荞麦属种质资源发芽种子酯酶同工酶研究

用聚丙烯酰胺凝胶电泳对荞麦属8个种(含大粒组7个和小粒组1个)33份材料发芽种子的酯酶同工酶进行了研究。结果表明:酯酶同工酶不同酶带合计22条,不同物种的酶带数4到8条。其中,甜荞有8条带,苦荞为7条。酶带及聚类分析表明,大粒组荞麦种的谱带与细野荞等小粒组荞麦种间差异极大,甜荞和苦荞酶带分别与大野荞和毛野荞相似,并分别与F.megaspartanium和F.pilus聚类最近,支持F.megaspartanium和F.pilus可能分别是甜荞和苦荞祖先种的假说。     

荞麦属种质资源发芽种子过氧化物酶同工酶研究

用聚丙烯酰胺凝胶电泳对荞麦属9个种(含大粒组8个和小粒组1个)32个收集系栽培及野生荞麦种子的过氧化物酶同工酶进行了研究。结果表明:过氧化物酶同工酶酶带23条,不同物种的酶带数4到8条。其中,甜荞有7条带,而苦荞为4条。酶带分析及聚类分析表明:大粒组荞麦种的谱带与F.gracilipes等小粒组荞麦种间差异极大,甜荞和苦荞酶带分别与F.megaspartanium和F.pilus相似,并分别与F.megas-partanium和F.pilus聚类最近,支持F.megaspartanium和F.pilus可能分别是甜荞和苦荞祖先种的假说。     

荞麦属植物淀粉酶和甲酸脱氢酶同功酶研究(英文)

以聚丙烯酰胺凝胶电泳方法研究了荞麦属植物8个种42个收集系干种子和发芽种子的淀粉酶和甲酸脱氢酶同功酶。结果表明,荞麦淀粉酶在于种子中缺乏活性,但是在发芽种子中活性很强。在供试材料的发芽种子中共发现23个淀粉酶谱带,其中甜荞和苦荞分别有10条和8条。不同荞麦种间淀粉酶谱带差异很大,但是同种内不同收集系间差异较小。谱带聚类分析表明大野荞和毛野荞分别与甜荞和苦荞较近缘,支持它们分别为甜荞和苦荞祖先种的假说。在干种子和发芽种子中,发现所有荞麦种类均只有1条位置一致的甲酸脱氢酶谱带,暗示该酶在进化中具有高度稳定性。     

荞麦属种间13S球蛋白基因序列比较研究

荞麦13S球蛋白是荞麦种子中的一类主要贮藏蛋白。本研究选用荞麦属植物甜荞栽培种及其野生类型、苦荞栽培种及其野生类型、毛野荞、左贡野荞、细柄野荞和硬枝万年荞6个种共44份材料,进行PCR特异性扩增、测序得到荞麦13S球蛋白基因的保守片段序列。对序列进行差异分析,结果发现44份供试材料13S球蛋白基因片段的285个排列位点中不变位点为24个,多态性位点S为261个(含简约信息位点数198个和单型可变位点63个),序列总突变位点Eta为503个。野生甜荞种内13S球蛋白基因序列差异明显高于栽培甜荞,但野生苦荞种内13S球蛋白基因序列差异仅稍高于栽培苦荞。推测其一方面可能与繁殖方式有关,另一方面可能与荞麦驯化过程中通常只有少数野生型群体被驯化有关。系统聚类分析发现栽培甜荞与野甜荞亲缘关系近,与左贡野荞亲缘关系次之;栽培苦荞与野苦荞亲缘关系近,与毛野荞亲缘关系次之;细柄野荞和硬枝万年荞的13S蛋白基因片段序列差异较小,说明其亲缘关系较近。上述结果为荞麦属种间遗传多样性与进化关系研究提供了理论依据。     

Complete Chloroplast Genome Sequence of Tartary Buckwheat (Fagopyrum tataricum) and Comparative Analysis with Common Buckwheat (F. esculentum)

We report the chloroplast (cp) genome sequence of tartary buckwheat (Fagopyrum tataricum) obtained by next-generation sequencing technology and compared this with the previously reported common buckwheat (F. esculentum ssp. ancestrale) cp genome. The cp genome of F. tataricum has a total sequence length of 159,272 bp, which is 327 bp shorter than the common buckwheat cp genome. The cp gene content, order, and orientation are similar to those of common buckwheat, but with some structural variation at tandem and palindromic repeat frequencies and junction areas. A total of seven InDels (around 100 bp) were found within the intergenic sequences and the ycf1 gene. Copy number variation of the 21-bp tandem repeat varied in F. tataricum (four repeats) and F. esculentum (one repeat), and the InDel of the ycf1 gene was 63 bp long. Nucleotide and amino acid have highly conserved coding sequence with about 98% homology and four genes—rpoC2, ycf3, accD, and clpP—have high synonymous (Ks) value. PCR based InDel markers were applied to diverse genetic resources of F. tataricum and F. esculentum, and the amplicon size was identical to that expected in silico. Therefore, these InDel markers are informative biomarkers to practically distinguish raw or processed buckwheat products derived from F. tataricum and F. esculentum.     

Progress and prospects for interspecific hybridization in buckwheat and the genus Fagopyrum

Cultivated buckwheat, such as common (Fagopyrum esculentum Moench.) and tartary (Fagopyrum tataricum (L.) Gaertn.) buckwheat, is one of the most versatile crops for forage and food and has several benefits for human health. Interspecific hybridization between Fagopyrum species is of great importance to improvement of buckwheat. Hybridization would allow the transfer of agronomical beneficial characteristics from wild Fagopyrum species, including self-pollination and increased fertility, frost tolerance, and higher content of beneficial compounds. However, conventional breeding methods are only partially applicable because of the self-incompatibility and incompatibility barriers between different species. Present review summarizes the morphology of self-incompatibility, the genetic and cellular basis of incompatibility between different Fagopyrum species. In many interspecific crosses hybrid embryos are aborted after successful pollination due to post-zygotic incompatibility. The use of in vitro embryo rescue after interspecific hybridization has been successful in circumventing breeding barriers between Fagopyrum species. Methods applied successfully for the construction of interspecific hybrids are discussed in detail.     

中国荞麦栽培品种的核型比较分析

通过对我国栽培的10个甜荞（Fagopyrun esculentum)品种和7个苦荞（F.tatricum)品种根尖染色体数目观察和核型比较分析,结果表明：甜荞和苦荞染色体数目都是由16条染色体构成的,2n=2x=16。甜荞有2对随体,而苦荞有1对随体,它们的核型公式分别为12m 4m(SAT)、12m 2sm 2sm(SAT);种内各品种在染色体相对长度、染色体长度比、随体染色体数目和形态等方面差异较小,但在种间的差异明显。     

Phylogenetic relationship of four new species related to southwestern Sichuan Fagopyrum based on morphological and molecular characterization

Background and aimsRecently, four wild Fagopyrum species, Fagopyrum crispatifolium J. L. Liu, Fagopyrum pugense T. Yu, Fagopyrum qiangcai D. Q. Bai and Fagopyrum wenchuanense J. R. Shao, have been identified and described based on their morphological characters. This study investigates the phylogenetic relationship, nucleotide sequence polymorphisms of internal transcribed spacers (ITSs) and the maturase K (matK) gene within four wild species related to western Sichuan buckwheat. F. wenchuanense is closely related to Fagopyrum gracilipes while F. qiangcai is closely related to Fagopyrum esculentum based on their morphological differences. However, F. wenchuanense is more closely related to Fagopyrum cymosum and F. qiangcai is closer to Fagopyrum lineare and Fagopyrum leptopodum from the viewpoint of the ITS, and matK analysis. In addition, F. gracilipes is closer to F. pugense and Fagopyrum crispatofolium than to F. qiangcai. F. wenchuanense belongs to the cymosum group, while F. qiangcai, F. pugense and F. crispatifolium are classified into the urophyllum group based on their morphological and molecular analysis. Conducting morphological and molecular studies provide a better understanding of evolutionary mechanisms and genetic relationships of cultivated and wild buckwheat in western Sichuan, China.     

Mycorrhizal status and diversity of fungal endophytes in roots of common buckwheat (Fagopyrum esculentum) and tartary buckwheat (F. tataricum)

To determine the mycorrhizal status and to identify the fungi colonising the roots of the plants, common buckwheat (Fagopyrum esculentum) and tartary buckwheat (F. tataricum) were inoculated with an indigenous fungal mixture from a buckwheat field. Root colonisation was characterised by the hyphae and distinct microsclerotia of dark septate endophytes, with occasional arbuscules and vesicles of arbuscular mycorrhizal fungi. Sequences of arbuscular mycorrhizal fungi colonising tartary buckwheat clustered close to the Glomus species group A. Sequences with similarity to the Ceratobasidium/Rhizoctonia complex, a putative dark septate endophyte fungus, were amplified from the roots of both common and tartary buckwheat. To the best of our knowledge, this is the first report of arbuscular mycorrhizal colonisation in tartary buckwheat and the first molecular characterisation of these fungi that can colonise both of these economically important plant species.     

UV-B radiation affects flavonoids and fungal colonisation in <Emphasis Type="Italic">Fagopyrum esculentum</Emphasis> and <Emphasis Type="Italic">F. tataricum</Emphasis>

In the present study, we have evaluated the effects of increased UV-B radiation that simulates 17% ozone depletion, on fungal colonisation and concentrations of rutin, catechin and quercetin in common buckwheat (Fagopyrum esculentum) and tartary buckwheat (Fagopyrum tataricum). Induced root growth and reduced shoot:root ratios were seen in both of these buckwheat species after enhanced UV-B radiation. There was specific induction of shoot quercetin concentrations in UV-B-treated common buckwheat, whereas there were no specific responses for flavonoid metabolism in tartary buckwheat. Root colonisation with arbuscular mycorrhizal fungi significantly reduced catechin concentrations in common buckwheat roots, and induced rutin concentrations in tartary buckwheat, but did not affect shoot concentrations of the measured phenolics. Specific UV-B-related reductions in the density of microsclerotia were observed in tartary buckwheat, indicating a mechanism that potentially affects fungus-plant interactions. The data support the hypothesis that responses to enhanced UV-B radiation can be influenced by the plant pre-adaptation properties and related changes in flavonoid metabolism.     

染料结合法测定荞麦种子蛋白质含量的研究

以考马斯亮蓝G250为染料,结合经典的凯氏定氮法测定结果,对影响染料结合法测定蛋白质含量的振荡时间、温度、考马斯亮蓝溶液浓度等因素进行了研究,并分析了由考马斯亮蓝染料和蛋白质结合后染料结合量(OD值差)与凯氏法测得的蛋白质百分含量之间的相关性。结果表明:测定的适宜条件是:温度15℃,处理时间50min,考马斯亮蓝溶液的浓度是0.06mg/mL。此条件形成的络合物较稳定,重复性较好,并且所测的染料结合量与凯氏定氮法测得的蛋白质含量间呈极显著的一元线性回归和相关关系。栽培甜荞和栽培苦荞的回归方程分别为:y=15.364x+3.865和y=10.769x+6.287,这两个回归方程差异显著,不能合并,分别适合于快速估计甜荞和苦荞种子的蛋白质含量。     

Combined effects of elevated UV-B radiation and the addition of selenium on common (<Emphasis Type="Italic">Fagopyrum esculentum</Emphasis> Moench) and tartary [<Emphasis Type="Italic">Fagopyrum tataricum</Emphasis> (L.) Gaertn.] buckwheat

The combined effects of UV-B irradiation and foliar treatment with selenium on two buckwheat species, common (Fagopyrum esculentum Moench) and tartary [Fagopyrum tataricum (L.) Gaertn.] buckwheat, that underwent different intensity of breeding, were examined. Plants grown outdoors under three levels of UV-B radiation were studied for 9 weeks, from sowing to ripening. At week 7 they were sprayed with solution containing 1 g(Se) m⁻³ that presumably mitigates UV-B stress. Morphological, physiological, and biochemical parameters of the plants were monitored. Elevated UV-B radiation, corresponding to a 17 % reduction of the ozone layer, induced synthesis of UV absorbing compounds. In both buckwheat species it also caused a reduction in amounts of chlorophyll a during the time of intensive growth, an effect, which was increased in tartary buckwheat in the presence of selenium. The respiratory potential, measured as terminal electron transport system activity, was lower in plants subjected to enhanced UV-B radiation during the time of intensive growth. The effective quantum yield of photosystem 2 was also reduced due to UV-B radiation in both buckwheat species and was mitigated by the addition of Se. Se treatment also mitigated the stunting effect of UV-B radiation and the lowering of biomass in common buckwheat.     

Search for the wild ancestor of buckwheat III. The wild ancestor of cultivated common buckwheat, and of tatary buckwheat

By surveying wild Fagopyrum species and their distribution in southern China and the Himalayan hills, I arrived at the conclusion that the newly discovered subspecies F. esculentum ssp. ancestralis Ohnishi is the wild ancestor of cultivated common buckwheat, while previously known wild tatary buckwheat,F. tataricum ssp. potanini Batalin is the wild ancestor of tatary buckwheat. Their original birthplace is revealed to be northwestern corner of Yunnan province for common buckwheat judging from the distribution of wild ancestor, and to be the northwest part of Sichuan province for tatary buckwheat judging from allozyme variability in wild tatary buckwheat. F. cymosum is not the ancestor of cultivated buckwheat; it is only distantly related to cultivated buckwheat, in morphology, isozymes and cpDNA. Several genetic, ecological and taxonomic categories which should be taken into consideration in examining the origin of buckwheat were discussed. Key Words: Fagopyrum esculentum ssp. ancestralis; Fagopyrum tataricum ssp. potanini; southern China theory of origin of buckwheat. Contribution from Plant Germ-Plasm Institute, Faculty of Agriculture, Kyoto University. No. 78.     

Identification,isolation and expression analysis of eight stress-related <Emphasis Type="Italic">R2R3</Emphasis>-<Emphasis Type="Italic">MYB</Emphasis> genes in tartary buckwheat (<Emphasis Type="Italic">Fagopyrum tataricum</Emphasis>)

Key message

Eight R2R3 - MYB genes in tartary buckwheat were identified, and their expression patterns were comprehensively analyzed, which reveals role in plant response to abiotic stresses.

Abstract

The proteins of the R2R3-MYB superfamily play key roles in the growth and development processes as well as defense responses in plants. However, their characteristics and functions have not been fully investigated in tartary buckwheat (Fagopyrum tataricum), a strongly abiotic resistant coarse cereal. In this article, eight tartary buckwheat R2R3-MYB genes were isolated with full-length cDNA and DNA sequences. Phylogenetic analysis of the members of the R2R3-MYB superfamily between Arabidopsis and tartary buckwheat revealed that the assumed functions of the eight tartary buckwheat R2R3-MYB proteins are divided into five Arabidopsis functional subgroups that are involved in abiotic stress. Expression analysis during abiotic stress and exogenous phytohormone treatments identified that the eight R2R3-MYB genes responded to one or more treatments. This study is the first comprehensive analysis of the R2R3-MYB gene family in tartary buckwheat under abiotic stress.

     

Metabolomic Analysis and Phenylpropanoid Biosynthesis in Hairy Root Culture of Tartary Buckwheat Cultivars

Buckwheat, Fagopyrum tataricum Gaertn., is an important medicinal plant, which contains several phenolic compounds, including one of the highest content of rutin, a phenolic compound with anti-inflammatory properties. An experiment was conducted to investigate the level of expression of various genes in the phenylpropanoid biosynthetic pathway to analyze in vitro production of anthocyanin and phenolic compounds from hairy root cultures derived from 2 cultivars of tartary buckwheat (Hokkai T8 and T10). A total of 47 metabolites were identified by gas chromatography–time-of-flight mass spectrometry (GC-TOFMS) and subjected to principal component analysis (PCA) in order to fully distinguish between Hokkai T8 and T10 hairy roots. The expression levels of phenylpropanoid biosynthetic pathway genes, through qRT-PCR, showed higher expression for almost all the genes in T10 than T8 hairy root except for FtF3’H-2 and FtFLS-2. Rutin, quercetin, gallic acid, caffeic acid, ferulic acid, 4-hydroxybenzoic acid, and 2 anthocyanin compounds were identified in Hokkai T8 and T10 hairy roots. The concentration of rutin and anthocyanin in Hokkai T10 hairy roots of tartary buckwheat was several-fold higher compared with that obtained from Hokkai T8 hairy root. This study provides useful information on the molecular and physiological dynamic processes that are correlated with phenylpropanoid biosynthetic gene expression and phenolic compound content in F. tataricum species.     

苦荞和甜荞查尔酮合成酶基因的克隆及序列比较

以苦荞品种‘西农9920’和甜荞品种‘西农9976’为材料,根据其它植物查尔酮合成酶(chalcone synthase,CHS)基因DNA序列的保守区域设计的一对简并引物,进行PCR扩增,从2种荞麦基因组中克隆出了长度均为860 bp的CHS基因片段,对其进行回收、克隆,挑选阳性克隆测序;序列分析表明这2个片段含有CHS基因的N端和C端的结构域,分别为苦荞和甜荞的CHS基因片段,命名为FtCHS和FeCHS。对获得的2种荞麦CHS基因的DNA序列进行比较分析,发现两者间存在多达43处单碱基多态性,这些单碱基多态性可能是苦荞和甜荞种子中类黄酮含量差异的重要原因之一。苦荞和甜荞CHS与其它植物CHS的氨基酸序列的进化分析表明,其与同为蓼科的掌叶大黄和石竹科的满天星的同源性较近。     

Editor's choice: Dissection of the Octoploid Strawberry Genome by Deep Sequencing of the Genomes of Fragaria Species

Cultivated strawberry (Fragaria x ananassa) is octoploid and shows allogamous behaviour. The present study aims at dissecting this octoploid genome through comparison with its wild relatives, F. iinumae, F. nipponica, F. nubicola, and F. orientalis by de novo whole-genome sequencing on an Illumina and Roche 454 platforms. The total length of the assembled Illumina genome sequences obtained was 698 Mb for F. x ananassa, and ∼200 Mb each for the four wild species. Subsequently, a virtual reference genome termed FANhybrid_r1.2 was constructed by integrating the sequences of the four homoeologous subgenomes of F. x ananassa, from which heterozygous regions in the Roche 454 and Illumina genome sequences were eliminated. The total length of FANhybrid_r1.2 thus created was 173.2 Mb with the N50 length of 5137 bp. The Illumina-assembled genome sequences of F. x ananassa and the four wild species were then mapped onto the reference genome, along with the previously published F. vesca genome sequence to establish the subgenomic structure of F. x ananassa. The strategy adopted in this study has turned out to be successful in dissecting the genome of octoploid F. x ananassa and appears promising when applied to the analysis of other polyploid plant species.     

Evolutionary analysis of circumsporozoite surface protein and merozoite surface protein-1 (CSP and MSP-1) sequences of malaria parasites

Malaria, one of the world''s most common diseases, is caused by the intracellular protozoan parasite known as Plasmodium. In this study, we have determined the evolutionary relationship of two single-copy proteins, circumsporozoite protein (CSP) and merozoite surface protein-1 (MSP-1), among Plasmodium species using various bioinformatics tools and softwares. These two proteins are major blood stage antigens of Plasmodium species. This study demonstrates that the circumsporozoite protein of Plasmodium falciparum shows similarity with Plasmodium cynomolgi and Plasmodium knowlesi. The merozoite surface protein-1 of Plasmodium coatneyi forms a monophyletic group with Plasmodium knowlesi, demonstrating their close relationship and these two species also reveal similarity between the human malaria Plasmodium vivax. This Plasmodium phylogenetic arrangement is evidently crucial to identify shared derived characters as well as particular adaptation of plasmodium species from inside and between monophyletic groups.