บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Spontaneous loss of a conditionally dispensable chromosome from the Alternaria alternata apple pathotype leads to loss of toxin production and pathogenicity.

Johnson, L.J., Johnson, R.D., Akamatsu, H., Salamiah, A., Otani, H., Kohmoto, K. and Kodama, M.

Current Genetics 40: 65 –72.

2001

บทคัดย่อ

Spontaneous loss of a conditionally dispensable chromosome from the Alternaria alternata apple pathotype leads to loss of toxin production and pathogenicity.

The Alternaria alternata apple pathotype causes Alternaria blotch of susceptible apple cultivars through the production of a cyclic peptide, host – specific toxin, AM - toxin. A cyclic peptide synthetase gene AMT, has been cloned whose product catalyses the production of AM- toxin and has been shown to reside on chromosomes of 1.8 Mb or less, depending on the A. alternata apple pathotype strain. Contourclamped homogeneous electric field eledtrophoresis and Southern hybridisation demonstrated the loss of a 1.1 – Mb chromosome in the non – toxin – producing isolate. Since this chromosome can be entirely lost without affectong growth, but is necessary for pathogenicity, it is proposed that this is a conditionally dispensable chromosome.