Chemical structure of two phytotoxic exopolysaccharides produced by Phomopsis foeniculi.
The two main exocellular polysaccharides produced in vitro by Phomopsis foeniculi, a fungal pathogen of fennel, were isolated and characterized by chemical and spectroscopic methods as a galactan with the known structure [-->6)-beta-D-Galf-(1-->5)-beta-D- Galf-(1-->5)-beta-D-Galf-(1-->]n and a mannan. The latter consists of a backbone of alpha-(1-->6)-linked mannopyranose units. Almost all of these are branched at the 2 position with arms containing 2- and 3-linked mannopyranose units. The crude polysaccharide fraction and its components, galactan and mannan, showed phytotoxic effects, i.e. chlorosis, necrosis and/or wilting, on fennel and on two non-host plants, tobacco and tomato.
Dipartimento di Chimica Organica e Biologica, Università di Napoli Federico II, Napoli, Italy.
M M
MM
Corsaro
C
C
De Castro
A
A
Evidente
R
R
Lanzetta
A
A
Molinaro
L
L
Mugnai
M
M
Parrilli
G
G
Surico
D001203:Ascomycota / Q000737:chemistry*; D001681:Biological Assay; D002240:Carbohydrate Sequence; D005309:Ferula / Q000469:parasitology; D005685:Galactans / Q000737:chemistry / Q000633:toxicity; D008351:Mannans / Q000737:chemistry / Q000633:toxicity; D008969:Molecular Sequence Data; D009183:Mycotoxins / Q000737:chemistry* / Q000633:toxicity; D010944:Plants / Q000187:drug effects*; D010946:Plants, Medicinal; D010947:Plants, Toxic; D011134:Polysaccharides / Q000737:chemistry* / Q000633:toxicity; D018675:Toxicity Tests
D005685:Galactans; D008351:Mannans; D009183:Mycotoxins; D011134:Polysaccharides