Title Evaluation of Bakanae Disease Progression Caused by Fusarium fujikuroi in Oryza sativa L.
Author In Sun Hwang1, Woo-Ri Kang1, Duk-Ju Hwang1, Shin-Chul Bae1, Sung-Hwan Yun2, and Il-Pyung Ahn1*
Address 1National Academy of Agricultural Science, Rural Development Administration, Suwon 441-707, Republic of Korea, 2Department of Medical Biotechnology, Soonchunhyang University, Asan 336-745, Republic of Korea
Bibliography Journal of Microbiology, 51(6),858–865, 2013,
DOI 10.1007/s12275-013-3472-3
Key Words Bakanae disease, Taqman real time PCR
Abstract Bakanae disease caused by Fusarium fujikuroi is an important fungal disease in rice. Among the seven strains isolated from symptomatic rice grains in this study, one strain, FfB14, triggered severe root growth inhibition and decay in the crown and root of rice seedlings. The remaining six strains caused typical Bakanae symptoms such as etiolation and abnormal succulent rice growth. To reveal the relationship between mycelial growth in the infected tissues and Bakanae disease progression, we have established a reliable quantification method using real time PCR that employs a primer pair and dual-labeled probe specific to a unigene encoding F. fujikuroi PNG1 (FfPNG1), which is located upstream of the fumonisin biosynthesis gene cluster. Plotting the crossing point (CP) values from the infected tissue DNAs on a standard curve revealed the active fungal growth of FfB14 in the root and crown of rice seedlings, while the growth rate of FfB20 in rice was more than 4 times lower than FfB14. Massive infective mycelial growth of FfB14 was evident in rice stems and crown; however, FfB20 did not exhibit vigorous growth. Our quantitative evaluation system is applicable for the identification of fungal virulence factors other than gibberellin.