Diversity and phylogeography of begomoviruses and DNA satellites associated with the leaf curl and mosaic disease complex of eggplant

• Published in: Microbial pathogenesis 2023-07, Vol.180, p.106127-106127, Article 106127
• Main Authors: Venkataravanappa, V., Ashwathappa, K.V., Kallingappa, Prasanna, Shridhar, Hiremath, Hemachandra Reddy, P., Reddy, M. Krishna, Reddy, C.N. Lakshminarayana
• Format: Article
• Language: English
• Subjects: Ageratum enation betasatellite (AEV); Alphasatellitidae; Bemisia tabaci; Chilli leaf curl ahmedabad virus (ChiLCAV); Chilli leaf curl bhavanisagar virus-(ChiLCBV); Chilli leaf curl Sri Lanka virus (ChiLCSLV); Chilli leaf curl virus; Chilli leaf curl virus (ChLCuV) tomato leaf curl New Delhi virus (ToLCNDV); DNA; Eggplant; eggplants; India; leaf curling; nucleotide sequences; pathogenesis; PCR; Pepper leaf curl Pakistan virus (PepLCPKV); petioles; Phylogenic analysis; phylogeography; sequence analysis; species; surveys; Tomato leaf curl betasatellite; Tomato leaf curl joydebpur virus (ToLCJV); Tomato leaf curl Palampur virus; Tomato leaf Karnataka virus (ToLCKV) tomato leaf curl palampur virus (ToLCPalV); tomatoes; viral genome; viruses
• ISSN: 0882-4010; 1096-1208
• DOI: 10.1016/j.micpath.2023.106127

Eggplant is one of the important vegetable crops grown across the world, and its production is threatened by both biotic and abiotic stresses. Diseases caused by viruses are becoming major limiting factors for its successful cultivation. A survey for begomovirus-like symptoms in 72 eggplant fields located in six different Indian states revealed a prevalence of disease ranging from 5.2 to 40.2%, and the symptoms recorded were mosaic, mottling, petiole bending, yellowing, and upward curling, vein thickening, and enation of the leaves, and stunting of plants. The causal agent associated with these plants was transmitted from infected leaf samples to healthy eggplant seedlings via grafting and whiteflies (Bemisia tabaci). The presence of begomovirus was confirmed in 72 infected eggplant samples collected from the surveyed fields exhibiting leaf curl and mosaic disease by PCR using begomovirus specifc primers (DNA-A componet), which resulted in an expected amplicon of 1.2 kb. The partial genome sequence obtained from amplified 1.2 kb from all samples indicated that they are closely related begomovirus species, tomato leaf Karnataka virus (ToLCKV, two samples), tomato leaf curl Palampur virus (ToLCPalV, fifty eggplant samples), and chilli leaf curl virus (ChLCuV, twenty samples). Based on the partial genome sequence analysis, fourteen representative samples were selected for full viral genome amplification by the rolling circle DNA amplification (RCA) technique. Analyses of fourteen eggplant isolates genome sequences using the Sequence Demarcation Tool (SDT) indicated that one isolate had the maximum nucleotide (nt) identity with ToLCKV and eight isolates with ToLCPalV. Whereas, four isolates four isolates (BLC1-CH, BLC2-CH, BLC3-CH, BLC4-CH) are showing nucleotide identity of less than 91% with chilli infecting viruses begomoviruses with chilli infecting begomoviruses and as per the guidelines given by the ICTV study group for the classification of begomoviruses these isolates are considered as one novel begomovirus species, for which name, Eggplant leaf curl Chhattisgarh virus (EgLCuChV) is proposed. For DNA-B component, seven eggplant isolates had the highest nt identity with ToLCPalV infecting other crops. Further, DNA satellites sequence analysis indicated that four betasatellites identified shared maximum nucleotide identity with the tomato leaf curl betasatellite and five alphasatellites shared maximum nucleotide identity with the ageratum enation alphasa