Agrobacterium-mediated co-inoculation of okra plants with cloned okra enation leaf curl virus DNA and bhendi yellow vein mosaic beta-satellite DNA furthers Koch’s postulates for enation leaf curl disease

2021 ◽  
pp. 114413
Author(s):  
Kanika Gupta ◽  
Rashmi Rishishwar ◽  
Zainul A. Khan ◽  
Indranil Dasgupta
Plant Disease ◽  
2000 ◽  
Vol 84 (1) ◽  
pp. 101-101 ◽  
Author(s):  
S. Mansoor ◽  
S. H. Khan ◽  
M. Hussain ◽  
Y. Zafar ◽  
M. S. Pinner ◽  
...  

Whitefly-transmitted geminiviruses (begomoviruses) cause heavy losses to many food and fiber crops in Pakistan. Many weeds also show symptoms typical of begomoviruses. Ageratum (Ageratum conyzoides) is a common perennial weed in Pakistan, growing along irrigation canals, that often shows symptoms, such as yellow vein and mosaic, suggesting infection by a begomovirus. To confirm this, symptomatic and asymptomatic ageratum plants were collected from three locations in the Punjab Province of Pakistan, and total DNA was isolated, subjected to agarose gel electrophoresis, transferred to a nylon membrane, and Southern blotted. Total DNA isolated from cotton infected with Cotton leaf curl virus (CLCuV), tomato infected with Tomato leaf curl virus from Pakistan (TLCV-Pak), tobacco infected with African cassava mosaic virus (ACMV) from Nigeria, and healthy tobacco were included as controls. A full-length clone of CLCuV DNA A was labeled with [32P]dCTP by oligo-labeling and hybridized at medium stringency. The probe detected characteristic geminivirus DNA forms in symptomatic ageratum and plants infected with CLCuV, TLCV-Pak, and ACMV, while no signal was detected in asymptomatic ageratum from the field or healthy tobacco. To confirm infection by a begomovirus, degenerate primers WTGF (5′-GATTGTACGCGTCCDCCTTTAATTT GAAYBGG-3′), designed in the rep gene of begomoviruses, and WTGR (5′-TANACGCGTGGC TTCKRTACATGGCCTDT-3′), designed in the coat protein gene of DNA A of begomoviruses, were used in polymerase chain reaction (PCR). Degenerate primers (PBLv2040 and PCRc1) also were used in PCR (2). A product of expected size (≈1.4 kb) was obtained with DNA A primers from symptomatic ageratum, while no product was obtained with DNA B primers in the same sample. Previously we were unable to detect a DNA component equivalent to begomovirus DNA B in cotton showing symptoms of cotton leaf curl disease (1). We recently reported a novel circular DNA molecule that was approximately half as long as the full-length DNA A (CLCuV DNA-1) associated with CLCuV that share homology to plant nanoviruses (1). The supercoiled replicative form of viral DNA isolated from infected ageratum plants indicated the presence of smaller molecules, as was found in cotton leaf curl disease, suggesting that a nanovirus-like molecule might be associated with ageratum yellow vein disease. A duplicate blot of samples used in Southern hybridization with the DNA A probe was prepared, and a probe of the full-length clone of the nanovirus-like molecule (CLCuV DNA-1) was prepared as described for DNA A. The probe detected characteristic nanovirus DNA forms in ageratum with yellow vein symptoms and cotton infected with CLCuV, while no signal was detected in plants infected with TLCV-Pak or ACMV, healthy tobacco, or asymptomatic ageratum. Abutting primers PB2-F and PB2R (1), designed based on the CLCuV DNA-1 sequence, were unable to amplify a PCR product from ageratum with yellow vein symptoms, suggesting the nanovirus-like molecule associated with ageratum yellow vein disease is distinct from CLCuV DNA-1. Our results show that yellow vein disease of ageratum in Pakistan is associated with a begomovirus infection and single-stranded circular DNA molecule with similarity to CLCuV DNA-1. References: (1) S. Mansoor et al. Virology 259:190, 1999. (2) M. R. Rojas et al., Plant Dis. 77:340, 1993.


Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 3089
Author(s):  
Aamir Lal ◽  
Eui-Joon Kil ◽  
Kainat Rauf ◽  
Muhammad Ali ◽  
Sukchan Lee

Plant Disease ◽  
2016 ◽  
Vol 100 (11) ◽  
pp. 2299-2305 ◽  
Author(s):  
Susheel Kumar ◽  
Ashish Srivastava ◽  
Meraj Jaidi ◽  
Puneet Singh Chauhan ◽  
S. K. Raj

Parthenium hysterophorus plants exhibiting severe leaf curl and stunting symptoms were observed near agriculture fields in Lucknow, India. The association of a begomovirus, β-satellite, and α-satellite with these symptoms of a Parthenium disease was investigated by sequence analyses of virus and satellite DNA amplified by rolling circle amplification and polymerase chain reaction. The highest sequence identities and closest phylogenetic relationships for the begomovirus, β-satellite, and α-satellite detected in P. hysterophorus plants were to Tomato leaf curl virus (ToLCV), papaya leaf curl β-satellite (PaLCuB), and Ageratum yellow vein India α-satellite (AYVIA), respectively. These findings identified the virus and satellites infecting the Parthenium sp. as ToLCV, PaLCuB, and AYVIA, respectively. P. hysterophorus and tomato seedlings infected with cloned ToLCV, PaLCuB, and AYVIA by agroinoculation developed leaf curl symptoms, whereas plants infected with ToLCV alone or with ToLCV and AYVIA developed mild yellowing. The results show that this complex infects and causes disease in P. hysterophorus and tomato. P. hysterophorus is an invasive weed commonly found around agricultural fields and along roadsides in India. These results indicate that P. hysterophorus plants infected with ToLCV and associated satellite DNA act as an alternate host (reservoir), and that could lead to increased incidence of tomato leaf curl disease.


2013 ◽  
Vol 24 (2) ◽  
pp. 188-198 ◽  
Author(s):  
V. Venkataravanappa ◽  
C. N. Lakshminarayana Reddy ◽  
A. Devaraju ◽  
Salil Jalali ◽  
M. Krishna Reddy

Author(s):  
Qixi Yao ◽  
Zhengke Peng ◽  
Hong Tong ◽  
Fengbo Yang ◽  
Gaoshan Xing ◽  
...  

Abstract Tomato yellow leaf curl virus (TYLCV), a begomovirus (genus Begomovirus) is the causal agent of tomato yellow leaf curl disease (TYLCD), which causes severe damage to tomato (Solanum lycopersicum) crops throughout tropical and subtropical regions of the world. TYLCV is transmitted by the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in a circulative and persistent manner. Our previous studies showed that tomato flavonoids deter B. tabaci oviposition, but the effects of tomato flavonoids on the settling and feeding behavior of B. tabaci and on its transmission of TYLCV are unknown. Using two near-isogenic tomato lines that differ greatly in flavonoid levels, we found that high flavonoid production in tomato deterred the landing and settling of B. tabaci. Moreover, electrical penetration graph studies indicated that high flavonoid levels in tomato reduced B. tabaci probing and phloem-feeding efficiency. As a consequence, high flavonoid levels in tomato reduced the primary and secondary spread of TYLCV. The results indicate that tomato flavonoids provide antixenosis resistance against B. tabaci and that the breeding of such resistance in new varieties could enhance TYLCD management.


2017 ◽  
Vol 29 (1) ◽  
pp. 17 ◽  
Author(s):  
Muhammad S. Hussain ◽  
Khalid Naveed ◽  
Muhammad Atiq

                                                                  Chilli leaf curl virus (ChiLCV) is a serious problem for chilli production in Pakistan and India. In this study, fourteen different chilli lines / varieties were screened for their resistance/susceptibility towards ChiLCV in open field trials. Data of disease severity and disease incidence was recorded on weekly basis. Out of all varieties screened, Tatapuri Chilli and CH111 showed high susceptibility towards the chilli leaf curl disease. Talhari, CH 99, CH103, CH 106, CH107, CH108, CH109, GSL111 showed susceptible response whereas CBS1292 showed moderately susceptible response towards the disease. Only two cultivars Hybrid-46 and Hot Queen were found as moderately resistant. The screening experiment showed that most of the chilli varieties are susceptible to chilli leaf curl disease and resistance is lacking in local germplasm. Furthermore, three insecticides: Imidacloprid, Polo and Emamectin were tested for their efficacy for the management of disease and whitefly vector in field conditions at weekly intervals. Out of three insecticides, Polo gave best results as compared to Emamectin and Imidacloprid against chilli leaf curl disease and whitefly vector.


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