Host–parasite interactions and host species susceptibility of the marine oomycete parasite, Olpidiopsis sp., from Korea that infects red algae

Abstract

Porphyra farms in Korea occasionally suffer from Olpidiopsis infection. As Porphyra farming proceeds from October to March, this obligatory biotrophic parasite may need an alternative host to survive during other months of the year. To find a possible alternative summer host, we collected algae from Wando, Korea, where extensive Porphyra plantations are located, and discovered an oomycete assignable to the genus Olpidiopsis from Heterosiphonia pulchra. Host susceptibility tests showed that this oomycete could also infect Heterosiphonia japonica, Dasya sp., Dasysiphonia chejuensis, and also blades of Porphyra tenera. The minimum incubation time for this Olpidiopsis sp. to infect its hosts was approximately 4 h. Zoosporangia matured in 2 days and biflagellate zoospores were released. Free zoospores remained infective in seawater for up to 7 days. The infection of Olpidiopsis sp. to H. japonica was cell-type specific and extended rhizoid-like apical cells of determinate branches were preferentially infected. FITC-conjugated lectin staining showed specific binding of concanavalin A (ConA) to extended rhizoidlike apical cells. Attachment of Olpidiopsis sp. zoospores to the host cells was inhibited by α-mannosidase.Monosaccharide inhibition experiments showed that D(+)-mannose, complementary to the lectin ConA, could also block the infection, suggesting a lectin-carbohydrate interaction during host-parasite recognition.

A revaluation of algal diseases in Korean Pyropia (Porphyra) sea farms and their economic impact

“…Isolated Olpidiopsis strain from Pyropia was designated as strain KNU-M-omc2. Host plants, Pyropia spp., were kept in MGM medium (Klochkova et al 2012) with constant aeration at 10°C with 16 : 8 h L : D cycle and 30 µmol m -2 s -1 light intensity. Cultures of Olpidiopsis sp.…”

“…About 80% of Korean Pyropia product is sold in Haenam-Jindo and Seocheon and can reduce outputs by an estimated 20% in some areas (Kawamura et al 2005, Klochkova et al 2012. A new Pyropia disease is reported almost every year as cultivation areas are rapidly expanding (Ding andMa 2005, Guan et al 2013), and the impact of disease is expected to increase with environmental changes, such as global warming.…”

“…A new Pyropia disease is reported almost every year as cultivation areas are rapidly expanding (Ding andMa 2005, Guan et al 2013), and the impact of disease is expected to increase with environmental changes, such as global warming. Although the infected crop is still harvested and used, its yield and quality are seriously lowered and the Pyropia products are less lustrous, uneven and discolored (Klochkova et al 2012). As some of these diseases may become chronic, they have the potential to cause serious economic damages to sea farmers.…”

“…We recorded Olpidiopsis spp. disease on Pyropia from Korean sea farms (Klochkova et al 2012). It is recognizable by the appear- gens communicate with and intoxicate host cells (Kuehn and Kesty 2005).…”

Infection and cox2 sequence of Pythium chondricola (Oomycetes) causing red rot disease in Pyropia yezoensis (Rhodophyta) in Korea

“…Diseases like greenspot disease and Olpidiopsis blight as well as red-rot disease, result in a great decrease in productivity, yield and crop value (Kawamura et al 2005, Klochkova et al 2012, 2016b, Kim et al 2014. With increasing farming intensity and increasing temperatures, caused by global warming, disease severity and occurrence is also expected to increase (Ding and Ma 2005, Gachon et al 2010).…”