Effects Of Cultivation Measures On LOX Activity And Fatty Acids Component Of Wine Grape

Green leaf volatiles(GLVs)are important components of grape aromas.The GLVs play an important role in quality of fruit,style of wine,biological control and so on.The pathway by which GLVs are formed during berry development is called GLV pathway.It is important for adjusting grape aromas development to study the synthesis mechanism of GLVs and realize the regulating effect.Taking Cabernet Sauvignon,Pinot Noir and Chardonnay as test materials,and applying treatments(including plant growth regulators,picking old leaves,mechanical injury,bagging,different harvest time)on the plant,this paper aimed to study the effects of different treatments on activities of lipoxygenase(LOX)which is the key enzyme of GLV pathway,and content of linoleic acid which is the direct substrate of GLV pathway.This paper can provide theoretical basis for production management of wine grapes.The treatments are applied during the beginning of the version,the LOX and fatty acid analyze take place when the grapes mature.The standard spectrophotometric method is used for analyzing the LOX activity,and the Gas chromatography-mass spectrometry(GC-MS)method is used for analyzing the fatty acids component.The results are as showed below.1.The linoleic acid content of rape skin from Pinot Noir went up gradually when the concentration of ABA increased,whereas the linoleic acid content of rape skin from Chardonnay or Cabernet Sauvignon went down.The linoleic acid content of samples by exogenous MeJA treatment is lower than control group.Besides,the content became lower,and then higher as the concentration of MeJA is increased.2.Light intensity,harvest time,mechanical injury can affect the content of linoleic acid.Besides,the effects are related to grape variety.3.After treatments on Pinot Noir,the variation trends of LOX activity and fatty acids content are exactly opposite.However,there was no significant correlation of LOX activities with linoleic acid content.4.Research on the three varieties has some similar results.Firstly,the three main unsaturated fatty acids are linoleic acid,oleic acid and palmitoleic acid.Secondly,there was no linolenic acid.Thirdly,the four main saturated fatty acids are hexadecanoic acid,stearic acid,docosanoic acid and eicosanoic acid.The linoleic acid content in skins of Pinot Noir berry was significantly higher than Chardonnay and Cabernet Sauvignon.