黑木相思愈伤组织诱导及植株再生

以黑木相思(Acacia melanoxylon)优良单株(AMY12004)的当年新生枝条带腋芽茎段为外植体, 灭菌后接入MS培养基上培养, 以其无菌萌芽的叶片、茎段和叶柄为实验材料, 通过间接器官发生途径建立黑木相思愈伤组织诱导及高频植株再生体系。研究结果表明, 诱导愈伤组织的最佳外植体为茎段; 愈伤组织诱导的最佳培养基为MS+1.5 mg·L–16-BA+0.2 mg·L–1NAA+3%蔗糖, 诱导率为93.33%; 愈伤组织再分化的最佳培养基为MS+2.0 mg·L^–16-BA+0.5 mg·L^–1NAA+3%蔗糖, 分化率为79.17%, 再生系数为9.58; 再生芽生根的最佳培养基为MS+0.5 mg·L^–1IBA+0.5 mg·L^–1NAA+4%蔗糖, 生根率为96.05%, 移栽存活率为81.40%。     

黑木相思根瘤菌遗传多样性

[目的]研究分离自广东、福建、江西等15个地点的174株黑木相思(Acacia melanoxylon)根瘤菌的遗传多样性.[方法]采用16S rDNA限制性片段长度多态性分析(Restriction fragment length polymorphism,RFLP)和16S rDNA基因、持家基因(recA、atpD、glnⅡ)系统发育分析的方进行研究.[结果]16S rDNAPCR-RFLP分析中,在70％的相似性水平上,所有供试菌株分成9个类群 ;16S rDNA基因和持家基因系统发育分析结果基本一致,34株代表菌株主要分布在α-变形菌纲(Alpha-Proteobacteria)的慢生根瘤菌属(Bradyrhizobium)、根瘤菌属(Rizobium)、中慢生根瘤菌属(Mesorhizobium),并与Bradyrhizobium liaoningense、Bradyrhizobium betae、Bradyrhizobium cytisi、Rizobium multihospitium、Mesorhizobium plurifarium亲缘关系较近.[结论]供试菌株被鉴定到属的水平,Bradyrhizobium、Rhizobium或Mesorhizobium为优势菌群,证明了黑木相思根瘤菌具有丰富的遗传多样性.     

First Cytogenetic Investigation in Populations of Acacia heterophylla, Endemic from La Reunion Island, with Reference to A. melanoxylon

Five populations of tetraploid Acacia heterophylla, endemic from La Réunion island, were compared together and with their Australian diploid relative A. melanoxylon for cytogenetic and DNA characteristics. A. melanoxylon (2n = 26) had 1·59 pg nuclear DNA; A. heterophylla (2n = 4x = 52) had double this value (3·19 pg), and there was no difference between populations within species. Both species had 39 % GC. Interchromosome connections were evident at metaphase and mitotic irregularities at anaphase were twice as frequent in A. heterophylla as in A. melanoxylon, again with no difference between populations within species. These results argue for a recent autotetraploid origin of A. heterophylla from A. melanoxylon. Yet, fluorochrome banding showed that in some A. heterophylla populations, GC-rich bands had slightly changed from the supposed ancestral pattern, probably by means of translocations involving parts of nuclear organizer areas. No clear relation was found between banding patterns and ecological factors.     

Diastereoisomeric leucoanthocyanidins from the heartwood of acacia melanoxylon

The isolation of two pairs of diastereoisomeric leucoanthocyanidins, namely (2R,3R,4R)-2,3-cis-3,4-cis-3,3′,4,4′,7,8-hexahydroxyflavan or melacacidin, (2R,3R,4S)-2,3-cis-3,4-trans-3,3′,4,4′,7,8-hexahydroxyflavan or isomelacacidin and(2R,3R,4R)-2,3-cis-3,4-cis-4-ethoxy-3,3′,4′,7,8-pentahydroxyflavan or 4-O-ethylmelacacidin, (2R,3R,4S)-2,3-cis-3,4-trans-4-ethoxy-3,3′,4′,7,8-pentahydroxyflavan or 4-O-ethylisomelacacidin is described. 4-O-Ethylmelacacidin is a new compound and all four leucoanthocyanidins are natural constituents of the heartwood of Acacia melanoxylon. Melacacinidin is the name proposed for the anthocyanidin 3,3′,4′,7,8-pentahydroxyflavylium and leucomelacacinidins for the corresponding leucoanthocyanidins. Quinone-methide formation is proposed to account for the difference in reactivity between the diastereoisomers.     

Gut Content Analysis to Distinguish Between Seed Feeding and Mycophagy of a Biphyllid Beetle Larva Found on Acacia melanoxylon

In a search for potential biocontrol agents for Acacia melanoxylon R. Br. (Mimosaceae), larvae of the beetle Diplocoelus dilataticollis Lea (Coleoptera; Biphyllidae) were found within damaged seeds of A. melanoxylon. The gut contents of larvae and adults were examined to determine whether their diet included seeds, in apparent contradiction to the known mycophagous diet of members of this family of beetles. Calcofluor M2R White, a plant cell-wall staining optical brightener was used to differentiate between plant cell fragments and fungal tissue in the gut content smears. Gut contents of adults of a known seed predator of A. melanoxylon, a weevil of the genus Melanterius, were examined in the same way to provide a benchmark. The gut contents of D. dilataticollis differed from those of Melanterius sp. Fungal structures and microbes were found in the gut of D. dilataticollis, in contrast to plant cell fragments found in the gut of the weevil and from scrapes made directly from seeds. We conclude that larvae of D. dilataticollis feed primarily on fungi associated with damaged seed and therefore may not be the proximate cause of seed damage.     

Neoflavanoids of Dalbergia melanoxylon

The heartwood of Dalbergia melanoxylon has yielded new examples of known neoflavanoid types. The isolates included 4-phenylcoumarins, (S)-4-methoxydalbergiones and benzophenones which have the corresponding oxygenation pattern. The structures of the extractives have been examined by physical methods, and confirmed by conversion to known compounds or by independent synthesis. A 2-cinnamylphenol (6) and 3-cinnamylflavan (7) were the only products in a condensation reaction in the attempted synthesis of the 4-methoxydalbergione (1b).     

黑木相思根瘤菌的系统发育分析及其结瘤效果研究

【目的】针对采集自福建、广东的34株黑木相思根瘤菌进行分类研究,进一步确定其分类地位,丰富我国黑木相思根瘤菌种质资源。【方法】对选取的34株菌株测定了16S rRNA基因、持家基因atpD和glnII序列,以14株菌为代表菌株分析其系统发育情况。而且选取了部分菌株进行结瘤实验。【结果】16S rRNA基因以及持家基因atpD和glnII的系统发育分析结果与16S rRNA PCR-RFLP分型结果基本一致,14株代表菌株被分为10个不同的类群,其中有2个群组属于中慢生根瘤菌属(Mesorhizobium),其余群组属于慢生根瘤菌属(Bradyrhizobium)。结瘤试验证明,相关的供试根瘤菌能与黑木相思、银合欢、南洋楹和网脉相思结瘤共生,显示出较广的宿主范围,且对黑木相思和银合欢的促生效果较明显。【结论】研究发现黑木相思根瘤菌具有丰富的遗传多样性和共生多样性。     

厚荚相思根瘤菌对盆栽苗木生长及土壤肥力的影响

从不同立地条件采集到的厚荚相思根瘤分离出9株根瘤菌株,接种于厚荚相思幼茁,6个月后测定苗木生长量及土壤N、P、K含量。试验结果表明：接菌桃株的高生长量、生物量都比对照(未接种根瘤菌)增加,其巾高生长量除R2外,增加幅度为0．89～40．18％,生物量增加52．33～147．67％,接种结瘤率、瘤的生物量也比对照高,结瘤率可达100％,根瘤生物量比对照高163．6～520％。土壤N、P、K元素分析结果表明,接种根瘤菌后土壤的营养元素发生了很大的变化,改善了土壤肥力。通过对接种不同菌株的厚荚相思苗木的茁高、生物量、土壤的全氮、速效磷、速效钾等元素的含量比较分析后筛选出R6和R7菌株为优良菌株。     

Cytotoxic lupane-type triterpenoids from Acacia mellifera

One new and eight previously described lupane-type metabolites were isolated for the first time from Acacia mellifera (Leguminosae). Based on spectral analyses, the structure of the new compound was elucidated as 28-hydroxy-3-oxo-lup-20-(29)-en-30-al (1), while the known compounds were identified as 3-oxo-lup-20-(29)-en-30-al (2), 3-hydroxy-lup-20-(29)-en-30-al (3), 28-hydroxy-lup-20-(29)-en-3-one (4), lupenone (5), lupeol (6), betulin (7), betulinic acid (8), and betulonic acid (9). Metabolites 2, 3, and 4 are reported for the first time in the Leguminosae family. The cytotoxicity of the isolated metabolites was evaluated on the NSCLC-N6 cell line, derived from a human non-small-cell bronchopulmonary carcinoma. Compounds 1 and 3 exhibited significant levels of activity.     

(4-->6)-Coupled proteracacinidins and promelacacinidins from Acacia galpinii and Acacia caffra

The series of naturally occurring proanthocyanidins with 7,8-dihydroxylated A-rings is extended by identification of the proteracacinidins epioritin-(4beta-->6)-oritin-4alpha-ol, epioritin-(4beta-->6)-ent-oritin-4alpha-ol, ent-oritin-(4beta-->6)-epioritin-4alpha-ol, ent-oritin-(4beta-->6)-oritin-4alpha-ol, ent-oritin-(4alpha-->6)-epioritin-4alpha-ol, ent-oritin-(4alpha-->6)-oritin-4alpha-ol, ent-oritin-(4alpha-->6)-epioritin-4beta-ol, the 'mixed' pro-teracacinidins/-melacacinidins epioritin-(4beta-->6)-epimesquitol-4alpha-ol, epioritin-(4beta-->6)-epimesquitol-4beta-ol and epimesquitol-(4beta-->6)- epioritin-4alpha-ol, and the promelacacinidin epimesquitol-(4beta-->6)-epimesquitol-4beta-ol.     

A chalcone glycoside from Acacia dealbata

A new yellow pigment isolated from the flowers of Acacia dealbata has been shown to be chalcononaringenin 2′-[O-rhamnosyl-(1→4)-xyloside] by chemical and spectroscopic methods.     

Flavanones and dihydroflavonols as biosynthetic intermediates in Matthiola incana

In anthocyanin-producing flowers of Matthiola incana, the presence of naringenin, naringenin 7-glucoside, dihydrokaempferol and dihydrokaempferol 7-glucoside could be demonstrated. The four isolated compounds initiated anthocyanin synthesis after administration to acyanic flowers of genetically defined lines of Matthiola incana and Antirrhinum majus. Therefore, these compounds cannot be regarded as end-products but rather as intermediates in anthocyanin biosynthesis. Furthermore, naringenin 7-glucoside and dihydrokaempferol 7-glucoside most probably act as a pool for their aglycones, which serve as the actual substrates.     

6-C-glucosylnaringenin from flowers of Acacia retinoide

From the flowers of Acacia retinoide 6-C-glucosylnaringenin has been identified.     

Trimeric proteracacinidins and a (6-->6)-bis-leucoteracacinidin from Acacia galpinii and Acacia caffra

The rare series of trimeric proteracacinidins is extended by identification of the first analogs with exclusive C-C interflavanyl bonds, i.e. epioritin-(4beta-->6)-oritin-(4alpha-->6)-epioritin-4alpha-ol,oritin-(4beta-->6)-oritin-(4alpha-->6)-epioritin-4alpha-ol, and epioritin-(4beta-->6)-epioritin-(4beta-->6)-epioritin-4alpha-ol. These compounds are accompanied by the bis-leucoteracacinidin, epioritin-4alpha-ol-(6-->6)-epioritin-4beta-ol, the first naturally occurring bis-flavan-3,4-diol.     

Diospyros melanoxylon,a bread-winner tree of India

This endemic plant of India and Ceylon is used in various ways. Besides being the source of Indian ebony, its wood is also utilized for making boxes, combs, ploughs and beams. The fruits are eaten and sold commercially. The bark is burnt by tribals to “cure” small-pox. The seeds are prescribed as cure for mental disorders, palpitation of heart and nervous breakdown. Above all, the leaves of this plant constitute one of the most important raw materials of the “Bidi” (Indian cheap smoke) industry.     

Effects of naturally occurring dihydroflavonols from Inula viscosa on inflammation and enzymes involved in the arachidonic acid metabolism

The anti-inflammatory properties of three flavanones isolated from Inula viscosa, sakuranetin, 7-O-methylaromadendrin, and 3-acetyl-7-O-methylaromadendrin, have been tested both in vitro and in vivo. Acute inflammation in vivo was induced by means of topical application of 12-O-tetradecanoylphorbol 13-acetate (TPA) to mouse ears or by subcutaneous injection of phospholipase A(2) (PLA(2)) into mouse paws. The test compounds were evaluated in vitro for their effect on both the metabolism of arachidonic acid and on the release and/or activity of enzymes involved in the inflammatory response such as elastase, myeloperoxidase (MPO), and protein kinase C (PKC). The most active compounds in vivo against PLA(2)-induced paw oedema were 7-O-methylaromadendrin (ED(50)=8 mg/kg) and sakuranetin (ED(50)=18 mg/kg). In contrast, the most potent compound against TPA-induced ear oedema was 3-acetyl-7-O-methylaromadendrin (ED(50)=185 microg/ear), followed by sakuranetin (ED(50)=205 microg/ear). In vitro, the latter compound was the most potent inhibitor of leukotriene (LT) B(4) production by peritoneal rat neutrophils (IC(50)=9 microM) and it was also the only compound that directly inhibited the activity of 5-lipoxygenase (5-LOX). 3-Acetyl-7-O-methylaromadendrin also inhibited LTB(4) production (IC(50)=15 microM), but had no effect on 5-LOX activity. The only flavanone that inhibited the secretory PLA(2) activity in vitro was 7-O-methylaromadendrin. This finding may partly explain the anti-inflammatory effect observed in vivo, although other mechanisms such as the inhibition of histamine release by mast cells may also be implicated. Sakuranetin at 100 microM was found to inhibit elastase release, although this result is partly due to direct inhibition of the enzyme itself. At the same concentration, 7-O-methylaromadendrin only affected the enzyme release. Finally, none of the flavanones exhibited any effect on MPO or PKC activities. Taken together, these findings indicate that sakuranetin may be a selective inhibitor of 5-LOX.     

Cross-amplification of nonnative Acacia species in the Hawaiian Islands using microsatellite markers from Acacia koa

Thirty-one microsatellite markers, developed from Acacia koa, were evaluated for cross-amplification of seven nonnative species of Acacia in the Hawaiian Islands. The number of alleles per locus ranged from one to seven, with 16 of the 31 markers showing polymorphism in at least two of the nonnative Acacia species. Of the Acacia species examined, A. melanoxylon showed the highest percentage of amplified loci.     

Acacipetalin in Acacia constricta from north America

Acacipetalin, previously known only from the African legumes Acacia sieberiana var. woodii and Acacia hebeclada, has been isolated from an American species of the genus, Acacia constricta.