Effects Of Postharvest Storage Temperature On Ginger Quality And Its Mechanis

Ginger is vulnerable to suffer diseases during postharvest storage,and environmental temperature is one of the important factors influence storage diseases.Environmental temperature not only influences the disease,but also affects the quality of ginger,which increases the difficulty of storage.The cause agents may be the change of endophytic microbial community structure and metabolites in ginger.Therefore,it is necessary to study the mechanism of microorganisms and metabolites effect on the storage quality of ginger.In this study,the effect of different storage temperature on the incidence of ginger was studied.Physiological and biochemical properties such as ginger hardness and the content of Vc,total sugar,total protein and crude fiber were detected in every temperature treatment group.The difference of microbial communities and metabolites in asmptomatic and symptomatic were analyzed by multi-omics.Meanwhile,the correlation between microorganisms and metabolites was also studied,which explore the effect of microbial communities on ginger metabolites and ginger quality.,The output of this study was exploring the suitable tempreature to storage ginger rhizomes.The main resultswere as follows:(1)In all of temperature treated group,the incidence of ginger rhizomes was loweest at 9 ℃,and the hardness,total sugar content,total protein content and Vc content were maintained at a highest value,while the crude fiber content was also lowest.With the extension of storage time,the rhizomes hardness,total sugar content,total protein content and Vc content in symptomatic group were obvious decline compared with asymptomatic group.Wile the crude fiber content in symptomatic group obviously increased.At the end of experiment,the changes of detected datas were significantly different from treated groups.In addition,the disease incidence,rhizomes hardness,total sugar content,total protein content,Vc content and crude fiber content of ginger in the in symptomatic group treated at 16℃ were 35.7 %、219、10.77 %、1.93 g / 100 g、0.21 g / 100 g and 10.9 %,respectively,which were significantly different from those treated at 9 ℃,but there is no significant difference with the change value of 12.5℃ treatment.In summary,9 ℃ was determined as the better temperature for postharvest storage of ginger.(2)At the end of experiment,the high-throughput sequencing technique was used to sequence the 16 Sr RNA of treated ginger rhizomes.It was found that the abundance and diversity of microbial communities in the symptomatic group were higher than that in the asymptomatic group.,And there were dynamic changes at different storage temperatures.Norrank＿f＿norrank＿o＿chloroplast and Coxiella were the dominant bacteria in the disease-free group(H),while unclassified＿f＿enterobacteriaceae and Enterobacter were the dominant bacteria,and the microbial community had a dynamic change.With the increase of storage temperature,the genera of unclassified＿f＿enterobacteriaceae were fluctuant in symptomatic group.(3)At the end of experiment,through the metabonomics analysis of ginger stored at different temperatures and before storage,1816 differential metabolites were identified in symptomatic group.The number of differential metabolites increased accompanied with temperature rise.The differential metabolites mainly included organic acids,nucleic acids,lipids,hormones and transmitters,carbohydrates,etc.,and the metabolic pathways that were significantly enriched were citric acid cycle,lysine degradation and so on.(4)Through Pearson correlation analysis of ginger stored at different temperatures,it was found that 5-methoxyindole acetate,uridine,yeast acid,N-acetylmannosamine and stachyose were closely related to the flora,and stachyose was significantly up-regulated in the differential metabolite analysis of D12.VS.H12,and stachyose promoted the growth of Enterobacter.In addition,Enterobacter showed a strong negative correlation with yeast amino acid and 5-methoxyindole acetate,and a strong positive correlation with stachyose.Compared with the analysis of differential metabolites of D12.VS.H12 and D16.VS.H16,yeast amino acid and 5-methoxyindole acetate were significantly down-regulated.The results showed that Enterobacter and its corresponding Proteobacteria might affect the storage quality of ginger to some extent.