Peptide signaling in plant development

Cell-to-cell communication is integral to the evolution of multicellularity. In plant development, peptide signals relay information coordinating cell proliferation and differentiation. These peptides are often encoded by gene families and bind to corresponding families of receptors. The precise spatiotemporal expression of signals and their cognate receptors underlies developmental patterning, and expressional and biochemical changes over evolutionary time have likely contributed to the refinement and complexity of developmental programs. Here, we discuss two major plant peptide families which have central roles in plant development: the CLAVATA3/ENDOSPERM SURROUNDING REGION (CLE) peptide family and the EPIDERMAL PATTERNING FACTOR (EPF) family. We discuss how specialization has enabled the CLE peptides to modulate stem cell differentiation in various tissue types, and how differing activities of EPF peptides precisely regulate the stomatal developmental program, and we examine the contributions of these peptide families to plant development from an evolutionary perspective.     

Phytophagous British insects and mites and their food-plant families: total numbers and polyphagy

The Phytophagous Insects Data Base (PIDB) was used to summarize information about 6933 species of British insects/mites and their food-plant families. Total species in 183 insect families on 127 vascular plant families were correlated with numbers of plant species in each family in Britain and Europe, accounting for 41.8% of the variation. Families with trees had more insects, while ferns and aquatic, uncommon and ephemeral plants, particularly orchids, had fewer. Seven individual insect families were analysed separately: Aphididae were more closely correlated with plant species numbers than were the more polyphagous Geometridae. Agromyzidae were uncommon on families with trees. Of insect species 75.8% fed on only one plant family and 10.1% were recorded on two families. Species feeding on three families or more were considered to be polyphagous. In the 30 largest insect families, eight had species feeding on only one plant family, while 12 had more than 20% of their species polyphagous. Proportions of family-restricted insects were high on Pinaceae, Gramineae and Compositae, but low on Corylaceae, Primulaceae and Tiliaceae. More pest species were polyphagous. Polyphagy was related to large larvae, larvae overwintering, wood-feeding, ephemeral food sources, poor dispersal abilities and omnivory. Some polyphagous species might be actively evolving in exploitation of vacant niches, leading to later progressive specialization to food-plants.     

The phylogenetics and biochemistry of host-plant specialization in Melitaeine butterflies (Lepidoptera: Nymphalidae)

Butterflies in the tribe Melitaeini (Lepidoptera: Nymphalidae) are known to utilize host plants belonging to 16 families, although most host-plant records are from four families. Of the 16 host-plant families, 12 produce secondary plant metabolites called iridoids. Earlier studies have shown that larvae of several melitaeine species use iridoids as feeding stimulants and sequester these compounds for larval defense. I investigate the evolutionary history of host-plant use in the tribe Melitaeini by testing a recent phylogenetic hypothesis of 65 species representing the four major species groups of the tribe. By simple character optimization of host-plant families and presence/absence of iridoids in the host plants, I find that plant chemistry is a more conservative trait than plant taxonomy. The ancestral host plant(s) of the entire tribe most likely contained iridoids and were likely to be in the plant family Plantaginaceae. A major host shift from plants containing iridoids to plants not containing iridoids has happened three times independently. The results show that the evolution of host-plant use in melitaeines has been (and still is) a dynamic process when considering plant taxonomy, but is relatively stable when considering host-plant chemistry.     

Introns in,introns out in plant gene families: a genomic approach of the dynamics of gene structure

Gene duplication is considered to be a source of genetic information for the creation of new functions. The Arabidopsis thaliana genome sequence revealed that a majority of plant genes belong to gene families. Regarding the problem of genes involved in the genesis of novel organs or functions during evolution, the reconstitution of the evolutionary history of gene families is of critical importance. A comparison of the intron/exon gene structure may provide clues for the understanding of the evolutionary mechanisms underlying the genesis of gene families. An extensive study of A. thaliana genome showed that families of duplicated genes may be organized according to the number and/or density of intron and the diversity in gene structure. In this paper, we propose a genomic classification of several A. thaliana gene families based on introns in an evolutionary perspective. abbreviations BGAL, -galactosidases; PCMP, plant combinatorial and modular protein     

植物microRNA的保守性及其分布的分析

MicroRNA(miRNA)是真核生物中具有重要调控作用的小分子非编码RNA。本文对miRNA官网miRBase数据库Release 22.1中隶属于植物界的绿藻门、苔藓植物门、蕨类植物门、裸子植物门、被子植物门共计82个物种的miRNA进行了统计分析。miRBase共收录植物miRNA 前体8 615个,成熟miRNA 10 414条,隶属于2 892个miRNA家族。绿藻门miRNA与其他4个门miRNA无同源性;对其他4个门植物miRNA的保守性进行研究,发现存在于2个植物门的miRNA家族有26个,属于中度保守miRNA家族;14个miRNA家族存在于3个及3个以上植物门中,属于高度保守miRNA家族,其中7个miRNA家族系苔藓、蕨类、裸子和被子植物共有,是植物中最保守的miRNA。分析表明,超过30个miRNA家族的植物有35种。进一步对40个中度或者高度保守miRNA在35种植物中的分布进行研究,发现miRNA家族及其成员在物种间的分布存在较大的差异。这些分布上的差异一方面反映不同植物中miRNA的研究深度不同,另一方面也反映出miRNA在植物进化过程中的适应性调整。研究不同植物中miRNA家族的分布,可在miRNA水平为植物早期进化同源性的研究提供分子依据。     

广东珠海万山群岛的植物资源

珠海万山群岛共有维管植物176科,547属,972种(含栽培84种),其中蕨类植物21科27属35种,裸子植物6科8属11种,被子植物139科510属926种。万山群岛共有国家重点野生保护植物11种,均为Ⅱ级;广东省珍稀濒危植物4种;药用植物492种、材用树种约109种、观赏植物143种、饲料植物21种、纤维植物105种、淀粉植物62种、油脂植物81种、芳香植物72种、鞣料植物58种;此外,还有其他用途植物若干种。     

中国高等植物多样性编目进展

中国高等植物多样性编目是“中国生物物种名录”项目中的重要组成部分, 旨在后植物志时代对中国高等植物的物种名录进行修订和年度更新。自2017年深圳国际植物学大会以来, 中国高等植物物种名录已进行了5次年度更新。名录参考最新的植物分类学研究进展, 对各大类群全面采用有分子证据的新分类系统, 收录5年来发表的中国植物新类群和新记录, 补充往年遗漏的部分类群, 并依据新的专科专属的修订结果对发生属间分类变动的类群进行了更新。目前的中国高等植物物种名录包含角苔类4科9属27种, 苔类62科170属1,081种94个种下等级, 藓类94科453属2,006种154个种下等级, 石松类3科12属165种4个种下等级, 蕨类38科177属2,215种228个种下等级, 裸子植物10科45属291种118个种下等级, 被子植物272科3,409属32,708种6,909个种下等级, 共计483科4,275属38,493种7,507个种下等级, 较5年前增加了19科270属2,334种。     

Molecular biology of K transport across the plant cell membrane: What do we learn from comparison between plant species?

Cloning and characterizations of plant K⁺ transport systems aside from Arabidopsis have been increasing over the past decade, favored by the availability of more and more plant genome sequences. Information now available enables the comparison of some of these systems between species. In this review, we focus on three families of plant K⁺ transport systems that are active at the plasma membrane: the Shaker K⁺ channel family, comprised of voltage-gated channels that dominate the plasma membrane conductance to K⁺ in most environmental conditions, and two families of transporters, the HAK/KUP/KT K⁺ transporter family, which includes some high-affinity transporters, and the HKT K⁺ and/or Na⁺ transporter family, in which K⁺-permeable members seem to be present in monocots only. The three families are briefly described, giving insights into the structure of their members and on functional properties and their roles in Arabidopsis or rice. The structure of the three families is then compared between plant species through phylogenic analyses. Within clusters of ortologues/paralogues, similarities and differences in terms of expression pattern, functional properties and, when known, regulatory interacting partners, are highlighted. The question of the physiological significance of highlighted differences is also addressed.     

植物microRNA的保守性及其分布的分析

MicroRNA(miRNA)是真核生物中具有重要调控作用的小分子非编码RNA。本文对miRNA官网miRBase数据库Release 22.1中隶属于植物界的绿藻门、苔藓植物门、蕨类植物门、裸子植物门、被子植物门共计82个物种的miRNA进行了统计分析。miRBase共收录植物miRNA 前体8 615个,成熟miRNA 10 414条,隶属于2 892个miRNA家族。绿藻门miRNA与其他4个门miRNA无同源性;对其他4个门植物miRNA的保守性进行研究,发现存在于2个植物门的miRNA家族有26个,属于中度保守miRNA家族;14个miRNA家族存在于3个及3个以上植物门中,属于高度保守miRNA家族,其中7个miRNA家族系苔藓、蕨类、裸子和被子植物共有,是植物中最保守的miRNA。分析表明,超过30个miRNA家族的植物有35种。进一步对40个中度或者高度保守miRNA在35种植物中的分布进行研究,发现miRNA家族及其成员在物种间的分布存在较大的差异。这些分布上的差异一方面反映不同植物中miRNA的研究深度不同,另一方面也反映出miRNA在植物进化过程中的适应性调整。研究不同植物中miRNA家族的分布,可在miRNA水平为植物早期进化同源性的研究提供分子依据。     

RAPID SCREENING METHOD TO DETECT POTENTIAL BIPARENTAL INHERITANCE OF PLASTID DNA AND RESULTS FOR OVER 200 ANGIOSPERM SPECIES

We have developed a diagnostic method to screen rapidly for plant species potentially capable of biparental inheritance of plastid DNA using the DNA fluorochrome 4′,6-diamidino-2-phenylindole (DAPI) in conjunction with epifluorescence microscopy. Pollen shed from 235 plant species (including about 50 of agronomic importance) representing 80 families were screened. Putative plastid DNA was detected in the generative and/or sperm cells of pollen from 26 genera (43 species) representing 15 families. Plastid DNA was not detected in the generative or sperm cells of pollen from 192 plant species, thereby strongly suggesting that these species have only maternal inheritance. Our cytological diagnosis corroborated the known genetic evidence in 42 plant species and conflicted with the genetic reports in five species, which are discussed. The data suggest that biparental inheritance of plastids is rare; overall, it may occur in about 14% of flowering plant genera, examples of which are scattered among 19% of the families examined. This methodology also readily reveals whether pollen is bi- or trinucleate.     

植物逆境抗性相关转录因子的研究进展

植物各种诱导性基因的表达主要受特定转录因子在转录水平的调控。转录因子也称反式作用因子,通过与靶基因启动子中的顺式作用元件结合发挥调节作用。根据与DNA结合的区域不同,转录因子分为若干个家族。本文综述了与植物逆境抗性相关的4个转录因子家族：bZIP类、WRKY类、AP2/EREBP类和MYB类在逆境信号转导中的作用以及它们在植物抗逆基因工程改良中的应用现状。     

Food-plant families of British insects and mites: the influence of life form and plant family

The dissimilarities between 107 British plant families with respect to the insect and mite species which feed on them were analysed using a principal co-ordinates analysis. The relationships between the plant families were strongly influenced by the plant life forms. Major groups were woody plants (trees and shrubs), aquatic plants and herbs. A wet to dry gradient was distinguished, as were evergreen plants, and early successional plant families with weeds and annuals. Taxonomically, plant families of the same order were closer together if they were predominantly of the same life form. Fagales and several orders of monocotyledons formed particularly clear groups. The three 'nearest neighbours' of each plant family based on the dissimilarities measures were listed. These provide some interesting, but conjectural, data on evolutionary aspects of plant families. This was illustrated briefly by the Cornaceae and Euphorbiaceae. The underlying progressive evolution of plants from woody species and wetter areas to herbs and annual plants of dry and cold places may be reflected by insect and mite food plant family associations.     

Exploring the plant transcriptome through phylogenetic profiling

Publicly available protein sequences represent only a small fraction of the full catalog of genes encoded by the genomes of different plants, such as green algae, mosses, gymnosperms, and angiosperms. By contrast, an enormous amount of expressed sequence tags (ESTs) exists for a wide variety of plant species, representing a substantial part of all transcribed plant genes. Integrating protein and EST sequences in comparative and evolutionary analyses is not straightforward because of the heterogeneous nature of both types of sequence data. By combining information from publicly available EST and protein sequences for 32 different plant species, we identified more than 250,000 plant proteins organized in more than 12,000 gene families. Approximately 60% of the proteins are absent from current sequence databases but provide important new information about plant gene families. Analysis of the distribution of gene families over different plant species through phylogenetic profiling reveals interesting insights into plant gene evolution, and identifies species- and lineage-specific gene families, orphan genes, and conserved core genes across the green plant lineage. We counted a similar number of approximately 9,500 gene families in monocotyledonous and eudicotyledonous plants and found strong evidence for the existence of at least 33,700 genes in rice (Oryza sativa). Interestingly, the larger number of genes in rice compared to Arabidopsis (Arabidopsis thaliana) can partially be explained by a larger amount of species-specific single-copy genes and species-specific gene families. In addition, a majority of large gene families, typically containing more than 50 genes, are bigger in rice than Arabidopsis, whereas the opposite seems true for small gene families.     

Identification of unique SUN-interacting nuclear envelope proteins with diverse functions in plants

Although a plethora of nuclear envelope (NE) transmembrane proteins (NETs) have been identified in opisthokonts, plant NETs are largely unknown. The only known NET homologues in plants are Sad1/UNC-84 (SUN) proteins, which bind Klarsicht/ANC-1/Syne-1 homology (KASH) proteins. Therefore, de novo identification of plant NETs is necessary. Based on similarities between opisthokont KASH proteins and the only known plant KASH proteins, WPP domain–interacting proteins, we used a computational method to identify the KASH subset of plant NETs. Ten potential plant KASH protein families were identified, and five candidates from four of these families were verified for their NE localization, depending on SUN domain interaction. Of those, Arabidopsis thaliana SINE1 is involved in actin-dependent nuclear positioning in guard cells, whereas its paralogue SINE2 contributes to innate immunity against an oomycete pathogen. This study dramatically expands our knowledge of plant KASH proteins and suggests that plants and opisthokonts have recruited different KASH proteins to perform NE regulatory functions.     

安徽合肥大蜀山维管植物区系地理成分研究

在野外调查和标本采集的基础上,对合肥大蜀山植物区系基本组成和科属地理成分进行了分析,并与邻近山地植物区系进行了R/T比值的比较。统计共有维管束植物120科、315属、508种（含种下等级）,其中蕨类植物10科、13属、14种,裸子植物7科、19属、47种,被子植物103科、283属、447种。壳斗科、松科、榆科、槭树科、椴树科和豆科等是该区系的主要表征科,构成了其各森林类型的主要树种组成。种子植物区系成分属的水平上可划分为14个类型,温带成分占有较高比例,热带种类丰富,北温带分布最多（23·81%）,其次为泛热带分布（18·52%）,表现出向北亚热带植物区系明显过渡的特征。中国特有成分较为缺乏。落叶阔叶林仍是该区相对稳定的森林植被类型。与其他山地植物区系R/T比值的比较表明,其热带性质大于安徽鹞落坪和皇藏峪,小于南京幕府山和滁州琅琊山,与南京紫金山和牛首山较为接近。     

植物逆境抗性相关转录因子的研究进展

植物各种诱导性基因的表达主要受特定转录因子在转录水平的调控.转录因子也称反式作用因子,通过与靶基因启动子中的顺式作用元件结合发挥调节作用.根据与DNA结合的区域不同,转录因子分为若干个家族.本文综述了与植物逆境抗性相关的4个转录因子家族:bZIP类、WRKY类、AP2/EREBP类和MYB类在逆境信号转导中的作用以及它们在植物抗逆基因工程改良中的应用现状.     

Evolution of plant nucleotide-sugar interconversion enzymes

Nucleotide-diphospho-sugars (NDP-sugars) are the building blocks of diverse polysaccharides and glycoconjugates in all organisms. In plants, 11 families of NDP-sugar interconversion enzymes (NSEs) have been identified, each of which interconverts one NDP-sugar to another. While the functions of these enzyme families have been characterized in various plants, very little is known about their evolution and origin. Our phylogenetic analyses indicate that all the 11 plant NSE families are distantly related and most of them originated from different progenitor genes, which have already diverged in ancient prokaryotes. For instance, all NSE families are found in the lower land plant mosses and most of them are also found in aquatic algae, implicating that they have already evolved to be capable of synthesizing all the 11 different NDP-sugars. Particularly interesting is that the evolution of RHM (UDP-L-rhamnose synthase) manifests the fusion of genes of three enzymatic activities in early eukaryotes in a rather intriguing manner. The plant NRS/ER (nucleotide-rhamnose synthase/epimerase-reductase), on the other hand, evolved much later from the ancient plant RHMs through losing the N-terminal domain. Based on these findings, an evolutionary model is proposed to explain the origin and evolution of different NSE families. For instance, the UGlcAE (UDP-D-glucuronic acid 4-epimerase) family is suggested to have evolved from some chlamydial bacteria. Our data also show considerably higher sequence diversity among NSE-like genes in modern prokaryotes, consistent with the higher sugar diversity found in prokaryotes. All the NSE families are widely found in plants and algae containing carbohydrate-rich cell walls, while sporadically found in animals, fungi and other eukaryotes, which do not have or have cell walls with distinct compositions. Results of this study were shown to be highly useful for identifying unknown genes for further experimental characterization to determine their functions in the synthesis of diverse glycosylated molecules.     

Vascular plant species counts in the rain forests of the middle Caquetá area,Colombian Amazonia

More than 1200 vascular plant species, distributed over 369 genera and 112 families were encountered in ten plots of 0.1 ha in the humid evergreen rain forests of the middle Caquetá area in eastern Colombia. The total number of vascular plant species in the two most diverse plots ranged from 310 to 313 species 0.1 ha^-1. These values indicate that high levels of vascular plant species densities may be encountered all over NW Amazonia, including the Colombian Amazon. The floodplain plots contained fewer vascular plant species and families than the well-drained upland plots. The high species density in the well-drained upland plots was mostly due to comparatively large numbers of species found among the very slender trees of diameter at breast (DBH)2.5 cm. Small and slender treelets (DBH < 10 cm) are by far the most species rich habit group. About 50% of the total number of vascular plant species in the plots was exclusively collected with a diameter of less than 2.5 cm. Shrubs, (hemi)epiphytes, and climbers were present with relatively few species. Many of the most species-rich families were tree families. The highest species richness was principally found among tree genera, as well. In this respect the floristic sample from the ten species count plots combined shows much affinity to the local florula around Manaus.     

黄山短尾猴（Macaca thibetana）的主要食性分析

2011年11月至2012年10月,作者采用粪便显微分析法研究了黄山短尾猴的四季食性.结果表明：黄山短尾猴共取食植物26科50种;不同季节间黄山短尾猴食性具有明显变化,冬季取食13科25种植物,春季取食23科46种植物,夏季取食14科32种植物,秋季取食17科37种植物;壳斗科、樟科是黄山短尾猴全年的主要食物,占短尾猴总取食量的51.26%～59.75%,其他科属植物也占有重要地位;甜槠在四季均为黄山短尾猴的主要取食食物,豹皮樟在冬季取食量相对较高,秋季最低,红楠、杉木在冬春季节的取食比例差异最大;黄山短尾猴采取与其他灵长类相似的觅食策略;黄山短尾猴四季食物生态位宽度差异不明显,受人为影响较为明显.