First report on polysaccharides of Asterochloris and their potential role in the lichen symbiosis.
A structural study of the carbohydrates from the aposymbiotically cultured Asterochloris sp., the algal symbiont of the lichen Cladina confusa was carried out for the first time. A xylorhamnogalactofuranan was purified and was predominated by (1-->3)-linked galactofuranosyl units with sidechains in position 6 on approximately 6.4% of the units. The sidechains have galactofuranosyl units 5-O and 6-O-substituted, as well rhamnopyranosyl units 2-O, 3-O and 2,3-di-O-substituted. Xylose was detected only as nonreducing end units, together with galactofuranosyl units. Amylose and a beta-(1-->4)-xylan were also present. These polysaccharides have not been found in the symbiotic thallus of C. confusa, which contained only glucans, galactomannoglucan and galactoglucomannan. A potential role of these carbohydrates in lichen recognition proccess is also discussed.
Cordeiro
Lucimara M C
LM
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19.046, CEP 81.531-990, Curitiba, PR, Brazil.
Sassaki
Guilherme L
GL
Iacomini
Marcello
M
D002240:Carbohydrate Sequence; D000460:Chlorophyta / Q000737:chemistry* / Q000502:physiology; D005936:Glucans / Q000737:chemistry* / Q000378:metabolism; D008011:Lichens / Q000737:chemistry* / Q000502:physiology; D013559:Symbiosis / Q000502:physiology*
D005936:Glucans