A quick and sensitive diagnostic tool for detection of Maize streak virus

Mathias Tembo,Gonҫalo Silva,Susan E Seal,Patrick C Chikoti,Sophie Bouvaine,Adedapo O Adediji

doi:10.1038/s41598-020-76612-2

Abstract

Maize streak virus disease (MSVD), caused by Maize streak virus (MSV; genus Mastrevirus), is one of the most severe and widespread viral diseases that adversely reduces maize yield and threatens food security in Africa. An effective control and management of MSVD requires robust and sensitive diagnostic tests capable of rapid detection of MSV. In this study, a loop-mediated isothermal amplification (LAMP) assay was designed for the specific detection of MSV. This test has shown to be highly specific and reproducible and able to detect MSV in as little as 10 fg/µl of purified genomic DNA obtained from a MSV-infected maize plant, a sensitivity 105 times higher to that obtained with polymerase chain reaction (PCR) in current general use. The high degree of sequence identity between Zambian and other African MSV isolates indicate that this LAMP assay can be used for detecting MSV in maize samples from any region in Africa. Furthermore, this assay can be adopted in minimally equipped laboratories and with potential use in plant clinic laboratories across Africa strengthening diagnostic capacity in countries dealing with MSD.

Highlights

Maize streak virus disease (MSVD), caused by Maize streak virus (MSV; genus Mastrevirus), is one of the most severe and widespread viral diseases that adversely reduces maize yield and threatens food security in Africa
To evaluate the suitability of loop-mediated isothermal amplification (LAMP) for the detection of MSV, DNAs obtained from 26 symptomatic maize plants were screened by both the new LAMP assay and the polymerase chain reaction (PCR) method in current general use
The same DNAs were analysed by PCR (Fig. 2) using primers designed by Martin et al[10]

Summary

Introduction

Maize streak virus disease (MSVD), caused by Maize streak virus (MSV; genus Mastrevirus), is one of the most severe and widespread viral diseases that adversely reduces maize yield and threatens food security in Africa. A loop-mediated isothermal amplification (LAMP) assay was designed for the specific detection of MSV This test has shown to be highly specific and reproducible and able to detect MSV in as little as 10 fg/μl of purified genomic DNA obtained from a MSV-infected maize plant, a sensitivity 105 times higher to that obtained with polymerase chain reaction (PCR) in current general use. The use of symptoms for disease diagnosis becomes unreliable since symptoms differ subject on the virus strain, the presence of any mixed viral infections, the cultivar and growth stage, growing environment, and the similarity of viral symptoms to those induced by environmental injury[13] Detection methods such as immunosorbent electron microscopy, enzyme-linked immunosorbent assay (ELISA)[14], Southern blot h ybridisation[15] and polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) have been developed to distinguish MSV strains[16]. In many African countries including Zambia, where there is inadequate laboratory equipment, isothermal amplification systems such as loop-mediated isothermal amplification (LAMP) offer a useful

Methods

Results

Discussion

Conclusion