Chilli leaf curl virus review of literature

1. Studies on Diversity of leaf curl virus
and it's associated satellites infecting
chilli

2.  Introduction:
 Chilli pepper Capsicum annuum L.,) is an important spice and vegetable
crop of family Solanaceae.
 Chilli is susceptible to various pathogens involving viruses, which cause
heavy production losses. So far 65 viruses have been reported throughout
the world including begomoviruses causing chilli leaf curl virus disease
(ChiLCVD).
 ChiLCVD is the most destructive virus disease in terms of incidence and
yield loss.

3.  The disease can be identified by typical upward leaf curling, crinkling, puckering
and reduction in leaf area along with stunting of whole plants.
 It is transmitted by the whitefly Bemisia tabaci in persistent manner.
 Conventional plant breeding techniques remain the major antiviral strategy so
far for the development of resistant chilli varieties.
 Recently, the concern about viral DNA methylation, activation of gene silencing
machinery and ubiquitination-mediated defence against begomoviruses has
been reported.

4. Brief review of work:
 R Vinoth Kumar et al they reported on a comprehensive survey across
major chilli-growing regions in India.
 ChiLCD-infected plants are associated with a complex of begomoviruses
with a diverse group of betasatellites found in crops and weeds.
 They concluded that ChiLCD-associated begomoviruses induced mild
symptoms on Capsicum spp., but both the level of helper virus that
accumulated and the severity of symptoms were increased in the
presence of cognate betasatellites.

5.  Prashant Raghunath Shingot they studied on ChiLCD, and concluded that
geographical distribution of ChiLCD is correlated with the incidence of whitefly
in the world.
 whitefly-specific insecticidal proteins such as Tma12 can be expressed in plants
to restrict spread of vectors and ultimately the ChiLCV infection.
 genome editing based on the CRISPR-Cas system has offered a new capable
 technique for developing resistance against ChiLCV through alteration in host
susceptibility factors.

6.  Megha Mishra conducted experiment on Chilli leaf curl virus (ChiLCV)
and associated satellites
 the factors accountable for genetic diversity, recombination, and evolution
of ChiLCV, and associated chilli leaf curl alphasatellite (ChiLCA) and
chilli leaf curl betasatellite (ChiLCB).
 The dN/dS ratio and Tajima D value of all viral DNA-A and associated
betasatellite showed selective control on evolutionary relationships.

7.  Bhavin et al they collected samples of chilli plants displaying leaf curl
disease were collected from the Ahmedabad district of Gujarat, India.
 Sequence analysis showed 90.4 % nucleotide sequence identity to the
previously reported chilli leaf curl virus.
 The associated betasatellite DNA showed a maximum of 93.5 %
nucleotide sequence identity to a previously reported tomato leaf curl
Bangladesh betasatellite.

8. Sneha Yogindran et al They screened for the presence of viral genome by rolling
circle amplification (RCA) followed by PCR using degenerate primer pairs.
 subsequent analyses using RFLP and sequencing revealed the presence of Cotton
leaf curl Multan virus (CLCuMuV), and Tomato leaf curl Patna betasatellite
(ToLCPaB).
 Their findings focus on the phylogenetic relatedness, probable recombinational hot-
spots and evolutionary divergence of the viral DNA sequences with the current
reported begomoviral genome.
 Their study reveals potential recombination sites on both viral genome and
betsatellite which, during the course of evolution, may have aided the virus to
progress and successfully establish infection in chilli plants.

9.  Sayed Sartaj Sohrab he worked on the molecular diagnosis, genetic
diversity, phylogenetic relationship, of begomovirus association with Chilli
leaf curl disease.
 The begomovirus was confirmed by coat protein gene specific primer, dot
blot hybridization, sequencing and sequence analysis.
 The nucleotide sequences analysis shared the highest identity with Tomato
yellow leaf curl virus reported earlier infecting tomato from Saudi Arabia,
and the lowest identity was observed with Tomato yellow leaf curl virus
Oman isolate.

10. Hament Thakur his review provides an overview of ChiLCVD, virus vector
relationship, its genome organization, replication, resistant sources, present
status of its spread in different regions of India and strategies employed for
controlling it.

11. Akhtar J.Khan et al they conducted survey to collect samples and assess the diversity of
begomoviruses associated with leaf curl disease of tomato and pepper.
 Some of the infected plant samples were also found to contain a betasatellite. A total of
19 potentially full-length begomovirus and eight betasatellite clones were sequenced.
 The begomovirus clones showed >96% nucleotide sequence identity.
 Comparisons to sequences available in the databases showed the highest levels of
nucleotide sequence identity (88.0–91.1%) to isolates of the “Pakistan” strain of ChLCV
(ChLCV-PK).

12. V. Venkataravanappa collected samples showing enation leaf curl symptoms tomato fields located
in Sonipet (ten infected and one healthy sample) of Haryana state and Varanasi (five infected and
one healthy sample) of Uttar Pradesh state, India.
 The Viral sequences represented in the begomovirus clones showed 89–100 % nucleotide
sequence identity, the betasatellite sequences obtained had 83.1–94.1 % identity with tomato
leaf curl Bangladesh betasatellite (ToLCBDB).
 An analysis for recombinant origin of genome and betasatellite showed major part of their
genome was likely to be originated by recombination of begomo viruses infecting different host
species resulting in evolution of new recombinant virus.

13.  Vineeta Pandey et al studied the genetic diversity with structural evaluation of
chilli leaf curl disease and satellite molecules infecting Chilli in India
 they retrieved 121 reference sequences of ChiLCD including DNA-A, DNA-B,
beta-satellite and alpha-satellites from GenBank reported from India.
 genetic mutations and recombination of ChiLCD which leads to rapid adaptation
and evolution of begomovirus and its satellite molecules accelerating its host
range and diversity within and across the Indian subcontinent.