VIEW ARTICLE

Physiology and Biochemistry

Influence of Changes in the Nurse Cell System (Syncytium) on the Development of the Cyst Nematode Heterodera schachtii: Single Amino Acids. Marlies Betka, Institut f?r Phytopathologie der Christian-Albrechts-Universit?t Kiel, Hermann-Rodewald-Stra?e 9, D-2300 Kiel 1, Germany; F. Grundler, and U. Wyss. Institut f?r Phytopathologie der Christian-Albrechts-Universit?t Kiel, Hermann-Rodewald-Stra?e 9, D-2300 Kiel 1, Germany. Phytopathology 81:75-79. Accepted for publication 30 July 1990. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/Phyto-81-75.

The metabolism of seedling roots of Brassica rapa var. silvestris f. campestris ?Stielmus? was manipulated to investigate the influence of amino acids on the development of the beet cyst nematode, Heterodera schachtii. After inoculation of single J2 juveniles to germinated roots in water agar drops under aseptic conditions, 50% of the seedlings were decapitated by removing shoot and root tips. One day later, nutrient solutions containing various amounts of sucrose were flooded over the drops. In this way, a total of 10 variants was obtained, out of which seven (?+? variants) supported and three (??? variants) inhibited female development. Using sensitive micromethods, we determined changes in the concentrations of 19 amino acids in the syncytia (nurse cell systems) and adjacent root segments, as well as in segments of uninoculated control roots. Glutamine appeared to play a beneficial role in the ?+? variants, whereas methionine, phenylalanine, lysine, and tryptophan played harmful roles in the ??? variants. Changes in the concentrations of the 14 other amino acids had no influence on nematode development.