Study On The Effect Of Cytokinin On The Development Of Cyathula Officinalis Kuan

Cyathula officinalis Kuan is the dry root of Cyathula officinalis Kuan,which has the functions of expediting channel and activating meridian.It is a famous Chuan-producing medicinal material.Since the planned economy,the quality of the medicinal materials has been significantly reduced due to the rough management of planting and the degeneration of varieties,and the “roots are thick and the branches are small”.The appearance characteristics of the products are judged,but it is still unclear which factors affect the development of the roots of Cyathula officinalis Kuan,which is also a problem for the breeding of the dominant Cyathula officinalis Kuan.In the early stage,the research team found that phytohormone(auxin and cytokinin)and root traits(the best quality of Jinkou River)were significantly correlated with climatic environmental factors,soil nutrients and endogenous hormones.The auxin is being developed for specific research.As one of the important factors,cytokinin is still unclear on the development of Cyathula officinalis Kuan.This study firstly analyzed the effects of cytokinin on the development of Cyathula officinalis Kuan.from external morphological features.on the basis of microstructural,endogenous hormone changes and balance,changes in primary metabolites and expression of genes involved in lateral root development,The internal analysis leads to the reasons for the changes in the above-mentioned morphological changes,and provides a theoretical basis for exploring the internal mechanism of the influence and regulation of the formation of the quality characteristics of the roots of the achyranthes.The main results of the study are as follows:1.Effect of cytokinin on the morphological development of Cyathula officinalis KuanThe seedlings of Cyathula officinalis Kuan were treated with different concentrations of exogenous cytokinin 6-BA for 31 days,and their external morphological characteristics and internal microstructure were analyzed.In terms of external morphology,6-BA significantly inhibited the development of lateral roots of Cyathula officinalis Kuan and promoted the thickening of the main root diameter,and also had a little effect on inhibiting the elongation of the main root;internal microscopic analysis,the development of the roots of Cyathula officinalis Kuan.The cells in the middle column sheath of the native xylem,and part of the phloem and formation may be involved,and 6-BA can promote the development of the roots of A.serrata into the abnormal structure,and promote the development of abnormal vascular bundles.To significantly promote the thickening of the main root.2.Correlation between changes of endogenous hormones and primary metabolites and morphological changes in Cyathula officinalis Kuan after cytokinin treatmentInternal hormone changes and balance analysis.In terms of internal hormonal changes,6-BA can promote the thickening of the main root by significantly promoting the accumulation of endogenous cytokinin and gibberellin.The effect on the accumulation of other hormones reflects the interaction of hormones;In the analysis,6-BA may slowly inhibit the elongation of the main root through the growth of ZT/IAA and ABA/IAA,and significantly inhibit the development of the lateral roots of Cyathula officinalis Kuan through high levels of ZT/IAA,ABA/IAA,and GA/IAA.Primary metabolite analysis.By analyzing the changes of internal primary metabolites combined with the morphological changes of Cyathula officinalis Kuan,cytokinin may promote the thickening of the main root diameter by regulating the content of soluble sugar,starch and soluble protein.3.Effect of cytokinin on the expression of genes related to lateral root development of Cyathula officinalis KuanBased on the current research progress of cytokinin signaling pathways regulating lateral root development,from the direction of cytokinin interaction auxin regulation of lateral root development,explore what signal elements cytokinin regulates PIN cycle and its effect on auxin What are the downstream genes that inhibit lateral root development after distribution and circulation.The results showed that with the increase of endogenous cytokinin,the average number of lateral roots of Achyranthes bidentata decreased significantly,while the PIP5K2 gene controlling PIN protein cycle was significantly up-regulated;and the expression of IAA8 gene which inhibited the activation of auxin response factor ARF was up-regulated.The expression levels of IAA14 and IAA28 genes were down-regulated.In general,cytokinins may inhibit the development of lateral roots by affecting the regulation of auxin transporters and the expression of auxin inhibitors,and this also reflects the interaction of the IAA-CTK signaling pathway.The results suggest that cytokinin can significantly promote the thickening of the main roots and inhibit the development of lateral roots by affecting the changes and balance of endogenous hormones,the accumulation of primary metabolites and the expression of related lateral root development genes,that is,Proper secretion of high cytokinins may promote the formation of "root thick,less branched" quality characteristics,but the role of other hormones may not be ignored.