The Antifungal Compound Totarol of Thujopsis dolabrata var. hondai Seeds Selects for Fungi on Seedling Root Surfaces

Abstract

Hinoki-asunaro (Thujopsis dolabrata Sieb. et Zucc. var. hondai Makino) is a tree endemic in Japan whose seeds produce several terpenoids. We hypothesized that antifungal compounds in seeds might select for fungi on the root surfaces of T. dolabrata var. hondai seedlings. We examined seed and soil fungi, their sensitivity to methanol extracts of the seeds, the fungi on root surfaces of seedlings grown in Kanuma pumice (a model mineral soil) and nursery soil, and the frequency at which each fungus was detected on the seedling root surface. We calculated correlation coefficients between fungal detection frequency on root surfaces and fungal sensitivity to seed extracts. We also isolated from the seeds the antifungal compound totarol that selected for fungi on root surfaces. Species of Alternaria, Cladosporium, Pestalotiopsis, and Phomopsis were the most frequently isolated fungi from seeds. Mortierella and Mucor were the dominant fungi isolated from Kanuma pumice, whereas Umbelopsis and Trichoderma were the main fungi isolated from nursery soil. Alternaria, Cladosporium, Mortierella, Pestalotiopsis, and Phomopsis were the dominant fungi isolated from root surfaces of seedlings grown in Kanuma pumice, and Alternaria, Cladosporium, Pestalotiopsis, Phomopsis, and Trichoderma were the main root-surface fungi isolated from seedlings grown in nursery soil. The fungal detection frequencies on root surfaces in both soils were significantly and negatively correlated with fungal sensitivity to the seed extract. A similar correlation was found between the fungal detection frequency on root surfaces and fungal sensitivity to totarol. We conclude that totarol is one factor that selects for fungi on root surfaces of T. dolabrata var. hondai in the early growth stage.

In vitro Na+/K+-ATPase inhibitory activity and antimicrobial activity of sesquiterpenes isolated from Thujopsis dolabrata

“…Compounds 1 and 9 have also been reported to show antignawing activity and potent larvicidal activity, respectively (Ahn et al, 1995;Lee et al, 1997). Compound 12 (hinokitiol) has been found to show a broad spectrum of biological activities, including antimicrobial activity (Inamori et al, 1993;Sakagami et al, 2000;Takahashi et al, 2001;Morita et al, 2003Morita et al, , 2004Yamaji et al, 2007;Noshita et al, 2009), and was also reported to be a useful agent for skin (Oreal Cosmetic, 1982;Sakai and Tamura, 1989;Akiyama et al, 1994;Baba et al, 1998). Considering that many applications of hinokitiol (12) to skin have been reported and sesquiterpenes (1, 5, 8-11) showed strong antibacterial activities (Table II), basic dermatological research on these compounds seems desirable.…”

“…hondai Makino (Cupressaceae) is widely distributed in Korea and Japan. This plant contains a number of neutral terpenoids, several acidic phenols, and lignans (Takahashi et al, 2001;Morita et al, 2003Morita et al, , 2004Yamaji et al, 2007;Noshita et al, 2009). In particular, essential oil extracted from T. dolabrata has antimicrobial activity against bacteria, wood-rotting fungi, and plant pathogens and is insecticidal against termites (Takahashi et al, 2001;Yamaji et al, 2007).…”

“…This plant contains a number of neutral terpenoids, several acidic phenols, and lignans (Takahashi et al, 2001;Morita et al, 2003Morita et al, , 2004Yamaji et al, 2007;Noshita et al, 2009). In particular, essential oil extracted from T. dolabrata has antimicrobial activity against bacteria, wood-rotting fungi, and plant pathogens and is insecticidal against termites (Takahashi et al, 2001;Yamaji et al, 2007). Among them, hinokitiol (β-thujaplicin), the major component of this plant, has been found to show a broad spectrum of biological activities, including antimicrobial activity (Morita et al, 2003(Morita et al, , 2004, insecticidal effects, phytogrowth-inhibitory activity (Sakagami et al, 2000), cytotoxic effects on mammalian tumor cells (Inamori et al, 1993), and enzyme inhibitory activities such as those on catechol-O-methyltransferase and metalloproteases (Borchardt, 1973;Inamori et al, 1999).…”

Essential Oil of Thujopsis dolobrata Suppresses Atopic Dermatitis-Like Skin Lesions in NC/Nga Mice

“…hondai Makino (Cupressaceae) is a plant that grows in Korea and Japan. Thujopsis dolobrata contains a number of neutral terpenoids (Takahashi et al, 2001;Yamaji et al, 2007) and several acidic phenols, tropolones, and lignans (Morita et al, 2003;Morita et al, 2004;Noshita et al, 2009). It has been reported that hinokitiol, the major component of Thujopsis dolobrata, has anti-bactericidal and anti-fungal activity (Morita et al, 2002;Morita et al, 2004).…”

The Synthesis and Antimicrobial Activity of Heterocyclic Derivatives of Totarol

“…2 Totarol exhibits antiplasmodial activity, 3 antifungal, 4 and antimicrobial activity against several organisms, including Propionibacterium acnes 5–6 and methicillin-resistant Staphylococcus aureus (MRSA). 5, 7 The mechanism of action by which totarol derives its antimicrobial activity has not been fully elucidated.…”