Simultaneous multiplex RT-PCR detection of four viruses associated with maize lethal necrosis disease

Development of a multiplex RT-PCR assay for simultaneous detection of Lily symptomless virus, Lily mottle virus, Cucumber mosaic virus, and Plantago asiatica mosaic virus in Lilies

BACKGROUND

Viral pathogens causing significant economic losses in lilies (Lilium spp. and hybrids) include Lily symptomless virus (LSV), Lily mottle virus (LMoV), Cucumber mosaic virus (CMV), and Plantago asiatica mosaic virus (PlAMV). Rapid and efficient virus detection methods are pivotal to prevent the spread of these viruses.

RESULTS

In this study, four specific primer pairs designed from conserved regions of genomic sequences of each virus were used to amplify a 116 bp product for LSV, a 247 bp product for LMoV, a 359 bp product for CMV, and a 525 bp product for PlAMV in a multiplex reverse transcription-polymerase chain reaction (multiplex RT-PCR). The amplified products were clearly separated by 2% agarose gel electrophoresis. The optimal reaction annealing temperature and cycle number were 53.8 °C and 35, respectively. The developed multiplex RT-PCR method was then used to test virus infections from lily samples collected from different regions of China.

CONCLUSIONS

An effective multiplex RT-PCR assay was established for the simultaneous detection and differentiation of LSV, LMoV, CMV, and PlAMV in lilies, which offers a useful tool for routine molecular diagnosis and epidemiological studies of these viruses.

Small RNA Sequencing and Multiplex RT-PCR for Diagnostics of Grapevine Viruses and Virus-Like Organisms

Metagenomic approaches used for virus diagnostics allow for rapid and accurate detection of all viral pathogens in the plants. In order to investigate the occurrence of viruses and virus-like organisms infecting grapevine from the Ampelographic collection Kromberk in Slovenia, we used Ion Torrent small RNA sequencing (sRNA-seq) and the VirusDetect pipeline to analyze the sRNA-seq data. The used method revealed the presence of: Grapevine leafroll-associated virus 1 (GLRaV-1), Grapevine leafroll-associated virus 2 (GLRaV-2), Grapevine leafroll-associated virus 3 (GLRaV-3), Grapevine rupestris stem pitting-associated virus (GRSPaV), Grapevine fanleaf virus (GFLV) and its satellite RNA (satGFLV), Grapevine fleck virus (GFkV), Grapevine rupestris vein feathering virus (GRVFV), Grapevine Pinot gris virus (GPGV), Grapevine satellite virus (GV-Sat), Hop stunt viroid (HSVd), and Grapevine yellow speckle viroid 1 (GYSVd-1). Multiplex reverse transcription-polymerase chain reaction (mRT-PCR) was developed for validation of sRNA-seq predicted infections, including various combinations of viruses or viroids and satellite RNA. mRT-PCR could further be used for rapid and cost-effective routine molecular diagnosis, including widespread, emerging, and seemingly rare viruses, as well as viroids which testing is usually overlooked.

Development of an RT-LAMP assay for the detection of maize yellow mosaic virus in maize

Maize is one of the most widely cultivated cereal crops worldwide. Maize yellow mosaic virus (MaYMV) (species Maize yellow mosaic virus, genus Polerovirus and family Luteoviridae) was first reported in maize from China. In this study, a one-step reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for detecting MaYMV. The optimal concentrations of betaine, Mg²⁺ and dNTPs for the assay were 0 M, 1.4 mM and 6 mM, respectively, and the optimal reaction time was 50 min. Using total plant RNA as the template, the detection limit of the RT-LAMP assay for MaYMV was 1 pg, while that of RT-PCR was 100 pg, indicating that the RT-LAMP assay developed was 100 times more sensitive than RT-PCR. Importantly, the RT-LAMP assay successfully detected MaYMV using rapidly extracted crude RNA from infected maize as a template. In conclusion, the RT-LAMP assay developed was a rapid, specific, sensitive and low-cost method for the detection of MaYMV in field samples of maize.