Assessment of the response reactions of tomatoes depending on the phytosanitary status in condition of infection with viral agents

Relevance. Oxidative reactions (based on peroxidase activity, POX and polyphenol oxidase, PPO; hydrogen peroxide content) that occur in response to infection or reinfection of the off-spring of infected plants depend on the type of host-virus interaction (sensitive, tolerant, stable) and the nature of the interaction with viral infection (primary infection, reinfection of second and third generations).Results. Reinfection with tomato aspermy virus (TАV) or tobacco mosaic virus (TMV) of the off-spring of third infected tomato generation caused a significant decrease in POX activity compared to successive generations of infected plants (G2) for Craigella (Tm-22/Tm- 22) and S. pimpinellifolium genotypes or an increase for Rufina and Craigella (Tm-1/Tm-1) ones. In genotypes containing resistance genes, Rufina and Craigella, no differences were observed in PPO of TMV primary infection and control, while significant differences were found in case of TAV (susceptibility). As a result of TMV infection, the sensitive (Elvira) and tolerant (S. pimpinellifolium) genotypes showed an increase in PPO values compared to the control. At the same time, in most genotypes primarily / secondarily infected with TAV or TMV, statistically significant differences were revealed in the activity of POX or PPO, as well as the accumulation of hydrogen peroxide in plant leaves, which indicates specific protective reactions of the genotypes.

Dinamica răspunsului antioxidativ la tomatele cu diferit tip de interacțiune cu agentul viral

The defensive response of 4 tomato genotypes to Tobacco Mosaic Virus or Tomato Aspermy Virus was evaluated according to 3 indices - peroxidase and catalase activities and hydrogen peroxide content. The response was differentiated according to the applied viral infection, the genotype and dynamics of the infection process. Particularities have been attested in the reaction of the antioxidative response at different stages of the pathogenesis - increasing or decreasing of the evaluated indices compared to the healthy control.

Heterologous Replicase from Cucumoviruses can Replicate Viral RNAs, but is Defective in Transcribing Subgenomic RNA4A or Facilitating Viral Movement

Interspecific exchange of RNA1 or RNA2 between the cucumoviruses cucumber mosaic virus (CMV) and tomato aspermy virus (TAV) was reported to be non-viable in plants previously. Here we investigated viability of the reassortants between CMV and TAV in Nicotiana benthamiana plants by Agrobacterium-mediated viral inoculation. The reassortants were composed of CMV RNA1 and TAV RNA2 plus RNA3 replicated in the inoculated leaves, while they were defective in viral systemic movement at the early stage of infection. Interestingly, the reassortant containing TAV RNA1 and CMV RNA2 and RNA3 infected plants systemically, but produced RNA4A (the RNA2 subgenome) at an undetectable level. The defect in production of RNA4A was due to the 1a protein encoded by TAV RNA1, and partially restored by replacing the C-terminus (helicase domain) in TAV 1a with that of CMV 1a. Collectively, exchange of the replicase components between CMV and TAV was acceptable for viral replication, but was defective in either directing transcription of subgenomic RNA4A or facilitating viral long-distance movement. Our finding may shed some light on evolution of subgenomic RNA4A in the family Bromoviridae.

Complete Genome Sequences of Three Tomato Aspermy Virus Isolates in Japan

ABSTRACT We report here the first complete nucleotide sequences of genomic RNAs of three Tomato aspermy virus (TAV) isolates in Japan. Analysis of these sequences showed that they have unique characteristics in RNAs 2 and 3. The Japanese isolates are similar to each other compared to other TAVs.

Tomato aspermy virus elimination improves medicinal quality of chrysanthemum

Chrysanthemum morifolium cv. ?Huaihuang?, a medicinal chrysanthemum of China, undergoes long-term asexual reproduction and virus infection that change its quality characteristics. Our previous studies have shown that tomato aspermy virus (TAV) is the main virus infecting ?Huaihuang?. Many studies indicate that plant virus elimination can improve plant growth, but only a few studies have focused on the effects of detoxification on the medicinal components of medicinal plants. In this paper, the content of medicinal components, including chlorogenic acid, luteoloside and 3,5-O-dicaffeoylquinic acid, was compared between the TAV-free and TAV-infected (control) chrysanthemum. In addition, the reason why TAV elimination improves the medicinal components of chrysanthemum is explored. Our results suggest that TAV elimination significantly improves plant growth, enhances the enzyme activities of phenylalanine ammonia-lyase, cinnamate-4-hydroxylase and 4-coumarate:CoA ligase, and increases the levels of CmHCT and CmCHS expression, thereby greatly improving the medicinal quality of chrysanthemum.

CARLAVIRUS IN LILY COLLECTION OF GRISHKO' NATIONAL BOTANICAL GARDEN

Screening of Lilium plants on virus diseases in the collections of M.M. Grishko' National Botanical Garden have been conducted. Basing on serological, biological and morphological properties, we suggest that filamentous virus is related to Lily symptomless virus. Another virus is not completely identified, but symptoms induced on indicator plants suggested that it was Tomato aspermy virus.