Root structure syndromes of four families of monocots in the Middle Urals

The present article tests the following general assumption:plant taxa with different specializations towards mycorrhizal interactions should have different root syndromes.Roots of 61 species common in boreal zone were studied:16 species of Poaceae,24 species of Cyperaceae,14 species of Orchidaceae,and 7 species of Iridaceae.Using a fixed material of 5 individuals of each species,the following was determined:number of orders of branching roots;transverse dimensions of root,stele and cortex;number of primary xylem vessels and exodermis layers;length of root hairs;abundance of mycorrhiza.Species of each family had well-defined syndromes.Roots of Orchidaceae and Iridaceae were thick with a large stele and developed exodermis.Orchidaceae had no branching roots and had long root hairs.In Iridaceae,roots were branched,and root hairs were short.Roots of Poaceae and Cyperaceae were thin with a relatively thin stele.Root hairs were short in Poaceae and long in Cyperaceae.Our finding that root syndromes of four families of monocots differed is a new and unexpected discovery.The high specificity of root syndromes in Cyperaceae,Iridaceae,Poaceae,and Orchidaceae indicates that species of these families use different strategies to obtain water and soil nutrients.

Diversification of the RAB Guanosine Triphosphatase Family in Dicots and Monocots

RAB guanosine triphosphatases （GTPases） are key regulators of vesicle trafficking and are essential to the growth and development of all eukaryotic cells. During evolution, the RAB family has expanded in different patterns to facilitate distinct cellular, developmental and physiological adaptations. Yeast has only 11 family members, whereas mammalian RABs have expanded to 18 RAB subfamilies. Plant RABs have diversified primarily by duplicating members within a single subfamily. Plant RABs are divided into eight subfamilies, corresponding to mammalian RAB1, RAB2, RAB5, RAB6, RAB7, RAB8, RAB11 and RAB18. Functional diversification of these is exemplified by the RAB1 ls, orthologs of which are partitioned into unique cell compartments in plants where they function to transport vesicles during localized tip growth. Similarly, the RAB2 family in grasses is likely involved in vesicle secretion associated with wall expansion, as determined by analysis of over-expression mutants. We propose that dicots and monocots have also diverged in their RAB profiles to accommodate unique cellular functions between the two groups. Here we present a bioinformatics analysis comparing the RAB sub-families of rice, maize and Arabidopsis. These results will guide future functional studies to test for the role of diversification of subfamilies unique to monocots compared to dicots.

Virus-Induced Gene Silencing in the Culinary Ginger （Zingiber officinale）： An Effective Mechanism for Down-Regulating Gene Expression in Tropical Monocots

Virus-induced gene silencing （VIGS） has been shown to be effective for transient knockdown of gene expression in plants to analyze the effects of specific genes in development and stress-related responses. VlGS is well established for studies of model systems and crops within the Solanaceae, Brassicaceae, Leguminaceae, and Poaceae, but only recently has been applied to plants residing outside these families. Here, we have demonstrated that barley stripe mosaic virus （BSMV） can infect two species within the Zingiberaceae, and that BSMV-VIGS can be applied to specifically down-regulate phytoene desaturase in the culinary ginger Zingiber officinale. These results suggest that extension of BSMV-VlGS to monocots other than cereals has the potential for directed genetic analyses of many important temperate and tropical crop species.

Shortened snRNA promoters for efficient CRISPR/Cas-based multiplex genome editing in monocot plants

Dear Editor,CRISPR(clustered regularly interspaced short palindromic repeats)/Cas genome editing is a powerful tool for introducing specific mutations in organisms including plants.The system is composed of a nuclease such as Cas9 or Cas12a and an engineered single-guide RNA(sgRNA)incorporating a target sequence(Li et al.,2019).A Cas9/sgRNA complex recognizes its target site in the genome,resulting in a mutation at that site.

Jack of Many Trades: The Multifaceted Role of miR528 in Monocots

MicroRNAs (miRNAs) are essential regulators,involved in almost all aspects of plant growth and development.In plants,miRNAs prese nt in all an giosperms are regarded as con served miRNAs;in contrast,miRNAs restricted to certain lineages (lessconserved) or a single species (species-specific) constitute the non-conserved miRNAs (Cuperus et al.,2011).Different members of a miRNA family usually target similar target genes from a gene family among different species.For in stance,in most analyzed plants,the well-known miR156 family,usually consist!ng of a number of members in a given species,collectively target SQUAMOSA-PROMOTER BINDING PROTEINLIKE (SPL) genes.Gen erally,con served miRNAs target genes encoding transcript factors which function in diverse biological processes.This functional diversity of miRNAs is mainly achieved by the plasticity of their target genes from the same family,such as miR156-targeted SPLs and miR167-targeted ARF (AUXIN RESPONSIVE FACTOR) genes,on regulating distinct downstream gen es.

The plant vascular systemⅠ:From resource allocation,inter-organ communication and defense,to evolution of the monocot cambium

In recent years, considerable attention has been paid to exploring the complex gene regulatory networks involved in the development of the plant vascular system. Such information is crucial to our understanding of the molecular and cellular events which give rise to the integrated tissues of the xylem and phloem, leading to the formation of structurally continuous conduits that interconnect various organs of the plant. Vascular development begins in the embryo to form progenitor cells, and upon germination, these progenitor cells and their decedents in the shoot and root meristems will form phloem and xylem, and the cambium.

The plant vascular system Ⅱ:From resource allocation,inter-organ communication and defense,to evolution of the monocot cambium

In this Special Issue, a focus is placed on the role of the xylem as an essential conduit for the long-distance delivery of water and mineral nutrients from the soil to the vegetative （above-ground） regions of the plant. Xylem cells destined to form tracheids or vessel members, which will make up the conduit for this water and mineral transport from the roots to the shoots, undergo apoptosis, a process of programmed cell death.

科尔沁沙地植物成熟叶片性状与叶凋落物分解的关系

采用室内培养的方法,对科尔沁沙质草地20个主要植物种(10个单子叶植物种和10个双子叶植物种)叶凋落物的CO2释放量和释放速率进行比较,同时测定了20种植物成熟叶片的热值、镁浓度、磷浓度、氮浓度、钾浓度、碳浓度、碳氮比、氮磷比、比叶面积、干物质含量以及叶面积等11项叶片性状,分析20种植物叶凋落物的CO2释放量和释放速率与11项叶片性状的相关关系。结果表明,20种植物的叶片性状在物种间变异范围很大,大多数指标的最大值和最小值的差异在3倍以上,而个别指标如叶镁浓度差异更大,接近9倍之多。由于本项研究中的20种植物均来自于同一样地,因此认为20种植物的自身性状和遗传特性决定了其叶片性状的变异。20种植物叶凋落物培养28d的CO2释放量平均值为(4121±1713)μgkg-1,释放量最大的是尖头叶藜(8767±177)μgkg-1干土,释放量最小的是马唐(1669±47)μgkg-1,二者相差5倍以上。但20种植物叶凋落物CO2释放速率表现相同的变化趋势,培养初期凋落物分解迅速,后期分解相对缓慢。比较分析发现,双子叶植物和单子叶植物叶凋落物CO2释放量、CO2释放速率,以及成熟叶片的叶氮浓度、叶碳浓度、叶C/N和叶干物质含量之间差异显著。相关分析揭示,20种植物成熟叶片叶氮浓度、叶碳浓度、叶C/N和叶干物质含量与叶凋落物分解过程中的CO2释放量和释放速率之间呈显著的相关关系,说明可以利用成熟叶片的N浓度、C浓度、C/N以及干物质含量间接的预测叶凋落物的分解速率。

Lfy cDNA高效单子叶植物表达载体的构建及转化兰花研究初报

构建一个适合在单子叶植物中高效表达的含有Ｌｆｙ ｃＤＮＡ的表达载体（ｐＢＩＬ－１），应用基因枪转化法将其导入兰花原球茎中，获得了一些卡那霉素抗性克隆。

基于ORF Finder方法的植物ITS片段结构特点分析

非编码区ITS(The Internal Transcribed Spacer)片段是目前分子系统学研究中应用最广的分子标记之一。运用生物信息学ORF finder技术,以单子叶网状叶脉植物的ITS片断为例进行分析,探讨了ITS内编码区5.8S和非编码区ITS1和ITS2的基本位置。并通过分析单子叶网状叶脉植物和菝葜科部分种类的ITS序列特点,研究了该片段在科、属、种间存在的关系和变异特点。

单子叶植物高级分类阶元系统演化:matK、rbcL和18S rDNA序列的证据

基于两个叶绿体基因(matK和rbcL)和一个核糖体基因(18S rDNA)的序列分析,对代表了基部被子植物和单子叶植物主要谱系分支的86科126属151种被子植物(单子叶植物58科86属101种)进行了系统演化关系分析。研究结果表明由胡椒目Piperales、樟目Laurales、木兰目Magnoliales和林仙目Canellales构成的真木兰类复合群是单子叶植物的姐妹群。单子叶植物的单系性在3个序列联合分析中得到98%的强烈自展支持。联合分析鉴定出9个单子叶植物主要谱系(广义泽泻目Alismatales、薯蓣目Dioscoreales、露兜树目Pandanales、天门冬目Asparagales、百合目Liliales、棕榈目Arecales、禾本目Poales、姜目Zingiberales、鸭跖草目Commelinales)和6个其他被子植物主要谱系(睡莲目Nymphaeales、真双子叶植物、木兰目、樟目、胡椒目、林仙目)。在单子叶植物内,菖蒲目Acorales(菖蒲属Acorus)是单子叶植物最早分化的一个谱系,广义泽泻目(包括天南星科Araceae和岩菖蒲科Tofieldiaceae)紧随其后分化出来,二者依次和其余单子叶植物类群构成姐妹群关系。无叶莲科Petrosaviaceae紧随广义的泽泻目之后分化出来,无叶莲科和剩余的单子叶植物类群形成姐妹群关系,并得到了较高的支持率。继无叶莲科之后分化的类群形成两个大的分支:一支是由露兜树目和薯蓣目构成,二者形成姐妹群关系;另一支是由天门冬目、百合目和鸭跖草类复合群组成,三者之间的关系在单个序列分析和联合分析中不稳定,需要进一步扩大取样范围来确定。在鸭跖草类复合群分支内,鸭跖草目和姜目的姐妹群关系在3个序列联合分析和2个序列联合分析的严格一致树中均得到强烈的自展支持,获得的支持率均是100%。但是,对于棕榈目和禾本目在鸭跖草类中的系统位置以及它们和鸭跖草目-姜目之间的关系,有待进一步解决。值得注意的是,无叶莲科与其他单子叶植物类群(除菖蒲目和泽泻目外)的系统关系在本文中获得较高的自展支持率,薯蓣目和天门冬目的单系性在序列联合分析中都得到了较好的自展支持,而这些在以往的研究中通常支持率较低。鉴于菖蒲科和无叶莲科独特的系统演化位置,本文支持将其分别独立成菖蒲目和无叶莲目Petrosaviales的分类学界定。

风雨花甘露糖结合凝集素基因克隆与序列分析

单子叶甘露糖结合凝集素具有抑制人类免疫缺陷病毒的活性。风雨花 (Zephyranthes grandiflora)球茎中含有亚基分子量为 12 KD的甘露糖结合凝集素 (ZGA)。运用同源克隆的方法设计简并引物 ,通过 3'和 5 'RACE技术 ,从风雨花总 RNA中克隆了编码此凝集素的全长 c DNA序列 ,其开放阅读框长 4 92 bp,编码 16 4个氨基酸 ,包含信号肽序列、成熟蛋白序列和 C-末端剪切序列的前体蛋白。成熟蛋白由 10 6个氨基酸残基组成 ,分子量为 11.6KD。成熟蛋白在氨基酸水平上与石蒜凝集素、雪花莲凝集素、水仙凝集素和君子兰凝集素分别有 71.8%、81%、81.8%和 84 .5 %的同源性 ;在 Blocks数据库中检索 ZGA蛋白氨基酸序列的结构域 ,发现有 3个凝集素功能结构域 ,并具有 3个典型的甘露糖专一结合位点盒 (QDNY)

农杆菌介导的病毒侵染方法在禾本科植物转化上的研究进展

综述了农杆菌介导的病毒侵染方法（Ａｇｒｏｉｎｆｅｃｔｉｏｎ）在禾本科植物转化研究方面的进展．利用农杆菌的Ｔｉ／Ｒｉ质粒载体将病毒或类病毒的核酸导入植物细胞的方法，近年来在禾本科植物包括水稻、大麦、小麦和玉米等具有经济重要性的粮食作物的转化研究上取得了长足的进展．它具有直接、高效、灵敏等特点，在导入植物过程中不需制备病毒或类病毒的核酸，也不需通过介体昆虫的介导．因此，农杆菌介导的病毒侵染方法是人们研究农杆菌及其禾本科寄主的相互关系、病毒的生物学特性、病毒基因功能和核酸序列的很好的方法．

陆生植物线粒体RNA编辑进化分析

线粒体中存在着数量最多的RNA编辑位点,RNA编辑为何在线粒体中频繁出现至今仍不清楚。对角苔、石松、蕨类、松柏、苏铁、单子叶植物和双子叶植物7个植物类群中6 838个C-U RNA编辑位点从(1)氨基酸转移概率、(2)密码子转移概率、(3)编辑位点在密码子中的位置、(4)编辑位点-1位置碱基出现频率、(5)编辑位点+1位置碱基出现频率5个方面进行了分析,发现被子植物(单子叶植物和双子叶植物)线粒体RNA编辑在密码子转移方面与其它植物类群存在显著差异。

广东甘蔗化学除草配套技术

近年来广东甘蔗化学除草正在迅速发展，主要是农村劳动力的供应短缺和工资高涨所致。蔗田主要杂草是一年生的禾本科杂草和宽叶杂草。在没有使用过除草剂的新植蔗田，马唐属占有很高的百分率。多年生禾本科杂草发生于地下水位高和排水设备不好的滨海蔗田。本文对芽前及芽后处理的甘蔗化学除草配套技术作出陈述和建议。

单子叶植物之起源:一例实验胚胎学证据

本文首次报道以禾本科植物马唐的幼穗为材料,应用组织培养技术,探讨植物的系统发育,结果表明,在马唐幼穗体细胞胚胎发生时,出现双子叶植物胚胎发生所特有的心形胚,从而为单子叶植物起源于双子叶植物提出了一个胚胎学证据。

Novel Type II Peroxiredoxin Gene Homologue from Chinese Wildrye Enhancing Salt Stress Tolerance of Transgenic Yeast

Peroxiredoxins（Prxs） are a large family of antioxidant enzymes of various types that take part in signal transduction via decomposing reactive oxygen species（ROS）. Although extensive efforts have been made over the last decades in understanding the structures and functions of Prxs, type II Prxs in monocots are hardly studied. In this work, a monocot type II Prx gene homologue from Chinese wildrye（Leymus Chinensis）, designated as LcTpxII, was isolated and characterized. LcTpxII encoding a 162-amino acid protein contains a thioredoxin domain and a cysteine residue at position 51, suggesting that it is a member of the Prxs family. The LcTpxII is capable of decomposing H2O2 and protecting plasmid DNA from damage caused by ROS. The expression of LcTpxII in Chinese wildrye was induced by 400 mmol/L NaCl and 100 mmol/L Na2CO3 in the experiment. The overexpression of LcTpxII enhances the tolerance of transgenic yeast to 1.6 mol/L NaCl and 10 mmol/L Na2CO3.

Inference of phylogenetic relationships among key angiosperm lineages using a compatibility method on a molecular data set

Phylogenetic relationships among the five key angiosperm lineages, Ceratophyllum, Chloranthaceae, eudicots, magnoliids, and monocots, have resisted resolution despite several large-scale analyses sampling taxa and characters extensively and using various analytical methods. Meanwhile, compatibility methods, which were explored together with parsimony and likelihood methods during the early development stage of phylogenetics, have been greatly under-appreciated and not been used to analyze the massive amount of sequence data to recon-struct the basal angiosperm phylogeny. In this study, we used a compatibility method on a data set of eight genes (mitochondrial atp1, matR, and nad5, plastid atpB, matK, rbcL, and rpoC2, and nuclear 18S rDNA) gathered in an earlier study. We selected two sets of characters that are compatible with more of the other characters than a random character would be with at probabilities of pM<0.1 and pM<0.5 respectively. The resulting data matrices were subjected to parsimony and likelihood bootstrap analyses. Our unrooted parsimony analyses showed that Cerato-phyllum was immediately related to eudicots, this larger lineage was immediately related to magnoliids, and monocots were closely related to Chloranthaceae. All these relationships received 76%–96% bootstrap support. A likelihood analysis of the 8 gene pM<0.5 compatible site matrix recovered the same topology but with low support. Likelihood analyses of other compatible site matrices produced different topologies that were all weakly sup-ported. The topology reconstructed in the parsimony analyses agrees with the one recovered in the previous study using both parsimony and likelihood methods when no character was eliminated. Parts of this topology have also been recovered in several earlier studies. Hence, this topology plausibly reflects the true relationships among the five key angiosperm lineages.

单子叶观赏植物花青素苷呈色机制研究进展

单子叶植物花色具有极高的观赏价值,广泛应用于园林景观配植中。花青素苷是植物主要的呈色物质,其种类、合成代谢途径等多种因素对花色形成具有重要影响。目前,花青素苷的生物合成代谢已在部分单子叶观赏植物中得到很好的研究,但其生物合成中复杂的调节机制,包括激活子和抑制子的分级反馈调节以及环境的调控作用研究深度有限。解析和整合这些反馈调节机制,对其花色育种具有重要意义。鉴此,从单子叶观赏植物的花色成因、花青素苷生物合成及转录调控机制、环境因素3个方面,对其花青素苷呈色机制进行了总结,分析环境因素的作用,探究稳定改变和优化单子叶观赏植物花色的育种手段,为单子叶观赏植物的花色呈色研究提供理论基础。

Science Letters:Two ancient rounds of polyploidy in rice genome

An ancient genome duplication (PPP 1) that predates divergence ofthe cereals has recently been recognihere another potentially older large-scale duplication (PPP2) event that predates monocot-dicot divergence in the genome of rice (Oryza sativa L.), as inferred from the age distribution of pairs of duplicate genes based on recent genome data for rice. Our results suggest that paleopolyploidy was widespread and played an important role in the evolution of rice.