Effects Of Brassinosteroids On The Development Of Wheat Primary Roots

The primary root is very important to the growth and development of seedlings and the structure of root system.Brassinosteroids(BRs)is an important plant hormone and plays an important role in the normal growth and development of plants.However,the specific effect of rapeseed on the development of wheat root system and its regulatory mechanism are not well understood.In this study,by the Chinese spring wheat as material,using Epi BL(50 n M and 1 ?M,a highly active BR)and BRZ(1 ?M,BR synthesis inhibitor)hydroponic treatment,assessment the effect of BR on root length,root number,root diameter and lateral root number.The effect of BR on root traits was further analyzed by root section.The effect of BR on the regulation of wheat root diameter and lateral root to break the epidermis was the main finding in this study,which was also confirmed by AtDWF4 overexpression material.The results of the whole study are as follows:(1)BR plays a conservative role in the regulation of root development.Both at the exogenous level and at the endogenous level,the root system will show the characteristics of smaller meristems and smaller root diameters;(2)A certain concentration of BR can inhibit the growth of the apical meristem of the primary root of wheat,which is the main reason for the shortening of the primary root.The same change was observed in Arabidopsis root with increased endogenous BR.The signal regulation network of BR may involve the signal regulation process of root tip growth point development;(3)BR can also promote the process of lateral root primordia breaking through the epidermis while promoting the occurrence of lateral root primordia,thus increasing the number of lateral roots;(4)BR can regulate the lateral growth of wheat primary root and Arabidopsis roots,and influence the external morphology and root diameter of roots.The regulation of BR in root lateral growth by influencing the root transverse different layer of cells(epidermis,outer cortex and inner cortex,etc.)which diameter and number.Moreover,BR regulates the lateral growth of roots as a whole,no matter the size or number of cells,it shows the overall changes,but the number of cell layers is not affected.