Physiological Metabolism Characteristics Of Early Spring Flowering Plants In Maoershan Forest Region In Heilongjiang Province

Early spring flowering plants are a special kind of plants that bloom in the cold early spring and quickly complete their life cycle.They quickly lose their leaves at the beginning of winter snow and bloom in early spring after a short vegetative growth.Therefore,they are highly adapted to the humidity in the cold habitat of forests.In order to better understand and utilize these special plants,understand their adaptability to the external environment,we collected five early spring flowering plants(Adonis amurensis Regel et Radde,Anemone amurensis(Korsh.)Kom.,Fritillaria ussuriensis Maxim,Smilacina japonica A.Gray,Gagea lutea(L.)Ker-Gawl.)and five unflowered plants(Aquilegia viridiflora Pall.,Cimicifuga foetida L.,Aconitum carmichaeli Debx.,Veratrum nigrum L.,Lilium distichum Nakai)for the study,based on non-targeted GC-MS and targeted LC/MS metabolomics technology Platform,combined with physiological and ecological indicators,comprehensively analyzed the physiological mechanism and metabolic characteristics of early spring flowering plants,and obtained the following conclusions:(1)The chlorophyll a,chlorophyll b and total chlorophyll of early spring flowering plants were lower than unflowered plants;meanwhile,the soluble sugar content of early spring flowering plants was higher than that of unflowered plants,while the soluble sugar content of early spring flowering plants was higher than that of unflowered plants.The protein content is lower than that of unflowered plants;the ratio between the endogenous hormones ABA,GA3,IAA,and ZT of the two types of plants shows that the IAA content in early spring flowering plants is lower,while the GA3 and ABA contents increase significantly in early spring flowering plants.(2)Using GC-MS non-targeted metabolomics technology to determine the primary metabolites in the leaves of the two types of plants,and using principal component analysis(PCA),partial least square discriminant analysis(PLS-DA)to select 18 kinds of amino acids,18 kinds of sugars and 50 kinds of organic acids,alanine,phenylalanine and tryptophan Acid,xylose,ribose and D-lactose,as well as malic acid and fumaric acid,are high in early spring flowering plants.At the same time,five key potential differential metabolic pathways,including aminoacyl-tRNA biosynthesis,have been identified through metabolic enrichment.Combining the results of the primary metabolites in the leaves of the two types of plants,we found that the carbon metabolism of early spring flowering plants is enhanced,while the nitrogen metabolism is reduced.(3)Using LC-MS targeted metabolomics technology to determined 31 kinds of phenolic compounds in the leaves of the two types of plants.Through compound cluster analysis,it was found that the relative content of L-phenylalanine and C6C1 type carbon skeleton phenolic compounds vanillic acid,syringic acid,protocatechuic acid and C6C3 type phenolic compounds ferulic acid,chlorogenic acid and caffeic acid in early spring flowering plants was lower,while 2,5-dihydroxybenzoic acid,benzoic acid,p-hydroxycinnamic acid,cinnamic acid and rosmarinic acid accumulate significantly in flowering plants.C6C3C6 type carbon skeleton flavonoids rutin,naringin,liquiritigenin,daidzein,isoquercitrin is also more accumulated in early spring flowering plants.(4)Correlation analysis of the four endogenous hormone contents,primary differential metabolites and phenolic compounds determined in the collected early spring plants was carried out.The results show that the four endogenous hormones ABA,GA3,IAA,and ZT have a significant positive correlation in two types of plants;at the same time,the four endogenous hormones are significantly positively correlated with most phenolic metabolites,but only a few.The primary differential metabolites are positively correlated.This study combines non-targeted GC-MS and targeted LC-MS technology to study the metabolic specificity of early spring flowering plants,and discusses the interaction of primary metabolites,phenolic metabolites in early spring flowering plants and unflowered plants,we found the difference in the carbon and nitrogen metabolism distribution of the two plants and the different levels of phenolic compounds.At the same time,these are also the key basis for distinguishing the two types of plants.These research results are helpful to the understanding of early spring flowering plants,and laid a theoretical foundation for the development and utilization of early spring flowering plants.