雪柑实生苗根及上下部叶对缺镁的生理生化响应

发布时间：2018-04-09 13:54

本文选题：氨基酸　切入点：雪柑　出处：《福建农林大学》2017年硕士论文

【摘要】：缺镁(Mg)是一个普遍的问题,严重影响着包括柑橘在内的许多重要农作物的质量和产量。尽管Mg对高等植物的正常生长和发育有着重要的作用,但是相对于其他大量元素如氮(N)、磷(P)、钙(Ca)而言,Mg还是被植物学家和农学家所忽视,被称为"被遗忘的元素"。据我们所知,目前很少有研究者比较调查根和不同叶位叶对缺Mg的生理生化响应。在中国,缺Mg是造成柑橘果实品质差、产量受损的一种常见问题。有鉴于此,本研究以雪柑(Citrussinensis)实生苗为试验材料,率先调查了缺Mg对实生苗生长、上(地上部3/4处)下(地上部1/4处)部成熟叶单位叶面积质量(LMA)、色素含量和核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubisco)活性,以及根和上下部叶气体交换、Mg、碳水化合物、有机酸、可溶性蛋白质、氨基酸、总酚和花青素含量以及有机酸、氨基酸和酚类代谢酶活性的影响,旨在明确缺Mg导致雪柑根和上下部叶气体交换,主要代谢产物和关键酶改变的差异,为柑橘的高产优质栽培提供理论依据。研究结果清楚地显示,除了非结构性碳水化合物外,缺Mg对气体交换(C02同化和暗呼吸)、主要代谢物(有机酸、氨基酸和酚类物质)含量和相关关键酶活性的影响均是下部叶比上部叶更严重,但二者之间的趋势是相似的。尽管缺Mg叶非结构性碳水化合物积累增加,但其C02同化的降低并不能由糖积累反馈抑制光合的机制来解释。为了"消耗"缺Mg下部叶过度积累的碳水化合物,暗呼吸和有机酸代谢在缺Mg下部叶中均上调;而为了保持非结构性碳水化合物积累少的缺Mg根的净碳平衡,暗呼吸和有机酸代谢在缺Mg根中均下调。缺Mg下部叶总酚含量增加,花青素含量减少,而这二者在缺Mg根中均下降。总之,缺Mg诱导的气体交换、主要代谢产物和关键酶的改变在雪柑根和上下部叶之间存在着巨大的差异。
[Abstract]:Magnesium deficiency is a common problem, which seriously affects the quality and yield of many important crops, including citrus.Although mg plays an important role in the normal growth and development of higher plants, it is still neglected by botanists and agronomists, and is called "forgotten element" compared with other elements such as N ~ (2 +), N ~ (2 +), P ~ (2 +), Ca ~ (2 +).As far as we know, few researchers have compared the physiological and biochemical responses of roots and different leaf leaves to mg deficiency.In China, mg deficiency is a common problem that results in poor quality and impaired yield of citrus fruits.Therefore, in this study, the seedling of Citrus sinensis was used as the experimental material, and the growth of the seedlings with mg deficiency was investigated firstly.Up (3 / 4 on the ground) under (1 / 4 on the ground) the unit leaf area per unit leaf area of the mature leaf is LMAA, pigment content and ribonose -1-diphosphate carboxylase / oxygenase Rubiscocoactivity, as well as gas exchange Mg, carbohydrate, organic acid in the root and upper and lower leaves.The effects of soluble protein, amino acid, total phenol and anthocyanin contents and the activities of organic acids, amino acids and phenolic metabolic enzymes on the gas exchange, major metabolites and key enzymes in the roots and upper and lower leaves of Citrus mandarin were determined.To provide theoretical basis for citrus cultivation with high yield and good quality.The results clearly show that, in addition to non-structural carbohydrates, mg deficiency is responsible for assimilation and dark respiration of gaseous exchangers C02, the main metabolites (organic acids, organic acids, etc.)The effects of amino acid and phenolic substances) and related key enzyme activities were more serious in the lower leaf than in the upper leaf, but the trend was similar between them.Although the accumulation of non-structural carbohydrates in mg deficient leaves increased, the decrease of CO2 assimilation could not be explained by the mechanism of feedback inhibition of photosynthesis by sugar accumulation.In order to "consume" the excessive accumulation of carbohydrates in mg deficient lower leaves, dark respiration and organic acid metabolism were up-regulated in mg deficient lower leaves, while in order to maintain the net carbon balance of mg deficient roots with little accumulation of non-structural carbohydrates,Dark respiration and organic acid metabolism were down-regulated in mg deficient roots.The contents of total phenol and anthocyanin in the lower leaves of mg deficiency increased, but both of them decreased in mg deficient roots.In conclusion, mg deficiency induced gas exchange, major metabolites and changes of key enzymes were significantly different between the roots and the upper and lower leaves of Citrus mandarinus.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S666.1

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