Abscisic acid from Pinus densiflora pollen

(+)-Abscisic acid was isolated as the methyl ester from Pinus densiflora pollen and identified spectroscopically.     

Dehydrochorismic Acid from Pinus densiflora Pollen

A human opioid peptide hormone, β-endorphin, was expressed in Escherichia coli as the C-terminal portion of a fused protein. The fused protein consisting of the N-terminal 62% of E. coli anthranilate synthetase (323 amino acids), a peptide corresponding to the linker DNA (7 amino acids), and the precursor form of β-endorphin (47 amino acids), was highly expressed under the control of a tryptophan promoter. The level of expression of β-endorphin was estimated to be 17 mg/liter broth by radioimmunoassay, and 51 mg/liter broth by SDS polyacrylamide gel electrophoresis followed by a densitometric analysis. β-Endorphin was cleaved from the fused protein and purified by HPLC, and is presumed to be identical with human β-endorphin because of its amino acid composition and amino acid sequence.     

Two new triterpenoids from the roots of Pinus densiflora

Chemical investigation of the roots of Pinus densiflora led to the isolation of two new triterpenoids, (24S)-3β-methoxy-24,25-epoxy-lanost-9(11)-ene (1) and 29-acetoxy-3α-methoxyserrat-14-en-21α-ol (2), together with three known serratene-type triterpenoids (3–5) and four known diterpenoids (6–9). Their structures were determined by spectroscopic analyses.     

天然赤松个体生物量的研究

对延边地区不同密度天然赤松林中不同生长势的赤松个体地上部生物量进行了研究。结果表明,不同生长势赤松生物量变化受密度影响的顺序为：优势木〈平均木〈被压木;各器官生物量分配比例受密度影响的顺序为：干〉枝〉叶〉皮。不同生长势赤松的生物量垂直分布虽然各具特点,但都表现为：树干和树皮生物量主要分布在６ｍ树高范围内,树枝则集中在６～１０ｍ范围,针叶在上、中、下３层林冠中均分,上层林冠的枝叶量受密度影响最小。     

Enhancement of somatic embryogenesis and plant regeneration in Japanese red pine (Pinus densiflora)

The highest proliferation rate (9.8-fold) of embryogenic suspensor mass (ESM) was obtained from half-strength Litvay (½LM, Litvay et al. 1985) medium supplemented with 3.42 mM l-glutamine, while the lowest rate was noted when 0.84 mM l-glutamine (0.6-fold) was added to the medium. The highest growth ratio with brassinolide (BL) was observed for 1.0 μM (2.3-fold, line 05-21) and 0.05 μM (2.9-fold, line 06-22). However, in the ESM lines 05-21 and 06-22, high ESM growth rates (2.3-fold, line 05-21 and 2.1-fold, line 06-3) were seen without BL when compared with 1.0 μM (05-21) or 0.05 μM (06-22). BL-supplemented medium has been shown to have diverse, genotype-specific effects on the degree of ESM proliferation. For somatic embryo maturation with 0.05 % activated charcoal (AC), the highest number (798 g^?1 FW) of cotyledonary somatic embryos (line 06-29) were obtained on a maturation medium supplemented with AC. The influence of light-emitting diode (LED) sources on the germination of somatic embryos (four genotypes) in this species was studied and was strongly genotype-dependent. Germination of somatic embryos from ESM line 05-3 was strongly inhibited by fluorescent, and red + blue light, while lines 05-12, 05-29, and 05-37 showed a similar germination frequency for the five LED sources, where red light most stimulated somatic embryo germination.     

Changes in Nucleic Acid Fractions of Seed Components of Red Pine (Pinus resinosa Ait.) during Germination

Changes in nucleic acid fractions of Pinus resinosa during seed germination were studied. At various stages of seed germination, embryos and megagametophytes were surgically separated and nucleic acids were extracted separately by a phenol-method. Total nucleic acids were fractionated on single-layer methylated albumin kieselguhr (MAK) columns. Total nucleic acids in embryos increased significantly 2 days after seeds were moistened, whereas, in megagametophytes, total nucleic acids stayed almost at a constant level until they degenerated at the time of shedding. In embryos, ribosomal RNAs (rRNA) increased 2 days after seeds were sown, whereas soluble RNA (sRNA) increased at 3 days. By comparison, nucleic acid fractions of megagametophytes did not show any quantitative changes during germination, except that rRNA fractions decreased shortly before shedding of seed coats. In dormant embryos the proportion of DNA was high and the proportions of sRNA and rRNA were low, whereas in megagametophytes at dormancy the proportions were completely reversed. As seed germination progressed, proportions of nucleic acid fractions in embryos changed significantly. In megagametophytes, although proportions of individual fractions remained almost constant throughout the experimental period, incorporation of ³²P into sRNA and rRNA of megagametophytes indicated turnover of these fractions.     

Rangewide Genetic Diversity in Natural Populations of Chinese Pine (Pinus tabulaeformis)

Thirteen natural populations from throughout the range of the Chinese pine (Pinus tabulaeformis Carr.) were examined using inter-simple sequence repeat markers to characterize the genetic structure at the species level and to compare the extent and distribution of genetic variation among central, intermediate, and marginal populations. Although the total genetic variation in the Chinese pine was mainly maintained within populations, the genetic differentiation among populations was significant (P < 0.001). The genetic divergence was significantly correlated with geographic distance (P < 0.05). Genetic diversity tended to decrease from the central to intermediate and marginal populations. The marginal populations had significantly lower intrapopulation genetic diversity than central populations (P < 0.05). Cluster analysis based on Nei’s unbiased genetic distances confirmed the difference among four central populations and the rest. Both historical and contemporary factors may have played key roles in shaping the spatial genetic structure of this species.     

Indole-3-acetic acid producing root-associated bacteria on growth of Brazil Pine (Araucaria angustifolia) and Slash Pine (Pinus elliottii)

Araucaria forests in Brazil today correspond to only 0.7 % of the original 200 km² of natural forest that covered a great part of the southern and southeastern area of the Atlantic Forest and, although Araucaria angustifolia is an endangered species, illegal exploitation is still going on. As an alternative to the use of hardwoods, Pinus elliottii presents rapid growth and high tolerance to climatic stress and low soil fertility or degraded areas. Thus, the objective of this study was to evaluate the effect of IAA-producing bacteria on the development of A. angustifolia and P. elliottii. We used five bacterial strains previously isolated from the rhizosphere of A. angustifolia, which produce quantities of IAA ranging from 3 to 126 μg mL^?1. Microbiolized seeds were sown in a new gnotobiotic system developed for this work, that allowed the quantification of the plant hormone IAA produced by bacteria, and the evaluation of its effect on seedling development. Also, it was shown that P. elliottii roots were almost as satisfactory as hosts for these IAA producers as A. angustifolia, while different magnitudes of mass increases were found for each species. Thus, we suggest that these microbial groups can be helpful for the development and reestablishment of already degraded forests and that PGPR isolated from Araucaria rhizosphere have the potential to be beneficial in seedling production of P. elliottii. Another finding is that our newly developed gnotobiotic system is highly satisfactory for the evaluation of this effect.     

Plasticity in Dendroclimatic Response across the Distribution Range of Aleppo Pine (Pinus halepensis)

We investigated the variability of the climate-growth relationship of Aleppo pine across its distribution range in the Mediterranean Basin. We constructed a network of tree-ring index chronologies from 63 sites across the region. Correlation function analysis identified the relationships of tree-ring index to climate factors for each site. We also estimated the dominant climatic gradients of the region using principal component analysis of monthly, seasonal, and annual mean temperature and total precipitation from 1,068 climatic gridpoints. Variation in ring width index was primarily related to precipitation and secondarily to temperature. However, we found that the dendroclimatic relationship depended on the position of the site along the climatic gradient. In the southern part of the distribution range, where temperature was generally higher and precipitation lower than the regional average, reduced growth was also associated with warm and dry conditions. In the northern part, where the average temperature was lower and the precipitation more abundant than the regional average, reduced growth was associated with cool conditions. Thus, our study highlights the substantial plasticity of Aleppo pine in response to different climatic conditions. These results do not resolve the source of response variability as being due to either genetic variation in provenance, to phenotypic plasticity, or a combination of factors. However, as current growth responses to inter-annual climate variability vary spatially across existing climate gradients, future climate-growth relationships will also likely be determined by differential adaptation and/or acclimation responses to spatial climatic variation. The contribution of local adaptation and/or phenotypic plasticity across populations to the persistence of species under global warming could be decisive for prediction of climate change impacts across populations. In this sense, a more complex forest dynamics modeling approach that includes the contribution of genetic variation and phenotypic plasticity can improve the reliability of the ecological inferences derived from the climate-growth relationships.     

山东赤松种群的数量动态

通过静态生命表分析赤松（Ｐｉｎｕｓ ｄｅｎｓｉｆｌｏｒａ Ｓｉｅｂ．ｅｔ Ｚｕｃｃ．）种群的生命结构与数量动态。结果表明,赤松种群具有不同年龄等级结构,死亡高峰出现在５～１５年,此时正是幼龄期向成年期的过渡阶段,度过此阶段的赤松个体大多能达到生理寿命。由此看出,赤松种群静态生命表能较精确地反映赤松种群的数量动态规律。     

Purification and Characterization of Catalase from Loblolly Pine (Pinus taeda L.) Megagametophytes

Catalase (EC 1.11.1.6) was purified to near homogeneity from isolated megagametophytes of germinated loblolly pine (Pinus taeda L.) seeds, and monospecific antibodies were elicited in rabbits. Following a procedure that involved acetone extraction, (NH4)2SO4 fractionation, and four chromatographic steps (i.e. DE-52 cellulose, Superdex-200, hydroxylapatite, and phenyl-Sepharose CL-4B), catalase was purified about 140-fold to a final specific activity of 2215 mmol min-1 mg-1 of protein. Cotton isocitrate lyase antibodies were used, and protein immunoblots revealed that the resolution on hydroxylapatite and phenyl-Sepharose allowed for the complete separation of catalase from contaminating isocitrate lyase. The molecular masses of the native enzyme and its subunit are 235 and 59 kD, respectively, indicating that the pine holoenzyme is a homotetramer. Loblolly pine catalase exists as multiple isoforms. When megagametophytes taken 7 d after imbibition at 30[deg]C were extracted, subjected to nondenaturing isoelectric focusing, and stained for catalase activity, at least four catalase isoforms were observed, including one dominant form with an isoelectric point of 6.87. Purified pine catalase is not a glycoprotein and has a ratio of absorbance at 208 nm to absorbance at 405 nm of 1.5. When probed with loblolly pine catalase antibodies, protein blots of cell-free extracts from megagametophytes of mature, stratified, and germinated loblolly pine seeds, the megagametophyte glyoxysomal fraction, and purified loblolly pine catalase all revealed one immunoreactive 59-kD polypeptide. This indicates that no detectable change in the enzyme's monomeric molecular mass occurs during seed stratification and germination, early seedling growth, and purification.     

Micropropagation of adult Stone Pine (Pinus pinea L.)

This paper describes a micropropagation protocol for in vitro propagation of mature Stone Pine trees. Axillary bud development was achieved by culturing bud explants in media containing various cytokinins. Experiments were conducted to test the effect of asepsis conditions, type and concentration of cytokinin and rooting protocol. Four cytokinins were tested, namely, benzyladenine, meta-topolin, N-benzyl-9-(2-tetrahydropyranyl)-adenine and thidiazuron (TDZ) of which TDZ gave the best results, as 59% shoot development was obtained following the application of 1 μM TDZ to the culture medium. The shoot development was significantly influenced by the genotype of the tree, but was effective in explants from all 20 genotypes used in the trial. In vitro rooting was, however, difficult to achieve and could only be induced at low rates. This protocol represents the first successful biotechnological approach to the micropropagation of adult Pinus pinea trees. Paloma Moncaleán and Ricardo Javier Ordás contributed equally.     

赤松枯梢病叶内生真菌多样性研究

在微生物层面研究枯梢病与植物针叶内生微生物的互作关系,分析内生真菌的多样性差异,为松枯梢病的防控提供基础数据。利用高通量测序技术测定赤松(Pinus densiflora)不同染病程度的针叶内生真菌的多样性。结果显示,随着病害的加重,P. densiflora针叶内生真菌丰富度呈现出上升的趋势,多样性指数表现为先下降后上升的趋势。无病斑针叶内生真菌中,子囊菌门(Ascomycota)与担子菌门(Basidiomycota)相对丰度最高,优势属为Lapidomyces和Selenophoma,病害导致优势菌相对丰度的降低。通过对不同染病情况的P. densiflora针叶内生真菌的测定,明确了枯梢病不同发病程度的P. densiflora针叶内生真菌的多样性及群落结构组成。