Functional Identification Of Flavonol Synthase Gene MdFLS1 In Apple

Any organism must undergo metabolism to maintain its life activities.Metabolism is the floorboard for all kinds of chemicals carried out by biological activities.During the metabolic process,a large variety of products forms and some are considered to have no clear metabolic function.Metabolism that does not play a major role in maintaining cell life is called secondary metabolism.Secondary metabolites produced by secondary metabolism.Flavonoids are a large class of plant secondary metabolites,which are widely distributed in different plants and have different functions.Flavonoids are phenolic compounds,that is,the hydrogen atoms on the aromatic ring are substituted by hydroxyl or functional derivatives.The flavonoids are conposed of two aromatic rings connected by three carbon bridges.The different structural substitution of flavonoids can form different compounds,so flavonoids have various functions.(1)Colouration.Most of the flowers and fruits are red,pale red,blue and purple,all of which are related to anthocyanins.Carotenoids are auxiliary pigments of photosynthesis,showing red,orange and yellow.Flavonoids contain a variety of colored substances,the most important of which is anthocyanin.The abundantly colouration of plants can attract insect to pollinate and can also attract animals to eat fruit and spread the seeds.(2)Defensive injury.Recent studies have shown that flavonoids are the photoprotection components of plants.The normal flavonoid metabolism is essential for plant survival.In addition,flavonoid metabolism also produces tannin(commonly known as tannin).Tannins are toxic and can inhibit their growth after eating.Flavonols,a major class of flavonoids,have the general properties of flavonoids,such as colouring and protecting the plants away from animals.In addition,flavonols have a higher health care function to human body.It can resist allergy,eliminate free radicals,delay senility,and prevent cardiovascular and cerebrovascular diseases and cancer.At present,some flavonoid compounds have been studied quite well,such as anthocyanins.However,there is less research on flavonols,their functions and regulation methods are not fully understood.Apple is a very important temperate fruit.The color and lustre of the fruit are always very important indexes for the fruit quality of the apple.The study of the color of the apple fruit should continue to deepen.With the improvement of the living standards of our country,we have higher requirements for the quality of fruits,and begin to pursue the so-called functional fruit with certain health care functions.China has avast territory,but the land suitable for farming is relatively small,soil salinization is serious,water resources and relatively few.How to improve the salt resistance of cro-ps is of great significance to increase crop yield.In this study,the MdFLS1 was cloned in apple,and its bioinformatics was analyzed.Its function was preliminarily studied,and some results were obtained.1.MdFLS1 was cloned in Apple,and its total length was 1014 bp,encoding 337 amino acids.2.Phylogenetic tree analysis showed that Md FLS1 had higher homology with sweet cherry,strawberry,peach and rose.MdFLS1 expressed mainly in the leaves,but rarely in the stems and mature fruits.The promoter analysis showed that MdFLS1 responded to a variety of plant hormones and abiotic stresses.3.High salt,low temperature,drought and abscisic acid all increased the expression of MdFLS1.4.Apple flavonol synthetase MdFLS1 had catalytic activity in vitro.Overexpression of MdFLS1 inhibits anthocyanin accumulation in Apple callus5.Overexpression of MdFLS1 inhibited the accumulation of anthocyanins and increased the resistance of apple callus to salt.