共查询到20条相似文献,搜索用时 15 毫秒
1.
Masahiro Yamaguchi Makoto Watanabe Mayumi Iwasaki Chikako Tabe Hideyuki Matsumura Yoshihisa Kohno Takeshi Izuta 《Trees - Structure and Function》2007,21(6):707-718
To obtain the basic data for evaluating the critical level of ozone (O3) to protect Japanese deciduous broad-leaved forest tree species, the growth and photosynthetic responses of Fagus crenata seedlings to O3 under different nitrogen (N) loads were investigated. The seedlings were grown in potted andisol supplied with N as NH4NO3 solution at 0, 20 or 50 kg ha−1 year−1 and were exposed to charcoal-filtered air or O3 at 1.0, 1.5 and 2.0 times the ambient concentration for two growing seasons. The interactive effect of O3 and N load on the whole-plant dry mass of the seedlings at the end of the second growing season was significant. The O3-induced reduction in the whole-plant dry mass of the seedlings was greater in the relatively high N treatment than that in
the low N treatment. This interactive effect was mainly due to the difference in the degree of O3-induced reduction in net photosynthesis among the N treatments. The degree of O3-induced reduction in N availability to photosynthesis was greater in the relatively high N treatment than that in the low
N treatment. In conclusion, the sensitivity of growth and photosynthetic parameters of F. crenata seedlings to O3 become high with increasing amounts of N added to the soil. Therefore, N deposition from the atmosphere should be taken into
account to evaluate the critical level of O3 to protect Japanese deciduous broad-leaved forest tree species. 相似文献
2.
We examined the carry-over effects of ozone (O3) and/or water stress on leaf phenological characteristics and bud frost hardiness of Fagus crenata seedlings. Three-year-old seedlings were exposed to charcoal-filtered air or 60 nl l–1 O3, 7 h a day, from May to October 1999 in naturally-lit growth chambers. Half of the seedlings in each gas treatment received 250 ml of water at 3-day intervals (well-watered treatment), while the rest received 175 ml of water at the same intervals (water-stressed treatment). All the seedlings were moved from the growth chambers to an experimental field on October 1999, and grown until April 2000 under field conditions. The exposure to O3 during the growing season induced early leaf fall and reduction in leaf non-structural carbohydrates concentrations in the early autumn, as well as resulting in late bud break and reduction in the number of leaves per bud in the following spring. However, O3 did not affect bud frost hardiness in the following winter. On the contrary, water stress did not affect leaf phenological characteristics, leaf and bud non-structural carbohydrates concentrations and bud frost hardiness. There were no significant synergistic or antagonistic effects of O3 and water stress on leaf phenological characteristics, concentrations of leaf and bud non-structural carbohydrates and bud frost hardiness of the seedlings. These results show that the carry-over effects of O3 can be found on the phenological characteristics and leaf non-structural carbohydrates concentrations, although there are almost no carry-over effects of water stress on phenological characteristics and winter hardiness of the seedlings. 相似文献
3.
To obtain basic information for evaluating critical loads of acid deposition for protecting Japanese beech forests, growth, net photosynthesis and leaf nutrient status of Fagus crenata seedlings grown for two growing seasons in brown forest soil acidified with H2SO4 or HNO3 solution were investigated. The whole-plant dry mass of the seedlings grown in the soil acidified by the addition of H2SO4 or HNO3 solution was significantly less than that of the seedlings grown in the control soil not supplemented with H+ as H2SO4 or HNO3 solution. However, the degrees of reduction in the whole-plant dry mass and net photosynthetic rate of the seedlings grown in the soil acidified by the addition of H+ as H2SO4 solution at 100 mg l–1 on the basis of air-dried soil volume (S-100 treatment) were greater than those of the seedlings grown in the soil acidified by the addition of H+ as HNO3 solution at 100 mg l–1 (N-100 treatment). The concentrations of Al and Mn in the leaves of the seedlings grown in the S-100 treatment were significantly higher than those in the N-100 treatment. A positive correlation was obtained between the molar ratio of (Ca+Mg+K)/(Al+Mn) in the soil solution and the relative whole-plant dry mass of the seedlings grown in the acidified soils to that of the seedlings grown in the control soil. Based on the results, we concluded that the negative effects of soil acidification due to sulfate deposition are greater than those of soil acidification due to nitrate deposition on growth, net photosynthesis and leaf nutrient status of F. crenata, and that the molar ratio of (Ca+Mg+K)/(Al+Mn) in soil solution is a suitable soil parameter for evaluating critical loads of acid deposition in efforts to protect F. crenata forests in Japan. 相似文献
4.
The seasonal occurrence of Mycosphaerella buna in leaves and contiguous organs of Fagus crenata was studied in a Japanese beech forest, Ibaraki, Japan, in 1998 and 1999. Mycosphaerella buna was not isolated from newly developed leaves in May, but it was isolated from asymptomatic leaves after June. The frequency of its occurrence gradually increased until leaffall. In contrast, M. buna was not isolated from overwintered buds, leaf petioles, or contiguous current-year twigs. The spermogonia and pseudothecia were observed in dead leaves after leaffall. The mature pseudothecia were found on dead leaves from May to July. The ascospores produced in the pseudothecia were suggested to infect newly developed leaves.Contribution no. 173, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan 相似文献
5.
Orobanche crenata Forsk is a chlorophyll lacking holoparasite that subsists on the roots of plants and causes significant damage to the culture
of leguminous plants and, in particular, to peas (Pisum sativum L.). Here, we investigated the potential of Rhizobium strains for biological control of Orobanche crenata using a commercial pea cultivar (Douce de province) and different Rhizobium strains. Firstly, benefit of bacterial inoculation on plant growth and efficiency in N-incorporation were demonstrated with
four isolates, P.SOM, P.1001, P.Mat.95 and P.1236. After five Rhizobium strains (three efficient: P.SOM, P.1236, P.Mat.95 and two not efficient: P.OM1.92, P.MleTem.92) were investigated for their
ability to control Orobanche crenata using pot and Petri dish experiments. Inoculation of peas with two (P.SOM and P.1236) of the five strains induced a significant
decrease in O. crenata seed germination and in the number of tubercles on pea roots. Furthermore, other symptoms, including the non-penetration
of the germinated seeds into pea roots followed by radicle browning and death of the parasites, were observed in the presence
of these inoculated pea plants. The hypothesis that roots secrete toxic compounds related to Rhizobium inoculation is discussed. 相似文献
6.
Kun-dong Bai De-bao Liao De-bing Jiang Kun-fang Cao 《Trees - Structure and Function》2008,22(4):449-462
Photosynthetic induction times and photoinhibition in relation to simulated sunflecks (sudden increase of irradiance from
20 to 1,500 μmol m−2 s−1) were examined in leaves of co-occurring Fagus lucida (a deciduous tree) and Castanopsis lamontii (an evergreen tree) saplings grown either in a beech forest understory or in an adjacent open site during a late rainy season.
Two hypotheses were tested: (1) understory leaves would display faster photosynthetic induction times and greater photoinhibition
than open-grown leaves; and (2) evergreen species would have slower photosynthetic induction times and lighter photoinhibition
than deciduous species. Times to reach 90% of maximal CO2 assimilation rate (t
90%A
) and stomatal conductance
did not differ between species, but showed faster by 3–5 min in open-grown leaves than understory leaves due to higher initial
stomatal conductance (g
s
initial) and induction state 1 min into simulated sunflecks (IS1min) in the former. Our analysis across the published data on photosynthetic induction of 48 broad-leaved woody species again
revealed the negative correlations between t
90%A
and either g
s initial or IS1min, and the similarity of t
90%A
and between evergreen and deciduous species. Measurements of maximum PSII photochemical efficiency (F
v/F
m) indicated that photoinhibition occurred in saplings in any of the growth habitats during sunfleck-induced photosynthetic
induction. Despite no interspecific differences in the degree of photoinhibition, understory leaves of both species suffered
heavier photoinhibition than open-grown leaves, as indicated by a stronger decrease of F
v/F
m in the former. Dynamic changes in the quantum yields of PSII photochemistry and ΔpH- and xanthophyll-regulated thermal dissipation
and adjustments in the partitioning of electron flow between assimilative and non-assimilative processes were functional to
resist photoinhibition. However, such photoinhibition, together with stomatal and biochemical limitations, would decrease
carbon gain during simulated sunflecks, particularly in understory leaves. 相似文献
7.
Distribution of small roots (diameter between 2 mm and 5 mm) was studied in 19 pits with a total of 72 m2 trench profile walls in pure stands of Fagus sylvatica and Picea abies. Root positions within the walls were marked and transformed into x-coordinates and y-coordinates. In a GIS-based evaluation, zones of potential influence around each root were calculated. The total potential
influence produced isoline maps of relative root influence zones, thus indicating small root clustering. The questions studied
were (1) whether there were marked clusters of small roots in the soil and (2) whether trees surrounding the pit (defined
as tree density) correlate with the root abundance and distribution on the trench profile walls. Small roots of both species
showed maximum abundance in the top 20 cm of the soil, where pronounced root clusters occurred next to areas with only low
root accumulation. The area of root clusters did not differ significantly between the two stands. Weighted clumping, WC, calculated
as a product of root class, and its area was used as an index of root clustering, which again did not differ between beech
and spruce stands. However, evaluations on a single root level showed that beech achieved the same degree of clustering with
lower number of roots. Regardless of soil properties related to root clusters, a significantly higher clustering acquired
per root for beech than for spruce suggests beech to be more efficient in belowground acquisition of space. Because none of
the parameters describing root clustering were correlated with tree density around the investigated soil profiles, clusters
of small roots are inherently present within the tree stands. 相似文献
8.
Diurnal changes in gas exchange, chlorophyll fluorescence and leaf water potential (leaf) were measured to determine the environmental and physiological factors that limit carbon gain in the horizontal leaves of Fagus crenata Blume at the canopy top. Although midday depression of the net CO2 assimilation rate (An) and stomatal conductance (gH2O) were clearly evident on a fine day, the potential quantum yield of PS II (Fv/Fm) was fairly constant around 0.83 throughout the day. This result indicates that the leaves at the canopy top do not suffer from chronic photoinhibition, and the excess energy is dissipated safely. Large reversible increases in non-photochemical quenching (NPQ) were evident on fine days. Therefore, the non-radiative energy dissipation of excess light energy contributed to avoid chronic photoinhibition. The electron transfer rate (ETR) reached maximum during the midday depression, and thus there was no positive relation between ETR and An under high light conditions, indicating a high rate of photorespiration and the absence of non-stomatal effect during midday. The protective mechanisms such as non-radiative energy dissipation and photorespiration play an important role in preventing photoinhibitory damage, and stomatal limitation is the main factor of midday depression of An. To separate the effect of air to leaf vapor pressure deficit (ALVPD) and leaf temperature (Tleaf) on gas exchange, the dependencies of An and gH2O on ALVPD and Tleaf were measured using detached branches under controlled conditions. An and gH2O were insensitive to an increase in Tleaf. With the increase in ALVPD, An and gH2O exhibited more than a 50% decrease even though water supply was optimum, suggesting the dominant role of high ALVPD in the midday depression of gH2O. We conclude that midday depression of An results from the midday stomatal closure caused by high ALVPD. 相似文献
9.
We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan. 相似文献
10.
Ardisia crenata, an evergreen shrub native to East Asia, has been a serious invasive plant to the southeastern USA. Here 13 polymorphic microsatellite
loci were isolated and characterized from an enrichment genomic library of A. crenata. The average allele number of these microsatellites was four per locus, ranging from two to seven. The ranges of observed
and expected heterozygosity were 0.000–1.000 and 0.239–0.789, respectively. These microsatellite markers will be useful for
investigating population genetics and reproductive ecology of A. crenata. 相似文献
11.
ANGUSTIFOLIA (AN), a plant homolog of C-terminal binding protein, controls the polar elongation of leaf cells and the trichome-branching pattern in Arabidopsis thaliana. In the present study, degenerate PCR was used to isolate an ortholog of AN, referred to as LgAN, from larch (Larix gmelinii). The LgAN cDNA is predicted to encode a protein of 646 amino acids that shows striking sequence similarity to AN proteins from other plants. The predicted amino acid sequence has a conserved NAD-dependent 2-hydroxy acid dehydrogenase (D2-HDH) motif and a plant AN-specific LxCxE/D motif at its N-terminus, as well as a plant-specific long C-terminal region. The LgAN gene is a single-copy gene that is expressed in all larch tissues. Expression of the LgAN cDNA rescued the leaf width and trichome-branching pattern defects in the angustifolia-1 (an-1) mutant of Arabidopsis, showing that the LgAN gene has effects complementary to those of AN. These results suggest that the LgAN gene has the same function as the AN gene. 相似文献
12.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
13.
Agrobacterium tumefaciens has the ability to transfer its T-DNA to plants, yeast, filamentous fungi, and human cells and integrate it into their genome. Conidia of the maize pathogen Helminthosporium turcicum were transformed to hygromycin B resistance by a Agrobacterium-tumefaciens-mediated transformation system using a binary plasmid vector containing the hygromycin B phosphotransferase (hph) and the enhanced green fluorescent protein (EGFP) genes controlled by the gpd promoter from Agaricus bisporus and the CaMV 35S terminator. Agrobacterium-tumefaciens-mediated transformation yielded stable transformants capable of growing on increased concentrations of hygromycin B. The presence of hph in the transformants was confirmed by PCR, and integration of the T-DNA at random sites in the genome was demonstrated by Southern blot analysis. Agrobacterium-tumefaciens-mediated transformation of Helminthosporium turcicum provides an opportunity for advancing studies of the molecular genetics of the fungus and of the molecular basis of its pathogenicity on maize. 相似文献
14.
FLORICAULA/ LEAFY-like genes were initially characterized as flower meristem identity genes. In a range of angiosperms, expression occurs also in vegetative shoot apices and developing leaves, and in some species with dissected leaves expression is perpetuated during organogenesis at the leaf marginal blastozone. The evolution of these expression patterns and associated functions is not well understood. We have isolated and characterized a FLORICAULA-like gene from California Poppy, Eschscholzia californica Cham. (Papaveraceae), a species belonging to the basal eudicot clade Ranunculales. EcFLO encodes a putative 416-amino-acid protein with highest similarity to homologous genes from Trochodendron and Platanus. We show that EcFLO mRNA is expressed during the vegetative phase of the shoot apical meristem and in developing dissected leaves in a characteristic manner. This pattern is compared to that of other eudicots and discussed in terms of evolution of FLORICAULA expression and function. 相似文献
15.
We analysed changes in AMP, ADP, and ATP concentrations and adenylate energy charge in Norway maple (Acer platanoides L.) and European beech (Fagus sylvatica L.) seeds during dormancy breaking (at 3 °C) and in the control variant at 15 °C. Values of the studied indicators in stratified
beech seeds were generally higher at 15 °C, at least until germination (+3 °C). By contrast, in maple seeds, the values recorded
during dormancy breaking by cold stratification were much higher than at 15 °C. Three peaks (usually in weeks 3, 6, and 8)
were observed in maple seeds at 3 °C, but not at 15 °C. Among adenine nucleotides, AMP reached the highest levels in both
species in both variants of the experiment. 相似文献
16.
The P transposable element invaded the Drosophila melanogaster genome in the middle of the twentieth century, probably from D. willistoni in the Caribbean or southeastern North America. P elements then spread rapidly and became ubiquitous worldwide in wild populations of D. melanogaster by 1980. To study the dynamics and long-term fate of transposable genetic elements, we examined the molecular profile of genomic P elements and the phenotype in the P-M system of the current North American natural populations collected in 2001-2003. We found that full-size P and KP elements were the two major size classes of P elements present in the genomes of all populations ("FP + KP predominance") and that the P-related phenotypes had largely not changed since the 1980s. Both FP + KP predominance and phenotypic stability were also seen in other populations from other continents. As North American populations did not show many KP elements in earlier samples, we hypothesize that KP elements have spread and multiplied in the last 20 years in North America. We suggest that this may be due to a transpositional advantage of KP elements, rather than to a role in P-element regulation. 相似文献
17.
18.
Circa 1900, a farmer from the eastern US planted 11 American chestnut (Castanea dentata) seeds on a newly established farm near West Salem in western Wisconsin. These trees were very successful, producing a large
stand of over 6,000 trees. Since this area is well outside the natural range of chestnut, these trees remained free from chestnut
blight until 1987. In the West Salem stand, chestnuts are the dominant species of a mixed forest community, reminiscent of
the chestnut–oak ecosystems of pre-1900 Appalachia. To identify putative mycorrhizal associates of chestnut in this unique
forest, our approach was twofold: (1) an extensive fruiting body survey was conducted for four seasons that yielded approximately
100 putative mycorrhizal species and (2) a belowground molecular approach was used to generate DNA sequences of the internal
transcribed spacer region from ectomycorrhizae. Unexpectedly, chestnut did not appear to be the dominant underground ectomycorrhizal-forming
plant species. This study highlights the need to identify the plant host species when conducting belowground molecular-based
surveys and provides preliminary identification of ectomycorrhizal fungi associated with a disjunct stand of American chestnut.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
Stefanie Kimbacher Ingrid Gerstl Branko Velimirov Sylvia Hagemann 《Molecular genetics and genomics : MGG》2009,282(2):165-172
P transposons belong to the eukaryotic DNA transposons, which are transposed by a cut and paste mechanism using a P-element-coded transposase. They have been detected in Drosophila, and reside as single copies and stable homologous sequences in many vertebrate species. We present the P elements Pcin1, Pcin2 and Pcin3 from Ciona intestinalis, a species of the most primitive chordates, and compare them with those from Ciona savignyi. They showed typical DNA transposon structures, namely terminal inverted repeats and target site duplications. The coding
region of Pcin1 consisted of 13 small exons that could be translated into a P-transposon-homologous protein. C. intestinalis and C. savignyi displayed nearly the same phenotype. However, their P elements were highly divergent and the assumed P transposase from C. intestinalis was more closely related to the transposase from Drosophila melanogaster than to the transposase of C. savignyi. The present study showed that P elements with typical features of transposable DNA elements may be found already at the base of the chordate lineage.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species. 相似文献