title: The entry of cucumber mosaic virus into cucumber xylem is facilitated by co-infection with zucchini yellow mosaic virus.
abstract: We investigated the synergistic effects of co-infection by zucchini yellow mosaic virus (ZYMV) and cucumber mosaic virus (CMV) on viral distribution in the vascular tissues of cucumber. Immunohistochemical observations indicated that ZYMV was present in both the phloem and xylem tissues. ZYMV-RNA was detected in both the xylem wash and guttation fluid of ZYMV-inoculated cucumber. Steam treatment at a stem internode indicated that ZYMV enters the xylem vessels and moves through them but does not cause systemic infection in the plant. CMV distribution in singly infected cucumbers was restricted to phloem tissue. By contrast, CMV was detected in the xylem tissue of cotyledons in plants co-infected with CMV and ZYMV. Although both ZYMV-RNA and CMV-RNA were detected in the xylem wash and upper internodes of steam-treated, co-infected cucumbers grown at 24 °C, neither virus was detected in the upper leaves using an ELISA assay. Genetically modified CMV harboring the ZYMV HC-Pro gene was distributed in the xylem and phloem tissues of singly inoculated cucumber cotyledons. These results indicate that the ZYMV HC-Pro gene facilitates CMV entry into the xylem vessels of co-infected cucumbers.
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Mochizuki
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Nobuhara
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Nishimura
authors.affiliation: Kyoto Biken Laboratories Inc., Uji, Kyoto, 611-0041, Japan.
authors.forename: Bo-Song
authors.initials: BS
authors.lastname: Ryang
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Naoe
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsumoto
authors.affiliation: Kyoto Prefectural Agriculture, Forestry, and Fisheries Technology Center, Seika-cho, Kyoto, 619-0244, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Kosaka
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan. ohki@plant.osakafu-u.ac.jp.
authors.forename: Satoshi T
authors.initials: ST
authors.lastname: Ohki
mesh_terms: D060085:Coinfection; D018553:Cucumis sativus / Q000821:virology*; D017799:Cucumovirus / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay; D007150:Immunohistochemistry; D052585:Phloem / Q000821:virology; D018515:Plant Leaves / Q000821:virology; D017800:Potyvirus / Q000502:physiology*; D053586:Virus Internalization; D052584:Xylem / Q000821:virology*