A leading-edge scenario in the phylogeography and evolutionary history of East Asian insular Taxus in Taiwan and the Philippines.

The cool temperate origin of gymnosperm Taxus species in East Asia is specifically diverse and widespread. Certain lineages have managed to extend their distribution further south to subtropical and tropical islands such as Taiwan and the Philippines. To address questions including whether these insular lineages, recently identified as T. phytonii, have become genetically distinct from each other and from their continental relatives, and when and how they colonized their residing islands, we sampled over 11 populations, covering 179 Taxus individuals from Taiwan and the Philippines. Using four cpDNA and one nuclear marker, we showed in population genetic and genealogical analyses that the two insular lineages were genetically distinct from each other and also from other continental Taxus and that they represented each other's closest relative. Estimated with the coalescent-based multi-type tree (MTT) analyses, we inferred an origin of Taiwanese T. phytonii more ancient than 2.49 Mya and that of Philippine T. phytonii more ancient than 1.08 Mya. In addition, the divergence demographic history revealed by both MTT and isolation with migration (IM) analyses indicated the presence of recent post-split migrations from a continental taxon, T. mairei, to Taiwanese T. phytonii, as well as from Taiwanese T. phytonii to Philippine T. phytonii. Overall, this study suggests Taiwan as a stepping stone through which the temperate-origin yew trees can extend their distributions to tropical regions such as the Philippines.

Bioactive Triterpenoids from the Leaves and Twigs of Lithocarpus litseifolius and L. corneus.

Phytochemical investigation of the leaves and twigs of Lithocarpus litseifolius and Lithocarpus corneus resulted in the isolation of four new triterpenoids (1: -4: ), three triterpenoids (5: -7: ) isolated from a natural source for the first time, and six known compounds (8: -13: ). In addition, four known triterpenoids (14: -17: ) were isolated from L. corneus. Compound 1: is a 3,4-seco-lupane-type triterpenoid, and compounds 2: -4: are lupane-type triterpenoids in different oxidation states. The structures of all isolated compounds were identified by spectroscopic methods, especially NMR and mass spectrometry data. The absolute configuration of 2: and 3: was confirmed by X-ray single crystallographic analysis. The anti-inflammatory activities of 1: -17: and anti-HIV activities of 2: -17: were evaluated. Among them, 3-epi-betulinic acid (8: ) showed a strong anti-HIV activity comparable to abacavir, a drug used for treating HIV/AIDS. 3,4-seco-4(23),20(29)-lupadiene-3,28-dioic acid (5: ) exhibited potent inhibition of superoxide-anion generation with 86.9 ± 2.8% inhibition at 1 µM.

Tetranortriterpenes and Limonoids from the Roots of Aphanamixis polystachya.

Phytochemical investigation of the acetone extract from the roots of Aphanamixis polystachya resulted in isolation of four new tetranortriterpenes (1-4) in addition to one protolimonoid (methyl-1ξ,7R-diacetoxy-23R,25-dihydroxy-20S,24R-21,24-epoxy-3,4-seco-apotirucall-4(28),14(15)-diene-3-oate (5)), five known limonoids (rohituka 3 (6), rohituka 7 (7), nymania 1 (8), rubrin G (9), prieurianin (10)) and a steroid (2,3-dihydroxy-5-pregnan-16-one (11)). Their structures were determined by spectroscopic analyses, including 2D-NMR (COSY, HMQC, HMBC, and NOESY) and high-resolution electrospray ionization mass spectrometry (HRESIMS). Cytotoxic and anti-inflammatory activities of these compounds were evaluated. Compounds 4 and 5 showed significant inhibition against superoxide generation and elastase release by human neutrophils in response to (formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B) (FMLP/CB).

The Arabidopsis glutamate receptor-like gene GLR3.6 controls root development by repressing the Kip-related protein gene KRP4.

In Arabidopsis, 20 genes encode putative glutamate receptor-like proteins (AtGLRs). However, the functions of most genes are unknown. In this study, our results revealed that loss of function of AtGLR3.6 (atglr3.6-1) leads to reduced primary root growth and fewer lateral roots, whereas AtGLR3.6 overexpression induced both primary and lateral root growth. The glr3.6-1 mutant exhibited a smaller root meristem size compared with the wild type, indicating that AtGLR3.6 controls root meristem size. In addition, atglr3.6-1 roots show a decreased mitotic activity accounting for the reduced root meristem size. Furthermore, expression of a gene encoding a cell cycle inhibitor, the cyclin-dependent kinase (CDK) inhibitor Kip-related protein 4 (KRP4), was significantly up-regulated in the mutant and down-regulated in AtGLR3.6-overexpressing roots, suggesting a role for KRP4 in AtGLR3.6-mediated root meristem maintenance. Importantly, the atglr3.6-1 mutant recovered most of its root growth when KRP4 expression is down-regulated, whereas elevated KRP4 expression in AtGLR3.6-overexpressing plants phenocopied the wild-type root growth, implying an underlying relationship between AtGLR3.6 and KRP4 genes. Cytosolic Ca(2+) elevation is reduced in atglr3.6-1 roots, suggesting impaired calcium signaling. Moreover, calcium treatment reduced the level of KRP4 and hence induced root growth. Collectively, we reveal that AtGLR3.6 is required for primary and lateral root development, and KRP4 functions as a downstream signaling element in Arabidopsis thaliana.

Effects of moist cold stratification on germination, plant growth regulators, metabolites and embryo ultrastructure in seeds of Acer morrisonense (Sapindaceae).

Breaking of seed dormancy by moist cold stratification involves complex interactions in cells. To assess the effect of moist cold stratification on dormancy break in seeds of Acer morrisonense, we monitored percentages and rates of germination and changes in plant growth regulators, sugars, amino acids and embryo ultrastructure after various periods of cold stratification. Fresh seeds incubated at 25/15 °C for 24 weeks germinated to 61%, while those cold stratified at 5 °C for 12 weeks germinated to 87% in 1 week. Neither exogenous GA3 nor GA4 pretreatment significantly increased final seed germination percentage. Total ABA content of seeds cold stratified for 12 weeks was reduced about 3.3-fold, to a concentration similar to that in germinated seeds (radicle emergence). Endogenous GA3 and GA7 were detected in 8-week and 12-week cold stratified seeds but not in fresh seeds. Numerous protein and lipid bodies were present in the plumule, first true leaves and cotyledons of fresh seeds. Protein and lipid bodies decreased greatly during cold stratification, and concentrations of total soluble sugars and amino acids increased. The major non-polar sugars in fresh seeds were sucrose and fructose, but sucrose increased and fructose decreased significantly during cold stratification. The major free amino acids were proline and tryptophan in fresh seeds, and proline increased and tryptophan decreased during cold stratification. Thus, as dormancy break occurs during cold stratification seeds of A. morrisonense undergo changes in plant growth regulators, proteins, lipids, sugars, amino acids and cell ultrastructure.

Hyperinakin, a new anti-inflammatory phloroglucinol derivative from Hypericum nakamurai.

Phytochemical investigation of Hypericum nakamurai (Masamune) Robson has led to the isolation of three phloroglucinol derivatives 1-3. The structures of these compounds were determined by the analysis of their spectroscopic data (IR, mass and UV), and by the application of 1-D and 2-D-NMR techniques. Hyperinakin (1) is a new compound. The anti-inflammatory activities of compounds 1-3 were also tested and evaluated. A biogenetic pathway for compounds 1-3 was also proposed.

Anti-liver fibrotic lignans from the fruits of Schisandra arisanensis and Schisandra sphenanthera.

Three new polyoxygenated C(18)-dibenzocyclooctadiene lignans, arisanschinins M and N (1 and 2) and schisphenin A (3), together with eight related metabolites (4-11), were isolated from the fruits of Schisandra arisanensis and Schisandra sphenanthera, respectively. The structures of 1-3 were elucidated on the basis of extensive spectroscopic and 2D NMR (HSQC, HMBC, and NOESY) analyses. The configuration of the biphenyl moiety in the octadiene ring was determined by circular dichroism (CD). Compound 1 possessed an unprecedented 3-(1-hydroxypropan-2-yl)-3-methyl-1,4-dioxo-2-one lactonide ring system attaching at C-6/C-14. Pharmacological studies revealed that compounds 3, 4, 6, 7, and 10 exhibited significant anti-hepatic fibrosis activity, while 9 and 11 showed cytotoxicity against HSC-T6 cells. The biogenetic pathway for compound 1 was also proposed.

Schisarisanlactones A and B: a new class of nortriterpenoids from the fruits of Schisandra arisanensis.

Two novel highly oxygenated nortriterpenoids, schisarisanlactones A (1) and B (2), have been isolated from the fruits of Schisandra arisanensis, an endemic plant of Taiwan. Compounds 1 and 2 possess an unprecedented 5/5/7/5/5-fused pentacyclic ring system. The structures of both compounds were determined on the basis of spectroscopic analyses, especially 2D NMR and MS. A plausible biogenetic pathway of 1 was proposed. Schisarisanlactone A (1) showed significant anti-HIV activity.

Drought and salt stress tolerance of an Arabidopsis glutathione S-transferase U17 knockout mutant are attributed to the combined effect of glutathione and abscisic acid.

Although glutathione S-transferases (GSTs) are thought to play major roles in oxidative stress metabolism, little is known about the regulatory functions of GSTs. We have reported that Arabidopsis (Arabidopsis thaliana) GLUTATHIONE S-TRANSFERASE U17 (AtGSTU17; At1g10370) participates in light signaling and might modulate various aspects of development by affecting glutathione (GSH) pools via a coordinated regulation with phytochrome A. Here, we provide further evidence to support a negative role of AtGSTU17 in drought and salt stress tolerance. When AtGSTU17 was mutated, plants were more tolerant to drought and salt stresses compared with wild-type plants. In addition, atgstu17 accumulated higher levels of GSH and abscisic acid (ABA) and exhibited hyposensitivity to ABA during seed germination, smaller stomatal apertures, a lower transpiration rate, better development of primary and lateral root systems, and longer vegetative growth. To explore how atgstu17 accumulated higher ABA content, we grew wild-type plants in the solution containing GSH and found that they accumulated ABA to a higher extent than plants grown in the absence of GSH, and they also exhibited the atgstu17 phenotypes. Wild-type plants treated with GSH also demonstrated more tolerance to drought and salt stresses. Furthermore, the effect of GSH on root patterning and drought tolerance was confirmed by growing the atgstu17 in solution containing l-buthionine-(S,R)-sulfoximine, a specific inhibitor of GSH biosynthesis. In conclusion, the atgstu17 phenotype can be explained by the combined effect of GSH and ABA. We propose a role of AtGSTU17 in adaptive responses to drought and salt stresses by functioning as a negative component of stress-mediated signal transduction pathways.

Deep simple epicotyl morphophysiological dormancy in seeds of two Viburnum species, with special reference to shoot growth and development inside the seed.

BACKGROUND AND AIMS: In seeds with deep simple epicotyl morphophysiological dormancy, warm and cold stratification are required to break dormancy of the radicle and shoot, respectively. Although the shoot remains inside the seed all winter, little is known about its growth and morphological development prior to emergence in spring. The aims of the present study were to determine the temperature requirements for radicle and shoot emergence in seeds of Viburnum betulifolium and V. parvifolium and to monitor growth of the epicotyl, plumule and cotyledons in root-emerged seeds. METHODS: Fresh and pre-treated seeds of V. betulifolium and V. parvifolium were incubated under various temperature regimes and monitored for radicle and shoot emergence. Growth of the epicotyl and cotyledons at different stages was observed with dissecting and scanning electron microscopes. KEY RESULTS: The optimum temperature for radicle emergence of seeds of both species, either kept continuously at a single regime or exposed to a sequence of regimes, was 20/10 °C. GA(3) had no effect on radicle emergence. Cold stratification (5 °C) was required for shoot emergence. The shoot apical meristem in fresh seeds did not form a bulge until the embryo had grown to the critical length for radicle emergence. After radicle emergence, the epicotyl--plumule and cotyledons grew slowly at 5 and 20/10 °C, and the first pair of true leaves was initiated. However, the shoot emerged only from seeds that received cold stratification. CONCLUSIONS: Seeds of V. betulifolium and V. parvifolium have deep simple epicotyl morphophysiological dormancy, C(1b)B (root)-C(3) (epicotyl). Warm stratification was required to break the first part of physiological dormancy (PD), thereby allowing embryo growth and subsequently radicle emergence. Although cold stratification was not required for differentiation of the epicotyl--plumule, it was required to break the second part of PD, thereby allowing the shoot to emerge in spring.

FAR-RED INSENSITIVE219 modulates CONSTITUTIVE PHOTOMORPHOGENIC1 activity via physical interaction to regulate hypocotyl elongation in Arabidopsis.

FAR-RED INSENSITIVE219 (FIN219) in Arabidopsis (Arabidopsis thaliana) is involved in phytochrome A-mediated far-red (FR) light signaling. Previous genetic studies revealed that FIN219 acts as an extragenic suppressor of CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1). However, the molecular mechanism underlying the suppression of COP1 remains unknown. Here, we used a transgenic approach to study the regulation of COP1 by FIN219. Transgenic seedlings containing ectopic expression of the FIN219 amino (N)-terminal domain in wild-type Columbia (named NCox for the expression of the N-terminal coiled-coil domain and NTox for the N-terminal 300-amino acid region) exhibited a dominant-negative long-hypocotyl phenotype under FR light, reflected as reduced photomorphogenic responses and altered levels of COP1 and ELONGATED HYPOCOTYL5 (HY5). Yeast two-hybrid, pull-down, and bimolecular fluorescence complementation assays revealed that FIN219 could interact with the WD-40 domain of COP1 and with its N-terminal coiled-coil domain through its carboxyl-terminal domain. Further in vivo coimmunoprecipitation study confirms that FIN219 interacts with COP1 under continuous FR light. Studies of the double mutant fin219-2/cop1-6 indicated that HY5 stability requires FIN219 under darkness and FR light. Moreover, FIN219 levels positively regulated by phytochrome A can modulate the subcellular location of COP1 and are differentially regulated by various fluence rates of FR light. We conclude that the dominant-negative long-hypocotyl phenotype conferred by NCox and NTox in a wild-type background was caused by the misregulation of COP1 binding with the carboxyl terminus of FIN219. Our data provide a critical mechanism controlling the key repressor COP1 in response to FR light.

Growth promotion of Chinese cabbage and Arabidopsis by Piriformospora indica is not stimulated by mycelium-synthesized auxin.

Piriformospora indica, an endophytic fungus of the order Sebacinales, interacts with the roots of a large variety of plant species. We compared the interaction of this fungus with Chinese cabbage (Brassica campestris subsp. chinensis) and Arabidopsis seedlings. The development of shoots and roots of Chinese cabbage seedlings was strongly promoted by P. indica and the fresh weight of the seedlings increased approximately twofold. The strong stimulation of root hair development resulted in a bushy root phenotype. The auxin level in the infected Chinese cabbage roots was twofold higher compared with the uncolonized controls. Three classes of auxin-related genes, which were upregulated by P. indica in Chinese cabbage roots, were isolated from a double-subtractive expressed sequence tag library: genes for proteins related to cell wall acidification, intercellular auxin transport carrier proteins such as AUX1, and auxin signal proteins. Overexpression of B. campestris BcAUX1 in Arabidopsis strongly promoted growth and biomass production of Arabidopsis seedlings and plants; the roots were highly branched but not bushy when compared with colonized Chinese cabbage roots. This suggests that BcAUX1 is a target of P. indica in Chinese cabbage. P. indica also promoted growth of Arabidopsis seedlings but the auxin levels were not higher and auxin genes were not upregulated, implying that auxin signaling is a more important target of P. indica in Chinese cabbage than in Arabidopsis. The fungus also stimulated growth of Arabidopsis aux1 and aux1/axr4 and rhd6 seedlings. Furthermore, a component in an exudate fraction from P. indica but not auxin stimulated growth of Chinese cabbage and Arabidopsis seedlings. We propose that activation of auxin biosynthesis and signaling in the roots might be the cause for the P. indica-mediated growth phenotype in Chinese cabbage.

Expression of an Oncidium gene encoding a patatin-like protein delays flowering in Arabidopsis by reducing gibberellin synthesis.

The involvement of lipase in flowering is seldom studied, and this research provides evidence that fatty acids produced by lipase affect flowering. OSAG78 encoding a patatin-like protein was isolated from Oncidium Gower Ramsey. OSAG78 fused with green fluorescent protein was found to localize at the cell membrane. Transgenic Arabidopsis overexpressing OSAG78 demonstrated higher lipase activity than the wild-type control. In addition, the amount of free linoleic acid and linolenic acid in transgenic Arabidopsis was found to be higher than that in the wild type. Transgenics overexpressing OSAG78 exhibited altered phenotypes, including smaller leaves and rounder flowers, and also demonstrated a late flowering phenotype that could be rescued by gibberellin A(3) (GA(3)) application. Several flowering-related genes were analyzed, indicating that the expression of gibberellin-stimulated genes was decreased in the plants overexpressing OSAG78. Also, the expression of AtGA2ox1, AtGA3ox1 and AtGA20ox1 genes encoding GA2-, GA3- and GA20-oxidases, respectively, which are mainly responsible for gibberellin metabolism, was decreased, and the level of GA(4), a bioactive gibberellin, measured by gas chromatography-mass spectrometry was also reduced in the overexpressing lines. Furthermore, the expression levels of AtGA3ox1 and AtGA20ox1 were significantly decreased in wild-type Arabidopsis treated with linoleic acid, linolenic acid or methyl jasmonate. The membrane-bound OSAG78 might hydrolyze phospholipids to release linoleic acid and linolenic acid, and then depress the expression of genes encoding GA3- and GA20-oxidase. These changes reduced the bioactive gibberellin level, and, finally, late flowering occurred. Our results indicate that a patatin-like membrane protein with lipase activity affects flowering through the regulation of gibberellin metabolism.

Schinarisanlactone A, a new bisnortriterpenoid from Schisandra arisanensis.

A novel triterpenoid, schinarisanlactone A (1), was isolated from the fruits of Schisandra arisanensis. Compound 1 possesses an unprecedented skeleton having a 5/7/7/5/7/5/6/5-fused octacyclic ring system. The structure of 1 was determined by 2D NMR techniques (COSY, HMQC, HMBC, and NOESY) and was confirmed by X-ray crystallographic analysis. Schinarisanlactone A (1) exhibited significant anti-HIV activity.

Nortriterpene lactones from the fruits of Schisandra arisanensis.

Fractionation of an acetone extract from the fruits of Schisandra arisanensis afforded five new nortriterpene lactones, compounds 1-5, together with four known compounds, schindilactones D and E (6 and 7) and preschisanartanins A and B (8 and 9). Compound 1, a wuweiziartane-type nortriterpenoid, possesses a new type of fused ring system with a gamma-lactone ring between C-15 and C-17. Compounds 2, 6, and 7 may be categorized as schisanartane-type nortriterpenoids and compounds 3-5, 8, and 9 as preschisanartane-type nortriterpenoids. The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopic data interpretation. The structure and relative configuration of 3 were supported by single-crystal X-ray diffraction analysis. The antiviral activity against HSV-1 and inhibitory effects on superoxide anion generation and elastase release by human neutrophils in response to FMLP/CB of compounds 1-9 were evaluated.

Arisanschinins A-E, lignans from Schisandra arisanensis hay.

Four new oxygenated dibenzocyclooctadiene lignans, arisanschinins A-D ( 1- 4), and a new 1,4-bis(phenyl)-2,3-dimethylbutane lignan, arisanschinin E ( 5), together with 15 known compounds, were isolated from the EtOAc-soluble fraction of the aerial parts of SCHISANDRA ARISANENSIS Hay. The structures of 1- 5 were elucidated on the basis of extensive spectroscopic analyses, including 2D NMR (HMQC, HMBC, and NOESY) experiments. The configurations of the biphenyl and octadiene moieties were deduced from circular dichroism (CD) and NOESY spectra, respectively. Compound 1 showed significant inhibition of α-glucosidase IN VITRO. The radical-scavenging activities of these compounds were evaluated using DPPH.

Arisandilactone A, a new triterpenoid from the fruits of Schisandra arisanensis.

A phytochemical investigation of the fruits of Schisandra arisanensis has yielded a novel triterpenoid, arisandilactone A (1). Compound 1 has an unprecedented skeleton having a 5/5/7/5/8/5-fused hexacyclic ring system. The structure of 1 was elucidated by spectroscopic methods, especially 2D NMR techniques (COSY, HMQC, HMBC, and NOESY) and was confirmed by X-ray crystallographic analysis. A plausible biosynthetic pathway for 1 is also discussed.

Storage behavior and changes in concentrations of abscisic acid and gibberellins during dormancy break and germination in seeds of Phellodendron amurense var. wilsonii (Rutaceae).

The medicinal Asian plant genus Phellodendron is known to contain several very important compounds that have biological action. The main purpose of this study was to determine whether seeds of Phellodendron amurense var. wilsonii can be stored and to characterize their dormancy. Seeds of this taxon stored at -20 and -80 degrees C and in liquid nitrogen retained their high germinability, indicating that they have orthodox storage behavior. Intact seeds from freshly collected fruits were dormant and required 12 weeks of cold stratification at 4 degrees C for complete germination. Scarifying the seed coat was partially effective in breaking seed dormancy. Exogenous gibberellins (GA(3), GA(4) and GA(4+7)) promoted germination of scarified seeds, GA(4) and GA(4+7) being more effective than GA(3). Fluridone, an abscisic acid (ABA) biosynthesis inhibitor, was efficient in breaking dormancy, but it was less effective than GA(4) or GA(4+7) alone. Paclobutrazol, a GA biosynthesis inhibitor, inhibited seed germination, and the inhibitory effect was reversed completely by GA(4) and by GA(4+7). ABA content of seeds subjected to cold stratification or to incubation at 35/10 degrees C, which enhanced seed germination, was reduced about four- to sixfold compared to that of fresh seeds. Higher concentrations of GA(3), GA(4) and GA(7) were detected in nondormant seeds and in seeds with an emerged radicle than in fresh seeds. Present results seem to indicate that dormancy in P. amurense var. wilsonii seeds is imposed partially by the seed coat and partially by high ABA content. ABA content decreased and GA(3), GA(4) and GA(7) content increased during germination.

abeo-taxane diterpenoids from the Taiwanese Yew Taxus sumatrana.

Chemical investigation of the acetonic extract of the leaves and twigs of Taxus sumatrana (Taxaceae) led to the isolation of four new taxane diterpene esters, taiwantaxins A-D (1-4, resp.). Their structures were determined primarily on the basis of 1D- and 2D-NMR techniques as well as MS. Compound 1 is a rearranged taxane diterpenoid possessing an opened oxetane ring moiety containing C(4), C(5), and C(20). The metabolites 2 and 3 belong to a 5/6/6 taxene system having a rare five-membered gamma-lactone ring comprising C(8), C(9), C(10), and C(19). Compound 4 is an example of a taxane diterpene containing a 6/8/6 ring system with a tetrahydrofuran ring comprising C(2), C(3), C(4), and C(20). The 11(15-->1)abeo-taxane diterpenoids, taiwantaxins A-C (1-3, resp.) are lacking an O-bearing functionality at either C(13) or C(14). Compound 2 showed significant cytotoxic activity against human PC-3 tumor cells.

Oxygenated lignans from the fruits of Schisandra arisanensis.

An acetone extract of the fruits of the Taiwanese medicinal plant Schisandra arisanensis has yielded 11 new oxygenated lignans. Four of these, named arisantetralones A-D (1-4), possess the aryltetralone skeleton, while the other seven, named arisanschinins F-L (5-11), are polyoxygenated C(18)-dibenzocyclooctadiene lignans. Structures were determined on the basis of spectroscopic analyses, especially 2D-NMR techniques. The structure of compound 1 was confirmed by X-ray crystallographic analysis. Immunomodulatory activity of the isolated lignans was tested and evaluated.