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Temporal Effects of a Begomovirus Infection and Host Plant Resistance on the Preference and Development of an Insect Vector, Bemisia tabaci, and Implications for Epidemics.

Legarrea S, Barman A, Marchant W, Diffie S, Srinivasan R - PLoS ONE (2015)

Bottom Line: Nevertheless, it remains unclear how these virus-induced modulations on vectors vary temporally, and whether host resistance to the pathogen influences such effects.Together, these results suggest that vector preference and development could be affected by the timing of infection and by host resistance.These effects could play a crucial role in TYLCV epidemics.

View Article: PubMed Central - PubMed

Affiliation: Department of Entomology, University of Georgia, Tifton, Georgia, United States of America.

ABSTRACT
Persistent plant viruses, by altering phenotypic and physiological traits of their hosts, could modulate the host preference and fitness of hemipteran vectors. A majority of such modulations increase vector preference for virus-infected plants and improve vector fitness, ultimately favouring virus spread. Nevertheless, it remains unclear how these virus-induced modulations on vectors vary temporally, and whether host resistance to the pathogen influences such effects. This study addressed the two questions using a Begomovirus-whitefly-tomato model pathosystem. Tomato yellow leaf curl virus (TYLCV) -susceptible and TYLCV-resistant tomato genotypes were evaluated by whitefly-mediated transmission assays. Quantitative PCR revealed that virus accumulation decreased after an initial spike in all genotypes. TYLCV accumulation was less in resistant than in susceptible genotypes at 3, 6, and 12 weeks post inoculation (WPI). TYLCV acquisition by whiteflies over time from resistant and susceptible genotypes was also consistent with virus accumulation in the host plant. Furthermore, preference assays indicated that non-viruliferous whiteflies preferred virus-infected plants, whereas viruliferous whiteflies preferred non-infected plants. However, this effect was prominent only with the susceptible genotype at 6 WPI. The development of whiteflies on non-infected susceptible and resistant genotypes was not significantly different. However, developmental time was reduced when a susceptible genotype was infected with TYLCV. Together, these results suggest that vector preference and development could be affected by the timing of infection and by host resistance. These effects could play a crucial role in TYLCV epidemics.

No MeSH data available.


Related in: MedlinePlus

TYLCV acquisition by whiteflies (B. tabaci) at 3, 6 and 12 weeks post inoculation (WPI).Circles with standard errors represent average number of TYLCV C2 copies accumulated in whitefly samples (5 whiteflies in each sample) that were exposed to a 72 h AAP on TYLCV infected foliage of TYLCV-resistant and -susceptible tomato genotypes followed by 72 h of caging on cotton plants. Copy numbers were estimated by qPCR followed by absolute quantification using plasmids containing TYLCV C2 gene inserts as standards. Different letters on bars indicate significant differences in copy numbers among treatments as deduced by Tukey-Kramer grouping (α = 0.05). Y-axis is shown in a logarithmic scale.
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pone.0142114.g004: TYLCV acquisition by whiteflies (B. tabaci) at 3, 6 and 12 weeks post inoculation (WPI).Circles with standard errors represent average number of TYLCV C2 copies accumulated in whitefly samples (5 whiteflies in each sample) that were exposed to a 72 h AAP on TYLCV infected foliage of TYLCV-resistant and -susceptible tomato genotypes followed by 72 h of caging on cotton plants. Copy numbers were estimated by qPCR followed by absolute quantification using plasmids containing TYLCV C2 gene inserts as standards. Different letters on bars indicate significant differences in copy numbers among treatments as deduced by Tukey-Kramer grouping (α = 0.05). Y-axis is shown in a logarithmic scale.

Mentions: Whiteflies were able to acquire the virus from infected plants regardless of the genotype for all time periods (Fig 4). In general, whiteflies acquired more TYLCV copies from TYLCV-susceptible genotypes than from TYLCV-resistant genotypes at 3 (F = 5.31; df = 5, 27; P = 0.0020), 6 (F = 10.43; df = 5, 30, P<0.0001), and 12 (F = 4.11; df = 5, 28; P = 0.0070) WPI, respectively. Accumulation of TYLCV in whiteflies following a 72h AAP on TYLCV-susceptible genotypes was up to three orders of magnitude greater than in whiteflies that were given an AAP on TYLCV-resistant genotypes. However, the ability of whiteflies to acquire the virus from infected plants of susceptible or resistant genotypes was not influenced by the time of inoculation (Fig 4).


Temporal Effects of a Begomovirus Infection and Host Plant Resistance on the Preference and Development of an Insect Vector, Bemisia tabaci, and Implications for Epidemics.

Legarrea S, Barman A, Marchant W, Diffie S, Srinivasan R - PLoS ONE (2015)

TYLCV acquisition by whiteflies (B. tabaci) at 3, 6 and 12 weeks post inoculation (WPI).Circles with standard errors represent average number of TYLCV C2 copies accumulated in whitefly samples (5 whiteflies in each sample) that were exposed to a 72 h AAP on TYLCV infected foliage of TYLCV-resistant and -susceptible tomato genotypes followed by 72 h of caging on cotton plants. Copy numbers were estimated by qPCR followed by absolute quantification using plasmids containing TYLCV C2 gene inserts as standards. Different letters on bars indicate significant differences in copy numbers among treatments as deduced by Tukey-Kramer grouping (α = 0.05). Y-axis is shown in a logarithmic scale.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4631503&req=5

pone.0142114.g004: TYLCV acquisition by whiteflies (B. tabaci) at 3, 6 and 12 weeks post inoculation (WPI).Circles with standard errors represent average number of TYLCV C2 copies accumulated in whitefly samples (5 whiteflies in each sample) that were exposed to a 72 h AAP on TYLCV infected foliage of TYLCV-resistant and -susceptible tomato genotypes followed by 72 h of caging on cotton plants. Copy numbers were estimated by qPCR followed by absolute quantification using plasmids containing TYLCV C2 gene inserts as standards. Different letters on bars indicate significant differences in copy numbers among treatments as deduced by Tukey-Kramer grouping (α = 0.05). Y-axis is shown in a logarithmic scale.
Mentions: Whiteflies were able to acquire the virus from infected plants regardless of the genotype for all time periods (Fig 4). In general, whiteflies acquired more TYLCV copies from TYLCV-susceptible genotypes than from TYLCV-resistant genotypes at 3 (F = 5.31; df = 5, 27; P = 0.0020), 6 (F = 10.43; df = 5, 30, P<0.0001), and 12 (F = 4.11; df = 5, 28; P = 0.0070) WPI, respectively. Accumulation of TYLCV in whiteflies following a 72h AAP on TYLCV-susceptible genotypes was up to three orders of magnitude greater than in whiteflies that were given an AAP on TYLCV-resistant genotypes. However, the ability of whiteflies to acquire the virus from infected plants of susceptible or resistant genotypes was not influenced by the time of inoculation (Fig 4).

Bottom Line: Nevertheless, it remains unclear how these virus-induced modulations on vectors vary temporally, and whether host resistance to the pathogen influences such effects.Together, these results suggest that vector preference and development could be affected by the timing of infection and by host resistance.These effects could play a crucial role in TYLCV epidemics.

View Article: PubMed Central - PubMed

Affiliation: Department of Entomology, University of Georgia, Tifton, Georgia, United States of America.

ABSTRACT
Persistent plant viruses, by altering phenotypic and physiological traits of their hosts, could modulate the host preference and fitness of hemipteran vectors. A majority of such modulations increase vector preference for virus-infected plants and improve vector fitness, ultimately favouring virus spread. Nevertheless, it remains unclear how these virus-induced modulations on vectors vary temporally, and whether host resistance to the pathogen influences such effects. This study addressed the two questions using a Begomovirus-whitefly-tomato model pathosystem. Tomato yellow leaf curl virus (TYLCV) -susceptible and TYLCV-resistant tomato genotypes were evaluated by whitefly-mediated transmission assays. Quantitative PCR revealed that virus accumulation decreased after an initial spike in all genotypes. TYLCV accumulation was less in resistant than in susceptible genotypes at 3, 6, and 12 weeks post inoculation (WPI). TYLCV acquisition by whiteflies over time from resistant and susceptible genotypes was also consistent with virus accumulation in the host plant. Furthermore, preference assays indicated that non-viruliferous whiteflies preferred virus-infected plants, whereas viruliferous whiteflies preferred non-infected plants. However, this effect was prominent only with the susceptible genotype at 6 WPI. The development of whiteflies on non-infected susceptible and resistant genotypes was not significantly different. However, developmental time was reduced when a susceptible genotype was infected with TYLCV. Together, these results suggest that vector preference and development could be affected by the timing of infection and by host resistance. These effects could play a crucial role in TYLCV epidemics.

No MeSH data available.


Related in: MedlinePlus