Journal of Applied Microbiology (2022) 133, 2618-2630

Pankhuri Singhal, Virendra Kumar Baranwal, Malyaj R. Prajapati and Jitender Singh (2022)
High-throughput RNA sequencing and genetic structure studies of Turnip mosaic virus infecting black and yellow mustard revealing emergence of world-B3 pathotype in India
Journal of Applied Microbiology 133 (4), 2618-2630
Abstract: The RNA viruses are marked by high genetic diversity, which allows them to quickly adapt to new and resistant hosts. The pathogenic turnip mosaic virus (TuMV) infects Brassicaceae plant species all over the world.
Aim
To study the evolution and host expansion of a TuMV for the first time in India using molecular population genetic framework.
Materials and Results
Here, we decipher the complete genome sequences of two TuMV world-B3 strains infecting yellow and black mustard in India through high-throughput RNA sequencing subjecting ribosomal RNA depleted mRNA isolated from leaves exhibiting puckering and mosaic symptoms with 100% incidence and high severity in the experimental field. The viral genomes of the two isolates were 9817 and 9829 nucleotides long. They featured two open reading frames (ORFs), one of which encoded a polyprotein comprised of 3164 amino acids and the other of which encoded a PIPO protein of 62 amino acids.
Conclusions
The two TuMV strains from New Delhi region shared identity with the world-B pathotype and subpathotype world B3 showcasing its emergence first time in South Asia. In contrast, other isolates reported previously from South Asia were all Asian-BR pathotypes.
Significance and Impact of the Study
According to our knowledge, this is the first instance of TuMV association with black mustard naturally. Their geographical prevalence justifies a lower degree of genetic differentiation and higher rate of gene flow calculated between the world-B and Asian-BR pathotypes. This study provides insights on population structuring, expansions and evolution, level of genetic heterogeneity and variability of worldwide prevalent isolates of TuMV which will further aid in understanding virus epidemiology and help prevent losses.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Virendra Kumar Baranwal

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Turnip mosaic virus	Brassica - other species	India