Secondary Needle Research Articles

Transcriptomic and targeted metabolomic unravelling the molecular mechanism of sugar metabolism regulating heteroblastic changes in Pinus massoniana seedlings

Pine seedling leaf characteristics show a distinct transition from primary to secondary needles, known as heteroblastic change. However, the underlying regulatory mechanism is poorly understood. The molecular mechanism of sugar metabolism involved in regulating heteroblastic changes in Pinus massoniana seedlings was investigated via transcriptomics and targeted metabolomics. The results identified 12 kinds of sugar metabolites in the foliage. Three types of sugar accumulated at the highest levels: sucrose, glucose and fructose. Compared to seedlings with only primary needles (PN), the contents of these soluble sugars were lower in seedlings with developing secondary needle buds (SNB). RNA-seq analysis highlighted 1086 DEGs between PN and SNB seedlings, revealing significant enrichment in KEGG pathways including starch and sucrose metabolism, plant hormone signal transduction and amino sugar and nucleic acid sugar metabolism. Combined transcriptomic and metabolomic analysis revealed that HK, MDH, and ATPase could potentially enhance sugar availability by stimulating the glycolytic/TCA cycle and oxidative phosphorylation. These processes may lead to a reduced sugar content in the foliage of SNB seedlings. We also identified 72 transcription factors, among which the expression levels of MYB, WRKY, NAC and C2H2 family genes were closely related to those of DEGs in the sugar metabolism pathway. In addition, we identified alternative splicing (AS) events in one NAC gene leading to two isoforms, PmNAC5L and PmNAC5S. PmNAC5L was significantly upregulated, while PmNAC5S was significantly downregulated in SNB seedlings. Overall, our results provide new insights into how sugar metabolism is involved in regulating heteroblastic changes in pine seedlings.

Barriers to hepatitis C treatment among secondary needle and syringe program clients and opportunities to intervene

At least 160,000 Australians are living with hepatitis C (HCV), many of whom are people who inject drugs and access needle and syringe programs (NSP). Secondary NSPs provide injecting equipment via health services that are not dedicated to the provision of services to people who inject drugs; these sites could be a suitable space to increase engagement of people who inject drugs in HCV treatment. Drawing on data from a pilot study exploring the potential of upscaling linkage to HCV care in secondary NSPs, the aim of this research was to explore barriers and enablers to HCV treatment for clients who use these services.We interviewed 34 people who inject drugs (who self-reported HCV positivity) from six secondary NSPs in urban and regional Victoria, Australia in 2018. Fifty per cent were male, with ages ranging from 33 to 58. Twenty-two (65%) had never received HCV treatment and none had experience with direct-acting antiviral (DAA) treatment. Interviews were transcribed and analysed thematically. Field notes from a program evaluation with feedback from secondary NSP staff was also used as a secondary data source.Five themes encompassing a set of contrasting barriers and enablers to accessing HCV care through secondary NSPs were uncovered. Themes included 'misinformation' vs. 'multiple trusted information sources; 'lack of symptoms and motivation' vs. 'benefits of cure'; 'competing priorities' vs. 'willingness and readiness to be cured'; 'unsupportive relationships with staff' vs. 'supportive relationships with staff'; and 'inaccessibility and stigma in health services' vs. 'enhanced support'. Secondary program evaluation data also highlighted that secondary NSP staff were under-resourced and had limited capacity to implement HCV care linkage and information.We identified contrasting barriers and opportunities for accessing DAAs among a sample of secondary NSP clients and staff. Interventions that consider individual, provider and health system level factors are needed if secondary NSP services are to become a suitable setting to initiate conversations with clients around HCV treatment and provide linkages to care.

Morphological and Physiological Responses of Pinus massoniana Seedlings to Different Light Gradients

Light intensity is a critical factor regulating photosynthetic capacity in plants. However, the effects of varying light intensity on morphological and photoprotective mechanisms in Pinus massoniana seedlings have not been explored in depth, especially those in the first seedling growing season. We measured the growth, photosynthetic physiology, biochemistry, and chlorophyll fluorescence of P. massoniana seedlings at four light gradients: 100% relative irradiance (RI, full sunlight), 70% RI, 50% RI, and 20% RI. The seedling height at 70% RI was 9.27% higher than that at 100% RI. However, seedling height was inhibited under low light intensity; at 20% RI, all seedlings died. The decreasing light intensity inhibited ground diameter growth but increased the height-diameter ratio. The secondary needle emergence rate was 53.4% higher at 70% RI than at 100% RI but was only 2% at 50% RI. The chlorophyll and carotenoid contents increased significantly with decreasing light intensity. The increased Chl b and Car contents promoted the photoreceptor potential of the violet (400~420 nm), blue (440~480 nm), and yellow-orange (597~655 nm) regions in leaves. Among the chlorophyll fluorescence parameters, Fv/Fm, Fv′/Fm′, Y(II), qp, and ETR all reached maximum values at 70% RI but were significantly lower at 50% RI than at 100% RI. However, decreasing the light intensity caused a reduction in NPQ. The 70% RI level increased POD and SOD activity and the contents of osmotic regulation substances and slowed MDA accumulation. Seedlings at 70% RI had a higher growth rate, higher photosynthetic activity and potential, and significantly greater stress resistance than the other seedlings. Therefore, appropriate shading measures were beneficial to the cultivation of vigorous seedlings. Furthermore, spectral reflectance indexes were found to be a suitable tool for monitoring the photosynthetic physiological characteristics, stress resistance characteristics, and growth status of P. massoniana seedlings in real time.

Effect of aging at 650 °C on microstructure and mechanical properties of GH783 alloy bolt

Taking the GH783 alloy bolt of intermediate pressure main stop valve used in 1000 MW ultra-supercritical unit as the research object, the optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD) and mechanical performance tests were carried out to study the microstructure transformation and mechanical properties of GH783 alloy bolts at different aging stages under 650 °C aging environment. The results showed that the secondary needle β phase began to appear in the bolts aged for 1000 h, and the density of secondary β-phases in bolts aged for 3000 h significantly increased. When the aging time reached up to 20,000 h, the secondary β phase coarsened significantly. At the same time, as the aging time prolonged, the morphology and quantity of the primary β phase changed significantly. In terms of mechanical properties, the tensile strength and impact toughness of the bolts gradually decreased. This was due to the growing γ' phase, the formation of Ni5Al3 phase and the Nb-rich Laves phase in the structure during the aging process.

Rural people who inject drugs: A cross-sectional survey addressing the dimensions of access to secondary needle and syringe program outlets

To better understand issues related to access to injecting equipment for people who inject drugs (PWID) in a rural area of New South Wales (NSW), Australia. Cross-sectional face-to-face survey using convenience and snowball sampling. Six regional and rural population centres in Northern NSW, within the Hunter New England Local Health District. The sample included 190 PWID who had accessed a needle and syringe program outlet within 4weeks of the survey. Data include demographic information, preferred location for accessing injecting equipment, reasons for that preference, whether they obtained enough equipment, travelling distance to an NSP and self-reported hepatitis C virus status. Sixty percent self-identified as Aboriginal people. The median age of respondents was 32years and 60% were men. A significantly larger proportion (P<0.05) of the Aboriginal respondents were women (27% versus 11.6%) and younger (37.6 versus 12.7%) compared to non-Aboriginal respondents. Most preferred to access injecting equipment at a community health facility (62.6%), as opposed to other secondary outlets, where they gained enough equipment (67.4%). Just over 80% said they were tested for HCV in the past year, with about 37% told they had tested positive. There are complex dimensions affecting how rural PWID access secondary NSP outlets. Although access is similarly limited as other rural health services because of the nature of injecting drug use and sensitivities existing in rural communities, there is potential for application of unique access models, such as, promoting secondary distribution networks.

Intradermal naked plasmid DNA immunization: mechanisms of action

Plasmid DNA is a promising vaccine modality that is regularly examined in prime–boost immunization regimens. Recent advances in skin immunity increased our understanding of the sophisticated cutaneous immune network, which revived scientific interest in delivering vaccines to the skin. Intradermal administration of plasmid DNA via needle injection is a simple and inexpensive procedure that exposes the plasmid and its encoded antigen to the dermal immune surveillance system. This triggers unique mechanisms for eliciting local and systemic immunity that can confer protection against pathogens and tumors. Understanding the mechanisms of intradermal plasmid DNA immunization is essential for enhancing and modulating its immunogenicity. With regard to vaccination, this is of greater importance as this routine injection technique is highly desirable for worldwide immunization. This article will focus on the current understanding of the mechanisms involved in antigen expression and presentation during primary and secondary syringe and needle intradermal plasmid DNA immunization.

Influence of Punch Density and Fiber Blends on Thermal Conductivity on Nonwoven

One of the major applications for nonwoven fibrous system is as thermal insulation materials. Many factors may affect thermal properties. This research attempts to study the effects of punch density and fiber blends on heat transfer in nonwoven. For this purpose the samples, whose properties are analyzed by using static methods for measuring their thermal conductivity, were constructed in blends of polyester with polypropylene. The blend ratios are 100% PET, 80/20, 60/40, 40/60, 20/80, and 100% PP. Six samples were produced from each blend by changing the primary needle punch density to115, 135, 155, 175, and 195 punches per cm 2 . The secondary needle punch density was held constant at 120 punches per cm 2 . The temperature of the hot plate, i.e. the applied temperature, was 40°C. Experimental results show that with increasing punch density and pressure, heat transfer decreases. Moreover, the results indicate that the blending of fiber types causes a reduction in fabric heat transfer.

6-Benzyladenine metabolism during reinvigoration of mature Pinus radiata buds in vitro

Maturation or phase change is a serious challenge in the deployment of superior trees of Pinus radiata D. Don because of the difficulties associated with propagation of cuttings from mature trees. We used an in vitro system to study 6-benzyladenine (BA)-induced reinvigoration of the fascicle meristems of mature buds during in vitro culture. Anatomical examinations revealed that BA inhibited the development of secondary needle primordia and 'rejuvenated' the fascicle meristems of the mature bud to produce primary needles, which are characteristic of the juvenile phase in P. radiata. Without BA supplement in the culture media, fascicle primordia continued developing secondary needles and quiescent fascicle meristems. BA metabolite analysis showed that the novel cytokinin pathway reported previously in P. radiata (H. Zhang, K.J. Horgan, P.H.S. Reynolds, G.E. Norris and P.E. Jameson. 2001. Novel cytokinins: The predominant forms in mature buds of Pinus radiata. Physiol. Plant. 112: 127-134) was mirrored in vitro, with BA converted into a variety of metabolites including 6-benzylamino-9-glucopyranosylribosyl-purine and its novel phosphorylated form, 6-benzylamino-9-glucopyranosylribosyl-purine. The culture of mature buds in the presence of BA caused a reduction in the level of endogenous cytokinins, suggesting a direct action of BA itself. Similar correlations are noted between levels of certain metabolites and the maturation status of buds from field-grown trees and buds in culture, indicating that this in vitro system may be a good model for studying the processes of maturation and reinvigoration.

Drug Use and HIV Risk Practices of Secondary and Primary Needle Exchange Users

This study examines HIV risk practices associated with secondary needle exchange, obtaining needles from a needle exchange program (NEP) through others who attend in person. We analyzed data from NEP logs, a survey and HIV testing from 901 drug injectors who (a) always visited NEPs themselves to get needles (primary-only NEP users), (b) obtained at least some NEP needles by having others exchange for them (mixed/secondary NEP users), and (c) obtained no needles from an NEP. About 22% of 40,000 NEP visits involved secondary exchanges, and these accounted for over half of all needles exchanged. In multiple logistic regression analyses, primary-only needle exchange was significantly associated with lower levels of receptive needle sharing, backloading, sharing other injection equipment and lending used needles, and positively associated with obtaining drug treatment. Mixed/secondary needle exchange was associated with less receptive needle sharing and a greater likelihood of drug treatment. Secondary exchange facilitated HIV risk reduction but the salutary effects of NEPs were attenuated in mixed/secondary exchangers.

Requirement for far-red light to maintain secondary needle extension growth in northern but not southern populations of Pinus sylvestris (Scots pine).

Extension growth of secondary needles is under photoperiodic control in Pinus sylvestris. To test for the effects of far-red light on maintaining this extension growth, seedlings of six populations originating from latitudes between 57 degrees and 67 degrees N were raised for 11 weeks in continuous incandescent (metal halogen) light at 300 &mgr;mol m-2 s-1 and 20 degrees C and then transferred at the same temperature to a daily regime of 8 h incandescent light (230 &mgr;mol m-2 s-1) followed by a 16 h day extension with cool white fluorescent light (40 &mgr;mol m-2 s-1, R/FR ratio 7.5) or with incandescent lamps (20 &mgr;mol m-2 s-1, R/FR ratio 2.0). For the seedlings from the three populations north of 64 degrees, needle extension growth over 42 days in the FR-poor day extension treatment was lower by up to 40% than in the FR-rich day extension treatment, whereas for the seedlings from the three southern populations the needle extension growth was similar in both day extension treatments. The requirement for FR in day extensions is characteristic of 'light-dominant' photoperiodic control mechanisms. It appears that P. sylvestris changes from dark-dominant night timekeeping to light-dominant day timekeeping with increasing latitude, as with the photoperiodic control of budset in Picea abies.

Responses of loblolly pine to ozone and simulated acidic rain

Acidic rain and ozone (O3) may have serious consequences on the growth and development of loblolly pine (Pinustaeda L.), a tree species of major economic importance in the southeastern United States. In two independent studies, seedlings of open-pollinated families of loblolly pine were exposed to five concentrations of O3 (0, 80, 160, 240, or 320 nL•L−1) and three simulated rain acidities (pH 5.3, 4.3, or 3.3). Following 23 weeks of growth (12 weeks in charcoal-filtered air and 11 weeks of O3 and simulated acidic rain exposures), stem height, secondary needle dry weight, top and total seedling dry weight, and root/shoot dry weight ratio all were related negatively and linearly with O3 concentration. Stem diameter and root dry weight were also suppressed by O3. Suppression of the growth parameters ranged from 14 to 35% for the greatest O3 concentration. Acidity of simulated rain did not affect seedlings, nor did it affect seedling responses to O3. Results indicate that acid rain probably has little effect on growth of loblolly pine seedlings, but O3 can suppress growth to varying degrees depending on family.

Loblolly pine needle nutrient and soil enzyme activity as influenced by ozone and acid rain chemistry

Atmospheric air pollutants such as acid rain and O 3 are present throughout the Southeastern U.S.A. and are known to suppress tree growth and crop productivity. Precipitation chemistry has shown changes in the ratio of N and S compounds in recent years. A greenhouse study was conducted using continuous stirred reactor chambers to determine the effects of simulated acid rain (SAR) chemistry, O 3 and their interaction on loblolly pine seedling biomass, loblolly pine secondary needly nutrient content and soil enzyme activities. The seedlings were exposed to 0, 80, 160, 240 or 320 nl O 3 l −1 at SAR pH 4.3 with two ratios of N-to-S (7N-to-3S and 3N-to-7S) for 11 wk. The secondary needle and root biomass were significantly suppressed by increasing O 3 concentrations. A decreased content of P, Ca and Mg in secondary needles was also found with increasing O 3 concentration. Neither SAR chemistry (N-to-S ratios) or the interaction of SAR chemistry and O 3 had significant effects on loblolly pine seedling biomass. Acid phosphatase and arylsulfatase activities were dependent on SAR chemistry. The activity of soil acid phosphatase and arylsulfatase was inhibited by O 3 when S application through simulated acid rain was higher (7-to-3, S-to-N). The inhibitory effects appeared at 160 nl O 3 l −1 for acid phosphatase and 240 nl O 3 l −1 for arylsulfatase. Dehydrogenase activity was not affected by either O 3 or SAR chemistry.

Growth and biomass partitioning of populations of European Pinus sylvestris L. under simulated 50° and 60° N daylengths: evidence for photoperiodic ecotypes

summarySeedlings of 24 European populations of Scots pine (Pinus sylvestris L.) were grown from seed for 4 months in controlled environments under photoperiod conditions of 50° or 60° N, but with similar temperatures and total daily quantum flux in both photoperiods. During the experiment the photoperiod was continually changed to simulate the photoperiod from 1 May to 1 September at each latitude. Secondary needle length, plant height and dry mass at harvest were greater at 60° than the 50° N photoperiod. All populations allocated significantly greater proportions of their biomass to roots at 50° than 60° N photoperiod, yet central populations allocated less to roots than northern ones in both photoperiods. Northern populations (origin &gt; 55° N latitude) stopped height growth up to 50 d earlier than the other populations when grown under 50° N photoperiod conditions. Under the 60° N photoperiod, all populations, except the most southern one, developed terminal leader buds and ceased growth in height between 87 and 105 d after sowing. Using cluster analysis, populations with similar growth and photoperiod responses were assigned to two major groups: northern (61–56° N from Sweden and USSR), and central (55–40° N from the USSR, Poland, Germany, Belgium, France, Czechoslovakia, Yugoslavia, and Turkey). The most southern population, from Turkey, was classified independent from the central group based on growth characteristics alone. No single mechanism of height growth cessation can explain the response of all populations of 1‐yr‐old seedlings of Scots pine. Our findings support the hypothesis that northern plants respond to a combination of increasing night length and accumulated degree‐days. However, the evidence suggests that central and southern populations do not respond to increased night length as they all ceased growth earlier in the 60° than the 50° photoperiod. As hypotheses for further testing, we propose that central and southern populations are either photoperiodically insensitive or respond to short nights or to accumulated degree‐days at their native latitudes.

Effects of ozone on three open-pollinated families of Pinus taeda L. grown in two substrates

Seedlings from three open-pollinated loblolly pine ( Pinus taeda L.) families grown in a mixture of commercial peat moss and grade 3 vermiculite (1:3 by volume) or a mixture of mineral soil and peat (1:1 by volume) were exposed to 0, 160 or 320 ppb ozone (O 3 ) for 6h/day, 4 days/week for 8 weeks beginning 12 weeks after transplanting. Before exposures began, seedlings grown in the vermiculite-peat substrate were taller but smaller in diameter than those grown in the mineral soil-peat substrate. After 8 weeks of exposure, seedlings grown in the mineral soil-peat substrate were significantly larger in diameter and total biomass than those grown in the vermiculite-peat substrate. Primary needle and secondary needle injury increased with increasing O 3 concentrations. Suppression of diameter growth, shoot weight and root weight was linear as O 3 concentration increased. The effect of O 3 on height or diameter growth or shoot biomass was not influenced by substrate type; but the suppression of root biomass due to O 3 was dependent on substrate, with greater suppression in biomass occurring in the vermiculite-peat substrate. Foliar injury due to O 3 was slightly greater in family 8–103, but growth suppression due to O 3 was not significantly different among the families. Based on root biomass, response of seedlings to O 3 was substrate-dependent.

Establishment of western white pine shoots invitro using needle fascicles

The foliage of 4-year-old western white pine (Pinusmonticola Dougl.) containerized seedlings was treated with 450 ppm benzylaminopurine weekly, for 8 weeks, to induce the development of fascicle buds. Fascicle buds were cultured invitro on five different media. Gresshoff and Doy 1 medium and Gresshoff and Doy 1 with an increased concentration of potassium nitrate (1500 mg L−1 KNO3 was added) yielded greater bud elongation and secondary needle growth than other media tested. An invitro dip in 2000 ppm naphthaleneacetic acid promoted the formation of white glassy callus, potential root primordia, and root growth in 33% of the explants. Only 10% of the explants developed elongated roots 120 days after initial culture.

Growth of Pinus Taeda L. Seedlings varies with Family and ozone exposure level

Loblolly pine seedlings of five half-sib families were grown under ambient, subambient (approximately 0.6 × ambient), and elevated [ambient + 60 ppb O3 (120 μg m−3)] O3 levels for one growing season in open-topped chambers. Diameter and height of the seedlings were measured periodically over the growing season, and above ground and below ground biomass were determined at harvest. Significant genetic differences were found in above ground volume (D2H) 1 mo after 03 fumigation began and continued until harvest. Biomass of secondary needles and coarse and fine roots also differed significantly among families. Elevated O3 resulted in significantly decreased D2H and secondary needle biomass relative to seedlings grown in ambient air. Seedlings receiving subambient O3 levels were intermediate in size, but were not significantly different from seedlings fumigated at ambient O3 levels. Root and stem biomass did not differ significantly among treatments. A significant interaction of O3 and genotype was detected, suggesting that the response of loblolly pine to O3 is influenced by genotype.

The effects of plant moisture stress on red pine (Pinusresinosa) seedling growth and establishment

Red pine (Pinusresinosa Ait.) 2-0 and 3-0 bare-root and 1-0 containerized seedlings were subjected to five different watering regimes (drying cycles). Overall, moisture stress as measured with a pressure bomb was highly correlated with seedling growth and survival. While shoot elongation during the drought period was unaffected, stressed seedlings showed pronounced decreases in cambial activity, secondary needle elongation, subsequent bud formation, root length, and number of active mycorrhizal root tips per centimetre compared with control treatments. This resulted in reduced top and root dry-matter production. Watering treatments with average seasonal internal moisture stress values in the range of −8 to −11 bar (1 bar = 100 kPa) showed no measurable reductions in seedling growth. Consistently, less internal moisture stress in the containerized seedlings indicate they are better able to avoid drought. Overall, performance of the 2-0 bare-root seedlings was superior to that of the 3-0 and containerized stock.

The effect of secondary needle compounds on the development of phytophagous insects

Compounds in spruce needles ( Picea abies Karst) were evaluated for their capacity to promote or inhibit the development of the European spruce sawfly, Gilpinia hercyniae Htg., (Hymenoptera, Diprionidae). Correlations were calculated between patterns of compounds in needles and developmental characters of the sawflies, such as mortality, development period, weight gain, egg number, and cocoon weight. The most satisfactory correlations were obtained ( P < 1%) when the particular patterns of compounds included both nutrients and inhibitory compounds. Two classes of inhibitory compounds can be distinguished, each in a close, antagonistic relation to a specific group of nutrients: 1. (1) low-molecular-weight phenols ( p-hydroxyacetophenone, catechin, gallocatechin), shikimic acid, quinic acid ↔ soluble carbohydrates; 2. (2) fraction of the soluble phenols ↔ proteins. The intestinal protein digestion of the sawfly is inhibited by catechin, shikimic acid and quinic acid. But the inhibiting effect can be compensated by the action of a detoxification metabolism which requires carbohydrates. Catechin is stored as a catechinglucoside in the silk glands of the larvae, shikimic acid and quinic acid are degraded by intestinal bacteria and the gut is deacidified by a postulated proton excretion system.

Summer Shoot Production and the Change to the Resting Bud in Young Seedlings of Pinus elliottii

SUMMARY The external morphology of summer shoot production in young Pinus elliottii Engelm. var. elliottii L. & D. is described. Phases of the cycle are classified in relation to bud formation, bud flushing and secondary needle elongation. The rate of shoot elongation within each phase of the cycle is detailed and the pattern of transition from the cycle to a resting bud described.

White pine blister rust: hypersensitive resistance in sugar pine

Resistance to white pine blister rust in sugar pine is simply inherited and can be identified by distinct needle spot morphs. After artificial inoculation at 2 years of age, seedlings from selfed and full-sib families developed either 'fleck' spots, characterized by a pale, yellow margin with a necrotic fleck in the center, or they developed typical yellow or red spots (or both). Seedlings segregated for needle spot reaction in monohybrid ratios with fleck dominant. Mycelium in secondary needle tissues of fleck spots, in contrast to yellow and red spots, was relatively sparse and confined by dense tannin deposits. Bark infection and mortality was heavy on seedlings with yellow and red spots. On seedlings with fleck spots, no bark symptoms developed from secondary needle infection but small, abortive cankers did develop on some of these seedlings as a result of primary needle infection. These atypical cankers did not sporulate or spread extensively, and had healed by the 2nd year after inoculation. The gene responsible for the fleck reaction thus elicits a hypersensitive response in secondary needles and, apparently, in bark tissues as well.