Silencing of vitellogenin gene contributes to the promise of controlling red palm weevil, Rhynchophorus ferrugineus (Olivier)

Khawaja G Rasool,Mureed Husain,Waleed S Alwaneen,Khalid Mehmood,Muhammad Tufail,Abdulrahman S Aldawood

doi:10.1038/s41598-021-01159-9

Abstract

Red palm weevil [Rhynchophorus ferrugineus (Olivier)], is native to South Asia and expanding its distribution range globally. Recent invasions of red palm weevil around the world, including Saudi Arabia, has become a global constraint for the production of palm species. Although, several control measures have been tested, none of them seemed successful against this invasive species. Therefore, we focused on silencing the reproduction control gene vitellogenin (Vg) based on RNA interference (RNAi) strategy for its possible application in the management of R. ferrugineus. The Vg is a major yolk protein precursor critical for oogenesis. To do this, fat body transcriptome of R. ferrugineus female adults was sequenced, which provided partial Vg gene transcript (FPKM 5731.60). A complete RfVg gene transcript of 5504 bp encoding 1787 amino acids was then sequenced using RCAE-PCR strategy and characterized. Phylogenetic analysis suggested that RfVg has closer ancestry to the coleopteran insects. The RfVg-based RNAi significantly suppressed the expressions of Vg gene. The 15, 20 and 25 days post-injection periods suppressed Vg expressions by 95, 96.6 and 99%, respectively. The suppressed Vg expressions resulted in the dramatic failure of Vg protein expression, which caused atrophied ovaries or no oogenesis and ultimately eggs were not hatched. These results suggest that knockdown of Vg gene involved in R. ferrugineus reproduction is a promising target for RNAi-based management of R. ferrugineus.

Highlights

Date palm, [Phoenix dactylifera (Linnaeus, 1753)] is one of the oldest fruit trees in the Arabian Peninsula and major economic fruit crop in Saudi Arabia (SA)
Three conserved domains were identified in the RfVg by using National Center for Biotechnology Information (NCBI) conserved domain database (CDD) search
To elucidate the evolutionary relationship of RfVg, a neighbor joining phylogenetic tree was generated based on 99 insect and non-insect Vgs sequences present in the NCBI database (Fig. 1)

Summary

Introduction

Date palm, [Phoenix dactylifera (Linnaeus, 1753)] is one of the oldest fruit trees in the Arabian Peninsula and major economic fruit crop in Saudi Arabia (SA). Rhynchophorus ferrugineus causes severe damages to palm trees while spending its entire life cycle inside the tree[3]. This species commonly attacks and feeds on young date palm trees, which are less than 20 years of age[4]. The RNAi technology could efficiently silence the targeted genes in the form of feeding and transgenic p lants[37,42,43] It is of vital importance for the management of pests resistant to pesticide or those having hidden nature such as R. ferrugineus. The RNAi results demonstrate that knockdown of RfVg gene has the potential to halt reproduction in R. ferrugineus, which warrants the development of novel control strategies against the pest

Methods

Results

Conclusion