Screening And Activity Test Of Novel Brassinosteroid Receptor Agonists

Brassionosteroids as a sixth class of plant hormones that plays a very important role in the growth and development of plants.Such as promoting cell elongation and division,improve crop yield and quality,enhance plant resistance,adjust the balance of the five hormones,reduce pesticide residues.But because of its little content in the plant,extraction and separation difficulties;synthetic route is complex;high cost,so the restrictions of the plant conditioner in agriculture to promote the application.The three-dimensional structure of the Brassinolide receptor protein has been analyzed by X-ray diffraction,which lays the foundation for the design and development of novel BRs receptor agonists using computer-aided molecular methods.In this paper,we constructed a virtual screening based on structure to find a new compound with bacon lactone-like bioactivity.The research contents and conclusions are as follows:?1?Using computer aided molecular design method to extract important pharmacophore characteristics of the interaction from BR insensitive receptor kinase1?BRI1?-Brassionolide?BL?,BRI1-BAK1?BRI1-association receptor kinase1?-BL,BRI1-BAK1-3a,4a-dihydroxy-7-oxo-5a-cholestane and to combine them into a comprehensive pharmacophore model.In the SPECS and Enamine compounds database for virtual screening.the screening results were analyzed by molecular docking method and 34 target compounds with the potantial activity were obtained.?2?Radish hypocotyl elongation method is used to model biological activity test of 34 kinds of compounds,The hypocotyls and cotyledons of radish seedlings were treated with different concentrations of compounds to promote elongation growth,thickening diameter and weight gain of cotyledons.Among them,compounds14,23,11,19,9,8,17 and 21 exhibited relatively strong biological activity as compared with BL and CK.The optimum concentration of compound 14 was 10^-8mol/L,the length of hypocotyl,the weight of cotyledons and the diameter of hypocotyl were increased by 59.65%,68.12%and 166.67%respectively compared with the control.The optimum concentration of compound 23 The results showed that the length of the hypocotyls,the weight of cotyledons and the diameter of hypocotyl were55.26%,112.23%and 250.00%respectively,the optimum concentration of compound11 was 10^-6mol/L,the length of hypocotyl,the weight of cotyledons,The diameter of the hypocotyls,the weight of the cotyledons and the diameter of the hypocotyls increased by 50%,80.79%and 216.67%,respectively,compared with the control.The diameter of the carcass was 50%,83.14%and 200%respectively.The optimum concentration of compound 19 was 10^-5mol/The optimum concentration of compound 9 was 10^-7mol/L,the length of hypocotyl,the weight of cotyledons and the diameter of hypocotyl were increased by 45.61%,56.50%and 166.67%respectively.The optimal concentration of compound 8 was 10^-7mol/L,Axis length,cotyledon weight and hypocotyl diameter increased by 42.98%,60.99%and 233.33%,respectively.The optimum concentration of compound 17 was 10-⁷mol/L,the length of hypocotyl,the weight of cotyledon and the diameter of hypocotyl were 42.11%,49.34%,150.00%,the optimum concentration of compound 21 is 10-⁷mol/L,the length of hypocotyl,the weight of cotyledons,Respectively,compared with the control increased by 40.35%,116.45%,133.33%.This paper uses the means of combining computer virtual screening with biological experimentIn this paper,eight relatively active compounds were obtained,and they had a new framework.Which provides a theoretical guidance for the synthesis of novel Brassinosteroid receptor agonists and is a valuable starting point for the design of exogenous plant regulators and laid the foundation for the popularization and application of agriculture.