Study On The Physiological Mechanism Of Formation Of Winter Bud In Brasenia Schreberi

Bud dormancy is a physiological phenomenon in the process of plant growth and development,and it’s a beneficial biological adaptation to seasonal or environmental changes.It’s an important significance to the survival,reproduction and agricultural production of species.Bud dormancy is affected by environmental factors such as temperature and water,and physiological factors such as endogenous hormones and enzyme activities.The formation of winter buds in Brasenia schreberi is related to temperature and water,but what are the specific influencing factors,changes in morphology and structure or other physiological mechanisms of the formation of winter buds under natural conditions?It’s unclear at this time.In this study,the winter buds in B.schreberi were used as experimental materials to study the changes in morphological structure and physiological indicators during the formation of them.The transcriptome sequencing technology was used to analyze the differences in gene expression during the non-formation,the initial formation and the complete formation period of them,and to explore the influencing factors and physiological mechanism.The main conclusions are as follows:（1）When the water and air temperature are continuously below 15℃.The water temperature difference is about 2℃,the winter buds in B.schreberi are easy to form.The internodes of the top bud in B.schreberi become shorter and thicker,they are easy to fall.The disappearance of the aeration tissue of the internodes of the stem,the casparin strip and the kjeldahl point successively appear as the morphological and structural signs of the formation of winter buds.（2）The increase of SOD,POD and CAT activities,and the continuous decrease of GA₁,IAA and GA₁/ABA all played a regulatory role in the process of winter bud formation.（3）A total of 45415 unigenes are sequenced and assembled,all of them are annotated in seven databases,3302 Unigenes were annotated in all databases at the same time.They are mainly related to metabolic processes,cellular processes,and catalytic activity.At the same time,the metabolic pathways are mostly involved in transport metabolism,carbohydrate metabolism,and signal transduction.The annotated Unigenes are most likely related to the formation of winter buds.（4）There are 9833 differentially expressed genes found during the formation of winter buds.KEGG enrichment results show that these differentially expressed genes are mainly related to starch and sucrose metabolism,hormone signal transduction,catalytic activity,and enzyme activity.Some hormone signal transduction genes have been annotated,and SAUR and GH3 genes regulate the synthesis of IAA,and the PYR/PYL gene family regulates the synthesis of ABA,which further regulates the formation of winter buds.It is speculated that the differential expression of these genes may be closely related to the regulatory network of winter bud formation.