Differences Of Gene Expression Of Characteristics Of Sprouting Of Hippophae Rhamniodes Ssp. Sinensis

Hippophae rhamniodes ssp.sinensis is an excellent multi-purpose tree species in northern China,and it is also a typical clonal plant.Its strong clonal diffusion capacity can make vegetation coverage of the hard-to-live areas of artificial forestation.However,in recent years,large-scale premature senescence or even death of H.rhamniodes plantations has occurred.The most effective and simple solution to this problem is to promote sprouting through stumping measures,so as to achieve the goal of renewal and rejuvenation.The effect of stumping and promoting budding is closely related to the height,age,and season of stumping.However,there is no report on the height of stumping of H.rhamniodes.At present,the research on the mechanism of promoting the development of the stump is almost limited to the physiological level and ecological level,but there are some limitations,and there is no discussion about the differences in gene expression.In fact,the change of the plasticity of plant phenotypes are due to changes in gene expression.In view of this,this study used H.rhamniodes as a test material to analyze the sprouting characteristics and gene expression differences in stump,reveals the mechanism of its development from the level of gene expression,and expands the research area in which tree stumping promotes sprouting.It enriches the research cases and provides the basis for the selection of the suitable height of H.rhamniodes plantation.(1)After stumping,the number of sprouting,the height growth of sprouting and the growth accumulation of shoots of no stumping plants can all be described by Logistic equations,showing the growth rhythm of "slow-fast-slow" and gradually increasing to the upper limit.Among them,the stumping plants were born in May and June,and the no stumping plants(control)were not born.The growth of plant height was mainly concentrated in May,June,July and September.The monthly growth showed a bimodal curve.The shoot growth of the no stumping plants was concentrated in June and July,and the monthly growth was a single-peak curve.Moreover,the upper limit of cumulative growth(K value of the regression equation)of the sprouting plants was significantly greater than that of the no stumping plants(control).This shows that the stump not only promotes sprouting but also promotes the growth of sprouted.(2)After stumping,the number of differential genes increased with the development of sprouting.Among them,the differential genes related to the birth andgrowth of the sprouted were mainly involved in biological processes such as cell growth and proliferation,enzyme activity,carbohydrate metabolism,organ development,and plant hormone signal transduction.The differential genes for plant growth of no stumping plants are mainly involved in biological processes such as cell growth and proliferation,phytohormone signal transduction,and spliceosomes.This shows that the birth and growth of the sprouting,that is,cell growth and proliferation are regulated by gene expression.Moreover,both the birth and growth of the sprouting and the growth of the no stumping planst are closely related to the hormone signal transduction process regulated by gene expression.(3)Between the different height of stumping plants,the number of differentially expressed genes in the early stages of development of sprouting is small,and there are a large number of differentially expressed genes in the late stages of development of sprouting.During the entire development of sprouting,differential genes are involved in cell differentiation and cell division,synthesis and metabolism of antioxidants,plant growth regulation,cell morphogenesis,carbohydrate metabolism,phytohormone signal transduction,jasmonate precursor metabolism,photosynthesis,ion transport,enzyme activity and other biological processes.This shows that gene expression responds to external stimuli(stumping)and that it makes corresponding adjustments to physiological processes.(4)The number of differential genes increased with the growth and development process between the stumping plant and the no stumping plants.The differential genes are mainly involved in biological processes such as photosynthesis,cell proliferation and cell growth,enzyme activity,carbohydrate metabolism,plant signal hormone transduction,brassinosteroid synthesis,respiration,photosynthesis,and secondary metabolites.This shows that the growth and development of stumping plant has changed from the gene level and is affected by the corresponding physiological processes of gene expression regulation.To sum up,after the stumping,H.rhamniodes responds to external stimuli first,and then regulates physiological processes and hormonal characteristics through gene expression,thereby promoting sprouting and birth.Among them,the regulation of hormones has been confirmed in the previous study of the project team,and the regulation of other physiological processes remains to be explored.