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1.
A. Kamierczak 《Biologia Plantarum》2001,44(3):439-441
The contents of endogenous gibberellic acid (GA3), sugars, and dry mass in apical parts of fertile and sterile thalli of Chara vulgaris were estimated. The GA3 concentration in the first node of fertile thallus, determined by capillary electrophoresis, was about 70.0 mg kg–1 of fresh mass (f.m.). Pisum sativum-bioassay showed GA3 concentration of 80.0 mg kg–1 (f.m.) which was about 3 times higher than in the first node of sterile thallus. The higher amount of GA3, glucose, and the lower starch content and dry mass in fertile plants than in sterile ones suggest the interdependence between fertility and contents of studied components. 相似文献
2.
Maria Kwiatkowska 《Planta》1991,183(2):294-299
Translocation of [14C]gibberellic acid into antheridial cells of Chara vulgaris L. was investigated in relation to the presence of symplasmic connections between the antheridium and the thallus. It was found that manubria, capitular cells, and antheridial filaments were about three-fold more strongly labelled in young antheridia connected to the thallus by plasmodesmata than in older antheridia in which spontaneous symplasmic isolation had occurred. Plasmolytically induced symplasmic isolation of young antheridia severely diminished the radioactivity of all the cells, down to the level characteristic for spontaneously isolated antheridia. It is concluded that plasmodesmata are the main channel of gibberellin transport into antheridia. The change in the character of symplasmic connections during the course of morphogenesis might, among other events, constitute a signal determining a shift of cell metabolism in a new direction, in response to a rapid change in gibberellin level.Abbreviations GA(n)
gibberellin (An)
- GA3
gibberellic acid
- IAA
indole-3-acetic acid
This study was supported by the Polish Academy of Sciences research project CPBP 04.01.5.05. 相似文献
3.
Andrzej Kaźmierczak 《Acta Physiologiae Plantarum》1998,20(3):277-283
In Schizaeaceae ferns, including Anemia phyllitidis, formation of antheridia is known to be induced by exogenously applied gibberellic acid. Also present studies show that GA3 (10−5 mol·dm−3) modifies the development of gametophytes of Anemia phyllitidis. Simultaneously with formation of antheridia, they exhibit
lower number of cells but only slightly lowered profile areas and lengths of prothalli. Growth in size of individual cells
compensates for lowered division frequency. Cytophotometric measurements reveal no essential changes in the DNA content in
vegetative cells of the control and GA3-stimulated gametophytes. It remains at haploid level and therefore it is assumed that cell cycle is blocked at G1 phase.
Application of GA3 increases the total amount of proteins. CZE (Capillary Zone Electrophoresis) separation of peptides extracted from control
and GA3-treated prothalli indicates the differences in the ratio of their particular forms. In GA3-treated gametophytes the activities of acid and basic phosphatases, contents of carbohydrates (glucose, starch), chlorophyll,
the number of chloroplasts and dry mass of prothalli are increased. GA3-intensified metabolism, evidenced in gametophytes of A. phyllitidis, may be interpreted as a stimulatory mechanism which influences metabolic pathways involved in forming, developing and maturing
of male sex organs. 相似文献
4.
Andrzej Ka mierczak 《Acta Physiologiae Plantarum》2005,27(4):447-454
One of the prime precursor for ethylene synthesis — L-methionine and the inhibitor of 1-aminocyclopropane-1-carboxylic acid
oxidase (ACO) — Co2+-were tested for their effects on sex expression and development of Anemia phyllitidis fern gametophytes. Five concentrations of both chemicals (0, 10, 25, 50, 100 μM) were analysed with reference to antheridia
and archegonia formation, number and size of cells as well as thalli length using the three-zone model of gametophyte structure.
Both substances, however at different concentrations, enhanced the number of GA3-induced antheridia and similarly stimulated the cell number and inhibited thalli length. Both of them at 100 μM concentrations
without GA3 induced meristematic area formation while methionine also induced archegonia in the apical parts of gametophytes. These findings
correspond with the previous observations concerning the important role of ethylene synthesis precursor (ACC) in controlling
gibberellic acid-induced male sex expression in ferns and broaden the knowledge about the mechanisms of fern gametophyte development. 相似文献
5.
Andrzej Kaźmierczak 《Acta Physiologiae Plantarum》1999,21(4):345-348
Method for simultaneous measurement of gibberellic acid was applied using capillary zone electrophoresis. Gibberellic acid
was identified in extracts of apical part of thallus of Chara vulgaris L. The amount of gibberellins measured on the basis of activity determined by the micro-drop bioassay (59.8 mg·kg−1; with gibberellic acid as a standard) was comparable with that estimated by capillary electrophoresis (54.9 mg·kg−1). 相似文献
6.
The influence of gibberellic acid (GA3) and kinetin (6-furfurylaminopurine) on the regeneration ability of the basal and apical thallus fragments ofFucus vesiculosus L. was examined. The naturally occurring gibberellin and kinetin-like substances in these thallus fragments were also studied. It was found that exogenously applied GA3 markedly increased the number of adventitious branches formed on the cut surface of the thallus fragments taken from the apical parts of plants. The concentration of 0.001 mg GA3 I-1 proved to be the most effective. The growth promoting effect of GA3 was increased by simultaneous action with kinetin. In experiments in which the fragments of the basal parts of the thallus were treated with GA3, as a rule a slight growth inhibition was observed. The growth responses of the investigated plant tissues to gibberellin and kinetin varied according to season. Usually their susceptibility to the applied plant hormones was greater in spring than is summer. The shifts in growth reaction were related to the seasonal changes in the content of endogenous gibberellin and kinetin-like substances in the investigated parts of the thallus. It is suggested that growth regulators of the gibberellin and cytokinin type are involved in the regeneration processes inFucus. 相似文献
7.
Low molecular weight peptidic component extracted from maturing male sex organs of Chara tomentosa, capable of inducing increased condensation of chromosomes and profound changes in the cell cycle progression, was applied
to gametophytes of Anemia phyllitidis. Morphogenetic effects were studied with regard to cell divisions and GA3-induced antheridiogenesis. As compared with both the GA
3
−
and GA
3
+
control samples, the extract-treated prothallia exhibited considerably lowered number of cells and altered morphology. Antheridial
differentiation in prothallia of A. phyllitidis was severely inhibited when peptidic extract was added to medium containing GA3. Considering endocytotic uptake, evidenced in root meristems, and those effects which have been observed in plant and human
cells, the activity of extracts obtained from male sex organs of Chara may be interpreted as inhibitory influence acting via repression or modification of the genetic device of the cells rather, than a direct consequence of the retardation of cell
division cycles. 相似文献
8.
Effect of Gibberellin on Growth, Protein Secretion, and Starch Accumulation in Maize Endosperm Suspension Cells 总被引:3,自引:0,他引:3
The physiologic effect of gibberellins (GA) in seed development is poorly understood. We examined the effect of gibberellic
acid (GA3) on growth, protein secretion, and starch accumulation in cultured maize (Zea mays L.) endosperm suspension cells. GA3 (5 and 30 μm) increased the fresh weight, dry weight, and protein content of the cultured cells, but the effect of GA3 at 50 μm was not significantly different. However, the protein content in the culture medium was increased by these three concentrations
of GA3. The effect of GA3 on the amount of cellular structural polysaccharides was not significant, but GA3 had a dramatic effect on the starch content. At 5 μm, GA3 caused an increase in the starch content, but at 50 μm the starch accumulation was reduced. Chlorocholine chloride (CCC), an inhibitor of GA biosynthesis, significantly increased
the starch content and decreased the structural polysaccharide content of the cultured cells. The effects of CCC at 500 μm on the starch and polysaccharide content were partially reversed by 5 μm GA3 applied exogenously. Based on these results we suggest that GA does not favor starch accumulation in the cell cultures and
that the addition of lower concentrations of GA3 in the medium may provide an improved balance among the endogenous GA in the cultured cells.
Received October 31, 1995; accepted March 25, 1997 相似文献
9.
Effect of gibberellic acid on carbonic anhydrase,photosynthesis, growth and yield of mustard 总被引:2,自引:0,他引:2
N. A. Khan 《Biologia Plantarum》1996,38(1):145-147
The plants of mustard (Brassica juncea L.) were treated with 0, 25 and 50 ΜM gibberellic acid (GA3) at three fully developed leaf stage (30 d after sowing). Effect of GA3 on carbonic anhydrase activity, photosynthetic rate, leaf area index and dry mass was studied at 50, 70 and 90 d after sowing.
At harvest 1000 seed mass, pod number and seed yield were recorded. GA3 treatment (50 ΜM) enhanced all the characteristics studied. 相似文献
10.
Encrustation and element content of six charophyte species from two hard‐water lakes were investigated monthly for a period of 1 year. Seasonal patterns were analyzed for the interaction of water chemistry. Encrustation followed a seasonal pattern for Chara contraria, Chara subspinosa, and Nitellopsis obtusa in Lake Krüselin and for Chara globularis and Chara tomentosa in Lake Lützlow. However, no seasonality in the precipitated CaCO3 was observed for C. subspinosa in Lake Lützlow and for C. tomentosa in Lake Krüselin, indicating a lake‐specific dependency. Species‐specific encrustation was found. Chara contraria and N. obtusa encrusted the most in June and August, whereas C. subspinosa and Nitella flexilis/opaca exhibited lowest encrustation in March and April. The precipitated CaCO3 of charophytes correlated negatively to the concentration of total inorganic carbon in both lakes. Element content of plant dry weight was species‐specific for Ca and K, and lake‐specific for Mg. No specific pattern was found for the TP and Fe contents. The results showed seasonal, species, and lake‐specific influences on the encrustation of charophytes. 相似文献
11.
In cowpea seedlings starch hydrolysing activity increases 35–50 fold on germination for 4 days. This increase in enzyme activity was inhibited by the in vivo addition of 1% glucose but this inhibition was completely overcome by the addition of gibberellic acid (GA3) (10?5 M) and adenosine-3′,5′-cyclic monophosphate (cAMP) (10?5 M). At 5% glucose, GA3 and cAMP were only partially effective. Structural analogues of cAMP failed to relieve the inhibitory effect of glucose. The inhibition by glucose is not direct but RNA and protein synthesis may be involved. Glucose appears to reduce the internal pool of cAMP which causes inhibition of RNA synthesis and decrease in starch hydrolysing activity. Exogenous application of cAMP may replenish the endogenous pool of cyclic nucleotide and thus overcome inhibition of RNA synthesis and enzyme activity. 相似文献
12.
Kwiatkowska Maria; Wojtczak Agnieszka; Poptoriska Katarzyna 《Plant & cell physiology》1998,39(12):1388-1390
The youngest nodes located under an apical bud of Chara vulgariswere isolated and cultivated in the presence or absence of 105M GA3 under laboratory conditions to form spermatozoids. GA3increased the DNA C-value in manubria by 20% and increased thenumber of spermatozoids per antheridium over 2-fold. (Received April 27, 1998; Accepted October 8, 1998) 相似文献
13.
The treatment of potato tubers with 150 µmol dm3gibberellic acid (GA3) stimulated starch breakdown and hexoseaccumulation in tuber tissues and the transfer of dry matterto stems. These effects could not be accounted for by enhancedactivities of starch phosphorylase, amylase and acid invertase.Indeed enzyme activities either declined or remained relativelyconstant as starch degradation and hexose accumulation proceeded.Changes in the rate of starch depletion were related to changesin sink strength and sink type, the onset of tuber initiationin controls causing the rate of starch degradation to exceedthat in GA3-treated tissues, in which tuberization was inhibited. Solanum tuberosum L., gibberellic acid, starch breakdown 相似文献
14.
This paper addresses the phenology of a Dictyota dichotoma population from the North Patagonian coasts of Argentina. The morphology of the individuals was characterized, and analyses of the temporal variations of vegetative features, diploid and haploid life cycle generations and sex ratios are provided. Individuals, represented by growing sporophytes and gametophytes, occurred simultaneously throughout the year. Morphological variables showed temporal variation, except the width and height of medullary cells, which did not vary between seasons. All vegetative variables were significantly correlated with daylength. Besides, frond length, frond dry mass and apical and basal branching angles were significantly correlated with seawater temperatures. Vegetative thalli were less abundant than haploid and diploid thalli. Sporophytes were less abundant than male and female gametophytes. Male gametophytes dominated in May, August, October and January, and female gametophytes were more abundant in September, November, December, February and March. The formation of female gametangia showed a significant correlation with daylength, and the highest number of gametangia was registered in spring. In general, the male/female sex ratio varied between 1:2 and 1:1. Apical regions were more fertile than basal regions. Our data about frequency in the formation of reproductive structures and male/female ratios are the first recorded in the Dictyota genus and thus could not be compared with populations from other regions of the world. Significant morphological variation was observed in thalli of both life cycle generations, regarding length and dry mass, number of primary branches and branching basal angle. In general, all variables analyzed varied seasonally except cortical cell width. 相似文献
15.
Daniela Moreno Federico J. Berli Patricia N. Piccoli Rub��n Bottini 《Journal of Plant Growth Regulation》2011,30(2):220-228
Carbon allocation within grapevines may affect berry growth and development. The plant hormones gibberellins (GAs) and abscisic
acid (ABA) control various processes across the plant life and both have been involved in assimilate production and transport
in different species. Hence, this work examined the distribution of sugars (sucrose, fructose, and glucose) and starch in
grapevines at veraison after foliar applications of GA3, ABA, and an inhibitor of GA biosynthesis, paclobutrazol (PBZ). The results demonstrated that GA3 increased total grapevine mass, with carbon allocated to the whole grapevine (as structural and soluble carbohydrates). Both
GA3 and ABA increased monosaccharide (glucose and fructose) levels in berries (up to tenfold) and roots (up to threefold). However,
GA3 increased the net carbon fixation whereas ABA did not. PBZ diminished most growth parameters except grapevine mass, and allocated
more carbohydrates to roots (up to threefold more sucrose and starch). Such results indicate that GAs promote net carbon fixation
and transport, whereas ABA as a stress signal only enhances sugar transport; notwithstanding the two hormones promoted carbon
allocation toward roots and berries. 相似文献
16.
Stacy A. Krueger-Hadfield Alexis P. Oetterer Lauren E. Lees Jessica M. Hoffman Erik E. Sotka Courtney J. Murren 《Journal of phycology》2023,59(5):926-938
Phenology, or seasonal variation in life cycle events, is poorly described for many macroalgal species. We describe the phenology of a non-native population of Gracilaria vermiculophylla whose thalli are free-living or anchored by decorating polychaetes to tube caps. At a site in South Carolina, USA, we sampled 100 thalli approximately every month from January 2014 to January 2015. We assessed the reproductive state and measured thallus size based on wet weight, thallus length, and thallus surface area from herbarium mounts. Because life cycle stage cannot be assigned using morphology, we implemented a PCR assay to determine the life cycle stage—tetrasporophyte, female gametophyte, or male gametophyte—of each thallus. Tetrasporophytes dominated throughout the year, making up 81%–100% of thalli sampled per month. Reproductive tetrasporophytes varied between 0% and 65% of monthly samples and were most common in warm summer months (July through September) when thalli also tended to be larger. The vast majority of the reproductive thalli were worm-anchored and not fixed to hard substratum via a holdfast. Thus, free-living thalli can be reproductive and potentially seed new non-native populations. Given G. vermiculophylla reproduction seems tied closely to temperature, our work suggests phenology may change with climate-related changes in seawater temperatures. We also highlight the importance of understanding the natural history of macroalgae to better understand the consequence of range expansions on population dynamics. 相似文献
17.
William H. Magruder 《Journal of phycology》1984,20(3):402-409
Culture and morphological studies showed that Galaxaura oblongata (Ellis et Solander) Lamouroux has a triphasic life history with conspicuous gametophytes and small filamentous tetrasporophytes. Development of male and female reproductive structures is very similar and both begin with the enlargement of a terminal cell of a filament branch occupying a normal vegetative position within the apical pit of a thallus branch. In male thalli this modified branch forms a conceptacle in which spermatangia are produced. In female thalli, this modified branch forms a three-celled carpogonial branch consisting of a carpogonium, hypogynous cell and basal cell. Filament branches from the basal cell form a pericarp and the gonimoblast develops directly from the carpogonium. Carposporangia are produced in conceptacles which resemble the male conceptacles. About the time the first carposporangia are produced, the carpogonium, hypogynous cell and basal cell form a large fusion cell. Released carpospores germinate in a unipolar or bipolar manner and form small filamentous thalli. Under short day conditions, cruciate tetrasporangia are produced in small clusters. Tetraspores germinate similarly to carpospores and also form small filamentous thalli. Under low nutrient conditions, small cylindrical thalli develop on the filaments and these appear similar to gametophytes collected in nature. 相似文献
18.
Tomato (Lycopersicon esculentum Mill.) plants homozygous for the mutant pro gene, exhibiting the distinctive procera phenotype, appeared virtually identical to gibberellic acid (GA3)-treated isogenic normal plants. The pro gene and GA3 caused analogous increases in internode length, and in the length and number of cells in the outer cell layers of each internode. Internode number was also increased by pro and GA3 over the period of the experiment. Despite their greater length, the internodes of GA3-treated and pro plants reached their final size within a time period similar to that of internodes of untreated normal plants. The pro mutant itself was responsive to GA3, especially in the seedling stage, but the proportional increase in height seen in the later stages of growth was less than that of normal plants.Abbreviations GA
gibberellin
- GA3
gibberellic acid
- LSD
least significant difference 相似文献
19.
Rosette-formed, circular thalli of Degelia plumbea were studied in the laboratory. Regardless of thallus size, the optimal quantum yield of photosystem II (F
V/F
M) remained at a high, constant level during a drying cycle starting with fully hydrated thalli until the thallus water content
reached about 200%. Net photosynthesis reached a maximum level at this hydration level. Thereafter, both F
V/F
M and net photosynthesis fell rapidly to zero at a water content of somewhat less than 100%. There was a highly significant,
positive relationship between thallus size and the water-holding capacity, as well as a strong, negative correlation between
size and water loss per thallus area. Consequently, an increase in thallus size from 1 to 36 cm2 lead to a tenfold prolongation of the photosynthetically active period during a drying cycle at a low radiation regime. The
improved water-holding capacity in larger thalli is mainly a result of a thicker hypothallus. The fast desiccation of small
thalli suggests that the regeneration of D. plumbea could be severely hampered by nearby logging that raises the evaporative demand by increasing radiation loads and wind exposure
at remaining lichen sites.
Received: 12 December 1997 / Accepted: 20 March 1998 相似文献
20.
Lettuce plants were treated with gibberellic acid (GA3) and uniconazole (UZ; a gibberellin synthesis inhibitor) to investigate the influence of GA3 on cell division frequency in the shoot apical meristem (SAM) during stem elongation and flower initiation in lettuce (Lactuca sativa) grown in a greenhouse. GA3 (0.1 mM) was sprayed on the surface of outer leaves and uniconazole solution (0.86 mM) was applied to the soil. GA3 increased cell division frequency in the peripheral zone and the rib meristem of shoot apices, and this was associated with
the stimulation of stem elongation. UZ treatment decreased cell division frequency in the peripheral zone, rib meristem and
subapical pith, and this was associated with restricted stem elongation. Treatment with UZ and GA3 together induced minor stem elongation. Flower induction occurred 3 d earlier in the GA3 and UZ+GA3 treatments than in the control, while the UZ treatment delayed flower initiation for more than 9 d relative to the control. 相似文献