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...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.展开更多
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 cha...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.展开更多
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 th...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.展开更多
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 w...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.展开更多
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 p...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.展开更多
基金a part of the research project of the Institute of Plant and Animal Ecology,Ural Branch,Russian Academy of Sciences (№122021000092-9)
文摘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.
基金supported by an Early Career Award(DEB 0332298)an ATOL grant(DEB 0431239)from the National Science Foundation,USA.
文摘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.
基金Supported by the Transgenic Plant Research Special Program of China(No.2008ZX08003-005)the Technology Development Project of Jilin Province,China(Nos.20086029,20076016)
文摘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.
文摘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.
基金Supported by the National Natural Science Foundation of China(30260062)to Jiaming Zhangthe US Department of Energy,Division of Energy Biosciences(PR 03-00ER15098.00)+1 种基金US Department of Agriculture-NRI(2001-35304-09899)National Science Foundation-Plant Genome Research Program DBI#0501862 to Anne Sylvester.
文摘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.
