TITLE:
Mitigating Root Knot Nematode Propagation on Transgenic Tobacco via in Planta Hairpin RNA Expression of Meloidogyne incognita—Specific PolA1 Sequence
AUTHORS:
Peter Nkachukwu Chukwurah, Samuel Aduse Poku, Akira Yokoyama, Ai Takeda, Masahiro Shishido, Ikuo Nakamura
KEYWORDS:
M. incognita, Nematode Resistance, N. tabacum, RNA Silencing, PolA1 Gene
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.10 No.5,
May
30,
2019
ABSTRACT: Root knot nematodes are top priority nematode pests that significantly constrain
agricultural productivity globally especially in developing countries. However,
expressing double stranded RNA (dsRNA) of
essential nematode genes in susceptible plants is known to confer protection
against these pests via RNA silencing. This molecular-based strategy is called host induced gene silencing (HIGS) and the
selection of appropriate target nematode gene is critical to its success. In this study, therefore, we focused on root knot nematode PolA1, an essential single copy
nuclear gene encoding the largest subunit of RNA polymerase I enzyme and
evaluated its effectiveness as a target in conferring nematode
resistance on Agrobacterium-mediated transformed tobacco plants. Transgenic tobacco
expressing Meloidogyne incognita-specific (MiS) dsRNA of PolA1 gene showed significant reduction in nematode fecundity and
multiplication compared to wild type plants in both T0 and T1 generations. T0 plants showed varying degrees of agronomic vigorover WT plants possibly due to varying
levels of processed siRNA. However, production of MiS siRNAs in the transgenic
plants coupled with significant reduction
of PolA1 transcript expression in
nematodes feeding on roots of transgenic plants provided evidence of HIGS.
Taken together, our results show that PolA1
is a potentially effective target for HIGS-mediated reduction of root knot nematode damage on transgenic
tobacco. Given the homology of our target sequence among Meloidogyne species, this protection could be broad range against
other root knot nematodes aside M. incognita.