Study On The Changes Of Sugar Accumulation,Metabolic Enzyme Activity And Gene Expression In The Fruits Of Jujube

Sugar composition and content in fruits is one of the important indicators to fruit quality,and the metabolism of sugar in fruit is extremely complex,controlled by a variety of enzymes.In order to understand the sugar accumulation regularity and the relationship between the main enzymes and related genes in jujube fruits,this paper used Junzao and Dongzao to make material,used HPLC-ELSD method,to detect and analyze the sugar compositions and contents during the development of jujube.To studied the activities of sugar metabolism related enzymes(invertase,sucrose synthase and sucrose phosphate synthetase)in jujube fruits,The real-time quantitative PCR technique was used to analyze sugar metabolism related enzyme gene transcription level has carried on the dynamic analysis in jujube fruits.The main results were as follows:1.High performance liquid chromatography with evaporative light-scattering detector(HPLC-ELSD)was developed for the determination of soluble sugar in jujube fruit: Waters XBridgeTM Amide(250mm×4.6mm,5?m)column,the column temperature of 30?,the mobile phase was 0.2% triethylamine ultrapure water and 0.2% Acetonitrile,the mobile phase ratio was 24:76(v/v),the atomization tube temperature was 60?,the drift tube temperature was 60?,the gas flow rate was 1.6 L/min,the gain value was 1.0;fructose,sucrose,maltose,lactose,arabinose and rhamnose were detected in mature jujube fruits using this HPLC-ELSD methods,the rhamnose was not detected in Junzao.Sucrose,glucose and fructose were the major components in jujube fruits,Junzao and Dongzao belong the Sucrose accumulates fruit.2.The sucrose content in the early stage of jujube fruit ripening was lower,the main accumulated sugar was glucose and fructose,and the sucrose began to accumulate at the mature stage,and reached the highest value at Junzao 27.34% and Dongzao 31.82%;Glucose and fructose in jujube fruit throughout the reproductive period haven't changed much,Dongzao sugar and total sugar content has been greater than Jun jujube.3.In the early stage of jujube fruit development,AI,NI and SS-c activity were high,SPS and SS-s activity were low,the mainly sucrose metabolism was decompose sucrose;With the growth and development of the fruit,SPS and SS-s activity were increased,AI,NI and SS-c activity were reduced,give priority to with sucrose synthesis metabolism.In the whole fruit maturation,sugar content and SPS and SS-s has very significant positive correlation.4.One AI gene expression analysis showed that,Relative expression of AI was not significantly related to fructose and glucose contentthere,but showed a regular relationship with the activity of AI,indicating that AI plays an important role in the regulation of hexose balance in jujube fruit effect.Five NI gene expression analysis showed that expression level of NI1 gene was the highest among NI genes investigated during fruit ripening,expression level of NI4 gene was the lowest,NI2 was only expressed in young fruit stage,NI5 and NI enzyme activity were consistent;The trend of gene expression abundance of NI3 and NI4 gene were similar Junzao and Dongzao,indicating that activity of NI during fruit ripening of jujube may be controlled by all of these five gene.Three SS gene expression analysis results show that the relative expression of three members of the family of sucrose synthase genes exist great differences,SS1 gene expression level was extremely low,and the SS-c reactive change trend was consistent,SS2 and SS-s activity trends was consistent,SS3 only abundantly expressed in the late development of Dongzao fruit,suggesting SS3 may play an important role in the Dongzao fruit,indicating that this three SS gene family members may be the common regulation of jujube fruit sugar metabolism;Four SPS gene expression analysis,according to the results of four SPS gene families gene expression in the peak volume time earlier than sucrose content peak time,different SPS gene expression differences in jujube fruit,SPS1 and SPS2 relative expression is low,SPS3 abundantly expressed in the late jun jujube fruit,SPS4 abundantly expressed in the late development of Dongzao fruit,speculation SPS3 on Junzao fruit sugar accumulation in the process of development regulation function was stronger,SPS4 of Dongzao fruit sugar accumulation in the process of development regulation function was stronger.