基于蛋白质组学探究AMF诱导玉米根系形态及生理变化的分子机制

Root system is vital organs of plant which uptake and transport water and nutrient, and synthesis and transformation of amino acids and hormones. It is also the direct user of soil resources, and has an extremely important role for crops to adapt to the environment, growth and yield formation. In the previous studies both at home and abroad, it was paid a little attention to the effect of arbuscular mycorrhizal fungi on the plant root system, especially on maize. Guangxi is the important area of maize production in south China, studies the effect of arbuscular mycorrhizal fungi on maize are very important to high product and benefit cultivation as well as safety production. It was found in previous studies that under the condition of soil phosphorus deficiency, arbuscular mycorrhizal fungi can promote the absorption of maize on phosphorus and promote the vegetative growth of maize; root volume and surface area were significantly increased in mycorrhizal maize plant, and resistance to disease was improved. But these are only on the phenotypic research results, it must be set up a project to research systematically from the perspective of proteomics in order to fully disclose growth-promoting effect and mechanisms of action, and find the reason and rule, to provide theoretical foundation for high product and benefit cultivation as well as safety production of maize in south China. Carry out the study no matter in theory or in practice, it is of great significance.

根系是植物吸收和运输水分及养分的重要器官，也是氨基酸、激素等物质合成与转化的重要器官，是土壤资源的直接利用者，对于作物适应环境、生长发育和产量形成具有极其重要的作用。在国内外以往的研究中，对于丛枝菌根真菌对植物地下部根系的影响重视不够，特别在玉米这种作物上这方面的研究尚未系统开展。广西是南方玉米生产的重要区域，研究丛枝菌根真菌对玉米的作用，对于广西玉米的高产高效栽培和安全生产具有十分重要的意义。课题组在前期的研究中发现，土壤缺磷的情况下，丛枝菌根真菌可以促进玉米对磷的吸收，促进玉米营养生长；形成丛枝菌根的玉米植株根系体积和表面积都明显增加，抗病力提高。但这些只是表型上的研究结果，要想全面揭示丛枝菌根真菌对玉米的促生作用及作用机理还必须从蛋白质组学的角度立项加以系统研究，从中找出原因和规律，为南方玉米高产高效栽培和安全生产提供理论依据。开展此项研究无论在理论上还是在实践中都具有重要意义。

前期研究已经发现，丛枝菌根真菌与玉米共生后会引起玉米的根系形态发生改变，但其机理尚不清楚，为更好地揭示其中的机理，本项目系统地研究了丛枝菌根真菌共生改变玉米根系形态的生理生化机制，丛枝菌根真菌共生对玉米根系分泌物的影响，并采用转录组，蛋白质组和代谢组联合的多组学方法分析了丛枝菌根真菌共生引起玉米根系形态变化的内在机制。结果表明：.①丛枝菌根真菌对玉米根系的侵染率随生长期延长而增加，在早期，侵染率增幅比较大，后期增幅趋缓。丛枝菌根真菌共生显著提高了玉米的根系活力、玉米根总长、根分叉数、根连接数、根尖数、根表面积和根体积，但降低了根直径；共生后玉米根系内源激素发生了显著变化，并且根系形态的变化与内源激素的变化显著相关。.②丛枝菌根真菌共生使玉米的根系分泌物中的有机酸成分和含量发生改变，并影响到玉米对养分的吸收和积累。.③多组学联合分析发现，有20个基因、8个蛋白质、12个代谢标志物与丛枝菌根真菌共生后玉米根系形态的变化高度相关，共涉及8条代谢通路。研究初步揭示了AMF共生后玉米根系形态变化的分子机制，表明丛枝菌根真菌共生后玉米根系形态发生变化受到相关的基因，蛋白质和代谢标志物调控，并影响到根系形态建成的代谢通路。.研究还发现丛枝菌根真菌共生后可以缓解苗期玉米的硒胁迫。.研究结果对于揭示丛枝菌根真菌与玉米共生的作用机制，丰富丛枝菌根真菌与作物共生的理论具有重要科学意义，同时对丛枝菌根真菌在作物生产上的应用也提供了理论基础。