viral diseases in plants

cauliflower mosaic virus (CaMV) causative agent

double-stranded DNA virus

caulimoviridae family

infects cruciferous plants (cauliflower, broccoli, turnips)

CaMV structure

icosahedral capsid

circular double stranded DNA genome

CaMV transmission

transmitted by aphids in a non-persistent manner

CaMV replication

replicates through reverse transcription

CaMV symptoms

chlorosis (yellowing) of leaves

mosaic patterns

stunted growth

distorted leaf shapes

vein clearing

necrotic spots

CaMV inclusion bodies

large inclusion bodies in cytoplasm of cell

used to identify the virus in histological examinations

CaMV viral movement

moves from cell to cell from plasmodesmata and through plant’s vascular system

CaMV economic impact

can reduce the yield and quality of the infected crops

CaMV diagnosis

serological assays

• ELISA 

PCR based methods

CaMV control methods

controlling aphid populations

planting virus-resistant varieties of crops

practicing crop rotation and sanitation 

CaMV use of biotechnology

CaMV 35S promoter is used in plant genetic engineering because it is a strong, constitutive promoter that drives high levels of gene expression in most plants

CaMV environmental stability

can persist on plant debris

African cassava virus (ACMV) causative agent 

single stranded DNA virus from Geminiviridae family 

infects cassava

ACMV transmission

transmitted by whitefly

ACMV symptoms

mosaic patterns

leaf curling

yellowing 

stunted growth

ACMV economic impact

responsible for devastating cassava mosaic disease, which impacts food security in African countries 

ACMV viral structure

geminivirus, meaning it has twin icosahedral capsid

circular single stranded DNA genome 

ACMV control

whitefly control

planting virus-resistant cassava varieties 

crop sanitation

ACMV prevention

virus-free planting material

cultural practices

tomato spotted wilt virus (TSWS) causative agent

negative sense

single stranded RNA virus

Tospoviridae family

TSWS transmission

thrips (western flower thrips) 

persistent propagative manner 

TSWS symptoms

necrotic spots

ring spots

leaf bronzing

wilting 

molting 

deformation 

chlorosis 

TSWS viral structure

spherical

enveloped virion 

triparitire genome 

small, medium, and large RNA segments 

TSWS economic impacts

severe yield losses in tomatoes, peppers, and lettuce

TSWS control

thrips control

insecticides

biological agents

cultural practices 

virus-resistant plant varieties 

TSWS prevention

integrated pest management

virus free transplants 

tobacco mosaic virus (TMV) causative agent

single stranded RNA virus

Virgaviridae family

TMV transmission

mechanical transmission via wounds, contaminated tools, etc

TMV symptoms

mosaic like patterns

leaf curling

stunted growth

TMV viral structure

ridged, rod-shaped capsid

linear, positive sense RNA genome

TMV economic impact

significant yield loss in tobacco, tomatoes, and peppers

TMV control

virus resistant plant varieties

disinfecting tools

practice crop rotation

infected plants should be removed and destroyed

TMV prevention

sanitation measures

cucumber mosaic virus (CMV) causative agent

single stranded RNA virus

Bromoviridae family

CMV transmission

aphids

non persistent manner

infected seeds

plant sap

mechanical contact

CMV symptoms

mosaic patterns

yellowing

leaf distortion

stunted growth 

reduced fruit quality

necrotic spots

malformation of fruits

CMV viral structure

icosahedral capsid

tripartite RNA genome

CMV host range

wide host range (can infect 1200 plant species)

CMV economic impact

significantly reduce yield and quality of vegetables and ornamental plants

CMV control

managing aphid populations

virus resistant plant varieties

crop sanitation

CMV prevention

integrated pest management

virus free seeds

insecticides

rice black streaked dwarf virus (RBSDV)

double stranded RNA virus

Reoviridae family 

affects rice and other grains

RBSDV transmission

small brown planthopper in a persistant manner

RBSDV symptoms

stunted growth

dark green leaves

lead stiffening

poor grain filling

RBSDV viral structure

non-enveloped, icosahedral capsid

double stranded RNA genome

10 segments that encodes for proteins involved in replication and infections 

RBSDV economic impact

severe damage to rice crops, leading to reduced yields, especially in East Asian countries 

RBSDV control

planthopper vector

insecticides

virus resistant rice varieties 

crop rotation

RBSDV prevention

integrated pest management

biological control of planthoppers 

virus free seedlings