Needles Of Pinus Radiata Research Articles

Electrical pruning of Pinus radiata epicormic growths

A novel method for pruning epicormic growths with high voltage energy pulses is presented. This method could be utilized in autonomous forest management, for example by a drone carrying an electrical pulse generator and applicator pruning device. In a laboratory setting, short duration, high voltage pulses of electricity were generated using a capacitor network and a current source. These pulses were applied to Pinus radiata needles and the relative tissue injury to the needles was assessed by estimating electrolyte leakage from the needles in deionised water using electrical conductivity (EC) measurements. EC was positively correlated with the electrical energy applied. This validated the theory that electrical stimuli can cause increased cell death in plant matter. The cell damage, based on electrolyte leakage, caused by stimulating a Pinus radiata needle with a single 1.5 J pulse of energy was 21 % of the maximum, where the maximum was found to result in an EC of 333 µS/cm per gramme of needle in a 45 ml solution. These results from testing on needles removed from the tree confirm the potential of electrical pruning of epicormic growths. Future testing on live in-situ needles will be implemented to determine the level at which cell death induced by the application of high voltage pulses is sufficient to prune epicormic growths, given that mechanical and biotic factors of needles removed from the tree may enhance the rate of cell death in harvested samples.

Seasonal Terpene Variation in Needles of Pinus radiata (Pinales: Pinaceae) Trees Attacked by Tomicus piniperda (Coleoptera: Scolytinae) and the Effect of Limonene on Beetle Aggregation.

Concentrations of four monoterpenes were determined in needles of Pinus radiata (D.Don) (Pinales: Pinaceae) trees that were attacked or nonattacked by Tomicus piniperda (L.) (Coleoptera: Scolytinae). Compounds were identified and quantified by gas chromatography–mass spectrometry. The mean ambient temperature was obtained using climate-recording data loggers. The effect of limonene on field aggregation was also evaluated at three limonene release rates using Lindgren attractant-baited traps and trap logs. Attacked trees produced less α-pinene in March, July, and November than nonattacked trees, less β-pinene in July and November, and less limonene from May to November. Limonene reduced the attraction of T. piniperda to attractant-baited traps and trap logs. Results were linked to better responses to high temperatures, with respect to terpene contents, by the nonattacked trees after the spring attack.

Diversity and identification of fungi associated with needles of Pinus radiata in Tasmania

Needle fungi have been extensively studied in conifers but rarely in Pinus radiata. Previous studies of P. radiata have been based on fungal isolation and not direct PCR detection from needles. This research was a component of a study examining factors linked to spring needle cast (SNC) in Tasmanian P. radiata plantations and aimed to identify as many as possible of the fungal species commonly associated with P. radiata needles in Tasmanian plantations. Needle samples were collected from 13 sites representative of the range of sites in which P. radiata is grown in Tasmania. Fungi were detected by a direct PCR approach and identified using barcode sequences from a reference collection of isolates from Tasmania, mainland Australia and New Zealand as well as sequences from the international nucleotide sequence databases. The total number of molecular operational taxonomic units (MOTUs) was 152, with 127 detected by direct PCR and sequencing, and only 35 operational taxonomic units (OTUs) isolated by culture-based methods. Dothideomycetes was the most diverse class detected in this study, with many MOTUs detected by direct PCR and not isolated. Leotiomycetes was the second-most diverse class and Sordariomycetes third, with several OTUs frequently isolated but rarely or not at all detected by direct PCR. DNA sequence data facilitated the discrimination and identification of OTUs, but some effort was required to avoid confusion caused by poorly identified isolates in public DNA databases. This is the most comprehensive study yet of fungi associated with pine needles in Australia and highlights the hitherto unrecognised diversity of Teratosphaeriaceae in P. radiata.

Improving the quality of protein identification in non-model species. Characterization of Quercus ilex seed and Pinus radiata needle proteomes by using SEQUEST and custom databases

Nowadays the most used pipeline for protein identification consists in the comparison of the MS/MS spectra to reference databases. Search algorithms compare obtained spectra to an in silico digestion of a sequence database to find exact matches. In this context, the database has a paramount importance and will determine in a great deal the number of identifications and its quality, being this especially relevant for non-model plant species. Using a single Viridiplantae database (NCBI, UniProt) and TAIR is not the best choice for non-model species since they are underrepresented in databases resulting in poor identification rates. We demonstrate how it is possible to improve the rate and quality of identifications in two orphan species, Quercus ilex and Pinus radiata, by using SEQUEST and a combination of public (Viridiplantae NCBI, UniProt) and a custom-built specific database which contained 593,294 and 455,096 peptide sequences (Quercus and Pinus, respectively). These databases were built after gathering and processing (trimming, contiging, 6-frame translation) publicly available RNA sequences, mostly ESTs and NGS reads. A total of 149 and 1533 proteins were identified from Quercus seeds and Pinus needles, representing a 3.1- or 1.5-fold increase in the number of protein identifications and scores compared to the use of a single database. Since this approach greatly improves the identification rate, and is not significantly more complicated or time consuming than other approaches, we recommend its routine use when working with non-model species. In this work we demonstrate how the construction of a custom database (DB) gathering all available RNA sequences and its use in combination with Viridiplantae public DBs (NCBI, UniProt) significantly improve protein identification when working with non-model species. Protein identification rate and quality is higher to those obtained in routine procedures based on using only one database (commonly Viridiplantae from NCBI), as we demonstrated analyzing Quercus seeds and Pine needles. The proposed approach based on the building of a custom database is not difficult or time consuming, so we recommend its routine use when working with non-model species. This article is part of a Special Issue entitled: Proteomics of non-model organisms.

The antibacterial efficacy of pine oils on pathogens commonly found in biosolids applied to pine plantations

This study investigated the antibacterial activity of oils from the needles of Pinus radiata, Pinus pinaster, Pinus nigra and Pinus sylvestris against strains of Escherichia coli, Salmonella spp. and Clostridium perfringens present in biosolids. The results showed that pine oil from fresh needles of P. radiata and P. pinaster trees have antibacterial properties against biosolids strains of E. coli and Salmonella spp. No potential antibacterial activity against C. perfringens was observed. Commercially produced pine oils, P.nigra and P. sylvestris oil had similar antibacterial actions to P. radiata and P. pinaster oil for E. coli.

Accumulation of polycyclic aromatic hydrocarbons and heavy metals in the tree foliage of Eucalyptus rostrata, Pinus radiata and Populus hybridus in the vicinity of a large aluminium smelter in Argentina

A pollution gradient of polycyclic aromatic hydrocarbons (PAHs) was observed in tree foliage sampled in the vicinity of a large aluminium production facility in Patagonia (Argentina). Leaves of Eucalyptus rostrata, Populus hybridus and one-year-old needles of Pinus radiata were collected, and concentrations of 12 PAHs including the so-called EPA priority pollutants as well as heavy metals (Cd, Cu, Fe, Mn, Ni and Zn) were analysed. The PAH concentrations indicated a steep pollution gradient in the study area associated with the Al-industry, while the heavy metal content was unrelated to this activity. The present study confirms that aluminium smelting results in the deposition of PAH in the study area, and therefore further studies should be carried out taking into account the potentially adverse effects of these compounds on human and ecosystem health.

Combined Proteomic and Transcriptomic Analysis Identifies Differentially Expressed Pathways Associated to Pinus radiata Needle Maturation

Needle differentiation is a very complex process that leads to the formation of a mature photosynthetic organ from pluripotent needle primordia. The proteome and transcriptome of immature and fully developed needles of Pinus radiata D. Don were compared to described changes in mRNA and protein species that characterize the needle maturation developmental process. A total of 856 protein spots were analyzed, defining a total of 280 spots as differential between developmental stages, from which 127 were confidently identified. A suppressive subtractive library (2048 clones, 274 non redundant contigs) was built, and 176 genes showed to be differentially expressed. The Joint data analysis of proteomic and transcriptomic results provided a broad overview of differentially expressed pathways associated with needle maturation and stress-related pathways. Proteins and genes related to energy metabolism pathways, photosynthesis, and oxidative phosphorylation were overexpressed in mature needles. Amino acid metabolism, transcription, and translation pathways were overexpressed in immature needles. Interestingly, stress related proteins were characteristic of immature tissues, a fact that may be linked to defense mechanisms and the higher growth rate and morphogenetic competence exhibited by these needles. Thus, this work provides an overview of the molecular changes affecting proteomes and transcriptomes during P. radiata needle maturation, having an integrative vision of the functioning and physiology of this process.

Variations in DNA methylation, acetylated histone H4, and methylated histone H3 during Pinus radiata needle maturation in relation to the loss of in vitro organogenic capability

Needle differentiation is a very complex process associated with the formation of a mature photosynthetic organ. From meristem differentiation to leaf maturation, gene control must play an important role switching required genes on and off to define tissue functions, with the epigenetic code being one of the main regulation mechanisms. In this work, we examined the connections between the variation in the levels of some epigenetic players (DNA methylation, acetylated histone H4 and histone H3 methylation at Lys 4 and Lys 9) at work during needle maturation. Our results indicate that needle maturation, which is associated with a decrease in organogenic capability, is related to an increase in heterochromatin-related epigenetic markers (high DNA methylation and low acetylated histone H4 levels, and the presence of histone H3 methylated at lys 9). Immunohistochemical analyses also showed that the DNA methylation of palisade parenchyma cell layers during the transition from immature to mature scions is associated with the loss of the capacity to induce adventitious organs.

Frost tolerance and ice formation in Pinus radiata needles: ice management by the endodermis and transfusion tissues.

Conifers are among the most frost tolerant tree species. Cryo-scanning electron microscopy (cryo-SEM) was used to visualise ice formation in pine needles to better understand how conifer leaves manage extracellular ice. Acclimated and unacclimated needles of Pinus radiata (D.Don) were subjected to freezing treatments (at a rate of 2°C h-1), tested for electrolyte leakage and sampled for cryo-SEM analysis. Half maximal electrolyte leakage occurred at -4 and -12°C for unacclimated and acclimated needles, respectively. Ice nucleation occurred at similar temperatures (-3°C) in both acclimated and unacclimated pine needles, indicating that frost tolerance did not increase supercooling. During freezing and thawing, the tissues outside and inside the endodermis shrank and swelled independently, with little or no transfer of water between the two regions. During freezing, mesophyll cells shrank, exhibiting cytorrhysis, and extracellular ice accumulated in gas spaces of the mesophyll tissue. Mesophyll cells from acclimated needles recovered their structure after thawing, and unacclimated mesophyll showed significant damage. In the vascular cylinder, ice accumulated in transfusion tracheids which expanded to occupy areas made vacant by shrinkage of transfusion parenchyma, Strasburger cells and the endodermis. This behaviour was reversible in acclimated tissue, and may play an important role in the management of ice during freeze/thaw events.

Age-related changes in the hormonal status of Pinus radiata needle fascicle meristems

Distinct developmental states in woody trees are associated with different types of plant hormones disclosing a variety of roles throughout ageing and maturation. The plant hormones abscisic and indole-3-acetic acids (ABA and IAA, respectively) as well as several cytokinins (Cks) were analysed to ascertain the effect of maturation processes over the hormonal status in the needle fascicle meristem of Pinus radiata. As plant material, needles from three different ages collected from trees with two different states of reinvigoration, one- and three-time-grafted material, were used. Once-reinvigorated material showed decreasing amounts of ABA, IAA and Cks throughout the needles maturation and ageing. Three-time-reinvigorated material presented the lowest levels of IAA and Cks in the oldest needle fascicle meristems. ABA content was similar in the current-year growth and the latest-year needle fascicle meristems, but a slight increase was obtained in the intermediate developmental state. The ratio of isopentenyladenine-type to zeatin-type Cks, reported as an index of ageing and vigour in previous studies, was ratified in the current work. Results might describe the role of several hormones during ageing and maturation processes, as well as might establish the importance of the different forms of Cks not only during tree ageing, but also throughout organ maturation. Our findings demonstrate that not all cytokinin forms are equally present in the regulation of maturation and ageing.

Age-related changes in the hormonal status of Pinus radiata needle fascicle meristems

Distinct developmental states in woody trees are associated with different types of plant hormones disclosing a variety of roles throughout ageing and maturation. The plant hormones abscisic and indole-3-acetic acids (ABA and IAA, respectively) as well as several cytokinins (Cks) were analysed to ascertain the effect of maturation processes over the hormonal status in the needle fascicle meristem of Pinus radiata . As plant material, needles from three different ages collected from trees with two different states of reinvigoration, one- and three-time-grafted material, were used. Once-reinvigorated material showed decreasing amounts of ABA, IAA and Cks throughout the needles maturation and ageing. Three-time-reinvigorated material presented the lowest levels of IAA and Cks in the oldest needle fascicle meristems. ABA content was similar in the current-year growth and the latest-year needle fascicle meristems, but a slight increase was obtained in the intermediate developmental state. The ratio of isopentenyladenine-type to zeatin-type Cks, reported as an index of ageing and vigour in previous studies, was ratified in the current work. Results might describe the role of several hormones during ageing and maturation processes, as well as might establish the importance of the different forms of Cks not only during tree ageing, but also throughout organ maturation. Our findings demonstrate that not all cytokinin forms are equally present in the regulation of maturation and ageing.

Variations in dark respiration and mitochondrial numbers within needles of Pinus radiata grown in ambient or elevated CO2 partial pressure.

Within-leaf variations in cell size, mitochondrial numbers and dark respiration rates were compared in the most recently expanded tip, the mid-section and base of needles of Pinus radiata D. Don trees grown for 4 years in open-top chambers at ambient (36 Pa) or elevated (65 Pa) carbon dioxide partial pressure (p(CO2)a). Mitochondrial numbers and respiratory activity varied along the length of the needle, with the highest number of mitochondria per unit cytoplasm and the highest rate of respiration per unit leaf area at the base of the needle. Regardless of the location of the cells (tip, middle or basal sections), needles collected from trees grown in elevated p(CO2)a had nearly twice the number of mitochondria per unit cytoplasm as those grown in ambient p(CO2)a. This stimulation of mitochondrial density by growth at elevated p(CO2)a was greater at the tip of the needle (2.7 times more mitochondria than in needles grown in ambient CO2) than at the base of the needle (1.7 times). The mean size of individual mitochondria was unaffected either by growth at elevated p(CO2)a or by position along the needle. Tree growth at elevated p(CO2)a had a variable effect on respiration per unit leaf area, significantly increasing respiration in the tip of the needles (+25%) and decreasing respiration at the mid-section and base of the needles (-14% and -25%, respectively). Although a simple relationship between respiration per unit leaf area and mitochondrial number per unit cytoplasm was found within each CO2 treatment, the variable effect of growth at elevated p(CO2)a on respiration along the length of the needles indicates that a more complex relationship must determine the association between structure and function in these needles.

Biochemical changes in needles of Pinus radiata D. Don trees in relationship to long-term ozone exposure indices

Ambient concentrations of ozone in Europe are high enough to cause negative effects on vegetation. Therefore, many efforts have been made to determine exposure indices and critical levels for protection of vegetation. In this context, the choice of a suitable attribute to determine the pollutant effect is of paramount importance. Until now, much of the work has been done with attributes such as biomass or growth. In the present work correlation factors have been established between biochemical parameters (peroxidase activity, ascorbate and sulfhydryl contents) of Pinus radiata trees and exposure indices of ozone. Our results show that peroxidase cannot be used as an indicator of effects of long-term exposure to ozone but still remains as an excellent indicator of short-term ozone fluctuations in the field. Ascorbate may act as an intermediate indicator responding to both short fluctuations and long-term exposures to ozone. Finally, sulfhydryl may be used as a long-term indicator in relation to the AOT (average over threshold) exposure index. Our results also point to the fact that Pinus radiata may be affected by ozone at AOT values lower than 10 ppm.h as already observed with other tree species.

Photosynthesis by mature needles of field-grown Pinus radiata

Gas exchange was measured on needles of 14-year-old Pinus radiata in the Australian Capital Territory. The trees were growing at very different rates as a result of different inputs of fertiliser and water. Measurements were taken from late spring (October) 1987 until mid-autumn (April) 1988, a period with little rain and moderate to high temperatures. Despite large differences in needle nitrogen concentration between trees, the major determinant of the light-saturated rate of photosynthesis was water availability. On irrigated trees, the needles had consistently higher assimilation rates, as well as higher stomatal conductances. Light-saturated photosynthesis and stomatal conductance were closely correlated, but the droughted trees had higher instantaneous water-use efficiency, as indicated by the steeper slope of the assimilation versus stomatal conductance relationship. This difference was also seen in intercellular CO 2 partial pressure. which was significantly lower for needles of water-stressed trees than for those on well-watered trees. Stomatal conductance was very sensitive to leaf-to-air vapour pressure deficit, with much higher conductances for needles on irrigated trees for a given vapour pressure deficit. The sensitivity of somatal conductance to vapour pressure deficit declined between spring and autumm. On the few occasions that stomatal conductance exceeded 75 mmol H 2O m −2 s −1, CO 2 uptake was positively correlated with needle nitrogen concentration. Although needle chlorophyll and nitrogen concentrations had high positive correlation, they were weakly associated with photosynthetic rate. These results are generally consistent with much of the literature on conifers, and their implications for plant growth analysis and modelling of Pinus radiata growth are discussed.

Phenology ofOosomus varius(Curculionidae) andPrasoidea sericea(Chrysomelidae) onPinus radiatain the South-western Cape Province

SYNOPSIS Oosomus varius and Prasoidea sericea adults feed on the needles of Pinus radiata planted within or adjacent to fynbos vegetation in the south-western Cape Province. Activity peaks were determined by counting, at weekly intervals, the number of beetles present on 10 young pine trees. The O. varius activity peak occurred in August where 42% of all beetles were active, with 87% of the beetles present in July, August and September. P. sericea also had their activity peak in August when 60 % of all beetles were active, but with August and September alone accounting for 87 % of all beetles. The occurrence of the activity peaks was consistent each year over the five-year study period. This information facilitates the correct timing of prophylactic insecticide sprays.

Regional variation of selected polyaromatic and chlorinated hydrocarbons over the South Island of New Zealand, as indicated by their content in Pinus radiata needles.

We analysed needles of Pinus radiata along three transects through the South Island of New Zealand for chlorinated hydrocarbons ( alpha- and gamma-HCH, HCB and PCB) and PAH (fluoranthene, 3,4-benzopyrene, benzo(ghi)perylene and indenopyrene). At rural sites we also collected samples of moss (Wijkia extenuata) and lichens (Usnea sp.) in order to compare the pollutant concentrations within these plants. A principal component analysis confirmed findings from moss and snow studies in Europe that the PAH concentrations vary regionally in the same way. The pattern of the principal component loadings of the chlorinated hydrocarbons reflects their heterogeneous immission and their different chemodynamics. The regional pattern indicates an increase of gamma-HCH from remote areas to those used intensively for agriculture and gardening, followed by a decrease towards the inner city of Christchurch. In contrast, PCB and PAH show their highest levels of contamination in the city. The regional distribution of PAH in Christchurch correlates well with traffic density, and particularly with the pattern of smoke from domestic fires. Our study demonstrates that needles of P. radiata can be better monitors of atmospheric pollution in New Zealand than mosses or lichens.

Proteinaceous deposits in primary vascular parenchyma cells in Pinus radiata needle traces.

The cytoplasm of the primary vascular parenchyma cells of Pinus radiata short shoots contains proteinaceous deposits which appear granular in composition and are not membrane limited. ER-derived sacs containing proteinaceous material and showing breaks in their limiting membrane are often found in proximity to proteinaceous deposits. Stages suggestive of the transformation of rough ER into sacs are identifiable. It is suggested that ER-derived sacs migrate to a site in the cytoplasm where they release their contents following the rupture of their limiting membrane.

The relationship between deuterium and oxygen-18 delta values in leaf water

The relationship between 180 and deuterium delta values in plant leaves has been studied under laboratory conditions. Our results, in agreement with some earlier studies on fruit juices, show that lines of slope much lower than expected from experiments with evaporating water bodies, are obtained. For needles of Pinus radiata grown under semi-arid conditions, slopes as low as 1.3 were obtained. These low slopes can be reconciled by using a model similar to one developed for lakes subject to evaporation under differing conditions.

The relationship between deuterium and oxygen-18 delta values in leaf water

The relationship between 180 and deuterium delta values in plant leaves has been studied under laboratory conditions. Our results, in agreement with some earlier studies on fruit juices, show that lines of slope much lower than expected from experiments with evaporating water bodies, are obtained. For needles of Pinus radiata grown under semi-arid conditions, slopes as low as 1.3 were obtained. These low slopes can be reconciled by using a model similar to one developed for lakes subject to evaporation under differing conditions.

Sulphur isotope ratio studies in a geothermal region

δ 34S Data have been obtained for rainwater, soils and the needles of Pinus radiata growing in a New Zealand geothermal region. It appears that most of the sulphur in P. radiata needles was soil-derived with a possible contribution from geothermal droplet sulphate in areas close to geothermal boreholes. Hydrogen sulphide contributions to plant nutrient sulphur in this geothermal region appear to be largely via the soil. The 34S-content of the soils of the geothermal region are depleted with respect to most other New Zealand soils probably because of their volcanic origin.