Record Details

Comparative analysis of host factors regulating phytohormones and viral pathogenicity factor during ToLCV infection

KrishiKosh

View Archive Info
 
 
Field Value
 
Title Comparative analysis of host factors regulating phytohormones and viral pathogenicity factor during ToLCV infection
Ph D
 
Creator VINUTHA T
 
Subject planting, biological phenomena, viruses, rna, dna, genes, diseases, vegetables, mutation, transcription
 
Description T-8686
Tomato leaf curl viruses occur in all tomato growing areas in the world and are
considered to be most damaging and highly evolving viruses. We investigated the
genetic variation in the pathogenecity factor of Tomato leaf curl New Delhi virus, a
prominent virus in South Asian countries. We performed mutation scanning of AC4
gene of ToLCNDV using high resolution DNA melting (HRM) analysis in serial
passages to differential hosts viz., Solanum lycopersicon, Nicotiana tobaccum and
Carica papaya. Results based on HRM analysis followed by cloning & sequencing
showed AC4 is prone to mutation at five different focal points. Most of the mutations
(four out of five) found in AC4 region belonged to transition type and were found to be
host independent. The transversion mutation at 2296 leading to Ser16 to Thr was found
to be predominant in solanaeous host and showed high frequency of reversion in the
subsequent passaging. Four transition mutations at 2312 leading Ile21 to Thr; 2339,
2365 and 2415 leading to Val30 to Ala, Thr55 to Met and Thr38 to Thr respectively (
synonymous mutation)were matching with the virus variants of Tomato leaf curl viruses
with different degree of symptom severity and pathogenecity at these focal points.
Three out of five mutations (one transversions and two transitions) lead to its homology
with other begomoviruses at the mutation point. Interestingly two mutations falling in
the N-terminal region of AC4 affects the consensus N-myristoylation motif required for
membrane binding and pathogencity. The mutation frequency was 10-4 nucleotide
substitution per site (subs/site), which is very close to plant RNA viruses. These
observations indicate that pathogenecity factor of Tomato leaf curl virus is important in
virus adaptation to different host in serial passages and might be playing a role in
evolution. This study also reveals that, AC4 mutation may have structural and
functional relationships in host-virus interactions.
 
Date 2016-09-17T17:16:45Z
2016-09-17T17:16:45Z
2012
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/77250
 
Format application/pdf
 
Publisher IARI, DIVISION OF BIOCHEMISTRY