Camila Nicolli, PhD
Assistant Professor - Extension Plant Pathologist
University of Arkansas
Stuttgart, Arkansas, United States
Ana C.B. Ferreira
Visiting Scholar
University of Arkansas System Division of Agriculture
Stuttgart, Arkansas, United States
Scott Belmar
Program Technician III
University of Arkansas System Division of Agriculture
Stuttgart, Arkansas, United States
Yixiao Huang
Postdoctoral Research Associate
USDA ARS Dale Bumpers National Rice Research Center (DB NRRC)
Stuttgart, Arkansas, United States
Rodrigo Pedrozo
Postdoctoral Research Associate
USDA ARS Dale Bumpers National Rice Research Center (DB NRRC)
Stuttgart, Arkansas, United States
Yulin Jia
Research Leader/Center Director/Location Coordinator
USDA ARS Dale Bumpers National Rice Research Center (DB NRRC)
Stuttgart, Arkansas, United States
Pantoea ananatis is an emerging bacterial pathogen that impacts a wide range of crops, such as rice, corn, sorghum and peanuts. This study aimed to fulfill Koch’s postulates for Pantoea ananatis isolates from infected rice tissues and seeds. Studies were conducted to isolate seedborne Pantoea ananatis using Pantoea-Genus Species Agar (PGSA). The seeds and leaves were surface disinfected by 70% (v/v) ethanol, followed by 10% (v/v) sodium hypochlorite, both for one minute and then rinsed twice with sterilized water. After seven days of incubation at 28°C, bacterial suspect colonies from both seeds and leaves were further analyzed using colony PCR to confirm bacterial identity. Pathogenicity was assessed through two methods: scissor clip and seed inoculation. The CLL16 rice variety was inoculated with two concentrations of OD600=0.2 and 2.0. Mock inoculation with sterile water was issued as negative control for both tests. Three isolates (PP081-83) were obtained from symptomatic rice leaves and the other five isolates (PP101-105) from rice seeds. Typical symptoms were developed in greenhouse pathogenicity test using the seed inoculation method, in comparison with scissor clip. Post inoculation, another PCR reaction was performed to verify bacterial presence and confirm identification in infected plants. While significant progress has been made, this study marks the first successful reproduction of typical leaf symptoms in a controlled environment. Further experiments will continue to fully elucidate the pathogenic potential of these isolates.