Regulatory role of external calcium on Pythium porphyrae (Oomycota) zoospore release, development and infection in causing red rot disease of Porphyra yezoensis (Rhodophyta)

• Published in: FEMS microbiology letters Vol. 211; no. 2; pp. 253 - 257
• Main Authors: Addepalli, M.K, Fujita, Y
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 04.06.2002; Blackwell; Oxford University Press
• Subjects: Animals; Appressoria; Biochemistry. Physiology. Immunology. Molecular biology; Biological and medical sciences; Calcium; Calcium (extracellular); Calcium - pharmacology; Calcium - physiology; Calcium ion; Calcium ions; calcium signaling; Calcium signalling; Cations; Chelating Agents - pharmacology; Chelation; Cytoplasm; Divalent cations; Egtazic Acid - pharmacology; ethylene glycol tetraacetic acid; Fundamental and applied biological sciences. Psychology; Infectivity; Ion concentration; Marine Pythium; Microbiology; Motility; pathogenicity; Plant diseases; Porphyra; Porphyra yezoensis; Protozoa; Pyropia yezoensis; Pythium; Pythium - drug effects; Pythium - growth & development; Pythium - pathogenicity; Red rot; Rhodophyta - microbiology; Spores - growth & development; Thalli; thallus; Zoosporangia; Zoospore; Zoospores; Marine; Calcium ion; Motility; Zoospore; Rhodophyta; Calcium; Algae; Germination; Phycomycetes; Inorganic element; Spores; Bangiophyceae; Fungi; Regulation(control); Infectivity; Development; Thallophyta
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2002.tb11233.x

Formation of zoosporangia and cleavage of zoosporangial cytoplasm to zoospores in Pythium porphyrae is absolutely dependent on extracellular calcium. Calcium ion could be substituted neither by monovalent nor divalent cations tested. Increased concentrations of extracellular calcium did not affect the release of zoospores from zoosporangia but inhibited the zoospore motility. Chelating calcium ion by EGTA has decreased the ability of encysted zoospores to germinate and form appressoria. The increased external calcium-ion concentration has decreased the infectivity of Porphyra yezoensis thalli in a linear fashion apparently indicating a role of calcium in the signaling mechanism.