VIEW ARTICLE

Biochemistry and Cell Biology

Interaction Between the Phytotoxin Dothistromin and Pinus radiata Embryos. William T. Jones, Plant Improvement Division, Horticulture and Food Research Institute of New Zealand, Private Bag 11-030, Palmerston North, New Zealand; Dawn Harvey(2), Stephen D. Jones(3), Paul W. Sutherland(4), Maurice J. Nicol(5), Nicholas Sergejew(6), Phillip M. Debnam(7), Nancy Cranshaw(8), and Paul H. S. Reynolds(9). (2)(3)(4)(5)(6)(9)Plant Improvement Division, Horticulture and Food Research Institute of New Zealand, Private Bag 11-030, Palmerston North, New Zealand; (7)(8)New Zealand Forest Research Institute, Private Bag 3020, Rotorua, New Zealand. Phytopathology 85:1099-1104. Accepted for publication 9 June 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/Phyto-85-1099.

Dothistromin (DOTH) is a fungal toxin occurring in Pinus radiata needles infected with Dothistroma pini. Dose-dependent toxicity of DOTH toward both P. radiata mature seed embryos and meristematic leaf callus was observed. DOTH effected 50 and 100% inhibition of embryo and leaf callus growth after absorbing 3 and 13 nmol of DOTH per g of tissue, respectively. DOTH-binding sites were localized, using immuno-histology for light and electron microscopy, within small vesicles in the embryos. A 40-kDa peptide was identified in the particulate fraction of mature embryo extracts that reacted specifically with a DOTH-mouse albumin conjugate.