Identification and quantification of viruliferous and non- viruliferous Polymyxa betae

Abstract

Rhizomania, caused by Beet Necrotic Yellow Vein Virus (BNYVV) is transmitted by plasmodiophorid Polymyxa betae. To investigate quantification of virulifeous and non- viruliferous P. betae isolates, different techniques including serological method (DAS- ELISA), PCR- based method and nanobiocensor method have been used. For this purpose, sugar beet susceptible cultivar (Regina) was cultivated in soils of different regions in greenhouse conditions. Six weeks after planting, lateral roots of beets from each soil were visually tested through microscopy and the of P. betae cystosori was seen and the lateral root sap was prepared. Then DAS- ELISA with polyclonal antibody against recombinant expressed fungal glutathione-s- transferase isolates of Shiraz was optimized. Optical density of different samples were calculated for both the vector and the virus using ELISA method. Simultaneously, confirmation of quantitative estimation P. betae in lateral root was conducted by nanobiosensor against vector. Nanobiosensor method was performed based on Florescent Resonance Transfer Energy (FRET) using antibody attached quantom dots and GST conjugated rhodamine. Microscopic results show presence of vector in all soils. BNYVV was found in soils Fars, Khorasan, Hamadan and Kermanshah. In soils of Azarbayjan, Gorgan, Dezfool, Kerman, Karaj and Arak were found no virus. Values of optical density of P. betae in soils with and without virus have no significantly difference. Because of high speed and sensitivity of nanobiosensor, its use for quantitative estimation of P. betae has been advised.