【作者】 原牡丹；

【导师】 徐程扬； 侯智霞；

【作者基本信息】 北京林业大学 ， 森林培育学， 2010， 博士

【摘要】 糖代谢和类黄酮代谢是草莓(Fragaria ananassa Duch.)果实发育过程中两个重要的生理代谢过程。草莓果实发育过程中,糖和类黄酮代谢途径都受到植物激素特别是生长素的调控。本研究以露地栽培的“全明星”草莓为试材,利用生长素极性运输抑制剂1-萘氨甲酰苯甲酸(NPA)和2,3,5—三碘苯甲酸(TIBA)处理发育着的草莓果实,从生长素自身代谢活动调节、生长素调控蔗糖代谢以及类黄酮响应生长素信号机制三个方面研究了生长素对草莓果实品质形成的调控机理。草莓果实发育过程中生长素主要作用时期在果实发育前期和转色期,细胞壁离子键结合的吲哚乙酸氧化酶(IAO)对吲哚乙酸(IAA)的降解起主要作用。草莓果实中,盛花期的瘦果和花托中都含有大量的吲哚乙酸,瘦果中的吲哚乙酸含量远高于花托中,分别为：2.34μg·g-1、0.065μg·g-1。吲哚乙酸及生长素结合蛋白(ABP1)均特异分布于维管束组织韧皮部。试材草莓果实中糖分的积累以已糖为主,生长素抑制剂处理使草莓果实含糖量增加。红熟期对照(CK)、NPA、TIBA含糖量分别为：0.39g·100g-1、0.40 g·100g-1、0.20g·100g-1(蔗糖)；0.41g·100g-1、0.40g·100g-1、0.26g·100g-1(果糖)；0.38g·100g-1、0.46g·100g-1、0.19g·100g-1(葡萄糖)。葡萄糖对生长素信号感应最明显,响应生长素信号的蔗糖代谢酶主要是蔗糖合成酶(SS)和酸性转化酶(AI)。其中,蔗糖合成酶分解活性和合成活性对生长素信号最敏感时期分别在果实发育前期和发育后期,而酸性转化酶在整个果实发育过程中对生长素信号的响应都较强。草莓果实中蔗糖合成酶和酸性转化酶分布的组织相同,均主要分布于维管束组织韧皮部。草莓果实发育过程中,花托内总类黄酮和总酚的含量先上升后下降,到转色期继续上升直至成熟。生长素极性运输抑制剂在发育前期可减缓果实中总类黄酮和总酚含量下降速度,发育后期增加花色苷的含量。类黄酮代谢关键酶查尔酮合成酶(CHS)和查尔酮异构酶(CHI)均主要分布于维管束细胞韧皮部。经蔗糖和吲哚乙酸渗透处理,草莓果实圆片中查尔酮合成酶和查尔酮异构酶的转录和翻译水平增强,蔗糖和吲哚乙酸诱导了CHS与CHI的表达,使得总类黄酮、总酚、花色苷的含量随之大量增加。吲哚乙酸和蔗糖互作试验结果表明,在对糖介导的类黄酮物质合成过程的调控上,吲哚乙酸的促进作用表现在转录水平和翻译水平。更多还原

【Abstract】 Sugars and Flavonoids are important plant primary and secondary metabolites respectively.Their metabolisms are regulated by Auxin in Strawberry fruit. The strawberry (Fragaria ananassa Duch.)(All-Star) fruit was used as materials to investigate the regulation of sugar metabolism and flavonoid metabolism by Auxin so that the effects of polar auxin transport inhibitors on the sugar and flavonoid accumulations and metabolisms can be clearly elucidated. Study methods emphasized on exogenous inhibitors of polar auxin transport application (NPA, TIBA). Experimental results were obtained as f followed.The most important period of IAA on developing strawberry was in the preceeding period and the inception period. Activities of ionic-bond IAO in cytoderm had great effect on the decomposing of IAA. IAA content in achenes was higher than that in receptacles: 2.34μg·g-1、0.065μg·g-1. IAA and ABP1 signal mainly localized in the vascular tissues of the receptacles, and mainly localized in the phloem.Hexose was the dominant sugar in the strawberry fruit development. After treatment with NPA and TIBA, the sugar contents of fruit increased:0.39g·100g-1、0.40 g·100g-1、0.20g·100g-1 (Sucrose); 0.41g·100g-1、0.40g·100g-1、0.26g·100g-1 (Fructose); 0.38g·100g-1、0.46g·100g-1、0.19g·100g-1 (Glucose). The most sensitive sugar to the IAA regulation was Glucose. The decomposing activity of SS and the synthesis activies of SS were in the preceeding period and the later period respectively were sentive to IAA. And the activity of AI was sensitive to IAA in the fruit development. AI and SS signal mainly localized in the vascular tissues of the receptacles, and mainly localized in the phloem.The treatments of NPA and TIBA slow down the drop of total flavonoids and total phenols contents in the preceeding period and increased anthocyanin content in the later period during the strawberry fruit development. CHS and CHI mainly localized in the vascular tissues of the receptacles, and mainly localized in the phloem. Sliced strawberry was used to assess the effect of sugars and IAA on flavonoids accumulation and CHS, CHI expression. The results showed that IAA and sucrose induced both the flavonoids accumulation and CHS and CHI expression by enhancing their amount in both transcription and translation levels. The Interaction between sucrose and IAA was studied in the expression of sucrose-induction of the flavonoids accumulation. The results indicated that IAA treatment inhance the transcription level and translation levels of flavonoids.更多还原