RESUMEN
A begomovirus isolate collected from bitter gourd plants showing yellowing, puckering and stunting symptoms from Coimbatore district, Tamil Nadu, India was characterized. The full-length genome of the virus isolate was amplified by rolling circle amplification using phi29 DNA polymerase. The virus isolate exhibited 98% identity in the nucleotide sequence of DNA-A component with the Coccinia mosaic Virudhunagar virus (GenBank accession no. KY860899). The DNA-B component was very distinct and shared only 60% identity with the begomovirus, Coccinia mosaic Tamil Nadu virus (GenBank accession no. KM244719). The virus renamed as new species Bitter gourd yellow mosaic virus (BgYMV) was detected in seeds from infected plants and in the grow-out test seedlings by ELISA and virus-specific PCR. The seed infectivity was 79.16% and transmission rate to seedling was 32.05%. The virus titre as indicated by A405 absorption value was high (0.854-0.280) in different seed parts. Results clearly indicated seed transmission of the begomovirus, BgYMV.
Asunto(s)
Begomovirus/clasificación , Begomovirus/genética , Begomovirus/aislamiento & purificación , Transmisión de Enfermedad Infecciosa , Momordica charantia/virología , Filogenia , Enfermedades de las Plantas/virología , Semillas/virología , Secuencia de Bases , Clonación Molecular , ADN Viral , Frutas , Genoma Viral , India , Hojas de la Planta/virología , Plantones/virología , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
Gemycircularviruses (genus Gemycircularvirus, family Genomoviridae) are single-stranded DNA viruses that are spread around the world in association with several organisms and environments. In this work, we identified two gemycircularviruses associated with two non-cultivated plants in Brazil, Momordica charantia and Euphorbia heterophylla. Both viruses display the general genome structure of gemycircularviruses. The virus isolated from M. charantia showed the highest nucleotide sequence identity with Pteropus associated gemycircularvirus 5, and an atypical structure consisting of a hairpin embedded in the major stem-loop was observed in the intergenic region. The virus from E. heterophylla showed the highest nucleotide sequence identity with Odonata associated gemycircularvirus 1. Phylogenetic analysis groups the two new viruses together with other genomoviruses of the genus Gemycircularvirus.
Asunto(s)
Virus ADN/genética , Euphorbia/virología , Genoma Viral , Momordica charantia/virología , Enfermedades de las Plantas/virología , Virus de Plantas/aislamiento & purificación , Secuencia de Aminoácidos , Secuencia de Bases , Brasil , Virus ADN/clasificación , Virus ADN/aislamiento & purificación , Datos de Secuencia Molecular , Filogenia , Virus de Plantas/clasificación , Virus de Plantas/genética , Análisis de Secuencia de ADNRESUMEN
Momordica charantia (Cucurbitaceae), a vegetable crop commonly cultivated throughout Pakistan, and begomoviruses, a serious threat to crop plants, are natives of tropical and subtropical regions of the world. Leaf samples of M. charantia with yellow vein symptoms typical of begomovirus infections and samples from apparently healthy plants were collected from areas around Lahore in 2004. Full-length clones of a bipartite begomovirus were isolated from symptomatic samples. The complete nucleotide sequences of the components of one isolate were determined, and these showed the arrangement of genes typical of Old World begomoviruses. The complete nucleotides sequence of DNA A showed the highest nucleotide sequence identity (86.9%) to an isolate of Tomato leaf curl New Delhi virus (ToLCNDV), confirming it to belong to a distinct species of begomovirus, for which the name Bitter gourd yellow vein virus (BGYVV) is proposed. Sequence comparisons showed that BGYVV likely emerged as a result of inter-specific recombination between ToLCNDV and tomato leaf curl Bangladesh virus (ToLCBDV). The complete nucleotide sequence of DNA B showed 97.2% nucleotide sequence identity to that of an Indian strain of Squash leaf curl China virus.
Asunto(s)
Begomovirus/genética , Momordica charantia/virología , Secuencia de Bases , Begomovirus/clasificación , ADN Viral/genética , FilogeniaRESUMEN
Natural occurrence of yellow mosaic disease was observed on bitter gourd (Momordica charantia). Association of geminivirus with the disease was investigated through polymerase chain reaction using geminivirus-specific primers and Southern hybridization with a probe prepared from the cloned DNA of a known geminivirus. The fruits, leaves and stem of infected and healthy plants were studied for phytochemical composition. The amounts of protein were 49%, 50% and 66% higher, total carotenoids were 36%, 33% and 40% lower, vitamin C were 23%, 48% and 50% lower, total phenols were 28%, 31% and 43% lower, and antioxidant activity were 36%, 48% and 43% lower in the severely virus infected fruits, leaves and stem, respectively, as compared with healthy plants. The loss in the quantity of these phytochemicals was also observed even in mild infected plants, which further increased with the severity of the symptoms. Similarly, ethanol and 50% ethanol soluble extractive were also 25-43% lower in the fruits, leaves and stem of infected plants as compared with the healthy plants. A 45% and 54% lower caffeic acid, and 78% and 59% lower amounts of ferulic acid in the fruits and stem, respectively, and a 25% loss of gallic acid were noticed in the leaves of the severely infected plants.