
• 1.2 Seed Germination
• 1.3 Determination of ALA
• 1.4 Method of Protoheme
• 1.5 Reagents
• 1.6 Determination of Protoheme
• 1.7 Data Collection and Statistical Analysis
• 2. Regults
• 2.1 Effect of ALA on Seed Germination under Salt Stress
• 2.2 Inhibition of Levulinic Acid（LA）on ALA-Enhanced Seed Germination
• 2.3 Effect of ALA on the Heme Content of Pak choi under Salt Stress
• 2.4 Determine the Endogenous ALA under Salt Stress
• 2.5 Effect of ALA on Respiration of Pak choi under Salt Condition
• 3 Discussion
• 4. Conclusion
• Literature Cited
• Chapter 3 Effect of ALA on the Mineral Element Content in Pak choi under Salt Stress
• Abstract
• Introduction
• 1. Materials and Methods
• 1.1 Seed Material
• 1.2 Preparation of Plant Materials
• 1.3 Preparation of Hoagland Solution
• 1.4 Determination of Elements
• 1.5 Data Collection and Statistical Analysis
• 2. Results
• 2.1 Effect of ALA on Mineral Element Content of "Qingdi" under Salt Stress
• 2.2 Effect of ALA on Mineral Element Content of "Aijiaohuang" under Salt Stress
• 2.3 Effect of ALA on Mineral Element Content of "Lichuandasuomian" under Salt Stress
• 3. Disussion
• 4. Conclusion
• Literature Cited
• Chapter 4 Role of ALA on Antioxidative Enzymes,Chlorophyll Content and Photosynthesis ofPak choi under Salt Stress
• Abstract
• Introduction
• 1. Materials and Methods
• 1.1 Seed Materials
• 1.2 Preparation of Plant Material
• 1.3 Determination of Chlorophyll
• 1.4 Measurement of Antioxidative Enzymes
• 1.5 Measurement of Photosynthesis Parameter
• 1.6 Data Collection and Statistical Analysis
• 2 Results
• 2.1 Effect of ALA on Antioxidative Enzyme under Salt Stress
• 2.2 Effect of ALA on Chlorophyll Content under S alt Stress
• 2.3 Effect of ALA Treatment on Photosynthesis under Salt Stress of Pak choi Leaves
• 3 Discussion
• 4.Conclusion
• Literature cited
• Chapter 5 Changes of Chlorophyll Fluorescence Parameters in Pak choi by ALA under Salt Stress
• Abstract
• Introduction
• 1. Materials and Methods
• 1.1 Seed Materials
• 1.2 Preparation of plant material
• 1.3 Measurement of Chlorophyll Fluorescence in Modulated Light
• 1.4 Statistical Analysis
• 2 Results
• 3. Discussion
• 4. Conclusion
• Literature cited
• Chapter 6 Expression of S44 Gene Induced by ALA in Pak choi under Salt Stress
• Abstract
• Introduction
• 1 Materials and Methods
• 1.1 Plant Materials and Nucleic Acid Extraction
• 1.2 Primer Designing
• 1.3 Cloning and DNA Sequencing
• 1.4 Construction of cDNA and Sequence Analysis
• 1.5 Real-time PCR analyses
• 1.6 Real-time PCR product sequence
• 2 Results
• 2.1 RT-PCR analysis under salt stress
• 2.2 Gene expression of S44 gene by ALA under Salt Stress
• 3 Discussion
• 4.Conclusion
• Literature Cited
• Chapter 7 Promotive Effect of ALA on Chlorophyll,Anti-oxidative Enzyme and Photosynthesison Pak choi under hot stress conditions
• Abstract
• Introduction
• 1. Materials and methods
• 1.1 Seed Materials
• 1.2 Preparation of Plant Materials
• 1.3 Determination of Chlorophyll
• 1.4 Determination of Antioxidative Enzymes
• 1.5 Measurement of Photosynthetic Parameter
• 1.6 Data Collection and Statistical Analysis
• 2 Results
• 2.1 Effect of ALA Treatment on Activity of POD of Pak choi Leaves
• 2.2 Effect of ALA Treatment on Activity of CAT of Pak choi Leaves
• 2.3 Effect of ALA Treatment on Activity of SOD of Pak choileaves
• 2.4 Effect of ALA Treatment on Chlorophyll Content of Pak choi
• 2.5 Effect of ALA Treatment on Photosynthesis of Pak choi
• 3. Discussion
• 4. Conclusion
• Literature Cited
• Summary and Conclusion
• Innovation
• Publications
• Acknowledgements