Molecular, serological and biological characterizations of Potato Leaf Roll Virus in infected potato plants in Egypt, and its effects on plant cell organelles

Abstract

Potato Leaf Roll Virus (PLRV) is one of the most serious viruses infecting potato plant (Solanum tuberosum L.) in Egypt. Indirect Enzyme Linked Immunosorbent Assay (Indirect- ELISA) results revealed that 70 % of the collected samples were infected with PLRV. A multiplex Polymerase Chain Reaction (PCR) was carried out using three different sets of primers, specific for both PLRV and Potato virus Y (PVY) isolates. For confirmation; the movement coat protein (MP) gene was isolated from the infected plant tissues, and a band with molecular size 336 bp was obtained using Reverse transcription-Polymerase chain reaction (RT-PCR). The DNA sequence of the Egyptian PLRV-Banha -MP gene was deposited in GenBank under an accession number of KR002119. Moreover, sequence analysis revealed that the Egyptian PLRV isolate was closely related to a New Zealand isolate of PLRV (GU002341), with identity of 100%. Transmission electron microscope (TEM) examination of PLRV showed isometric particles, with approximate size of 24-30 nm. The cytopathological examination of the potato plant infected with PLRV revealed many cellular effects such as; partially degraded and deformed chloroplast, starch with an increased size and color change, in addition to nucleus and cytoplasmic bridge. It could be concluded that PLRV is present in Egypt, infecting most of the potato cultivars. Moreover, four different strains of PLRV were detected based on the Single strand conformation polymorphism (SSCP) of the MP gene. The aims of the current study were to identify the PLRV infection of potato plant in Egypt using; molecular, serological and biological methods, in addition to studying the effect of this virus on potato cell organelles. This is the first record of the presence of four different strains of PLRV infecting potato in Egypt, using SSCP assay.