Ethylene And Its Main Biochemical Components After In Vitro Tea Tree Shoots Regulation Research

Ethylene is an important plant hormone,which has the ability of enhancing color and aroma,regulating acidity and sweetness,and regulating volatile components,and plays an important role in plant postharvest physiology.Wistering provides conditions for material accumulation and transformation during tea processing.In vitro tea shoots are subjected to water stress,but in vivo tea shoots still perform physiological activities.Based on the application example of ethylene,this study took the fresh shoots of isolated tea tree with one bud and two leaves as the material,set up three treatments,and applied exogenous ethylene to the withering of fresh shoots of isolated tea tree.Normal withering was used as control group,spray method in auxiliary production and ethylene by air as ethylene group,and ethylene inhibitor was used as 1-MCP group.In order to provide theoretical basis for the new wither technology and the improvement of tea processing quality,the dynamic changes of main biochemical components in different treatments of wither were analyzed to explore the changes of biochemical components in the fresh shoots of isolated tea trees regulated by ethylene.The main results of this study are as follows:(1)Changes of main biochemical components during spraying treatmentFresh flavor amino acids,theanine,aspartic acid and glutamic acid are up-regulated by ethylene.The sweet amino acids showed three trends in response to ethylene spraying.Ethylene significantly up-regulated the contents of glycine and threonine,and alanine had different responses to different withering stages.These results indicated that glycine was up-regulated by ethylene,threonine content might be affected by water,and alanine was not completely regulated by ethylene.The bitter amino acids histidine,tyrosine,valine,isoleucine and leucine are up-regulated by ethylene.Ethylene down-regulated EGCG,up-regulated ECG,up-regulated GCG at the early stage of wilting,and down-regulated GCG at the late stage.GC and C were not regulated by ethylene,while EGC and EC were down-regulated by ethylene.The main component of alkaloids,caffeine,was significantly down-regulated by 1-MCP group,and significantly down-regulated by ethylene group at 8h and 12 h.The content of theobromine and theophylline in alkaloids was low,and there was little difference among different treatments.The response of each volatile component to ethylene group and 1-MCP group was different.Geraniol and jasmonone were significantly up-regulated during withering,and jasmonone had the most significant effect.Ethylene significantly decreased 2-phenylethanol,oxides,oxides and some esters.(2)Changes of main biochemical components in gas treatmentThe contents of theanine,glycine and histidine were upregulated by ethylene in the early stage of withering.The contents of glutamic acid,serine,threonine,alanine,proline,tyrosine,valine,isoleucine,leucine and phenylalanine were down-regulated by ethylenes,and the overall differences were not significant.EGCG was significantly up-regulated in ethylene group,and GCG was significantly up-regulated in early withering.GC,EGC,C were not completely up-regulated by ethylene,while EC was generally down-regulated by ethylene.Theobromine and theobromine were significantly up-regulated by ethylene in the early withering period,but down-regulated significantly in the late withering period.Ethylene group significantly reduced the contents of various volatile substances.In conclusion,exogenous application of ethylene plays a regulatory role in the main biochemical components of tea shoots after isolation,which can be summarized as follows: spraying increases the content of free amino acids,and decreases the content of bitter and astringent substances such as caffeine and catechin.The effect of gas application on the up-regulation of free amino acids was limited,the contents of caffeine and catechin were up-regulated,and the contents of volatile substances were significantly reduced.