Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Picea”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed2005

Growth responses of Picea mongolica seedlings to defoliation rate.

Picea mongolica W. D. Xu. is an endemic species in China. The spruce forest is only found in semi-arid habitat in Inner Mongolia Autonomous Region of China. Based on the simulative defoliation experiment, it was proved that Picea mongolica seedlings had the compensatory and overcompensatory effects under the certain defoliation rate. The results of variance analysis on growth indexes showed that in PM I (natural regeneration seedlings under Picea mongolica forest), the differences of H1 (height in June 23) and H2 (height in September 3) were extremely significant, and the difference of D(diameter at the breast height) were not significant. In PM II (artificial regeneration seedlings under Betula platyphylla Suk. forest), the difference of H1 was significant, the difference of H2 was not significant, and the difference of D was extremely significant. The regression equations were established and the compensatory and overcompensatory points were obtained. In PM I, the compensatory points of H1, H2, and D were 0.7628, 0.7436, 0.5725, and the overcompensatory points were 0.6056, 0.5802 and 0.2909 respectively. In PM II, the compensatory points of H,, H2, and D are 0.5012, 0.3421, 0.2488, and the overcompensatory points are 0.4137, 0.2633 and 0.0747 respectively. These results suggested that the induction of compensatory growth mechanisms in spruce seedlings required a threshold level of defoliation, and the insects in Picea mongolica forest could be controlled in a certain degree.

Analysis of Variance↗
PubMed1994

Phylogenetic inferences on the relationship of North American and European Picea species based on nuclear ribosomal 18S sequences and the internal transcribed spacer 1 region.

We have used PCR (polymerase chain reaction) to isolate nuclear ribosomal sequences from seven species of Picea (spruce). The amplified products contained approximately 200 base pairs from the 3' end of the 18S rRNA gene and the entire first internal transcribed spacer (ITS1). The sequences from these two functionally distinct regions were aligned and variable positions were used to construct a character matrix for cladistic-based phylogenetic analysis. Short insertions or deletions (indels) were common in the ITS1 and distinguished some intragenus phylogenetic relationships. In the present study, evolutionary relationships, based on DNA sequence variation within the ribosomal repeat, were determined for seven North American and European species of Picea. The results support the hypothesis of Wright (1955) that P. rubens and P. mariana are more closely related to the European species P. omorika than to other North American Picea. Molecular data suggest P. pungens has a closer relationship to eastern North American and European Picea than its presumed affiliation with northwestern American species.

Base Sequence↗
PubMed1998

Molecular evolution of cdc2 pseudogenes in spruce (Picea).

The p34cdc2 protein and other cyclin-dependent protein kinases (CDK) are important regulators of eukaryotic cell cycle progression. We have previously cloned a functional cdc2 gene from Picea abies and found it to be part of a family of related sequences, largely consisting of pseudogenes. We now report on the isolation of partial cdc2 pseudogenes from Picea engelmannii and Picea sitchensis, as well as partial functional cdc2 sequences from P. engelmannii, P. sitchensis and Pinus contorta. A high level of conservation between species was detected for these sequences. Phylogenetic analyses of pseudogene and functional cdc2 sequences, as well as the presence of shared insertions or deletions, support the division of most of the cdc2 pseudogenes into two subfamilies. New cdc2 pseudogenes appear to have been formed in Picea at a much higher rate than they have been obliterated by neutral mutations. The pattern of nucleotide changes in the cdc2 pseudogenes, as compared to a presumed ancestral functional cdc2 gene, was similar to that previously found in mammalian pseudogenes, with a strong bias for the transitions C to T and G to A, and the transversions C to A and G to T.

Amino Acid Sequence↗
PubMed1999

Phytochrome types in Picea and Pinus. Expression patterns of PHYA-Related types.

Knowledge of the genes in gymnosperms encoding the apoproteins of the plant photoreceptor phytochrome is currently scanty as for gymnosperm nuclear protein coding sequences in general. Here we report two complete cDNA-derived sequences which code for two different types of gymnosperm phytochrome. One sequence stems from Norway spruce (Picea abies) and the other from Scots pine (Pinus sylvestris). More detailed studies have shown that both types of phytochrome gene are present in Norway spruce. From phylogenetic analyses, these types appear to branch off from progenitors that are also the common ancestors of the angiosperm PHYA/PHYC and PHYB/PHYD/PHYE lineages. Partial phytochrome sequences of other gymnosperms cluster with either the one type or the other of the gymnosperm phytochrome genes characterized here. Southern blot analysis of Picea DNA using probes derived from the full-length Picea gene indicated a family of at least five members. Whether they code for new types may be doubted since only two phylogenetic clusters were found. Studies using RNA-PCR of Picea RNA extracted from either light- or dark-grown seedlings indicated that the steady-state levels of the transcripts of two PHYA/C-related genes were hardly affected by light.

Cycadopsida↗
PubMed2006

Molecular phylogeny and biogeography of Picea (Pinaceae): implications for phylogeographical studies using cytoplasmic haplotypes.

The center of diversity is not necessarily the place of origin, as has been established by many plant molecular phylogenies. Picea is a complicated but very important genus in coniferous forests of the Northern Hemisphere, with a high species diversity in Asia. Its phylogeny and biogeography were investigated here using sequence analysis of the paternally inherited chloroplast trnC-trnD and trnT-trnF regions and the maternally inherited mitochondrial nad5 intron 1. We found that the North American P. breweriana and P. sitchensis were basal to the other spruces that were further divided into three clades in the cpDNA phylogeny, and that the New World species harbored four of five mitotypes detected, including two ancestral ones and three endemics. These results, combined with biogeographic analyses using DIVA and MacClade and fossil evidence, suggest that Picea originated in North America, and that its present distribution could stem from two times of dispersal from North America to Asia by the Beringian land bridge, and then from Asia to Europe. Most of the northeastern Asian species and the European P. abies could arise from a recent radiation given the very low interspecific genetic differentiation and pure mitotype of them. Considering that the ancestral mtDNA polymorphism can be preserved in many descendant species, even distantly related ones, we suggest that more species, at least the closely related ones, should be sampled in the phylogeographical study using cytoplasmic haplotypes if possible. In addition, we also discussed the evolution and phylogenetic utility of morphological characters in Picea.

Base Sequence↗
PubMed2006

Effect of ascorbate and its oxidation products on H2O2 production in cell-suspension cultures of Picea abies and in the absence of cells.

Dehydroascorbate and traces of ascorbate were present apoplastically in living spruce (Picea abies) twigs. Since the proposed apoplastic ascorbate degradation pathway contains several steps that possibly generate H(2)O(2), the effects of ascorbate and some of its degradation products were tested on apoplastic H(2)O(2) concentrations in a cell culture of P. abies as a model and on non-enzymic H(2)O(2) production in vitro. Ascorbate scavenged H(2)O(2) in the culture medium of lignin-producing Picea cells and in spent and boiled spent medium; in the presence of Cu(2+) or fresh medium, ascorbate led to the non-enzymic generation of H(2)O(2). Preparations of dehydroascorbate (the initial oxidation-product of ascorbate), and diketogulonate (the hydrolysis-product of dehydroascorbate) induced H(2)O(2) accumulation both non-enzymically and enzymically in Picea cell-suspensions. Paper electrophoresis showed that the dehydroascorbate and diketogulonate preparations contained several degradation products; some of these probably contributed to H(2)O(2) production and/or scavenging in these experiments, and would also do so in vivo. These results indicate a complex ability of apoplastic ascorbate, dehydroascorbate, diketogulonate, and further products to modulate H(2)O(2) concentrations, with potential consequences for the control of growth, development and lignification.

2,3-Diketogulonic Acid↗
PubMed2003

Cross-species amplification of mitochondrial DNA sequence-tagged-site markers in conifers: the nature of polymorphism and variation within and among species in Picea.

Primers previously developed to amplify specific non-coding regions of the mitochondrial genome in Angiosperms, and new primers for additional non-coding mtDNA regions, were tested for their ability to direct DNA amplification in 12 conifer taxa and to detect sequence-tagged-site (STS) polymorphisms within and among eight species in Picea. Out of 12 primer pairs, nine were successful at amplifying mtDNA in most of the taxa surveyed. In conifers, indels and substitutions were observed for several loci, allowing them to distinguish between families, genera and, in some cases, between species within genera. In Picea, interspecific polymorphism was detected for four loci, while intraspecific variation was observed for three of the mtDNA regions studied. One of these (SSU rRNA V1 region) exhibited indel polymorphisms, and the two others ( nad1 intron b/c and nad5 intron1) revealed restriction differences after digestion with Sau3AI (PCR-RFLP). A fourth locus, the nad4L- orf25 intergenic region, showed a multibanding pattern for most of the spruce species, suggesting a possible gene duplication. Maternal inheritance, expected for mtDNA in conifers, was observed for all polymorphic markers except the intergenic region nad4L- orf25. Pooling of the variation observed with the remaining three markers resulted in two to six different mtDNA haplotypes within the different species of Picea. Evidence for intra-genomic recombination was observed in at least two taxa. Thus, these mitotypes are likely to be more informative than single-locus haplotypes. They should be particularly useful for the study of biogeography and the dynamics of hybrid zones.

Base Sequence↗
PubMed2002

Production, isolation and characterization of a sterol esterase from Ophiostoma piceae.

We studied extracellular sterol esterase production by the ascomycete Ophiostoma piceae in liquid culture. Esterase activity was found in low levels in glucose medium but it was strongly induced by olive oil. An esterase was purified from the 0.5% olive oil-supplemented cultures using ultrafiltration followed by a single chromatographic step on a hydrophobic interaction column. The enzyme was a glycoprotein with 8% N-linked carbohydrate content, a molecular mass by SDS/PAGE around 56.5 kDa and an isoelectric point of 3.3. Its N-terminal sequence was TTVNVKYPEGEVV. Substrate specificity studies showed that the O. piceae esterase hydrolyzes p-nitrophenol esters, tributyrin, triolein and different cholesterol esters. Both affinity (Km) and catalytic constant (k(cat)) were positively affected by the length of the fatty acid esterifying glycerol and cholesterol. The presence of double bonds in the acyl chain increased the enzyme efficiency, although it affected the k(cat) values rather than the Km on the cholesterol esters. The O. piceae enzyme showed no interfacial activation. This enzyme could have biotechnological applications in paper manufacturing since it efficiently hydrolyzes both triglycerides and sterol esters, which form pitch deposits during manufacturing of softwood and hardwood paper pulps, respectively.

Ascomycota↗
PubMed2003

The Ophiostoma piceae complex in the Southern Hemisphere: a phylogenetic study.

The Ophiostoma piceae species complex incorporates several economically important species, including serious tree pathogens and agents of bluestain. The species in the complex are morphologically similar, but can be distinguished from each other based on morphology, biology, mating type studies and molecular data. At present, all the species in the complex are considered to be native to the Northern Hemisphere, most of them with a very wide distribution. Only a few sporadic reports of members of the complex are available from the Southern Hemisphere, where they are believed to have been introduced, including New Zealand, Australia, Chile, Brazil and Uruguay. This study aims to confirm the identity of isolates resembling O. piceae originating from three Southern Hemisphere countries, using mating compatibility and rDNA sequencing. Our results show that O. quercus is widely distributed throughout South Africa on both native and exotic hardwoods. O. quercus is also reported for the first time from Brazil, again from a native host. O. floccosum is reported for the first time from South Africa, but from an exotic Pinus sp. These results suggest that species of the O. piceae complex are common in the Southern Hemisphere, and that current views on the origins of especially O. quercus need to be reconsidered.

Ascomycota↗
PubMedDate not supplied

The role of acrotony in reproductive development in Picea.

The expression of acrotony (i.e., the increasing size of comparable lateral shoots toward the apex of the main shoot) was similar among first-order shoots borne along previous-year leaders of young Picea glauca (Moench) Voss, Picea mariana (Mill.) B.S.P. and Picea rubens Sarg. trees. The position and nature (i.e., whether cones, second-order shoots or non-flushed buds) of lateral axes borne along the first-order shoots were investigated. Seed cones occurred in proximal to distal positions, but not in terminal positions, on upper shoots, in medial to terminal positions on middle shoots, and in distal to terminal positions on lower shoots. Most non-flushed buds occurred in proximal positions on middle and lower shoots. In P. rubens, rate, duration and amount of elongation of first-order shoots increased acropetally. Thus lower shoots stopped elongating before upper shoots. Evidence of bud differentiation in P. rubens, as indicated by the presence of initiating leaf primordia, was seen first in sections of terminal buds of upper shoots. Differentiation of buds then proceeded basipetally along shoots and among shoots down the crown. Differentiation of buds in positions where cones are commonly borne became evident soon after shoot elongation was completed.

Journal Article↗
PubMed1988

Organogenesis and embryogenesis in mature zygotic embryos of Picea sitchensis.

Differentiation of adventitious buds and somatic embryos from mature zygotic embryos of Picea sitchensis (Bong.) Carr. is described. Adventitious buds were formed on embryos pulse-treated with 250 microM benzyladenine for 2 h and cultured on medium lacking growth regulators. Buds were initiated at different frequencies and sites depending on when the BA-pulsed embryos were transferred to fresh culture medium. Embryogenic callus was formed when the zygotic embryos were cultured on medium containing 10 microM 2,4-dichlorophenoxyacetic acid and 5 microM benzyladenine. Although 50% of the embryos gave rise to embryogenic callus, only 20% of the callus continued to proliferate after subculture. Proliferation of new somatic embryos occurred from both the embryonic region and the suspensor region on previously formed somatic embryos. The pattern for development of adventitious buds and somatic embryos in Picea sitchensis is compared to that in Picea abies under similar culture conditions.

Journal Article↗
PubMed2004

A full saturated linkage map of Picea abies including AFLP, SSR, ESTP, 5S rDNA and morphological markers.

Based on an F(1) progeny of 73 individuals, two parental maps were constructed according to the double pseudo-test cross strategy. The paternal map contained 16 linkage groups for a total genetic length of 1,792 cM. The maternal map covered 1,920 cM, and consisted of 12 linkage groups. These parental maps were then integrated using 66 intercross markers. The resulting consensus map covered 2,035 cM and included 755 markers (661 AFLPs, 74 SSRs, 18 ESTPs, the 5S rDNA and the early cone formation trait) on 12 linkage groups, reflecting the haploid number of chromosomes of Picea abies. The average spacing between two adjacent markers was 2.6 cM. The presence of 39 of the SSR and/or ESTP markers from this consensus map on other published maps of different Picea and Pinus species allowed us to establish partial linkage group homologies across three P. abies maps (up to five common markers per linkage group). This first saturated linkage map of P. abies could be therefore used as a support for developing comparative genome mapping in conifers.

Chromosome Mapping↗
PubMed2006

Regulation of the beta-hydroxyacyl ACP dehydratase gene of Picea mariana by alternative splicing.

The gene for beta-hydroxyacyl ACP dehydratase, a de novo fatty acid biosynthetic enzyme, was cloned from Picea mariana (black spruce) and consists of five exons and four introns. The first intron of the beta-hydroxyacyl ACP dehydratase mRNA is alternatively spliced. Retention of intron 1 in splice variants results in truncation of the beta-hydroxyacyl ACP dehydratase ORF at a premature termination codon. In addition, splicing of intron 1 was found to be associated with cold temperature. mRNAs retaining intron 1 increase with seed imbibition at 22 degrees C but not 4 degrees C, whereas, splicing of intron 1 increases in winter weeks with temperatures below freezing. These results provide evidence that alternative splicing may also contribute to regulation of lipid biosynthesis in Picea mariana.

Alternative Splicing↗
PubMed2006

APETALA2 like genes from Picea abies show functional similarities to their Arabidopsis homologues.

In angiosperm flower development the identity of the floral organs is determined by the A, B and C factors. Here we present the characterisation of three homologues of the A class gene APETALA2 (AP2) from the conifer Picea abies (Norway spruce), Picea abies APETALA2 LIKE1 (PaAP2L1), PaAP2L2 and PaAP2L3. Similar to AP2 these genes contain sequence motifs complementary to miRNA172 that has been shown to regulate AP2 in Arabidopsis. The genes display distinct expression patterns during plant development; in the female-cone bud PaAP2L1 and PaAP2L3 are expressed in the seed-bearing ovuliferous scale in a pattern complementary to each other, and overlapping with the expression of the C class-related gene DAL2. To study the function of PaAP2L1 and PaAP2L2 the genes were expressed in Arabidopsis. The transgenic PaAP2L2 plants were stunted and flowered later than control plants. Flowers were indeterminate and produced an excess of floral organs most severely in the two inner whorls, associated with an ectopic expression of the meristem-regulating gene WUSCHEL. No homeotic changes in floral-organ identities occurred, but in the ap2-1 mutant background PaAP2L2 was able to promote petal identity, indicating that the spruce AP2 gene has the capacity to substitute for an A class gene in Arabidopsis. In spite of the long evolutionary distance between angiosperms and gymnosperms and the fact that gymnosperms lack structures homologous to sepals and petals our data supports a functional conservation of AP2 genes among the seed plants.

Arabidopsis↗
PubMed2004

The influence of O3, NO2 and SO2 on growth of Picea abies and Fagus sylvatica in the Carpathian Mountains.

At 17 long-term pollution monitoring sites throughout the Carpathian Mountains, tree growth patterns and variation in growth rate were examined to determine relationship of tree growth to specific pollutants. Canopy dominant Picea abies and Fagus sylvatica were selected at each site. Basal area increment (BAI) values were calculated from raw ring widths and used as an estimate of tree growth. Across all sites, BAI chronologies were highly variable, therefore local conditions and forest structure accounted for considerable variation. Several significant relationships, however, implicated a role of pollutants on tree growth. Average levels (1997-1999) of NO(2) and SO(2) were inversely related to BAI means (1989-1999). Although average O(3) alone was not related to growth, the maximum O(3) value reported at the sites was negatively correlated with overall growth. A variable representing the combined effect of O(3), NO(2) and SO(2) was negatively correlated with both P. abies and F. sylvatica growth. Pollution data were used to categorize all sites into 'high' or 'low' pollution sites. Difference chronologies based on these categories indicated trends of decline in the 'high' pollution sites relative to 'low' pollution site. In the more heavily polluted sites, the BAI of Fagus sylvatica has declined approximately 50% and Picea abies has declined 20% over the past 45 years.

Air Pollutants↗
PubMed2003

Albatrellus citrinus sp. nov., connected to Picea abies on lime rich soils.

Field observations indicated that a morphotype of Albatrellus subrubescens seemed connected to Picea abies and lime rich soils, while the original morphotype seemed connected with Pinus sylvestris and indifferent to lime. We conducted a molecular study (ITS sequencing of 22 Albatrellus specimens) to test the hypothesis that we in fact had discovered a new species. Our results confirmed the hypothesis, i.e. the Picea taxon (604 bp ITS) had little intraspecific variation in spite of 1600 km distance between samples, but compared with the Pinus taxon (598 bp ITS) the sequence difference was constantly 5.6% regardless of close distance (75 km). We describe the new species A. citrinus, which apart from ecology and ITS sequence, is different from A. subrubescens by a distinct yellowing with age, lack of dark spots of the cap, a mild taste and somewhat narrower spores. A. citrinus seems to be more related to A. ovinus than to A. subrubescens, and A. syringae may not even be a true Albatrellus.

Basidiomycota↗
PubMed2003

Juvenile nitrogen uptake capacities and root architecture of two open-pollinated families of Picea abies. Effects of nitrogen source and ectomycorrhizal symbiosis.

This study was carried out to find early physiological differences occurring in young seedlings between two contrasting Picea abies open-pollinated families (OPF), one with high- and one with low-growth performance in the field by, determining their N uptake capacities and their root architecture. We used three potential N-sources in forest soil solution, NO3-, NH4+ and amino acids, to establish N uptake rates by the plants, whether or not associated with a fungus isolated from the field and identified as Paxillus involutus. NO3- fluxes were determined locally at the root surface using NO3(-)-selective microelectrodes whereas NH4+ and amino acid (L-glutamate and L-aspartate) uptake rates were calculated from their depletion of the incubation solution by the whole root system. Root systems were digitised in order to determine the number and the length of different root types. In non-mycorrhizal plants, the results showed that the most distinguishing parameters between OPF were NO3- uptake rates measured in the white tip of the secondary roots and the root architecture, with higher values determined in high-growth than in low-growth field performance OPF. The presence of the mycorrhizal fungus decreased NO3- uptake rates in both OPF and had an opposite effect on root architecture by increasing it in low-growth and decreasing it in high-growth field performance OPF, respectively. In non-mycorrhizal plants, NH4+ and amino-acid uptake rates were not different between OPF. Mycorrhizal symbiosis did not change NH4+ uptake rates whereas it increased that of amino acids, specifically that of L-aspartate in the low-growth field performance OPF. Taken together these results suggest that the measurement of local fluxes in roots of young plants could be a good potential tool for the early evaluating of growth capacity of Picea abies OPF.

Amino Acids↗
PubMed2007

Microarray gene expression profiling of developmental transitions in Sitka spruce (Picea sitchensis) apical shoots.

The apical shoot drives the yearly new stem growth of conifer trees, is the primary site for the establishment of chemical and physical defences, and is important in establishing subsequent perennial growth. This organ presents an interesting developmental system, with growth and development progressing from a meristematic tip through development of a primary vascular system, to a base with fully differentiated and lignified secondary xylem on the inside and bark tissue with constitutive defence structures such as resin, polyphenolic phloem parenchyma cells, and sclereids on the outside. A spruce (Picea spp.) microarray containing approximately 16.7K unique cDNAs was used to study transcript profiles that characterize the developmental transition in apical shoots of Sitka spruce (Picea sitchensis) from their vegetative tips to their woody bases. Along with genes involved in cell-wall modification and lignin biosynthesis, a number of differentially regulated genes encoding protein kinases and transcription factors with base-preferred expression patterns were identified, which could play roles in the formation of woody tissues inside the apical shoot, as well as in regulating other developmental transitions associated with organ maturation. Preferential expression of known conifer defence genes, genes encoding defence-related proteins, and genes encoding regulatory proteins was observed at the apical shoot tip and in the green bark tissues at the apical shoot base, suggesting a commitment to constitutive defence in the apical shoot that is co-ordinated with rapid development of secondary xylem.

Antigens, Plant↗