title: Molecular chaperons and co-chaperons, Hsp90, RAR1, and SGT1 negatively regulate bacterial wilt disease caused by Ralstonia solanacearum in Nicotiana benthamiana.
abstract: Ralstonia solanacearum is the causal agent of bacterial wilt disease. To better understand the molecular mechanisms involved in interaction between Nicotiana benthamiana and R. solanacearum, we focused on Hsp90, RAR1 and SGT1. Appearances of wilt symptom were significantly suppressed in Hsp90, RAR1 and SGT1-silenced plants compared with control plants. In RAR1-silenced plants, population of R. solanacearum increased in a similar manner to control plants. In contrast, multiplication of R. solanacearum was significantly suppressed in Hsp90 and SGT1-silenced plants. In addition, expression of PR genes were increased in Hsp90 and SGT1-silenced plants challenged with R. solanacearum. Therefore, RAR1 might be required for disease development or suppression of disease tolerance. These results also suggested that Hsp90 and/or SGT1 might play an important role in suppression of plant defenses leading to disease susceptibility and disease development.
authors.affiliation: a Laboratory of Plant Pathology and Biotechnology ; Faculty of Agriculture; Kochi University ; Nankoku , Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ito
authors.forename: Kouhei
authors.initials: K
authors.lastname: Ohnishi
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Hikichi
authors.forename: Akinori
authors.initials: A
authors.lastname: Kiba
mesh_terms: D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology*; D010940:Plant Proteins / Q000378:metabolism*; D043368:Ralstonia solanacearum / Q000502:physiology*; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology*
chemical_list: D018841:HSP90 Heat-Shock Proteins; D010940:Plant Proteins
keywords: HR, hypersensitive response; Hsp, heat shock protein; Hsp90; Nicotiana benthamiana; PCR, polymerase chain reaction; RAR1, required for Mla12 resistance 1; RT-PCR, reverse transcription-polymerase chain reaction; SGT1 suppressor-of-G2-allele-of-skp1; TTSS, type III secretion system; VIGS, virus-induced gene silencing.; plant immunity; qRT-PCR, quantitative real time polymerase chain reaction; required for Mla12 resistance 1; suppressor-of-G2-allele-of-skp1; virus-induced gene silencing