玉米粒位效应的差异蛋白质组学机制及其对6-BA调控的响应

发布时间：2018-07-07 08:24

本文选题：夏玉米 + 6-BA　；参考：《山东农业大学》2017年博士论文

【摘要】：在大田生产中,增加种植密度是当前玉米品种获得高产的重要举措。但玉米籽粒发育存在显著粒位效应,即与雌穗中、下部强势籽粒相比,上部弱势籽粒灌浆启动慢,灌浆充实不充分,最终粒重低。过高的种植密度会加剧这种粒位差异,甚至导致弱势籽粒败育,严重限制玉米高产潜力的发挥。因此,密植条件下探究玉米粒位效应的成因,并采取有效栽培措施促进籽粒灌浆不仅是理论研究的必要,并且在生产实践中也具有重要的指导意义。本研究于2015-2016年在山东农业大学黄淮海区域玉米技术创新中心和作物生物学国家重点实验室进行,选用高产夏玉米品种郑单958和登海661为试验材料,种植密度90000株hm-2,采用田间试验小区的方法从生理学层面研究玉米强、弱势籽粒发育差异的原因以及喷施6-BA对玉米强、弱势籽粒生长发育的调控效应,同时重点利用i TRAQ为基础的蛋白质组学技术探讨玉米强、弱势籽粒发育过程中差异蛋白质组的表达特性,着重在蛋白水平上揭示玉米粒位效应的成因,以期为改善籽粒灌浆,实现玉米高产高效栽培提供理论依据和技术支持。主要研究结果如下:1.玉米弱势籽粒的库容与库活性显著低于强势籽粒籽粒库容建成期,弱势籽粒最大胚乳细胞增殖速率及平均增殖速率、最大胚乳细胞数目均显著低于强势籽粒,导致弱势籽粒库容量较低。籽粒灌浆期,强、弱势籽粒间同化物供应无显著差异,但弱势籽粒的淀粉和蛋白积累量均显著低于强势籽粒,造成弱势籽粒灌浆速率慢、最终粒重低。弱势籽粒较低的淀粉积累量与其灌浆期较低的蔗糖-淀粉代谢相关酶Su Sy、AGPase、SSS、GBSS以及SBE活性有关。玉米籽粒内源激素含量与籽粒灌浆速率呈显著或者极显著正相关。但玉米强、弱势籽粒间内源激素含量存在显著差异,灌浆前、中期弱势籽粒ZR、IAA、GA3以及ABA含量均明显低于强势籽粒,这也是造成弱势籽粒灌浆较差的重要原因。2.玉米籽粒不同发育阶段展现相异的蛋白表达特性本研究首次利用i TRAQ蛋白质组学技术分析了玉米籽粒发育过程中的蛋白表达特性,在玉米籽粒中共鉴定到4751种蛋白,这些蛋白涉及多种生物过程与分子功能,其中生物过程主要涉及代谢过程和分子过程;分子功能主要行使催化活性和绑定功能,这些生物过程与分子功能对籽粒发育具有重要作用。玉米籽粒发育过程中1235种蛋白显著差异表达,其功能涉及多种分子及代谢途径,蛋白代谢和基础代谢相关蛋白表达差异最大。籽粒发育过程中不同蛋白功能组的表达存在时序性差异。玉米籽粒发育早期细胞生长与分裂相关蛋白显著积累,而淀粉合成相关蛋白以及贮藏蛋白分别在玉米籽粒发育中、后期显著积累。中心碳代谢途径(EMP、TCA、PPP以及EF)在玉米籽粒发育过程中动态变化,其中TCA以及PPP途径主要在玉米籽粒发育早期表现活跃,而EMP和EF途径主要在玉米籽粒发育中期表现活跃。123种胁迫相关蛋白在玉米籽粒发育过程中显著差异表达,主要参与籽粒蛋白修饰、ROS体内平衡、贮藏物质保护、病虫害响应及其它胁迫响应过程。其中,蛋白修饰相关蛋白在籽粒不同发育阶段均显著积累,有助于稳定籽粒的蛋白结构;ROS体内平衡相关蛋白主要在籽粒发育前、后期显著积累,有利于维持籽粒ROS体内平衡;贮藏物质保护以及病虫害响应相关蛋白主要在籽粒发育后期显著积累,进而保护贮藏物质的正常合成以及增强籽粒对生物胁迫的抗性。3.玉米强、弱势籽粒间蛋白质组表达特性存在差异玉米籽粒发育前、中期利用i TRAQ蛋白质组学技术在玉米强、弱势籽粒间发现305种显著差异表达蛋白。这些蛋白涉及多种分子和代谢途径,其中表达差异较大的是与蛋白代谢和基础代谢相关的蛋白。与强势籽粒相比,弱势籽粒中细胞增殖相关蛋白显著滞后表达,而淀粉合成相关蛋白显著下调表达,进而导致弱势籽粒较小的库容量以及较低的库活性。同时,弱势籽粒中低活性的糖酵解途径,减少了其物质合成所需的能量供应。此外,面对氧化应激等逆境时,弱势籽粒相关的抗氧化酶系统以及胁迫响应蛋白表达紊乱,降低了其对逆境胁迫环境的抵抗力。4.外源6-BA促进了玉米强、弱势籽粒的发育外源6-BA处理提高了灌浆前、中期玉米强、弱势籽粒中内源激素ZR、IAA、ABA、GA3的含量,通过影响玉米强、弱势籽粒内源激素水平,增加了胚乳细胞增殖速率以及胚乳细胞数目,进而提高了籽粒库容,为积累更多的干物质提供了基础;同时6-BA处理显著增加了玉米强、弱势籽粒中可溶性糖含量,提高了同化物供应,另一方面通过提高蔗糖-淀粉代谢相关酶Su Sy、AGPase、SSS、GBSS以及SBE的活性,促进了淀粉积累,增加了灌浆速率,进而最终提高了籽粒粒重及产量。
[Abstract]:In the field production, increasing the planting density is an important measure for the current maize varieties to obtain high yield. But there is a significant grain position effect in maize grain development, that is, compared with the female ear, the lower grain grain filling is slow, the grain filling is insufficient and the final grain weight is low. The high planting density will aggravate the grain difference, and the difference of grain position will be aggravated. Therefore, it is not only necessary for theoretical research to explore the causes of corn grain position effect and to take effective cultivation measures to promote grain filling under dense planting conditions, but also have important guiding significance in production practice. This study was in Shandong agriculture in 2015-2016 years. The maize technology innovation center and the State Key Laboratory of Crop Biology were studied in the Huang Huai Hai region. The High Yield Summer Maize Variety Zhengdan 958 and 661 of the land on the sea were selected as the experimental materials, and the planting density was 90000 hm-2. The reasons for the difference of corn strong, weak grain development and the spraying of 6-BA to jade were studied by the method of field experiment. The regulation effect of rice strong and disadvantaged grain growth and development, and focusing on I TRAQ based proteomics technology to explore the expression characteristics of different protein groups in the process of maize strength and disadvantaged grain development, and to reveal the cause of corn grain position effect on the protein level, in order to improve grain filling and realize high yield and high efficiency cultivation of maize. The theoretical basis and technical support were provided. The main results were as follows: 1. the storage capacity and the activity of the disadvantaged grains were significantly lower than that of the strong grain reservoir capacity, the maximum endosperm cell proliferation rate and average proliferation rate of the disadvantaged grains, the maximum endosperm cell number were significantly lower than that of the strong grain, which resulted in the lower seed bank capacity. There was no significant difference in the supply of assimilates between grain filling, strong and disadvantaged grains, but the accumulation of starch and protein in weak grains was significantly lower than that of strong grain, which resulted in slow grain filling rate and low grain weight. The low starch accumulation of weak grains and low starch metabolism related enzymes Su Sy, AGPase, SSS, GBSS and S were lower in the grain filling period. BE activity was related. The content of endogenous hormones in corn grains and grain filling rate showed significant or very significant positive correlation. But corn was strong and the content of endogenous hormones in disadvantaged grains was significantly different. Before filling, the content of ZR, IAA, GA3 and ABA in the weak grain were significantly lower than that of strong grains in the middle period, which was also an important source of poor grain filling. The protein expression characteristics of different developmental stages of.2. corn grain were presented in this study. The protein expression characteristics during the development of corn kernel were analyzed by I TRAQ proteomics technology for the first time. 4751 kinds of proteins were identified in maize grains. These proteins involved a variety of biological processes and molecular functions, among which biological processes were mainly involved. And the metabolic processes and molecular processes; molecular functions mainly exercise catalytic activity and binding function. These biological processes and molecular functions play an important role in the development of grain. 1235 proteins are significantly different in the process of maize grain development, and their functions involve a variety of molecules and metabolic pathways, protein metabolism and the expression of basic metabolic related proteins. The difference was the greatest. The expression of different protein functional groups in the process of grain development had a temporal difference. In the early stage of maize grain development, cell growth and mitotic proteins accumulated significantly, while starch synthesis related proteins and storage proteins were accumulated during the development of corn grain, and the central carbon metabolism pathway (EMP, TCA, PPP and EF) was in jade. In the development process of rice grain, TCA and PPP pathway were mainly active in the early stage of maize grain development, while EMP and EF pathway mainly expressed active.123 stress related proteins in maize grain development during the middle period of maize grain development, and mainly involved in grain protein modification, ROS balance and storage. The protein modification related proteins accumulated significantly in the different stages of grain development, which could help stabilize the protein structure of grain, and the balance related protein in ROS was mainly accumulated before the grain development and later in the later period, which was beneficial to the balance of the ROS in the Yu Weichi grain, the preservation of storage material and the disease. The response related proteins of insect pests mainly accumulate at the late stage of grain development, and then protect the normal synthesis of storage materials and enhance the resistance of.3. corn to the grain to biological stress. The expression characteristics of protein groups in the disadvantaged seeds are different before the development of corn grains. In the medium term, the I TRAQ proteomics technology is used in the strong and disadvantaged grains between the corn and the weak grain. 305 distinct differentially expressed proteins were found. These proteins involved a variety of molecular and metabolic pathways, in which the protein metabolism and basal metabolism were significantly different. Compared with the strong grains, the cell proliferation related proteins in the weak grains were significantly lagged, and the starch synthesis related proteins were significantly downregulated and then resulted in a significant decrease in the expression of protein related proteins. At the same time, the low active glycolysis pathway in the disadvantaged grains reduces the energy supply needed for its material synthesis. In addition, in the face of adverse conditions such as oxidative stress, the weak grain related antioxidant enzymes and stress response proteins are expressed in disorder, which reduces the stress environment for adversity stress. Resistance.4. exogenous 6-BA promoted maize strong, the disadvantaged grain development exogenous 6-BA treatment improved the content of endogenous hormone ZR, IAA, ABA, GA3 in the weak grain before grain filling, and increased the growth rate of endosperm cells and the number of endosperm cells by affecting the maize strong and weak grain endogenous hormone levels, and then increased the grain size. The storage capacity provides a basis for accumulating more dry matter; at the same time, 6-BA treatment significantly increases corn strength, soluble sugar content in disadvantaged grains, increases the supply of assimilates, on the other hand, enhances the accumulation of starch, increases the grain filling rate by increasing the viability of sucrose starch metabolism related enzymes Su Sy, AGPase, SSS, GBSS and SBE. The seed weight and yield were improved.
【学位授予单位】：山东农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S513

【参考文献】