TITLE:
Transgenic Tobacco Lines Expressing Yam Mosaic Virus Coat Protein-Derived dsRNA Are Resistant to Yam Mosaic Virus
AUTHORS:
Effiom Eyo Ita, Edak Aniedi Uyoh, Ikuo Nakamura, Valentine Otang Ntui
KEYWORDS:
Yam Mosaic Virus, dsRNA, PTGS, Coat Protein Gene, RNAi
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.11 No.9,
September
28,
2020
ABSTRACT: Yam mosaic virus (YMV), a Potyvirus, is a highly
destructive pathogen of yam accounting for yield losses up to 40%. Apart from
causing significant reduction in tuber size and quality, it restricts
international exchange of germplasms. It thus becomes crucial to get resistant
or at least virus-free planting materials for farmers. This study was aimed at
inducing resistance to YMV in tobacco by RNA silencing. An RNAi construct
containing 161 bp fragment of YMV-coat protein (CP) gene was developed and used to produce transgenic tobacco lines
expressing YMV-coat protein (CP) derived double stranded RNA (dsRNA) via Agrobacterium-mediated
transformation. Of the eight T1 transgenic lines inoculated with YMV,
six (L1, L2, L3, L5, L7 and L8) showed immunity to YMV as no symptoms were
detected, whereas two (L4 and L10) exhibited high resistance with mild symptoms
limited to inoculation portions. No virus could be detected in uninoculated new
leaves of the transgenic lines after RT-PCR and qPCR analyses of YMV-coat protein (CP). The presence of small interfering RNAs in transgenic lines after virus challenge
indicates that the resistance was acquired through RNA
silencing.