【作者】 刘红开；

【导师】 康玉凡；

【作者基本信息】 中国农业大学 ， 种子科学与技术， 2014， 博士

【摘要】 绿豆芽具有良好的营养保健功能越来越受到人们的青睐,但是随着我国对芽菜食品安全的重视,取缔了6-BA和赤霉素在豆芽生产中的使用,而用清水生产出的绿豆芽不能满足消费者对豆芽感官和品质的要求。乙烯是一种气体植物生长调节剂,广泛应用于果实催熟等过程中。以往研究表明,乙烯可以抑制绿豆芽的生长,改善绿豆芽的营养品质,然而乙烯影响绿豆芽生长和品质改善的机理还不清楚。本试验在研究乙烯对绿豆芽下胚轴差异蛋白质组的基础上,进一步分析了乙烯对绿豆芽活性氧代谢、酚类物质代谢、蔗糖代谢和细胞壁代谢的影响,揭示了乙烯改善绿豆芽外观品质和营养品质以及诱导抗性的变化机制。研究结论如下：(1)本研究利用TMT技术结合质谱分析,对绿豆芽下胚轴蛋白质进行了有效分离和检测。共筛选鉴定蛋白1765个,其中选出上调蛋白共30个,占所有鉴定蛋白总数的1.7%,下调蛋白40个,占所有鉴定蛋白总数的2.3%。差异蛋白等电点范围为4.68-11.6,蛋白质分子量分布范围为9.79-210.93kDa,主要分布范围为9.79-97.14kDa。差异蛋白大多具有结合功能和催化活性等功能,参与到了胁迫抵御、内源乙烯合成、苯丙胺类代谢等代谢过程中。(2)乙烯显著影响到绿豆芽下胚轴的活性氧代谢。乙烯显著增加了过氧化氢等活性氧成分,其中试验处理后第1和第2天,乙烯处理极显著增加了绿豆芽中H202含量,分别是对照的1.24倍和1.15倍,使绿豆芽下胚轴MDA含量增加,造成膜脂过氧化,打破了绿豆芽体内的氧化还原平衡。为抵御乙烯对绿豆芽造成的氧化胁迫,绿豆芽体内的酶促氧化系统和非酶促氧化系统得到了加强。酶促氧化系统中SOD、POD和CAT活性增强,非酶促氧化系统中G6PDH和PAL促进了酚类物质的合成,且酚类物质含量随着乙烯浓度的升高而增大,其中乙烯处理后第1天100mg/L乙烯利处理绿豆芽总酚含量为最高达0.59mg/g,是对照的1.31倍,从而增加绿豆芽下胚轴的抗氧化能力。(3)乙烯促进了绿豆芽下胚轴的蔗糖代谢。乙烯增强了绿豆芽下胚轴SS.AI和SPS活性,促进了蔗糖从子叶到下胚轴的转运和蔗糖的分解,使得绿豆芽下胚轴葡萄糖和果糖含量升高,其中乙烯处理后第4天绿豆芽下胚轴葡萄糖和果糖含量最高,分别为184.67mg/g和186.90mg/g,为豆芽的呼吸消耗和植物细胞的生长提供了物质基础。(4)乙烯抑制了绿豆芽下胚轴的纵向生长,促进了绿豆芽下胚轴的横向生长,改善了绿豆芽的外观品质。在乙烯处理后第4天,乙烯增加了绿豆芽下胚轴体积和鲜重,分别是对照的1.21倍和1.11倍,从而增加了绿豆芽的产量。绿豆芽下胚轴体积和鲜重可作为衡量乙烯对绿豆芽生长影响的指标。乙烯促进了绿豆芽下胚轴细胞壁的合成代谢,使得下胚轴细胞壁含量增加；同时某种程度提高了细胞壁降解酶活性,总体上促进了下胚轴的生长。乙烯诱导了绿豆芽的抗性,改善了绿豆芽的外观品质和营养品质,增加了绿豆芽的产量。研究结果对工厂化绿豆芽高效安全生产提供一定的理论和技术支持。更多还原

【Abstract】 With the nutrition value andhealthyfunction, mungbean sprouts is becoming more and more popular. But along with our country’s emphasis on food safety, the application of6-BA and gibberellic acid are banned in mung bean sprouts production. While mung bean sprouts produced with fresh watercannotmeetthedemand of bean sprouts quality and senses. Ethylene, a gas hormone, is been widely used in fruit ripening and other process. Past research has shown thatethylene can inhibit the growth of mungbean sprout, improve the nutrition quality of mungbean sprout, while the mechanism of ethylene affecting the mungbean sprout growth and quality is still unclear. On the basis of the effect of ethylene on mungbean sprout differential proteome research, the effects of ethylene on mungbean sprout hypocotyl active oxygen metabolism, sucrose metabolism and cell wall metabolism were studied, revealed variation mechanisms of ethylene improving mung bean sprouts appearance and nutrient qualityas well as increasing resistance. Specific research conclusions are as follows:(1) Mungbean sprout hypocotyl protein was separated and detected efficientlyusing the TMT technology and mass spectrometry analysis.1765proteins were screened,30proteins were up-regulated, accounted for1.7%cof screened proteins,40proteins were down-regulated, accounted for2.3%of screened proteins. The isoelectric point range of differential protein is4.68-11.6, the molecular weight distribution rangeof differential protein is9.79-210.93kDa and the main distribution range is9.79-97.14kDa. Most of differential protein have the function of combination and catalytic activity, are involved in resistance to stress, the synthesis of endogenous ethylene, phenylalanine metabolismand other metabolic process.(2) Ethylene affectedsignificantly the active oxygen metabolism of mungbean sprouts hypocotyl.Ethylene increasedsignificantly the hydrogen peroxide and other reactive oxygen species composition, then MDA content of mungbean sprout hypocotyl was increased and membrane lipid peroxidationhappened, and finally the redox balance of mungbean sprouthypocotyl was broken. To protectagainst oxidativestress ethylene causedto mungbean sprout, enzymatic oxidation system and the enzymatic oxidation system of mungbean sproutswere enhanced. SOD, POD and CATactivityin enzymatic oxidation system increased.The increase of G6PDH and PAL activity promoted the synthesis of phenolic substances, thereby antioxidant capacity of.mungbean sprout hypocotyl was enhanced. The increase of phenolics increased the nutritional value of mungbean sprout.(3)Ethylene promotedthe sucrose metabolism of mungbean sprouts hypocotyl. The increase of SS、Aland SPS activity ethylene caused promoted thesucrosetransport from cotyledon to hypocotyl and sucrose decomposition, then glucose and fructose content of mung bean sprouts hypocotylwas elevated. So the the nutritional quality of mungbean sprouts was improved and meanwhile it provided a material basisfor bean sprouts respiration consumption and the plant cell growth. (4) Ethylene inhibited the longitudinal growthof mungbean sprouts hypocotyl and promoted the lateral growth of mungbean sprouts hypocotyl, and then the appearance quality of mungbean sproutgreatly improved. Hypocotyl volume and fresh weight were promoted in four days after ethylene treatment, were1.21times and1.11times compared with controls respectively, thus the production of mungbean sprout hypocotyl was increased. The mungbean sprouts hypocotyl volume volume and fresh weight can be used as an index of measuring the mungbean sprouts growth. Ethylene promoted the synthesis of cell wall metabolism of the mungbean sprouts hypocotyl, so the cell wallcontent was increased, at the same time the cell wall degradation enzymes activity was increased, the growth of the hypocotyl as a whole was promoted.The ethylene induced resistance, improved the appearance quality and nutritional quality of the mungbean sprout, and finally could increase the yield of mungbean sprout. Our research provides theory and technique supports for safe and efficient factory production of mungbean sprouts.更多还原