外源褪黑素緩解苦蕎干旱脅迫的生理機(jī)制研究
發(fā)布時(shí)間：2021-09-25 10:35
干旱脅迫是全球農(nóng)業(yè)生產(chǎn)的主要障礙之一,常發(fā)生在自然界和農(nóng)業(yè)生態(tài)系統(tǒng)中。證據(jù)表明,干旱脅迫對(duì)植物有拮抗作用,尤其是對(duì)生長(zhǎng)、光合活性、抗氧化活性以及分子水平的變化。然而,由于有限的抗氧化和解毒能力,植物在高強(qiáng)度的干旱脅迫下會(huì)遭受毒性�？嗍w是一種營(yíng)養(yǎng)豐富的小雜糧作物,生長(zhǎng)在干旱半干旱地區(qū)的高寒山地,干旱是一種常見現(xiàn)象,會(huì)延緩生長(zhǎng)和降低產(chǎn)量,因此,提高作物的抗旱性是獲得經(jīng)濟(jì)效益的前提。通過(guò)補(bǔ)充外源激素可以提供額外的功效來(lái)加強(qiáng)植物的解毒系統(tǒng),以抵抗由外源物質(zhì)產(chǎn)生的脅迫。多功能信號(hào)分子褪黑素（N-乙酰-5-甲氧基色胺）廣泛分布于植物的不同部位,在惡劣環(huán)境條件下產(chǎn)生許多生理反應(yīng)。因此,本研究旨在通過(guò)一系列試驗(yàn)研究苦蕎對(duì)干旱脅迫的反應(yīng),并闡明褪黑素在緩解干旱脅迫過(guò)程中可能存在的保護(hù)機(jī)制。主要研究結(jié)果如下:1、本試驗(yàn)研究了干旱脅迫對(duì)苦蕎種子萌發(fā)、生理和生物學(xué)機(jī)制的影響,并篩選抗性最強(qiáng)的苦蕎品種。對(duì)14個(gè)品種進(jìn)行了聚乙二醇（PEG）模擬干旱脅迫處理并設(shè)置4個(gè)脅迫程度（0%、10%、20%和30%）來(lái)評(píng)價(jià)發(fā)芽率和幼苗生長(zhǎng)參數(shù)。結(jié)果表明,在干旱脅迫下,不同品種的發(fā)芽率、相對(duì)含水量（RWC）和各生長(zhǎng)參數(shù)存在顯著...
【文章來(lái)源】：西北農(nóng)林科技大學(xué)陜西省 211工程院校 985工程院校 教育部直屬院校
【文章頁(yè)數(shù)】：188 頁(yè)
【學(xué)位級(jí)別】：博士
【文章目錄】：
Abstract
摘要
Chapter 1.General Introduction
1.1 Background of the study
1.2 Problem statement and justification
1.3 General objectives
1.4 Specific Objectives
1.5 Hypothesis
Chapter 2.Review of Literature
2.1 Tartary buckwheat
2.2 Drought stress and its consequences
2.2.1 Plant stress
2.2.2 PEG6000
2.2.3 What is drought stress?
2.2.4 Concepts and consequences of drought stress on plants
2.3 Effects of drought stress on plant morphology
2.3.1 Germination
2.3.2 Plant growth and development
2.4 Impacts of drought stress on plant physiology
2.4.1 Water relations
2.4.2 Photosynthesis
2.4.3 Stomata properties under drought stress
2.4.4 Oxidative stress and enzymatic regulation
2.4.5 Compatible solutes in the regulation of ROS level
2.4.6 Secondary metabolism in plants
2.5 Mechanisms of adaptation to drought stress
2.6 Gene expression,proteomics,metabolomics
2.7 Melatonin and its overview in plants
2.7.1 History of melatonin in plants
2.7.2 Biosynthesis of melatonin in plants
2.7.3 Melatonin as a plant growth regulator
2.7.4 Melatonin acts as a bio-stimulator and an antioxidant in plants
2.7.5 Exogenous melatonin and plant stress tolerance
2.8 Melatonin in Tartary buckwheat plant under drought stress condition
Chapter 3.Screening of Drought Tolerant Cultivar under Drought Stress in Tartary Buckwheat Genotypes at Germination Stage
3.1 Introduction
3.2 Materials and Methods
3.2.1 Germination percentage, morphological parameter and relative water content
3.2.2 Determination of superoxide anion,MDA content,and osmotic solutes
3.2.3 Quantification of enzymatic antioxidant activity
3.2.4 Statistical analysis
3.3 Results
3.3.1 Effect of PEG induced drought stress on seed germination and morphology
3.3.2 Measurement of stress tolerance index based on seed germination and morphology
3.3.3 Effect of PEG induced drought stress on physiological and biochemical mechanisms
3.3.4 Pearson’s correlation analysis
3.4 Discussion
3.5 Conclusions
Chapter 4.Comparative Study on Physiological and Biochemical Mechanism under Drought Stress in Tartary Buckwheat Plant
4.1 Introduction
4.2 Materials and Methods
4.2.1 Assessment of growth parameter
4.2.2 Estimation of photosynthesis activity and relative leaf water content
4.2.3 Measurement of stomata properties
4.2.4 Quantification of osmotic solutes
4.2.5 Determination of ROS,MDA content and antioxidant activity
4.2.6 Investigation of non-enzymatic antioxidant activity and total antioxidant capacity
4.2.7 Statistical analysis
4.3 Results
4.3.1 The effect of drought stress on plant growth
4.3.2 Chlorophyll, carotenoids and chlorophyll fluorescence
4.3.3 Relative leaf water content
4.3.4 Stomatal properties
4.3.5 Osmotic adjustment
4.3.6 ROS and Malondialdehyde(MDA)content
4.3.7 Enzymatic antioxidant activities
4.3.8 Secondary metabolites antioxidant activities and total antioxidant capacity
4.3.9 Multivariate analysis
4.4 Discussion
4.5 Conclusion
Chapter 5.Exogenous Melatonin Modulates the Physiological and Biochemical Mechanisms of Drought Tolerance in Tartary Buckwheat
5.1.Introduction
5.2.Materials and Methods
5.2.1.Measurement of plant growth parameters
5.2.2.Determination of chlorophyll content and photosynthesis activity
5.2.3.Leaf Ultrastructure
5.2.4.Relative leaf water content and osmotic solutes
5.2.5.Determination of ROS activity,MDA content and Enzymatic antioxidant activities
5.2.6.Contents of secondary metabolites non-enzymatic antioxidant activity and total antioxidant capacity
5.2.7.Statistical analysis
5.3.Results
5.3.1.Effect of exogenous melatonin on plant growth parameters and relative leaf water content
5.3.2.The influence of melatonin supplementation on photosynthesis
5.3.3.Impact of melatonin supplementation on Stomatal properties under drought stress
5.3.4.Impact of foliar application of melatonin on osmotic solutes content under drought stressed plants
5.3.5.Effect of exogenous melatonin on ROS activity and MDA content
5.3.6.Effect of exogenous melatonin on enzymatic antioxidant activities
5.3.7.Impact of melatonin supplementation on enzymatic and non-enzymatic secondary metabolites and total antioxidant capacity
5.3.8 Evaluation of melatonin effects under drought stress by heatmap hierarchical clustering and principal component axis analysis
5.4.Discussion
5.5 Conclusions
Chapter 6.Transcriptome Profiles Revealed the Role of Melatonin in Inducing Drought Tolerance in Tartary Buckwheat Plant
6.1.Introduction
6.2.Materials and Methods
6.2.1.Plant materials and treatments
6.2.2.RNA extraction
6.2.3.Library preparation,Clustering and RNA-sequencing
6.2.4.Transcriptome analysis
6.2.5.Quantitative real-time PCR(q TPCR)method
6.2.6.Statistical analysis
6.3.Results
6.3.1 RNA quality test results
6.3.2 RNA-sequencing analysis
6.3.3 Differentially expressed genes(DEGs)
6.3.4 Mutual DEGs analysis
6.3.5 Gene ontology analysis of DEGs
6.3.6 KEGG pathway analysis of DEGs
6.3.7 Transcript factors
6.3.8 Confirmation of gene expression by q RT-PCR
6.3.9 Photosynthesis pathway
6.3.10 Carotenoid biosynthesis
6.3.11 Biosynthesis of secondary metabolite
6.4 Discussion
6.5 Conclusion
Chapter 7 General Discussion,Conclusions and Future Perspectives
7.1 General discussion
7.2 Conclusions
7.3 Future perspectives
References
Nomenclature
Acknowledgement
About the Author
List of Published Articles
本文編號(hào)：3409567
【文章來(lái)源】：西北農(nóng)林科技大學(xué)陜西省 211工程院校 985工程院校 教育部直屬院校
【文章頁(yè)數(shù)】：188 頁(yè)
【學(xué)位級(jí)別】：博士
【文章目錄】：
Abstract
摘要
Chapter 1.General Introduction
1.1 Background of the study
1.2 Problem statement and justification
1.3 General objectives
1.4 Specific Objectives
1.5 Hypothesis
Chapter 2.Review of Literature
2.1 Tartary buckwheat
2.2 Drought stress and its consequences
2.2.1 Plant stress
2.2.2 PEG6000
2.2.3 What is drought stress?
2.2.4 Concepts and consequences of drought stress on plants
2.3 Effects of drought stress on plant morphology
2.3.1 Germination
2.3.2 Plant growth and development
2.4 Impacts of drought stress on plant physiology
2.4.1 Water relations
2.4.2 Photosynthesis
2.4.3 Stomata properties under drought stress
2.4.4 Oxidative stress and enzymatic regulation
2.4.5 Compatible solutes in the regulation of ROS level
2.4.6 Secondary metabolism in plants
2.5 Mechanisms of adaptation to drought stress
2.6 Gene expression,proteomics,metabolomics
2.7 Melatonin and its overview in plants
2.7.1 History of melatonin in plants
2.7.2 Biosynthesis of melatonin in plants
2.7.3 Melatonin as a plant growth regulator
2.7.4 Melatonin acts as a bio-stimulator and an antioxidant in plants
2.7.5 Exogenous melatonin and plant stress tolerance
2.8 Melatonin in Tartary buckwheat plant under drought stress condition
Chapter 3.Screening of Drought Tolerant Cultivar under Drought Stress in Tartary Buckwheat Genotypes at Germination Stage
3.1 Introduction
3.2 Materials and Methods
3.2.1 Germination percentage, morphological parameter and relative water content
3.2.2 Determination of superoxide anion,MDA content,and osmotic solutes
3.2.3 Quantification of enzymatic antioxidant activity
3.2.4 Statistical analysis
3.3 Results
3.3.1 Effect of PEG induced drought stress on seed germination and morphology
3.3.2 Measurement of stress tolerance index based on seed germination and morphology
3.3.3 Effect of PEG induced drought stress on physiological and biochemical mechanisms
3.3.4 Pearson’s correlation analysis
3.4 Discussion
3.5 Conclusions
Chapter 4.Comparative Study on Physiological and Biochemical Mechanism under Drought Stress in Tartary Buckwheat Plant
4.1 Introduction
4.2 Materials and Methods
4.2.1 Assessment of growth parameter
4.2.2 Estimation of photosynthesis activity and relative leaf water content
4.2.3 Measurement of stomata properties
4.2.4 Quantification of osmotic solutes
4.2.5 Determination of ROS,MDA content and antioxidant activity
4.2.6 Investigation of non-enzymatic antioxidant activity and total antioxidant capacity
4.2.7 Statistical analysis
4.3 Results
4.3.1 The effect of drought stress on plant growth
4.3.2 Chlorophyll, carotenoids and chlorophyll fluorescence
4.3.3 Relative leaf water content
4.3.4 Stomatal properties
4.3.5 Osmotic adjustment
4.3.6 ROS and Malondialdehyde(MDA)content
4.3.7 Enzymatic antioxidant activities
4.3.8 Secondary metabolites antioxidant activities and total antioxidant capacity
4.3.9 Multivariate analysis
4.4 Discussion
4.5 Conclusion
Chapter 5.Exogenous Melatonin Modulates the Physiological and Biochemical Mechanisms of Drought Tolerance in Tartary Buckwheat
5.1.Introduction
5.2.Materials and Methods
5.2.1.Measurement of plant growth parameters
5.2.2.Determination of chlorophyll content and photosynthesis activity
5.2.3.Leaf Ultrastructure
5.2.4.Relative leaf water content and osmotic solutes
5.2.5.Determination of ROS activity,MDA content and Enzymatic antioxidant activities
5.2.6.Contents of secondary metabolites non-enzymatic antioxidant activity and total antioxidant capacity
5.2.7.Statistical analysis
5.3.Results
5.3.1.Effect of exogenous melatonin on plant growth parameters and relative leaf water content
5.3.2.The influence of melatonin supplementation on photosynthesis
5.3.3.Impact of melatonin supplementation on Stomatal properties under drought stress
5.3.4.Impact of foliar application of melatonin on osmotic solutes content under drought stressed plants
5.3.5.Effect of exogenous melatonin on ROS activity and MDA content
5.3.6.Effect of exogenous melatonin on enzymatic antioxidant activities
5.3.7.Impact of melatonin supplementation on enzymatic and non-enzymatic secondary metabolites and total antioxidant capacity
5.3.8 Evaluation of melatonin effects under drought stress by heatmap hierarchical clustering and principal component axis analysis
5.4.Discussion
5.5 Conclusions
Chapter 6.Transcriptome Profiles Revealed the Role of Melatonin in Inducing Drought Tolerance in Tartary Buckwheat Plant
6.1.Introduction
6.2.Materials and Methods
6.2.1.Plant materials and treatments
6.2.2.RNA extraction
6.2.3.Library preparation,Clustering and RNA-sequencing
6.2.4.Transcriptome analysis
6.2.5.Quantitative real-time PCR(q TPCR)method
6.2.6.Statistical analysis
6.3.Results
6.3.1 RNA quality test results
6.3.2 RNA-sequencing analysis
6.3.3 Differentially expressed genes(DEGs)
6.3.4 Mutual DEGs analysis
6.3.5 Gene ontology analysis of DEGs
6.3.6 KEGG pathway analysis of DEGs
6.3.7 Transcript factors
6.3.8 Confirmation of gene expression by q RT-PCR
6.3.9 Photosynthesis pathway
6.3.10 Carotenoid biosynthesis
6.3.11 Biosynthesis of secondary metabolite
6.4 Discussion
6.5 Conclusion
Chapter 7 General Discussion,Conclusions and Future Perspectives
7.1 General discussion
7.2 Conclusions
7.3 Future perspectives
References
Nomenclature
Acknowledgement
About the Author
List of Published Articles
本文編號(hào)：3409567
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