scholarly journals Rate of Tomato yellow leaf curl virus Translocation in the Circulative Transmission Pathway of its Vector, the Whitefly Bemisia tabaci

2001 ◽  
Vol 91 (2) ◽  
pp. 188-196 ◽  
Author(s):  
Murad Ghanim ◽  
Shai Morin ◽  
Henryk Czosnek

Whiteflies (Bemisia tabaci, biotype B) were able to transmit Tomato yellow leaf curl virus (TYLCV) 8 h after they were caged with infected tomato plants. The spread of TYLCV during this latent period was followed in organs thought to be involved in the translocation of the virus in B. tabaci. After increasing acquisition access periods (AAPs) on infected tomato plants, the stylets, the head, the midgut, a hemolymph sample, and the salivary glands dissected from individual insects were subjected to polymerase chain reaction (PCR) without any treatment; the presence of TYLCV was assessed with virus-specific primers. TYLCV DNA was first detected in the head of B. tabaci after a 10-min AAP. The virus was present in the midgut after 40 min and was first detected in the hemolymph after 90 min. TYLCV was found in the salivary glands 5.5 h after it was first detected in the hemolymph. Subjecting the insect organs to immunocapture-PCR showed that the virus capsid protein was in the insect organs at the same time as the virus genome, suggesting that at least some TYLCV translocates as virions. Although females are more efficient as vectors than males, TYLCV was detected in the salivary glands of males and of females after approximately the same AAP.

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 115 ◽  
Author(s):  
Nicholas Johnston ◽  
Xavier Martini

The silverleaf whitefly, Bemisia tabaci, is one of the most destructive agricultural pests in the world, vectoring a large number of devastating viruses, including Tomato Yellow Leaf Curl Virus (TYLCV). When selecting a host, B. tabaci is primarily influenced by a range of visual and olfactory cues. Therefore, elucidating how such cues become modified in the presence of whitefly-vectored begomoviruses is critical to better understanding the epidemiology of many economically important diseases. The goal of this study was to determine how both visual and odor cues interact in the presence of TYLCV. In Y-tube olfactometer assays, whiteflies were submitted to a range of isolated visual and olfactory cues to determine behavioral changes. B. tabaci choices were then compared to both stimuli combined in the presence or absence of TYLCV. Under visual stimuli only, B. tabaci exhibited a visual attraction to the color yellow, TYLCV-infected tomato leaves, and TYLCV-infected tomato volatiles. Attraction was the strongest overall when both visual and olfactory cues from TYLCV-symptomatic tomato plants were combined, as opposed to a single isolated cue. These results highlight the importance of both sensory stimuli during B. tabaci host selection in the presence of an associated begomovirus.


2020 ◽  
Author(s):  
Liping Huang ◽  
Shuaixin Wang ◽  
Zhuo Zhang ◽  
Xuguo Zhou ◽  
Zhanhong Zhang ◽  
...  

Abstract Background: Tomato yellow leaf curl virus (TYLCV) causes critical production loss in tomato cultivation. The control of TYLCV in tomato is done mainly by using pesticide which is difficult and expensive, making it essential to find an environmentally friendly chemical agent to control TYLCV. Dufulin has been widely used to prevent and control viral diseases in tobacco and rice in recent years. In this study, we investigated the effect and mechanism of Dufulin on TYLCV on tomato plants.Methods: The control effect of Dufulin on TYLCV was evaluated by field experiments. The expression level of PI II and NPR1 in healthy and TYLCV-infected tomato after treatments were determined by Real-time fluorescent quantitative PCR (qRT-PCR). Handheld chlorophyll meter was applied to compare the content of chlorophyll and nitrogen in healthy and TYLCV-infected tomato after treatments.Results: It showed that the relative control effect of 20% Dufulin on TYLCV reached above 68% in 2018 to 2020. Jasmonic acid (JA) level was higher on healthy tomato, but lower on TYLCV-infected tomato plants treated with Dufulin compared to control. Salicylic acid (SA) level was higher on healthy and TYLCV-infected tomato plants treated with Dufulin compared to control. Chlorophyll content on healthy and TYLCV-infected tomato plants was higher after treatment with Dufulin compared to control. Nitrogen content on tomato plants showed no significant difference after spraying Dufulin compared to control.Conclusions: We found the first evidence of control effects TYLCV using Dufulin. It induced plant defense and increased plant chlorophyll content to help plants resist infection which is helpful for future control of TYLCV in tomato.


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