The pepper cultivar Yellow Lantern, one of the spiciest pepper varieties, is a local germplasm of Capsicum chinense, cultivated exclusively on Hainan Island, China. However, this variety is susceptible to viral diseases that severely affect its production. In this study, we report that pepper veinal mottle virus (PVMV) is associated with foliar chlorosis and rugosity symptoms in Yellow Lantern. To verify this correlation, we constructed a full-length cDNA clone of a PVMV isolate named HNu. The virus progeny derived from the cDNA clone replicated and moved systemically in the pepper, inducing the same symptoms as those induced by PVMV-HNu in Yellow Lantern peppers in the field. The results support that PVMV-HNu is the causal agent of foliar chlorosis and rugosity disease in Yellow Lantern. This knowledge will help in the diagnosis and prevention of disease caused by PVMV. Furthermore, the cDNA clone serves as a reverse genetic tool to study the molecular pathogenesis of PVMV.
Aims: This study aimed to investigate the changes in antioxidant activity and protein content between non-infected and infected leaves of three Capsicum annuum varieties against Pepper veinal mottle virus.
Materials and Methods: Pepper veinal mottle virus isolated from infected pepper plants was inoculated to three healthy varieties of pepper (Pepper Narval, Yolo Wonder and Chili pepper) by gently rubbing on the leaves of 14-day-old seedlings. Control peppers of each variety were treated in the same way with distilled water. The infection of inoculated plants was confirmed by the enzyme-linked immunosorbent assay method. Control and infected leaves were collected 21 days after inoculation (when symptoms manifested) and used for biochemical analyses. Change in different biochemical parameters (catalase, superoxide dismutase, malondialdehyde and protein) in infected pepper plant was observed compared to control non-infected ones.
Results: Catalase and superoxide dismutase activities were increased in Pepper Narval and Pepper Yolo Wonder infected leaves compared to non-infected, while a significant decrease was observed in infected Chili pepper compared to control. Higher malondialdehyde content was found in Pepper Yolo Wonder and Chili pepper infected leaves (P < 0.05) than control while a non-significant difference was shown between the infected and non-infected of Pepper Narval variety (P > 0.05). Infected Chili pepper showed high protein content compared to control (P < 0.05). An opposite trend was observed in pepper Narval and Yolo Wonder varieties (P < 0.05).
Conclusion: The results of this study showed that Pepper veinal mottle virus infection induces changes in antioxidant enzymes activities, malondialdehyde and total protein levels. These biochemical components were greatly expressed differentially between Pepper veinal mottle virus infected and non-infected in Pepper Yolo Wonder variety. Further studies with more biochemical parameters may contribute to improve the pepper tolerance mechanism to Pepper veinal mottle virus in a breeding program.
Abstract
A new distribution map is provided for Pepper veinal mottle virus. Potyviridae: Potyvirus. Hosts: Capsicum spp., tomatoes (Solanum lycopersicum) and aubergines (Solanum melongena). Information is given on the geographical distribution in Asia (Afghanistan, China, Hunan, India, Andhra Pradesh, Himachal Pradesh, Karnataka, Maharashtra, Iran, Japan, Ryukyu Archipelago, Taiwan), Africa (Benin, Burkina Faso, Cameroon, Cote d'Ivoire, Ethiopia, Ghana, Kenya, Liberia, Mali, Nigeria, Senegal, South Africa, Togo, Tunisia), Central America & Caribbean (Cuba).
Use of an Infectious cDNA Clone of Pepper Veinal Mottle Virus to Confirm the Etiology of a Disease in Capsicum chinense
