Study On The Sugar And Flavonoid Metabolisms And Their Responses To Auxin Signal In Developing Fruit Of Strawberry

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.