Mycorrhiza-induced differential response to a yellows disease in tomato.
The protective effects induced by arbuscular mycorrhizal (AM) fungi against a phytoplasma of the Stolbur group have been investigated in tomato by morphometry and flow cytometry. Symptoms induced by the phytoplasma were less severe when the plants also harboured AM fungi. Morphological parameters such as shoot and root fresh weight, shoot height, internode length, leaf number and adventitious root diameter were closer to those of healthy plants when arbuscular mycorrhiza were present. Reduced nuclear senescence was observed in AM plants infected with phytoplasmas; the percentages of nuclear populations with different ploidy levels were intermediate between AM and phytoplasma-infected plants. The mechanisms underlying these interactions are discussed and a direct action of the AM fungus is hypothesized.
Lingua
Guido
G
Dipartimento di Scienze e Tecnologie Avanzate, Università del Piemonte Orientale Amedeo Avogadro, Corso Borsalino 54, 15100 Alessandria, Italy.
D'Agostino
Giovanni
G
Massa
Nadia
N
Antosiano
Michele
M
Berta
Graziella
G
D005434:Flow Cytometry; D005658:Fungi / Q000502:physiology; D018551:Solanum lycopersicum / Q000382:microbiology*; D038821:Mycorrhizae / Q000502:physiology*; D009868:Oomycetes / Q000502:physiology; D010935:Plant Diseases / Q000382:microbiology*; D018517:Plant Roots / Q000382:microbiology / Q000648:ultrastructure; D018520:Plant Shoots / Q000502:physiology