Abstract
The effect of carrageenans on tomato chlorotic dwarf viroid (TCDVd) replication and symptom expression was studied. Three-week-old tomato plants were spray-treated with iota(ɩ)-, lambda(λ)-, and kappa(κ)-carrageenan at 1 g·L−1 and inoculated with TCDVd after 48 h. The λ-carrageenan significantly suppressed viroid symptom expression after eight weeks of inoculation, only 28% plants showed distinctive bunchy-top symptoms as compared to the 82% in the control group. Viroid concentration was reduced in the infected shoot cuttings incubated in λ-carrageenan amended growth medium. Proteome analysis revealed that 16 tomato proteins were differentially expressed in the λ-carrageenan treated plants. Jasmonic acid related genes, allene oxide synthase (AOS) and lipoxygenase (LOX), were up-regulated in λ-carrageenan treatment during viroid infection. Taken together, our results suggest that λ-carrageenan induced tomato defense against TCDVd, which was partly jasmonic acid(JA) dependent, and that it could be explored in plant protection against viroid infection.
Highlights
Viroids are the smallest (246–400 nucleotides) single-stranded, non-protein-coding circular RNA molecules [1]
Sheyenne) plants were treated with carrageenans (ɩ, κ, λ) and inoculated with tomato chlorotic dwarf viroid (TCDVd)
Based on the phenotype of the plant at 35-days post inoculation, a higher number (82%) of untreated plants were infected with TCDVd, whereas less than 30% plants that were treated with λ-carrageenan exhibited TCDVd symptoms
Summary
Viroids are the smallest (246–400 nucleotides) single-stranded, non-protein-coding circular RNA molecules [1] Since their initial discovery in 1971 [2,3], almost 30 types of viroids belonging to the Pospiviroidae and Avsunviroidae families have been reported to infect a wide array of plants, and the number may increase with the discovery of additional hosts [4]. Pospiviroidae, contains about nine viroid species, including tomato chlorotic dwarf viroid (TCDVd) [1], which causes more than 25 diseases in agricultural, horticultural and ornamental plants [5]. Due to their destructive nature, there is growing interest to develop strategies to control viroids. Considerable advances have been made in the characterization of viroids, mechanisms of viroid pathogenicity and symptom expression [6,7,8,9], mechanisms of plant resistance to viroid infection is not understood.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
