Effect of Ribitol and Plant Hormones on Aposymbiotical Growth of the Lichen-forming Fungi of Ramalina farinacea and Ramalina fastigiata.

This study was aimed at evaluating the growth promoting effect of symbiotic algal polyol (ribitol) and plant hormones on the lichen-forming fungi (LFF), Ramalina farinacea (CH050010 and 40403) and Ramalina fastigiata. The addition of ribitol to basal (malt-yeast extract) medium enhanced the relative growth rates of all three LFF. R. farinacea (CH050010), R. farinacea (40403) and R. fastigiata (H06127) showed 35.3%, 29.0% and 29.3% higher growth rates, respectively, compared to the control. IBA (indole-3-butyric acid) and TIBA (2,3,5-tridobenzoic acid) also increased growth rates of the LFF by 34 to 64% and 7 to 28%, respectively, compared to the control. The combination of ribitol with IBA or TIBA synergistically increased the growth of all LFF. For example, ribitol and IBA treatments increased growth rates of R. farinacea (CH050010), R. farinacea (40403) and R. fastigiata (H06127) by 79.4%, 40.3% and 72.8% in, respectively, compared to those grown on the basal medium. The stimulating effect of ribitol and IBA on the LFF growth induced vertical development of the fungal mass in culture. We suggest that lichen-forming fungal growth of Ramalina lichens can be stimulated aposymbiotically by supplementing polyols and plant hormones to the basal medium in the mass production of lichen secondary metabolites under large scale culture conditions.

New Record of Lecanora muralis (Lichenized Fungus) in South Korea.

Lecanora muralis was found on the rock along coastal line during the field trip in Jeju island in 2006. Thallus crustose, placodioid, closely adnate, forming orbicular patches; upper surface grayish green, glossy; central lobes areolate, marginal parts plane, edges thin pruinose; lower surface ecorticate; apothecia sessile, lecanorine type, exciple dense and intact when young, and disc plane, but when mature, exciple laciniate, disc protrudent, yellowish brown to orange, 0.5~1.5 mm in diameter; ascospores ellipsoid, simple, colorless, 12.5~15.0 × 5.0~7.5 µm. Usnic acid and zeorin contained in thallus. This is the first record of this species in South Korea.

Taxonomic study on the lichen genus cetrelia (lecanorales, ascomycota) in South Korea.

Seventy-two lichen specimens of Cetrelia collected in South Korea since 2003 were examined by both phenotypic and phylogenetic analyses. The phenotypic analysis was based on morphological and chemical characters, and the phylogenetic analysis was based on nrDNA ITS sequences. The result suggested that the presence and absence of isidia, soredia, lobules and medullar reaction C+ or C- are the important characters in the taxonomy of this genus. Four species of Cetrelia, C. chicitae, C. braunsiana, C. japonica, and C. pseudolivetorum have been identified in this study. Description of each species is presented with morphological and chemical characters. A key to the Cetrelia species is also presented.

Taxonomic study on the lichen genus coccocarpia (lecanorales, ascomycota) in South Korea.

Three species of Coccocarpia have been reported from Korean Peninsular. However, there was no revisional study on this genus before. After careful examination of the specimens deposited in the Korean Lichen Research Institute (KoLRI) and collected from main mountain areas of Korea, two species of Coccocarpia, C. palmicola and C. erythroxyli, have been revealed to occur and confirmed in South Korea. The presence and absence of isidia and apothecia are the most important characters for the South Korean species. We provide the detailed description and illustration of the available two species. A key to the species is also provided.

Molecular cloning and mRNA expression analysis of a novel rice (Oryzasativa L.) MAPK kinase kinase, OsEDR1, an ortholog of Arabidopsis AtEDR1, reveal its role in defense/stress signalling pathways and development.

Mitogen-activated protein kinase (MAPK) cascade(s) is important for plant defense/stress responses. Though MAPKs have been identified and characterized in rice (Oryza sativa L.), a monocot cereal crop research model, the first upstream component of the kinase cascade, namely MAPK kinase kinase (MAPKKK) has not yet been identified. Here we report the cloning of a novel rice gene encoding a MAPKKK, OsEDR1, designated based on its homology with the Arabidopsis MAPKKK, AtEDR1. OsEDR1, a single copy gene in the genome of rice, encodes a predicted protein with molecular mass of 113046.13 and a pI of 9.03. Using our established two-week-old rice seedling in vitro model system, we show that OsEDR1 has a constitutive expression in seedling leaves and is further up-regulated within 15 min upon wounding by cut, treatment with the global signals jasmonic acid (JA), salicylic acid (SA), ethylene (ethephon, ET), abscisic acid, and hydrogen peroxide. In addition, protein phosphatase inhibitors, fungal elicitor chitosan, drought, high salt and sugar, and heavy metals also dramatically induce its expression. Moreover, OsEDR1 expression was altered by co-application of JA, SA, and ET, and required de novo synthesized protein factor(s) in its transient regulation. Furthermore, using an in vivo system we also show that OsEDR1 responds to changes in temperature and environmental pollutants-ozone and sulfur dioxide. Finally, OsEDR1 expression varied significantly in vegetative and reproductive tissues. These results suggest a role for OsEDR1 in defense/stress signalling pathways and development.