New Diterpenes of Torreya nucifera Sieb. et Zucc.

Three new labdane type diterpenes; 4-epiagathadiol (named kayadiol), 18-hydroxymanool (named torreferol), 18-hydroxy-13-epimanool (named 13-epitorreferol), were isolated from the non-steam-volatile fraction of leaves of Torreya nucifera Sieb. et Zucc. (Taxaceae, Japanese name “Kaya”).

This is the first reported isolation these three diterpenes in a natural source.     

The chromosome-scale reference genome of Rubus chingii Hu provides insight into the biosynthetic pathway of hydrolyzable tannins

Rubus chingii Hu (Fu-Pen-Zi), a perennial woody plant in the Rosaceae family, is a characteristic traditional Chinese medicinal plant because of its unique pharmacological effects. There are abundant hydrolyzable tannin (HT) components in R. chingii that provide health benefits. Here, an R. chingii chromosome-scale genome and related functional analysis provide insights into the biosynthetic pathway of HTs. In total, sequence data of 231.21 Mb (155 scaffolds with an N50 of 8.2 Mb) were assembled into seven chromosomes with an average length of 31.4 Mb, and 33 130 protein-coding genes were predicted, 89.28% of which were functionally annotated. Evolutionary analysis showed that R. chingii was most closely related to Rubus occidentalis, from which it was predicted to have diverged 22.46 million years ago (Table S8). Comparative genomic analysis showed that there was a tandem gene cluster of UGT, carboxylesterase (CXE) and SCPL genes on chromosome 02 of R. chingii, including 11 CXE, eight UGT, and six SCPL genes, which may be critical for the synthesis of HTs. In vitro enzyme assays indicated that the proteins encoded by the CXE (LG02.4273) and UGT (LG02.4102) genes have tannin hydrolase and gallic acid glycosyltransferase functions, respectively. The genomic sequence of R. chingii will be a valuable resource for comparative genomic analysis within the Rosaceae family and will be useful for understanding the biosynthesis of HTs.     

Antifungal activity of Rubus chingii extract combined with fluconazole against fluconazole‐resistant Candida albicans

This study aimed to investigate the antifungal activity of Rubus chingii extract in combination with fluconazole (FLC) against FLC‐resistant Candida albicans 100 in vitro. A R. chingii extract and FLC‐resistant C. albicans fungus suspension were prepared. The minimum inhibitory concentration and fractional inhibitory concentration index of R. chingii extract combined with FLC against C. albicans were determined, after which growth curves for C. albicans treated with R. chingii extract, FLC alone and a combination of these preparations were constructed. Additionally, the mechanisms of drug combination against C. albicans were explored by flow cytometry, gas chromatographic mass spectrometry and drug efflux pump function detection. R. chingii extract combined with FLC showed significant synergy. Flow cytometry suggested that C. albicans cells mainly arrest in G1 and S phases when they have been treated with the drug combination. The drug combination resulted in a marked decrease in the ergosterol content of the cell membrane. Additionally, efflux of Rhodamine 6G decreased with increasing concentrations of R. chingii extract. R. chingii extract combined with FLC has antifungal activity against FLC‐resistant C. albicans.     

Anti-inflammatory flavonoids from Cryptocarya chingii

Six flavonoids named cryptogiones A–F, and nine known compounds were isolated from an ethanol extract of stems of Cryptocarya chingii. The structures of the compounds were elucidated by interpretation of comprehensive spectroscopic data and X-ray analysis. A majority of these flavonoids contained an acetic acid/lactone moiety, a possible taxonomic marker. Anti-inflammatory effects of the compounds were evaluated using in vitro assays. At 20 μM concentration, three compounds significantly inhibited TNFα-induced NF-кB activation and LPS-induced IL-1β expression.     

Ruizgenin,a new steroidal sapogenin diol from AgaveLecheguilla

From the leaves of Agavelecheguilla Torrey, two steroidal sapogenin diols have been isolated. Mass spectral, infra-red and nuclear magnetic resonance data of these two compounds showed them to be (25R) spirost-5-ene-2α, 3β-diol (yuccagenin) and (25R)-5β-spirostane-3β,6α-diol. The latter is a new compound to which the trivial name ruizgenin has been given.     

Isolation and structure of a chlorosis-inducing toxin of Pseudomonas phaseolicola

A toxin, named phaseolotoxin, which causes leaf-chlorosis in bean leaves has been isolated from liquid cultures of Pseudomonas phaseolicola, and purified. Its structure is (N^δ-phosphosulphamyl)ornithylalanylhomoarginine.     

Dammarane saponins of leaves of Panax pseudo-ginseng subsp. himalaicus

From dried leaves of Panax pseudo-ginseng subsp. himalaicus collected in Eastern Himalaya, new dammarane saponins, named pseudo-ginsenosides-F₁₁ and -F₈ were isolated along with the known Ginseng-root saponins, ginsenosides-Rb₃, Rd and -Re. Pseudo-ginsenoside-F₈ was proved to be a mono-acetyl-ginsenoside-Rb₃ and the location of its acetyl group was established mainly by ¹³C NMR spectroscopy. Pseudo-ginsenoside-F₁₁, was identified as the 6-O-α-rhamnopyransyl(1 → 2)-β-glucopyranoside of 3β,6α,12β,25-tetrahydoxy-(20S,24R)-epoxy-dammarane. The C-24 configuration of ocotillone and its related triterpenes was confirmed to be 24R excluding the recent comment by Lavie et al.     

Leaf alkaloids of Rauwolfia oreogiton

Twenty-one indole alkaloids were isolated from the leaves of Rauwolfia oreogiton and identified. The alkaloids comprised E-seco heteroyohimbine, heteroyohimbine, akuammiline, akuammicine, pleiocarpamine, picraline, picrinine, dihydroindole and sarpagan types. No chemical differentiation between the leaves of R. oreogiton and R. volkensii could be established.     

Regeneration and characterization of somatic hybrids combining sweet orange and mandarin/mandarin hybrid cultivars for citrus scion improvement

Protoplast fusion between sweet orange and mandarin/mandarin hybrids scion cultivars was performed following the model ??diploid embryogenic callus protoplast?+?diploid mesophyll-derived protoplast??. Protoplasts were isolated from embryogenic calli of ??Pera?? and ??Westin?? sweet orange cultivars (Citrus sinensis) and from young leaves of ??Fremont??, Nules??, and ??Thomas?? mandarins (C. reticulata), and ??Nova?? tangelo [C. reticulata?×?(C. paradisi?×?C. reticulata)]. The regenerated plants were characterized based on their leaf morphology (thickness), ploidy level, and simple sequence repeat (SSR) molecular markers. Plants were successfully generated only when ??Pera?? sweet orange was used as the embryogenic parent. Fifteen plants were regenerated being 7 tetraploid and 8 diploid. Based on SSR molecular markers analyses all 7 tetraploid regenerated plants revealed to be allotetraploids (somatic hybrids), including 2 from the combination of ??Pera?? sweet orange?+???Fremont?? mandarin, 3 ??Pera?? sweet orange?+???Nules?? mandarin, and 2 ??Pera?? sweet orange?+???Nova?? tangelo, and all the diploid regenerated plants showed the ??Pera?? sweet orange marker profile. Somatic hybrids were inoculated with Alternaria alternata and no disease symptoms were detected 96?h post-inoculation. This hybrid material has the potential to be used as a tetraploid parent in interploid crosses for citrus scion breeding.     

角倍蚜虫瘿对盐肤木光合特性和总氮含量的影响

通过温室栽培和接种实验,以接种角倍蚜形成虫瘿的盐肤木和未接种角倍蚜的盐肤木为实验材料,测定和分析虫瘿对盐肤木光合特性和不同组织氮含量的影响。结果表明虫瘿对盐肤木的光合作用形成扰动,与对照植株相比较：(1)有虫瘿复叶的最大净光合速率升高,其中虫瘿初期、中期和后期分别升高14.49%、32.17%和42.01%;虫瘿还引起无虫瘿复叶最大净光合速率升高,但中期以后下降到正常水平;(2)虫瘿中期有虫瘿复叶的光饱和点升高、无虫瘿复叶光饱合点下降;虫瘿初期和中期有虫瘿复叶的光补偿点升高、无虫瘿复叶光补偿点下降;(3)虫瘿初期引起有虫瘿复叶及邻近无虫瘿复叶暗呼吸速率升高,但中期和后期影响不显著。虫瘿对盐肤木光合作用的扰动程度与小叶的位置和虫瘿生长时期密切相关。同时,虫瘿改变了盐肤木叶片氮含量分布,其中虫瘿外壁、有虫瘿复叶和无虫瘿复叶的氮含量分别为1.13%、1.98%和2.14%,这可能是营养物质从无虫瘿复叶流向有虫瘿复叶,并最终流向虫瘿,满足虫瘿和瘿内蚜虫生长需求的原因。     

Tirumalin,a new prenylated dihydroflavonol from Rhynchosia cyanosperma

A new dihydroflavonol has been isolated together with the known flavonol-O- glycosides, rutin and kaempferol-3-rutinoside, and (+)-pinitol from the leaves of R. cyanosperma Benth. The dihydroflavonol was identified as (+)-(2R, 3R)-8-C-prenyltaxifolin-7, 4′-dimethyl ether on the basis of spectroscopic studies and the compound given the trivial name tirumalin.     

New sweet diterpene glucosides from Stevia rebaudiana

From the leaves of Stevia rebaudiana, two new sweet glucosides, rebaudiosides A and B, were isolated besides the known glucosides, stevioside and steviolbioside. On the basis of IR, MS, ¹H and ¹³C NMR as well as chemical evidences, the structure of rebaudioside B was assigned as 13-O-[β-glucosyl(1-2)-β-glucosyl(1-3)]-β-glucosyl-steviol and rebaudioside A was formulated as its β-glucosyl ester.     

Definition of a novel symbiovar (sv. retamae) within Bradyrhizobium retamae sp. nov., nodulating Retama sphaerocarpa and Retama monosperma

In this paper we analyze through a polyphasic approach several Bradyrhizobium strains isolated in Spain and Morocco from root nodules of Retama sphaerocarpa and Retama monosperma. All the strains have identical 16S rRNA genes and their closest relative species is Bradyrhizobium lablabi CCBAU 23086^T, with 99.41% identity with respect to the strain Ro19^T. Despite the closeness of the 16S rRNA genes, the housekeeping genes recA, atpD and glnII were divergent in Ro19^T and B. lablabi CCBAU 23086^T, with identity values of 95.71%, 93.75% and 93.11%, respectively. These differences were congruent with DNA–DNA hybridization analysis that revealed an average of 35% relatedness between the novel species and B. lablabi CCBAU 23086^T. Also, differential phenotypic characteristics of the new species were found with respect to the already described species of Bradyrhizobium. Based on the genotypic and phenotypic data obtained in this study, we propose to classify the group of strains isolated from R. sphaerocarpa and R. monosperma as a novel species named Bradyrhizobium retamae sp. nov. (type strain Ro19^T = LMG 27393^T = CECT 8261^T). The analysis of symbiotic genes revealed that some of these strains constitute a new symbiovar within genus Bradyrhizobium for which we propose the name “retamae”, that mainly contains nodulating strains isolated from Retama species in different continents.     

Raimondal,a new sesquiterpenoid from pigment glands of Gossypium raimondii

A new sesquiterpenoid isolated from pigment glands of leaves and immature bolls of Gossypium raimondii has been named raimondal and identified as 5-iso-propyl-2-methoxy-3-methyl-1,6,7-trihydroxy-8-naphthaldehyde. Raimondal was oxidized by ferric chloride to o-hemigossypolone (8-formyl-5-iso-propyl-3-methyl-6,7-dihydroxy-1,2-naphthoquinone) which was readily reduced to its hydroquinone, 2-hydroxyhemigossypol. Neither of the two oxidation products were detected in extracts from G. raimondii.     

Isolation of 6-Hydroxydehydroabietinol and Hinokiol from the Leaves of Torreya nucifera Sieb,et Zucc

6-Hydroxydehydroabietinol and hinokiol were isolated from the non-steam-volatile fraction of the leaves of Torreya nucifera Sieb, et Zucc. (Taxaceae) (Japanese name “Kaya”). The former was also isolated from the immature fruits of the same plant. This is the first report of the isolation of 6-hydroxydehydroabietinol from a natural source. This compound was prepared previously and reported to show marked estrogenic activity.     

Neolignans from Magnolia kachirachirai

Two new neolignans named kachirachirol-A and B were isolated from the leaves of Magnolia kachirachirai and their chemical structures determined to be 2-(p-hydroxyphenyl)-7-methoxy-3-methyl-5-trans-propenylbenzofuran and rel-(2S,3S)-2-catechyl-2,3-dihydro-7-methoxy-3-methyl-5-trans-propenylbenzofuran.     

The Use of Olfactory and Visual Cues in Host Choice by the Capsid Bugs Lygus rugulipennis Poppius and Liocoris tripustulatus Fabricius

Lygus rugulipennis Poppius and Liocoris tripustulatus Fabricius (Heteroptera: Miridae) are pests of glasshouse cucumber and sweet pepper crops respectively. L. rugulipennis has a wide range of foodplants, but L. tripustulatus is specialised with very few food plants. We report behavioural assessments to investigate whether either species exhibits a preference for salad over wild hosts, and whether the role of olfaction and vision in response to cues from host plants can be distinguished. Olfactory responses to leaves were tested in choice chambers. L. rugulipennis was presented nettle (wild host) and a salad leaf of cucumber or sweet pepper, where the salad leaves had higher nitrogen content. L. tripustulatus was tested with nettle and sweet pepper of two different nitrogen contents. Female L. rugulipennis spent more time on the cucumber salad host, and chose it first most often, but males showed no preference. Neither sex discriminated between sweet pepper or nettle leaves, but males made more first contacts with sweet pepper. Neither sex of L. tripustulatus discriminated between sweet pepper and nettle leaves when the sweet pepper had higher nitrogen. When the plant species contained equivalent nitrogen both sexes spent more time on nettle. There was no difference in first choice made by either sex. When visual stimuli were available, and leaves had equivalent nitrogen, L. rugulipennis showed no preference and L. tripustulatus preferred nettle leaves. We conclude that the generalist L. rugulipennis has the ability to use remote olfactory cues for host choice whereas the specialist L. tripustulatus relies mainly on contact chemosensory and gustatory cues.     

Molecular cloning and characterization of ascorbate oxidase gene in non-heading Chinese cabbage

The cDNA clone of ascorbate oxidase gene was isolated from non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino, cv. Suzhouqing) and characterized. Sequence analysis showed that there was a high similarity between this sequence (named BcAO) and its homologues in other plant species. Southern blotting indicated that more than one nuclear gene encoded this enzyme in non-heading Chinese cabbage. The mRNA level of the BcAO gene in leaves was monitored by real-time PCR at different developmental stages and under different stress conditions. Results showed that the expression of BcAO was upregulated by light, and the BcAO gene responded to copper stress as well. After inoculation with Alternaria brassicae, the expression of BcAO in the leaves was increased in general and peaked at 12 and 72 h post inoculation, with much higher expression at the later date. Cloning the BcAO gene will enable us to further understand its function and would provide useful information for resistance breeding program for non-heading Chinese cabbage.     

Genotypic and phenotypic diversity of rhizobia isolated from Lathyrus japonicus indigenous to Japan

Sixty-one rhizobial strains from Lathyrus japonicus nodules growing on the seashore in Japan were characterized and compared to two strains from Canada. The PCR-based method was used to identify test strains with novel taxonomic markers that were designed to discriminate between all known Lathyrus rhizobia. Three genomic groups (I, II, and III) were finally identified using RAPD, RFLP, and phylogenetic analyses. Strains in genomic group I (related to Rhizobium leguminosarum) were divided into two subgroups (Ia and Ib) and subgroup Ia was related to biovar viciae. Strains in subgroup Ib, which were all isolated from Japanese sea pea, belonged to a distinct group from other rhizobial groups in the recA phylogeny and PCR-based grouping, and were more tolerant to salt than the isolate from an inland legume. Test strains in genomic groups II and III belonged to a single clade with the reference strains of R. pisi, R. etli, and R. phaseoli in the 16S rRNA phylogeny. The PCR-based method and phylogenetic analysis of recA revealed that genomic group II was related to R. pisi. The analyses also showed that genomic group III harbored a mixed chromosomal sequence of different genomic groups, suggesting a recent horizontal gene transfer between diverse rhizobia. Although two Canadian strains belonged to subgroup Ia, molecular and physiological analyses showed the divergence between Canadian and Japanese strains. Phylogenetic analysis of nod genes divided the rhizobial strains into several groups that reflected the host range of rhizobia. Symbiosis between dispersing legumes and rhizobia at seashore is discussed.