酸性土壤占世界可耕地面積的40%。鋁（A1）是地殼中繼氧和硅之后的第三豐富元素,約占地殼的7%。另外,紅壤面積占全國總土地面積的20%以上,且主要分布在中國的熱帶和亞熱帶地區(qū)。在酸性土壤中,鋁毒害是限制作物生長發(fā)育和生產(chǎn)力的主要環(huán)境因素。其中,鋁毒對(duì)植物的毒害癥狀最初和最明顯的癥狀是抑制植物根系伸長。硼（B）是高等植物生長發(fā)育最重要的微量營養(yǎng)素之一,缺硼通常誘導(dǎo)植物根系的異常生長,側(cè)根發(fā)育受阻。硼定義了細(xì)胞壁結(jié)構(gòu)并確保植物受到逆境脅迫時(shí)細(xì)胞壁的穩(wěn)定性。高等植物的細(xì)胞壁含有大量的多糖,包括鼠李半乳糖醛酸（RG-Ⅱ）,硼通過雙酯鍵與RG-Ⅱ交聯(lián)結(jié)合以穩(wěn)定細(xì)胞壁結(jié)構(gòu),充分堆積的細(xì)胞網(wǎng)絡(luò)形成穩(wěn)定的細(xì)胞壁,孔徑減小,細(xì)胞壁收緊,限制大分子/元素進(jìn)入細(xì)胞。由于植物的細(xì)胞壁是鋁積累的主要部位,因此細(xì)胞壁在植物抗鋁毒機(jī)制中具有重要作用。據(jù)報(bào)道,具有羧酸鹽基團(tuán)的初生細(xì)胞壁是鋁吸附的主要位點(diǎn)。目前已研究出幾種農(nóng)藝措施可以減輕鋁的毒害,比如說酸性土壤中施用石灰。然而,施用石灰會(huì)降低必需元素的可用性而對(duì)植物生長產(chǎn)生不利影響,并且在經(jīng)濟(jì)上并不總是可行的。另外,一些學(xué)者已經(jīng)提出硼可以減輕鋁對(duì)植物生長的毒性作用,并... 

【文章來源】：華中農(nóng)業(yè)大學(xué)湖北省 211工程院校 教育部直屬院校

【文章頁數(shù)】：122 頁

【學(xué)位級(jí)別】：博士

【文章目錄】：
摘要
Abstract
CHAPTER 1 Introduction
    1.1 Acid soils and aluminum toxicity
        1.1.1 Acid soils and distribution of acid soils
        1.1.2 Occurrence of aluminum
    1.2 Symptoms of A1 toxicity
        1.2.1 Root growth inhibition
        1.2.2 Alterations in the cell wall structure
        1.2.3 Induction of callose
        1.2.4 Plasma membrane damages
        1.2.5 Nutritional imbalance
        1.2.6 Oxidative stress
    1.3 Measures of alleviating Al toxicity
        1.3.1 Importance of B
        1.3.2 Role of B in the cell wall
        1.3.3 RG-Ⅱ borate complexes in the primary cell wall
        1.3.4 Bio-synthesis of pectic wall polymers (pectin methyltransferase)
        1.3.5 B induced alleviation of Al toxicity
        1.3.6 B induced regulation of apoplastic binding of Al and root injury
        1.3.7 B induced activation of antioxidant defense system
    1.4 Trifoliate orange
    1.5 Research objectives
CHAPTER 2 Boron alleviates aluminum toxicity in trifoliate seedling by regulatingantioxidant defense system and reducing root cell injury
    2.1 Introduction
    2.2 Objective
    2.3 Materials and methods
        2.3.1 Plant material and growth conditions
        2.3.2 Experimental treatments
        2.3.3 Leaf gas exchange parameters and root length measurement
        2.3.4 FDA-PI double staining, hematoxylin and morin staining
        2.3.5 Antioxidant enzyme assay, and determination of MDA, H_2O_2 content
        2.3.6 Assay of phenylalanine ammonia lyase and polyphenol oxidase
        2.3.7 Measurement of total soluble proteins and free proline contents
        2.3.8 Determination of B and A1 concentrations
        2.3.9 Statistical analysis
    2.4 Results
        2.4.1 Effect of B on the plant growth parameters under Al toxicity
        2.4.2 Influence of B on leaf gas exchange parameters under Al toxicity
        2.4.3 FDA-PI double staining, hematoxylin and morin staining
        2.4.4 Effect of B on the total soluble protein, proline, MDA, H_2O_2 contents andantioxidant enzymes activities under Al toxicity
        2.4.5 Effect of B on the PAL and PPO contents under Al toxicity
        2.4.6 B and Al concentration in plant parts
    2.5 Discussion
    2.6 Conclusion
CHAPTER 3 Boron reduces aluminum-induced growth inhibition and oxidativedamages in roots of trifoliate seedling
    3.1 Introduction
    3.2 Objectives
    3.3 Materials and methods
        3.3.1 Plant material
        3.3.2 Growth conditions
        3.3.3 Experimental treatments
        3.3.4 Measurement of root growth and dry biomass
        3.3.5 Extraction of cell wall
        3.3.6 Quantification of total B and A1 concentrations
        3.3.7 Assessment of plasma membrane (PM) integrity and electrolyte leakage in roots
        3.3.8 Measurement of reactive oxygen species, and malondialdehyde contents
        3.3.9 Statistical analysis
    3.4 Results
        3.4.1 Effect of B on root growth, dry weight, and visible symptoms of A1 toxicity
        3.4.2 B and A1 distribution in roots and root cell wall
        3.4.3 Influence of B on ROS levels in roots under A1 stress
        3.4.4 Influence of B and Al on the MDA contents and root electrolyte leakage
    3.5 Discussion
    3.6 Conclusion
CHAPTER 4 Boron increases root growth by reducing aluminum-induced disorganizeddistribution of HG epitopes and alterations in the subcellular cell wall structure oftrifoliate orange roots
    4.1 Introduction
    4.2 Objectives
    4.3 Material and methods
        4.3.1 Plant materials and growth conditions
        4.3.2 Experimental treatments
        4.3.3 Extraction of cell wall
        4.3.4 Determination of B and Al concentrations
        4.3.5 Lumogallion staining and confocal microscopy
        4.3.6 Immunolabelling of low and high-methyl esterified pectin epitope
        4.3.7 Transmission electron microscopy of roots
        4.3.8 FTIR sample preparation and analysis
        4.3.9 Statistical analysis
    4.4 Results
        4.4.1 Root growth response to Al toxicity
        4.4.2 Localization of A1 with lumogallion staining
        4.4.3 Transmission electron microscope of roots
        4.4.4 Effect of A1 toxicity on JIM5 and JIM7 homogalacturonan epitopes
        4.4.5 FT-IR analysis of root cell wall
    4.5 Discussion
    4.6 Conclusion
CHAPTER 5 Boron supply maintains efficient antioxidant system, cell wall componentsand reduces aluminum concentration in roots of trifoliate orange
    5.1 Introduction
    5.2 Objectives
    5.3 Materials and methods
        5.3.1 Plant material and growth condition
        5.3.2 Experimental treatments
        5.3.3 Plant sampling and specimen preparation
        5.3.4 Extraction of cell wall material
        5.3.5 Quantification of Al and B in root apex and cell wall
        5.3.6 Fractionation of cell wall components
        5.3.7 Measurement of monoamine oxidase,xanthine,T-AOC,and VC concentrations
        5.3.8    Histochemical analysis of callose deposition
        5.3.9 Statistical analysis
    5.4 Results
        5.4.1 Effect of B on the root growth under A1 toxicity
        5.4.2 Localization of A1 in the root tips through confocal laser microscope
        5.4.3 Fractionation of Al
        5.4.4 Cell wall components
        5.4.5 Activities of monoamine oxidase, xanthine oxidase, vitamin C (VC) and totalantioxidant capability (T-AOC) in leaves
        5.4.6 Effect of A1 on callose deposition
        5.4.7 Principal component analysis
    5.5 Discussion
    5.6 Conclusion
CHAPTER 6 General conclusion
    6.1 Plant growth characteristics
    6.2 Al concentration in roots
    6.3 Alteration in cell wall components
    6.4 Distribution of HG epitopes
    6.5 Efficient antioxidant system
    6.6 Oxidative stress and root injuries
    6.7 Current issues and future directions
Reference
Major Achievements during PhD
Achievements/Awards
Acknowledgement


【參考文獻(xiàn)】：
期刊論文
[1]贛南臍橙葉片黃化及施硼效應(yīng)研究[J]. 姜存?zhèn)},王運(yùn)華,劉桂東,夏穎,彭抒昂,鐘八蓮,曾慶鑾.  植物營養(yǎng)與肥料學(xué)報(bào). 2009(03)



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