Moses muriithi Mathenge
Karatina University, Kenya
Title: METAGENOMIC-BASED SCREENING AND MOLECULAR CHARACTERIZATION OF YAMS-INFECTING VIRUSES BY HIGH-THROUGHPUT SEQUENCING AND POX MARKER.
Biography
Biography: Moses muriithi Mathenge
Abstract
To date Dioscorea (Yams) in Kenya are neglected crops, notwithstanding its potential as a source of functional foods and as a drug source in the pharmaceutical industry. Dioscorin proteins exhibit biological activities both in vitro and in vivo, including enzymatic antioxidant, antihypersensitive, immunomodulatory, lectin activities and can also do the protective role on airway epithelial cells against allergens in vitro. Research on neglected crops specifically Dioscorea is a sure way of sensitizing the scientific community and policy makers about it. Several viruses of different genera have been reported to infect yams (Dioscorea spp.), therefore they attack the alkaloids (dioscorin) lowering the health benefit of yams. The full diversity of viruses infecting yam, however, remains to be explored.
High-throughput Sequencing (HTS) and use of POX marker techniques are progressively being used in the discovery of new plant viral genomes and metabolism processes in plants.
During this study, HTS was employed on yams to determine whether any undiscovered viruses would be present which would restrict the internal distribution of yam germplasm. The findings worked on discovery of a new virus sequence present. Thirty one (31) yam samples were tested and were tentatively named as virus “yam virus Y” (YVY). Peroxidase marker was used to test the metabolic reaction which would bring about mutation as the samples achieved the Arabiodisis process in metabolism of the organism. Complete genome sequences of two YVY viral isolates were assembled and further investigation was carried out to test five open reading frames (ORFs). ORF1 encoded a large replication-associated protein, ORF2, ORF3 and ORF4 constituted the putative triple gene block proteins, and ORF5 encoded a putative coat protein as yams contain dioscorin which has high protein content. Considering the species demarcation criteria of the family Betaflexiviridae, YVY should be considered a novel virus species in the family Betaflexiviridae. Further finding work is necessary to understand the association of this
new virus with any symptoms and yield loss and its implication on virus-free seed yam production.
Keywords: RNA-Seq, virus detection, Betaflexiviridae, next-generation sequencing; HTS.