Advertisement

Journal of General Plant Pathology

, Volume 67, Issue 1, pp 7–14 | Cite as

Genetic Analysis of Pathogenicity and Host-specific Toxin Production of Alternaria alternata Tomato Pathotype by Protoplast Fusion

  •  SALAMIAH
  • Yukitaka FUKUMASA-NAKAI
  • Hajime AKAMATSU
  • Hiroshi OTANI
  • Keisuke KOHMOTO
  • Motoichiro KODAMA

Several pathotypes of Alternaria alternata are known to produce host-specific toxins (HSTs) as agents of pathogenicity or virulence. However, investigations into the genetic controls of HST biosynthesis and pathogenicity of Alternaria pathogens have been limited by the lack of a sexual stage in the life cycle of these pathogens. We report here the development of a protoplast fusion system and its use for genetic analysis of HST production and specific pathogenicity of the tomato pathotype of A. alternata that produces AAL-toxin as a HST. Drug-resistant transformants have been isolated by genetic transformation of nonpathogenic A. alternata (strain O-94) and A. alternata tomato pathotype (strain As-27) with vectors conferring resistance to hygromycin B and geneticin, respectively. Protoplasts of the respective transformants were fused by polyethylene glycol treatment or electrofusion. Fusion products were selected by culturing in the presence of both hygromycin B and geneticin, then confirmed by amplification using a polymerase chain reaction with specific primers to the transforming drug-resistance genes. Stable fusants were purified by successive subcultures on selective medium and single-spore isolation. The resultant stable fusants, probably inter-strain hybrids, had the same pathogenicity and toxin production as the wild-type strain As-27. These results suggest that protoplast fusion has potential applications for genetic analysis of A. alternata pathogens.

Key words : Alternaria alternata, AAL-toxin, protoplast fusion, tomato. 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© The Phytopathological Society of Japan 2001

Authors and Affiliations

  •  SALAMIAH
    • 1
  • Yukitaka FUKUMASA-NAKAI
    • 2
  • Hajime AKAMATSU
    • 1
  • Hiroshi OTANI
    • 1
  • Keisuke KOHMOTO
    • 1
  • Motoichiro KODAMA
    • 1
  1. 1.Faculty of Agriculture, Tottori University, Koyama, Tottori 680–8553, JapanJP
  2. 2.The Tottori Mycological Institute, Kokoge, Tottori 689–1125, JapanJP

Personalised recommendations