Natural variation in the expression and catalytic activity of a naringenin 7‐O‐methyltransferase influences antifungal defenses in diverse rice cultivars

Phytoalexins play a pivotal role in plant–pathogen interactions. Whereas leaves of rice (Oryza sativa) cultivar Nipponbare predominantly accumulated the phytoalexin sakuranetin after jasmonic acid induction, only very low amounts accumulated in the Kasalath cultivar. Sakuranetin is synthesized from naringenin by naringenin 7‐O‐methyltransferase (NOMT). Analysis of chromosome segment substitution lines and backcrossed inbred lines suggested that NOMT is the underlying cause of differential phytoalexin accumulation between Nipponbare and Kasalath. Indeed, both NOMT expression and NOMT enzymatic activity are lower in Kasalath than in Nipponbare. We identified a proline to threonine substitution in Kasalath relative to Nipponbare NOMT as the main cause of the lower enzymatic activity. Expanding this analysis to rice cultivars with varying amounts of sakuranetin collected from around the world showed that NOMT induction is correlated with sakuranetin accumulation. In bioassays with Pyricularia oryzae, Gibberella fujikuroi, Bipolaris oryzae, Burkholderia glumae, Xanthomonas oryzae, Erwinia chrysanthemi, Pseudomonas syringae, and Acidovorax avenae, naringenin was more effective against bacterial pathogens and sakuranetin was more effective against fungal pathogens. Therefore, the relative amounts of naringenin and sakuranetin may provide protection against specific pathogen profiles in different rice‐growing environments. In a dendrogram of NOMT genes, those from low‐sakuranetin‐accumulating cultivars formed at least two clusters, only one of which involves the proline to threonine mutation, suggesting that the low sakuranetin chemotype was acquired more than once in cultivated rice. Strains of the wild rice species Oryza rufipogon also exhibited differential sakuranetin accumulation, indicating that this metabolic diversity predates rice domestication.     

A systematic study of the polyphenolic composition of aqueous extracts deriving from several Cistus genus species: evolutionary relationship

Introduction – Cistaceae is a large family of shrubs widely spread over the Mediterranean area. It includes Helianthemum, Halimium and Cistus genus. Cistus genus contains approximately 20 species distributed in three subgenus. The essential oil of Cistus species has been thoroughly studied, but the polyphenolic composition of the aerial parts of the different Cistus species needs further characterisation. Objective – To perform a comparative analysis of the qualitative and quantitative polyphenolic composition of the aerial parts of the most commonly distributed Spanish Cistus species in order to find a relationship between chemotype and subgenus. Methodology – Thirteen aqueous extracts derived from 10 different Cistus species were analysed by using HPLC with diode array‐detection coupled to electrospray ion trap mass spectrometry technique (HPLC‐DAD‐ESI‐MS/MS). Their major compounds were identified and ellagitannins were quantified. Principal component analysis (PCA) was performed on the most relevant compounds to find out the statistical association between chemotype and variety. Results – Three main groups of compounds were found, i.e. ellagitannins, flavonoids and phenolic acids derivatives. The polyphenolic profile was specific for each species, although the abundance of some compounds also varied depending on the soil type. Whereas C. ladanifer, C. salviifolius, C. populifolius and C. libanotis were specially rich in ellagitannins, C. clusii, C. laurifolius and C. monspeliensis contained significant amounts of flavonoids and much less ellagitannins. In contrast, C. crispus, C. incanus and C. albidus showed a polyphenolic profile mostly based on flavonoids. PCA analysis showed a strong relationship between Cistus subgenus and its chemotype based on the most relevant water‐soluble polyphenolic compounds. Conclusions – Chemical composition of the leaves' aqueous extracts from plants belonging to the Cistus genus is strongly related to their subgenus, in agreement to previous taxonomical and phylogenetic divisions. In contrast, soil and climate are less influencing factors. Leucocistus and Halimioides subgenus showed a higher content in ellagitannins. However, Cistus subgenus had higher flavonoid content. Copyright © 2011 John Wiley & Sons, Ltd.     

Involvement of nitric oxide (NO) signalling pathway in the antidepressant activity of essential oil of Valeriana wallichii Patchouli alcohol chemotype

Valeriana wallichii DC (Valerianaceae), popularly named as Indian valerian has been shown to exist as three chemotypes. The present study evaluated the antidepressant like effect of root essential oil of Valeriana wallichii patchouli alcohol chemotype in both acute and chronic treatment study using forced swim test (FST). Mice (n = 6 per group) received 10, 20 and 40 mg/kg p.o. doses of test drug. Single administration of oil significantly inhibited the immobility period (57.6% and 46.9%) at doses 20 and 40 mg/kg respectively without changing the motor function (p < 0.05). Similarly, daily administration of essential oil (20 mg/kg) for 14 days significantly reduced the immobility period (69.9%) in FST (p < 0.05). The neurotransmitter levels in mouse brain were estimated on day 14 after the behavioral study. Significant increase in the level of norepinephrine (29%) and serotonin (19%) (p < 0.05) was found at 20 mg/kg dose, while no change was observed at 10 and 40 mg/kg doses. The antidepressant-like effect of essential oil (20 mg/kg) was prevented by pretreatment of mice with l-arginine (750 mg/kg i.p.) and sildenafil (5 mg/kg i.p). On the contrary, pretreatment of mice with l-NAME (10 mg/kg i.p.) or methylene blue (10 mg/kg i.p.) potentiated the antidepressant action of essential oil (10 mg/kg). Taken together, these findings demonstrated that nitric oxide pathway is involved in mediating antidepressant like effect of essential oil from this chemotype.     

国产野生薄荷挥发油化学组分变异及其化学型

采用气－质联用的方法,对国产野生薄荷（ＭｅｎｔｈａｈａｐｌｏｃａｌｙｘＢｒｉｑ．）居群的挥发油成分进行了分析,２２个样品可归纳为６个化学型：（１）薄荷酮－胡薄荷酮型（ｍｅｎｔｈｏｎｅ－ｐｕｌｅｇｏｎｅｔｙｐｅ）;（２）胡椒酮型（ｐｉｐｅｒｉｔｏｎｅｔｙｐｅ）;（３）氧化胡椒酮－氧化胡椒烯酮型（ｐｉｐｅｒｉｔｏｎｅｏｘｉｄｅ－ｐｉｐｅｒｉｔｅｎｏｎｅｏｘｉｄｅｔｙｐｅ）;（４）芳樟醇－氧化胡椒酮型（ｌｉｎａｌｏｏｌ－ｐｉｐｅｒｉｔｏｎｅｏｘｉｄｅｔｙｐｅ）;（５）香芹酮型（ｃａｒｖｏｎｅｔｙｐｅ）;（６）薄荷醇－乙酸薄荷酯型（ｍｅｎｔｈｏｌ－ｍｅｎｔｈｙｌａｃｅｔａｔｅｔｙｐｅ）。结合地理分布和薄荷属单萜类成分生物合成途径,对上述主要类型进行了讨论。     

红脐鳞种群界定的综合研究

对于以表面色泽与化学成分为根据从红脐鳞种内分出褐脐鳞作为另一独立种的综合性状进行了比较研究。该研究是以干标本及活菌培养的形态学、化学及分子数据为基础进行的。研究结果并不支持褐脐鳞作为独立种级单位的存在,而被作为红脐鳞种下的化学型予以订正。     

Plant regeneration of Iris pallida Lam. and Iris germanica L. via somatic embryogenesis from leaves,apices and young flowers

Irones are violet-scented ketonic compounds contained in the rhizome of certain species of iris. As cultivation of the iris tends to decrease, a selection program has been initiated to find the best performing clones in terms of growth and yield. Parallel to this selection, in vitro regeneration studies have been carried out in order to multiply interesting clones. A method of rapid multiplication by somatic embryogenesis associated with multibudding was developed. Callus was obtained from leaf bases, flower pieces or rhizome apices; the best explants were flower pieces. The induction media used to obtain embryogenic callus were Murashige & Skoog (1962) media. Assays with adding of proline in these media have showed that it could double the yield of embryogenic callus. The embryogenic expression medium was the Knudson's orchid agar (Knudson 1946) medium. Conformity of the plants obtained was checked by comparing their chemotypes with those of the mother plants.Abbreviations AIB indolyl butyric acid - BAP 6-benzylaminopurine - Kin 6-furfurylaminopurine - KN Knudson's orchid Agar - MS Murashige & Skoog medium - NAA naphthaleneacetic acid - N6 Chu et al. medium - Pro proline - 2,4-D dichlorophenoxyacetic acid     

Influence of Soil Variation on Diosgenin Content Profile in Costus speciosus from Indo-Gangetic Plains

Costus speciosus is a rich source of commercially important compound Diosgenin, distributed in different regions of India. The present investigation was aimed to quantify diosgenin through High Performance Thin Layer Chromatography in 34 germplasms of Costus speciosus and also to identify the superior sources and to correlate the macronutrients of rhizospheric soil. The starch content varied in microscopic examination and correlated inversely (r=−0.266) with diosgenin content. Findings revealed that the extraction process with acid hydrolysis yielded higher diosgenin content (0.15–1.88 %) as compared to non-hydrolysis (0.009–0.368 %) procedure. Germplasms from Uttar Pradesh (NBCS-4), Jharkhand (NBCS-39) and Bihar (NBCS-2) were identified as elite chemotypes based on hierarchical clustering analysis. The phosphorous content of respective rhizospheric soil correlated positively (r=0.742) with diosgenin content. Findings of present study are useful to identify the new agrotechniques. The elite germplasms can also be used as quality planting material for large scale cultivation in order to assure a sustained supply to the herbal drug industry.     

苗药大果木姜子挥发油成分变化及其地理分布

采用ArcGIS地理信息系统软件的空间分析方法和SPSS13.0统计软件的统计分析方法,分析了大果木姜子化学型及其地理分布。结果显示:(1)大果木姜子果实挥发油的化学组分主要存在3种化学型:HS型、PJ型和LS型,其中PJ型和LS型的化学成分构成较为相近。(2)HS型主要分布在苗岭的西南部、红水河流域800 m以下的区域,以1,8-桉叶素和α-松油醇的百分含量高于60%(1,8-桉叶素大于55%)、α-水芹烯和D-柠檬烯的百分含量低于10%为特征;PJ型主要分布在南北盘江流域、乌蒙山东南部800 m左右的区域,以1,8-桉叶素和α-松油醇的百分含量低于50%(1,8-桉叶素小于40%)、α-水芹烯和D-柠檬烯的百分含量介于(10%-20%)为特征;LS型主要分布在岑王老山900 m以上的区域,1,8-桉叶素小于30%。(3)分布区内的气候在一定程度上影响了大果木姜子果实挥发油的形成与变化,太阳辐射和日照时数是其主要影响因素之一。     

Identification and Genetic Division of Fusarium graminearum and Fusarium asiaticum by Species‐Specific SCAR Markers

Fusarium head blight (FHB), also called scab, is a devastating and insidious disease of cereals including wheat (Triticum spp.) and barley (Hordeum vulgare L.) worldwide. Apart from direct yield losses, the most serious concern about FHB is the contamination of the crop with mycotoxins, which pose a health risk to human and livestock. Recent research reported that phylogenetic species F. asiaticum (Fa) and F. graminearum (Fg) were the major causal agents of FHB from infected wheat heads in China. To investigate the population structure of Fusarium species in China by species‐specific as well as the chemotype‐specific markers, sequence‐related amplified polymorphism (SRAP) markers were screened on representative isolates of F. asiaticum‐NIV, F. asiaticum‐ 3ADON and F. graminearum‐15ADON to find amplification products characteristic of either species or chemotypes. Selected amplified fragments were cloned and sequenced so that sequence‐characterized amplified region (SCAR) primer pairs could be developed which permit specific detection of Fusarium species using conventional PCR. Primer pairs SCAR‐Fa1 and SCAR‐Fg1 were confirmed to be able to amplify specific products only in F. asiaticum and F. graminearum isolates, respectively. These species‐specific primers were applied to determine genetic division of F. asiaticum and F. graminearum isolates collected in Yangtze–Huaihe valley. The results indicated that F. asiaticum was the predominant species causing FHB in this wheat production area. It is the first report that SRAP markers were adapted for species characterization in Fusarium isolates.     

滇南农家大麻品种中大麻素化学型及基因型研究

以1个滇南农家大麻品种群体为研究对象,通过化学分析及同源克隆方法,研究了21个单株中2种主要大麻素——四氢大麻酚(THC)和大麻二酚(CBD)的化学型和基因型,以揭示大麻素含量、化学型以及基因型三者之间的关系,为工业大麻新品种选育提供理论依据。研究表明:(1)化学检测结果显示,21个单株均含有THC,THC含量在0.07%~1.35%之间,其中7个单株仅含THC,5个单株含THC和微量CBD,9个单株同时含有THC和CBD,CBD含量范围为0~0.58%。(2)CBD/THC比值显示,该群体仅存在毒品型和中间型2种化学型,且中间型大麻中THC和CBD含量显著正相关。(3)基因扩增及测序分析结果显示,该群体为基因型杂合群体,群体内THCA合成酶基因存在5个变异位点,CBDA合成酶基因存在2个变异位点,但变异位点和THC及CBD的含量无直接关系。(4)群体内单株的基因型和化学型完全对应,且THCA合成酶基因及CBDA合成酶基因可作为分子标记来鉴定单株化学型。