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At least 19 recordsLinked to original sources

PubMed1996

Growth and carbon accumulation in root systems of Pinus taeda and Pinus ponderosa seedlings as affected by varying CO(2), temperature and nitrogen.

It has been hypothesized that increasing atmospheric CO(2) concentration enhances accumulation of carbon in fine roots, thereby altering soil carbon dynamics and nutrient cycling. To evaluate possible changes to belowground pools of carbon and nitrogen in response to elevated CO(2), an early and a late successional species of pine (Pinus taeda L. and Pinus ponderosa Dougl. ex Laws, respectively) were grown from seed for 160 days in a 35 or 70 Pa CO(2) partial pressure at low or high temperature (30-year weekly mean and 30-year weekly mean + 5 degrees C) and a soil solution nitrogen concentration of 1 or 5 mM NH(4)NO(3) at the Duke University Phytotron. Seedlings were harvested at monthly intervals and growth parameters of the primary root, secondary root and tap root fractions evaluated. Total root biomass of P. ponderosa showed a positive CO(2) response (105% increase) (P = 0.0001) as a result of significant increases in all root fractions in the elevated CO(2) treatment, but all other main effects and interactions were insignificant. In P. taeda, there were significant interactions between CO(2) and temperature (P = 0.04) and CO(2) and nitrogen (P = 0.04) for total root biomass. An allometric analysis indicated that modulation of the secondary root fraction was the main response of the trees to altered environmental conditions. In P. ponderosa, there was an increase in the secondary root fraction relative to the primary and tap root fractions under conditions of low temperature. In P. taeda, there was a shift in carbon accumulation to the secondary roots relative to the primary roots under low temperature and low nitrogen. Neither species exhibited shifts in carbon accumulation in response to elevated CO(2). We conclude that both species have the potential to increase belowground biomass substantially in response to rising atmospheric CO(2) concentration, and this response is sensitive to temperature and nitrogen in P. taeda. Both species displayed small shifts in belowground carbon accumulation in response to altered temperature and nitrogen that may have substantial ecosystem consequences over time.

Journal Article↗

PubMed2002

Nucleotide sequences of the internal transcribed spacers and 5.8S region of nuclear ribosomal DNA in Pinus taeda L. and Pinus echinata Mill.

The 615-bp nucleotide sequences of the first partial internal transcribed spacer (ITS-1), 5.8S rDNA and ITS-2 region from Pinus taeda L. (loblolly pine) and Pinus echinata Mill. (shortleaf pine) are reported. The two pine species show the same nucleotide sequences in this region, which indicates their close phylogenetic relationship. However, our reported nucleotide sequence in this region from shortleaf pine is different from the previous report for shortleaf pine in GenBank (accession number: AF037016). Our PCR-RFLP analysis of this region confirms our sequencing data. This correction is important for pine phylogenetic studies because it is located in the conserved 5.8S rDNA region.

Amino Acid Sequence↗

PubMed1999

Influence of rate of change in stomatal conductance to fluctuating irradiance on estimates of daily water use by Pinus taeda leaves.

Pinus taeda L. stomata respond slowly to changes in irradiance. Because incident irradiance on a leaf varies constantly, the rate of change in stomatal conductance to fluctuating irradiance may have a large effect on plant water use. We estimated total daily water use of Pinus taeda foliage for 10 days with very different irradiance patterns, assuming that rates of stomatal opening and closing were similar. To determine how the most extreme imbalance in rates of stomatal opening and closing affects estimates of water use, we also estimated total daily water use assuming instantaneous stomatal opening and a realistic rate of stomatal closing. Total daily water use was calculated by summing estimates of transpiration based on irradiance and vapor pressure deficit measured every minute at locations atop and within a canopy. Estimates of total daily water use calculated on the basis of realistic rates of stomatal opening and closing were similar to estimates calculated assuming instantaneous stomatal change (mean difference between methods of calculation was less than 0.2%). Estimates of total daily water use assuming instantaneous stomatal opening and a realistic rate of closing differed from estimates of total daily water use based on similar rates of stomatal opening and closing. The discrepancy was greater within the canopy (mean difference 6%) than at the top of the canopy (mean difference 1%). Calculation of mean daily conductance from mean daily irradiance, without accounting for minute-by-minute variations in irradiance, resulted in overestimations of daily stomatal conductance (13% mean error) and the magnitude of the error was directly related to the variation in irradiance for that day. We conclude that, provided variation in irradiance is accounted for, rates of stomatal opening and closing have little effect on estimates of daily water use.

Journal Article↗

PubMed1989

Assay and Electrophoresis of Superoxide Dismutase from Red Spruce (Picea rubens Sarg.), Loblolly Pine (Pinus taeda L.), and Scotch Pine (Pinus sylvestris L.) : A Method for Biomonitoring.

This paper reports a method for extracting the antioxidant enzyme superoxide dismutase (SOD) from the needles of red spruce (Picea rubens Sarg.), loblolly pine (Pinus taeda L.), and scotch pine (Pinus sylvestris L.) with high efficiency and free from interfering compounds. The extraction employs phosphate buffer with polyvinylpolypyrrolidone and Triton X-100 followed by dialysis overnight. The isozymes of SOD in each species were separated electrophoretically and tested for their sensitivity to KCN and H(2)O(2). An isozyme resistant to these inhibitors was found in the spruce but not the pine needles. The isozymes from the spruce needles were examined for individual responses to aging and H(2)O(2) inhibition. Four of the five CuZn isozymes in spruce were found to have increased significantly but equally by October of their first year and two of those four isozymes were found to be more sensitive to H(2)O(2). The response of the SOD isozymes in loblolly pine seedlings to O(3) was also examined and the isozymes were found to be induced equally. Because the SOD activity in the young pine needles was too low to electrophorese, the SOD activity from the pines in the O(3) experiment had to be partially purified using CHCl(3) and ethanol, then concentrated.

Journal Article↗

PubMed1999

Multi-site modulation of flux during monolignol formation in loblolly pine (Pinus taeda).

Loblolly pine (Pinus taeda L.) cell suspension cultures secrete monolignols when placed in 8% sucrose/20 mM KI solution, and these were used to identify phenylpropanoid pathway flux-modulating steps. When cells were provided with increasing amounts of either phenylalanine (Phe) or cinnamic acid, cellular concentrations of immediate downstream products (cinnamic and p-coumaric acids, respectively) increased, whereas caffeic and ferulic acid pool sizes were essentially unaffected. Increasing Phe concentrations resulted in increased amounts of p-coumaryl alcohol relative to coniferyl alcohol. However, exogenously supplied cinnamic, p-coumaric, caffeic, and ferulic acids resulted only in increases in their intercellular concentrations, but not that of downstream cinnamyl aldehydes and monolignols. Supplying p-coumaryl and coniferyl aldehydes up to 40, 000-320,000-fold above the detection limits resulted in rapid, quantitative conversion into the monolignols. Only at nonphysiological concentrations was transient accumulation of intracellular aldehydes observed. These results indicate that cinnamic and p-coumaric acid hydroxylations assume important regulatory positions in phenylpropanoid metabolism, whereas cinnamyl aldehyde reduction does not serve as a control point.

Aldehydes↗

PubMed2000

The influence of elevated carbon dioxide and water availability on herbaceous weed development and growth of transplanted loblolly pine (Pinus taeda).

Loblolly pine (Pinus taeda L.) seedlings were grown in competition with native weeds using soil and seed bank collected from recently chopped and burned areas near Appomattox, Virginia. One-year-old seedlings were planted and weeds allowed to germinate from the native seed bank while being exposed to CO(2) (ambient and elevated - approximately 700 ppm) and water (water stressed and well watered) treatments for approximately one growing season in a greenhouse. Elevated CO(2) did not influence total weed biomass; however, C(3) weed community development was favored over C(4) weed community development in elevated CO(2) regardless of water availability. This suggests that weed community composition may shift toward C(3) plants in a future elevated CO(2) atmosphere. Pine growth was significantly greater in the well watered and elevated CO(2) treatments compared to the water stressed and ambient treatments, respectively, even though they were competing with native herbaceous weeds for resources. There was a significant water and CO(2) interaction for pine root:shoot ratio. Under elevated CO(2), root:shoot ratio was significantly greater in the water stressed treatment than the well watered treatment. In contrast, there was no significant difference in the root:shoot ratio under the ambient CO(2) treatment for either water treatment. These results suggest that loblolly pine seedlings will respond favorably in an elevated CO(2) atmosphere, even under dry conditions and competing with herbaceous weeds.

Journal Article↗

PubMed2001

Mean canopy stomatal conductance responses to water and nutrient availabilities in Picea abies and Pinus taeda.

We compared sap-flux-scaled, mean, canopy stomatal conductance (GS) between Picea abies (L.) Karst. in Sweden and Pinus taeda (L.) in North Carolina, both growing on nutritionally poor soils. Stomatal conductance of Picea abies was approximately half that of Pinus taeda and the sensitivity of GS in Picea abies to vapor pressure deficit (D) was lower than in Pinus taeda. Optimal fertilization increased leaf area index (L) two- and threefold in Pinus taeda and Picea abies, respectively, regardless of whether irrigation was increased. Although it increased L, fertilization did not increase GS in Picea abies unless irrigation was also provided. In Pinus taeda growing on coarse, sandy soils, the doubling of L in response to fertilization reduced GS sharply unless irrigation was also provided. The reduction in GS with fertilization in the absence of irrigation resulted from the production of fine roots with low saturated hydraulic conductivity. When Pinus taeda received both fertilization and irrigation, the increase in L was accompanied by a large increase in GS. In Pinus taeda, a reference GS (defined as GS at D = 1 kPa; GSR) decreased in all treatments with decreasing volumetric soil water content (theta). In Picea abies, theta varied little within a treatment, but overall, GSR declined with theta, reaching lowest values when drought was imposed by the interception of precipitation. Despite the large difference in GS both between Picea abies and Pinus taeda and among treatments, stem growth was related to absorbed radiation, and stem growth response to treatment reflected mostly the changes in L.

Biomass↗

PubMed2003

Comparing EST-based genetic maps between Pinus sylvestris and Pinus taeda.

A genetic map of Pinus sylvestris was constructed using ESTP (expressed sequence tag polymorphism) markers and other gene-based markers, AFLP markers and microsatellites. Part of the ESTP markers (40) were developed and mapped earlier in Pinus taeda, and additional markers were generated based on P. sylvestris sequences or sequences from other pine species. The mapping in P. sylvestris was based on 94 F(1) progeny from a cross between plus-tree parents E635C and E1101. AFLP framework maps for the parent trees were first constructed. The ESTP and other gene sequence-based markers were added to the framework maps, as well as five published microsatellite loci. The separate maps were then integrated with the aid of AFLPs segregating in both trees (dominant segregation ratios 3:1) as well as gene markers and microsatellites segregating in both parent trees (segregation ratios 1:1:1:1 or 1:2:1). The integrated map consisted of 12 groups corresponding to the P. taeda linkage groups, and additionally three and six smaller groups for E1101 and E635C, respectively. The number of framework AFLP markers in the integrated map is altogether 194 and the number of gene markers 61. The total length of the integrated map was 1,314 cM. The set of markers developed for P. sylvestris was also added to existing maps of two P. taeda pedigrees. Starting with a mapped marker from one pedigree in the source species resulted in a mapped marker in a pedigree of the other species in more than 40% of the cases, with about equal success in both directions. The maps of the two species are largely colinear, even if the species have diverged more than 70 MYA. Most cases of different locations were probably due to problems in identifying the orthologous members of gene families. These data provide a first ESTP-containing map of P. sylvestris, which can also be used for comparing this species to additional species mapped with the same markers.

Base Sequence↗

PubMed2003

Apparent homology of expressed genes from wood-forming tissues of loblolly pine (Pinus taeda L.) with Arabidopsis thaliana.

Pinus taeda L. (loblolly pine) and Arabidopsis thaliana differ greatly in form, ecological niche, evolutionary history, and genome size. Arabidopsis is a small, herbaceous, annual dicotyledon, whereas pines are large, long-lived, coniferous forest trees. Such diverse plants might be expected to differ in a large number of functional genes. We have obtained and analyzed 59,797 expressed sequence tags (ESTs) from wood-forming tissues of loblolly pine and compared them to the gene sequences inferred from the complete sequence of the Arabidopsis genome. Approximately 50% of pine ESTs have no apparent homologs in Arabidopsis or any other angiosperm in public databases. When evaluated by using contigs containing long, high-quality sequences, we find a higher level of apparent homology between the inferred genes of these two species. For those contigs 1,100 bp or longer, approximately 90% have an apparent Arabidopsis homolog (E value < 10-10). Pines and Arabidopsis last shared a common ancestor approximately 300 million years ago. Few genes would be expected to retain high sequence similarity for this time if they did not have essential functions. These observations suggest substantial conservation of gene sequence in seed plants.

3' Untranslated Regions↗

PubMed2004

Structural characterization of lignin during Pinus taeda wood treatment with Ceriporiopsis subvermispora.

Pinus taeda wood chips were biotreated with Ceriporiopsis subvermispora under solid-state fermentation for periods varying from 15 to 90 days. Milled wood lignins extracted from sound and biotreated wood samples were characterized by wet-chemical and spectroscopic techniques. Treatment of the lignins by derivatization followed by reductive cleavage (DFRC) made it possible to detect DFRC monomers and dimers that are diagnostic of the occurrence of arylglycerol-beta-O-aryl and beta-beta, beta-5, beta-1, and 4-O-5 units in the lignin structure. Quantification of these DFRC products indicated that beta-O-aryl cleavage was a significant route for lignin biodegradation but that beta-beta, beta-5, beta-1, and 4-O-5 linkages were more resistant to the biological attack. The amount of aromatic hydroxyls did not increase with the split of beta-O-4 linkages, suggesting that the beta-O-4 cleavage products remain as quinone-type structures as detected by UV and visible spectroscopy. Nuclear magnetic resonance techniques also indicated the formation of new substructures containing nonoxygenated, saturated aliphatic carbons (CH(2) and CH(3)) in the side chains of lignins extracted from biotreated wood samples.

Biodegradation, Environmental↗

PubMed1993

Lignification in cell suspension cultures of Pinus taeda. In situ characterization of a gymnosperm lignin.

Pinus taeda suspension cultures grown in medium containing 2,4-dichlorophenoxyacetic acid showed only primary cell wall formation and essentially no lignification, as determined by histochemical, ultrastructural, chemical, and NMR spectroscopic analyses. However, these cultures maintained a functional phenylpropanoid pathway as demonstrated by formation of the lignans (-)-matairesinol and (-)-pinoresinol. Administration of [1-13C]Phe to these cultures, followed by solid-state carbon-13 NMR spectral analysis of their cell walls, demonstrated that the phenylalanine incorporated into the cell wall matrix was primarily as protein, rather than lignin. Successive transfer of the 2,4-dichlorophenoxyacetic acid-grown cultures to alpha-naphthaleneacetic acid-containing medium induced cell wall thickening concomitant with lignification. The presence of lignin was confirmed by histochemical, ultrastructural, chemical, biochemical, and NMR spectroscopic analyses. Specific labeling of the lignin polymer in situ with [1-13C]-, [2-13C]-, and [3-13C]Phe and analysis of the cell wall preparations by solid-state carbon-13 NMR spectroscopy permitted the first direct determination of the in situ bonding patterns in a gymnosperm lignin. Several dominant interunit linkages were observed, including beta-O-aryl, furanofuran, phenylcoumarin, and phenolic-linked monolignols, consistent with those predicted but hitherto not proven. Finally, milled wood lignin derivatives prepared from these 13C-specifically enriched lignin tissues gave a relatively high fidelity copy of the native lignin.

Cell Wall↗

PubMed1986

Evidence of competition for photosynthates between growth processes and oleoresin synthesis in Pinus taeda L.

A group of 10 pines (Pinus taeda L.) in a 35-year-old stand in Central Louisiana was sampled periodically from March through December 1984 for oleoresin flow from small wounds. Oleoresin yield was closely associated with periods of calculated moderate soil water deficit and presumed growth reduction. The period of maximum oleoresin flow coincided with the period of calculated maximum soil water depletion. Calculated potential evapotranspiration reached a maximum in late June, but water deficits did not reach maximum levels until September. Apparently, moderate seasonal water deficits that limit growth, but do not limit photosynthesis and translocation of photosynthates, favor differentiation processes, such as oleoresin synthesis. Because oleoresin is a primary defense against southern pine beetle (Dendroctonus frontalis Zimm.) attack in pines, recognition of these relationships should contribute to an understanding of southern pine beetle-host tree interactions.

Journal Article↗

PubMedDate not supplied

Three highly oxygenated caryophyllene sesquiterpenes from Pestalotiopsis sp., a fungus isolated from bark of Pinus taeda.

A Pestalotiopis sp. was isolated from the trunk bark of Pinus taeda. The fungus was cultivated in liquid medium and produced three highly oxygenated caryophyllene sequiterpene derivatives, named pestalotiopsolide A, taedolidol and 6-epitaedolidol, respectively. The sesquiterpenes were isolated by silica gel based chromatographic procedures and their structures were elucidated by NMR spectroscopic data.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2002

The role of the megagametophyte in maintaining loblolly pine (Pinus taeda L.) seedling arginase gene expression in vitro.

Following loblolly pine (Pinus taeda L.) seed germination, storage-protein breakdown in the megagametophyte and in the seedling results in a large increase in the seedling's free amino acid pool. A substantial portion of both the storage proteins and the amino acid pool is arginine, a very efficient nitrogen-storage compound. Free arginine is hydrolyzed in the seedling by the enzyme arginase (EC 3.5.3.1), which is under strong developmental control. At present, regulation of arginase in conifers is not well understood. Here we report the utilization of an in vitro culture system to address the separate impacts of the seedling and megagametophyte tissues on arginase enzyme activity, protein levels and patterns of gene expression. We also describe the generation of an anti-arginase antibody prepared from a histidine-tagged loblolly pine arginase fusion protein expressed in Escherichia coli. Our results indicate that arginase gene expression in the seedling is initiated by the seedling itself and then maintained or up-regulated by the megagametophyte. The contribution of storage-protein breakdown and the free amino acid pool, particularly arginine, in this regulation is also addressed.

Arginase↗

PubMed2000

Microsatellite analysis of Pinus taeda L. in Zimbabwe.

Deducing the origin of early 20th century introductions of Pinus taeda into Zimbabwe is possible given microsatellite markers and clear population differentiation in ancestral U.S. populations. This study was designed to determine whether P. taeda introductions into Zimbabwe came from one U.S. region or whether the present-day population is an admixture of introductions from east and west of the Mississippi River Valley. Principal components analysis, Cavalli-Sforza and Edwards' chord distances and presence of diagnostic alleles each indicate that the Zimbabwe population is an admixture. There were five novel alleles in the Zimbabwe population not represented in the indigenous U.S. populations, possibly because of de novo mutation, introgression with other introduced North American pines or sampling error.

Alleles↗

PubMed2003

Somatic embryogenesis in loblolly pine (Pinus taeda L.): improving culture initiation with abscisic acid and silver nitrate.

Loblolly pine ( Pinus taeda L.) culture initiation was improved by the addition of abscisic acid (ABA) (3.7 micro M), silver nitrate (20 micro M), and guanosine 3',5'-cyclic monophosphate, 8-bromo-, sodium salt (10 micro M) to the medium and by raising cytokinin levels in the presence of 50 mg/l activated carbon (AC). Basal medium contained modified 1/2-P6 salts, 50 mg/l AC, Cu and Zn added to compensate for adsorption by AC, 1.5% maltose, 2% myo-inositol, 500 mg/l casamino acids, 450 mg/l glutamine, 2 mg/l alpha-naphthaleneacetic acid (NAA), 0.55 mg/l 6-benzylaminopurine (BA), 0.53 mg/l kinetin, and 2 g/l Gelrite. Across 32 open-pollinated families initiation ranged from 0 to 53.4%, with an average of 17.9%. Further optimization of cytokinins to 0.63 mg/l BA and 0.61 mg/l kinetin along with the removal of ABA maintained initiation at 18.2% across 19 families. Survival of 2001 new initiations was tracked for 4-6 months. Survival averaged 28.8%. A test of 68 new initiations tracked closely for 4 months demonstrated that at least 80% of the cultures lost did not grow after transfer to the multiplication media, suggesting that many new initiations abort during the initiation process.

Abscisic Acid↗

PubMed2003

Aux/IAA gene family is conserved in the gymnosperm, loblolly pine (Pinus taeda).

We isolated five members of the Aux/IAA gene family in loblolly pine (Pinus taeda L.). Degenerate primers complementary to conserved regions of angiosperm Aux/IAA genes were used to amplify fragments that were, in turn, used as probes to screen a cDNA library constructed from auxin-treated hypocotyls. The five unique clones, named PTIAA1-5, contain the four highly conserved domains that are characteristic of the Aux/IAA proteins. All clones contain the bipartite nuclear localization signal (NLS) between Domains I and II that is predicted in most angiosperm Aux/IAA genes, but only one, PTIAA2, contains the conserved NLS in Domain IV. The five invariant residues in Domain II that have been found to constitute part of a protein destabilization element in Arabidopsis thaliana (L.) Heynh. are conserved in all the PTIAAs. A postulated phosphorylation site located between Domains I and II and proximal to the conserved bipartite NLS was conserved in 20 out of 36 genes in this analysis, including the pine genes. Transcripts of all five PTIAAs accumulated specifically in the hypocotyls in response to exogenous auxin treatment and were induced by all auxins tested. Transcript abundance above basal levels in response to 1-naphthaleneacetic acid treatment was first detected after 10 min (PTIAA3) to 3 h (PTIAA2) in the different genes and remained above basal levels throughout 7 days. Induction of PTIAA2 was inhibited by the protein synthesis inhibitor cycloheximide, indicating that PTIAA2 is a secondary response gene. Phylogenetic analysis showed that all five pine genes clustered within a single class (Class I) of the dendrogram. Clone PTIAA2 has a sequence that is relatively distinct from the other four and is the most closely related to the angiosperm genes of Class I. Class I contains both primary and secondary auxin response genes, suggesting that it is the original lineage and that other gene classes have evolved subsequent to the angiosperm/gymnosperm divergence.

Amino Acid Sequence↗

PubMed2002

Ozone impacts on loblolly pine (Pinus taeda L.) grown in a competitive environment.

One-year old, bare-root, loblolly pine (Pinus taeda L.) seedlings grown in an early successional plant community, were exposed to four ozone treatments, 12 h day(-1) (09:00-21:59 h CST), 7 day week(-1) in east-central Alabama for 2 years (1994-1995). Treatments included AA=ambient air (open plot; no chamber), CF = carbon-filtered air (approximately 0.5xAA), 1X = non-filtered air, and 2X = twice ambient (AA) air. Pine height and diameter were measured monthly for 2 years and total above-ground biomass determined at termination of the experiment. In addition, height, diameter and volume (d2h) growth was modeled for the 2-year study. Trees growing in the CF chambers exhibited the least growth for any variable measured. The predicted height growth rate (r) was the least for the CF- and 2X-treated pines when compared with the AA and 1X treatments. In addition, percent total vegetative cover was significantly negatively correlated with height. diameter and volume growth in 1994, but not 1995. Our findings regarding the trees growing in the CF treatments, are contrary to previous reports regarding ozone impacts to loblolly pine grown without competition from other vegetation.

Dose-Response Relationship, Drug↗