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1.
With the discovery of targeted gene replacement, moss biology has been rapidly advancing over the last 10 years. This study demonstrates the usefulness of moss as a model organism for plant photosynthesis research. The two mosses examined in this study, Physcomitrella patens and Ceratodon purpureus, are easily cultured through vegetative propagation. Growth tests were conducted to determine carbon sources suitable for maintaining heterotrophic growth while photosynthesis was blocked. Photosynthetic parameters examined in these plants indicated that the photosynthetic activity of Ceratodon and Physcomitrella is more similar to vascular plants than cyanobacteria or green algae. Ceratodon plants grown heterotrophically appeared etiolated in that the plants were taller and plastids did not differentiate thylakoid membranes. After returning to the light, the plants developed green, photosynthetically active chloroplasts. Furthermore, UV-induced mutagenesis was used to show that photosynthesis-deficient mutant Ceratodon plants could be obtained. After screening approximately 1000 plants, we obtained a number of mutants, which could be arranged into the following categories: high fluorescence, low fluorescence, fast and slow fluorescence quenching, and fast and slow greening. Our results indicate that in vivo biophysical analysis of photosynthetic activity in the mosses can be carried out which makes both mosses useful for photosynthesis studies, and Ceratodon best sustains perturbations in photosynthetic activity. 相似文献
2.
Photosynthetic characteristics were compared between plants of low altitude (LA) grown at LA (Palampur; 1 300 m) and at high altitude, HA (Kibber; 4 200 m), and plants naturally occurring at different altitudes (Palampur, 1 300 m; Palchan, 2 250 m; and Marhi, 3 250 m). Net photosynthetic rate (P
N) was not significantly different between altitudes. However, the slopes of the curve relating P
N to intercellular CO2 concentration (C
i) were higher in plants at Palchan, Marhi, and Kibber compared to those at Palampur, indicating that plants had higher efficiency of carbon uptake (the initial slope of P
N/C
i curve is an indication) at HA. They had also higher stomatal conductance (g
s), transpiration rate, and lower water use efficiency at HA. g
s was insensitive to photosynthetic photon flux density (PPFD) for plants naturally occurring at Palampur, Palchan, and Marhi, whereas plants from LA grown at Palampur and Kibber responded linearly to increasing PPFD. Insensitivity of g
s to PPFD could be one of the adaptive features allowing wider altitudinal distribution of the plants.This research is supported by the Department of Biotechnology (DBT), Government of India vide grant number BT/PR/502/AGR/08/39/966-VI. 相似文献
3.
Summary Coconut (Cocos nucifera L.) plantlets grown in vitro often grow slowly when transferred to the field possibly, due to a limited photosynthetic capacity of in vitro-cultured plantlets, apparently caused by the sucrose added to growth medium causing negative feedback for photosynthesis.
In this paper, we tested the hypothesis that high exogenous sucrose will decrease ribulose 1,5-bisphosphate carboxylase (Rubisco)
activity and photosynthesis resulting in limited ex vitro growth. Plantlets grown with high exogenous sucrose (90 gl−1) had reduced photosynthetic activity that resulted in a poor photosynthetic response to high levels of light and CO2. These plantlets also had low amounts of Rubisco protein, low Rubisco activity, and reduced growth despite showing high survival
when transferred to the field. Decreasing the medium’s sucrose concentration from 90 to 22.5 gl−1 or 0 gl−1 resulted in increased photosynthetic response to light and CO2 along with increased Rubisco and phosphoenolpyruvate carboxylase (PEPC) activities and proteins. However, plantlets grown
in vitro without exogenous sucrose died when transferred ex vitro, whereas those grown with intermediate exogenous sucrose showed intermediate photosynthetic response, high survival, fast
growth, and ex vitro photosynthesis. Thus, exogenous sucrose at moderate concentration decreased photosynthesis but increased survival, suggesting
that both in vitro photosynthesis and exogenous sucrose reserves contribute to field establisment and growth of coconut plantlets cultured in vitro. 相似文献
4.
Summary
Lilium Asiatic hybrid ‘Mona’ bulblets were cultured in vitro for 100 d under photoautotrophic (CO2-enriched conditions and without sucrose in the medium) and heterotrophic (non-enriched CO2 conditions and sucrose-supplemented medium) methods and under various levels of photosynthetic photon flux (PPF). Bulblet
growth and net photosynthetic rate (NPR) were analyzed. CO2− and PPF-enriched conditions enhanced the overall growth of bulblets, scale leaves, and roots. Heterotrophic conditions enhanced
bulblet growth but higher PPF levels were inhibitory to the development of scale leaves. These results indicate the CO2− and PPF-enriched conditions (photoautotrophic conditions) are beneficial for the production of high-quality bulblets of Asiatic
hybrid lilies in vitro 相似文献
5.
The changes in the fresh biomass accumulation, photosynthetic and anthocyanin pigments, photosystem 2 (PS 2) activity, ultrastructure
of chloroplast, total lipids and fatty acid composition of thylakoid membrane were followed in the aquatic fern Azolla caroliniana grown on medium either deficient or supplied with various phosphorus concentrations. The content of photosynthetic pigments
and the anthocyanin/chlorophyll ratio increased significantly with increasing PO4
3− concentration. Phosphate deficiency inhibited growth and PS 2 activity and decreased content of total lipids and phospholipids
in isolated thylakoids. This was accompanied with a significant increase in the percentage of galalactolipids. 相似文献
6.
Ginger (Zingiber officinale Rosc.) plantlets were propagated in vitro and acclimated under different photosynthetic photon flux densities (60 and 250 μmol m−2 s−1 = LI and HI, respectively). Increases in chlorophyll (Chl) content and Chl a/b ratio were found under both irradiances. In vitro plantlets (day 0) exhibited a low photosynthesis, but chloroplasts from in vitro leaves contained well developed grana and osmiophillic globules. Photoinhibition in leaves formed in vitro was characterized by decrease of photochemical efficiency and quantum efficiency of photosystem 2 photochemistry in HI treatment
during acclimation. The new leaves formed during acclimation in both treatments showed a higher photosynthetic capacity than
the leaves formed in vitro. Also activities of antioxidant enzymes of micropropagated ginger plantlets changed during acclimation. 相似文献
7.
The aim of this research was to determine whether exogenous abscisic acid (ABA) applied immediately after ex vitro transfer of in vitro grown plants can improve their acclimatization. Tobacco (Nicotiana tabacum L.) plantlets were transferred into pots with Perlite initially moistened either by water or 50 μM ABA solution and they
were grown under low (LI) or high (HI) irradiance of 150 and 700 μmol m−2 s−1, respectively. Endogenous content of ABA in tobacco leaves increased considerably after ABA application and even more in
plants grown under HI. Stomatal conductance, transpiration rate and net photosynthetic rate decreased considerably 1 d after
ex vitro transfer and increased thereafter. The gas exchange parameters were further decreased by ABA application and so wilting of
these plants was limited. Chlorophyll (a+b) and β-carotene contents were higher in ABA-treated plants, but the content of xanthophyll cycle pigments was not increased.
However, the degree of xanthophyll cycle pigments deepoxidation was decreased what also suggested less stress in ABA-treated
plants. No dramatic changes in most chlorophyll a fluorescence parameters after ex vitro transfer suggested that the plants did not suffer from restriction of electron transport or photosystem damage. 相似文献
8.
A. M. Fonini J. B. Barufi É. C. Schmidt A. C. Rodrigues Á. M. Randi 《Photosynthetica》2017,55(3):401-410
This paper reports effects of ultraviolet B (UVB) radiation on leaf anatomy and contents of chlorophyll and carotenoids, as well as photosynthetic parameters, in young sporophytes of Acrostichum danaeifolium Langsd. & Fisch. (Polypodiopsida, Pteridaceae) exposed to UV radiation treatments for 1 h daily for six weeks. The leaves showed large aerenchyma and present chloroplasts in both epidermises. After cultivation under PAR + UVA + UVB, leaves showed curling and malformed stomata on the abaxial face. After the UV treatment, chloroplasts in leaves were arranged against the inner wall of the epidermal cells. Transmission electron microscopy analysis showed some dilated thylakoids and plastoglobuli in chloroplasts and vesicles containing phenolic compounds in the cytoplasm. Differences were not observed between control and UV-treated plants in their contents of chlorophylls, carotenoids, and photosynthetic parameters. A. danaeifolium grown in sunny mangrove environment seems to have mechanisms preventing photosystem damage. 相似文献
9.
R. Dibax C. Deschamps J. C. Bespalhok Filho L. G. E. Vieira H. B. C. Molinari M. K. F. De Campos M. Quoirin 《Biologia Plantarum》2010,54(1):6-12
The purpose of this research was Eucalyptus saligna in vitro regeneration and transformation with P5CSF129A gene, which encodes Δ1-pyrroline-5-carboxylate synthetase (P5CS), the key enzyme in proline biosynthesis. After selection of the most responsive genotype, shoot organogenesis was induced
on leaf explants cultured on a callus induction medium (CI) followed by subculture on a shoot induction medium (SI). Shoots
were subsequently cultured on an elongation medium (BE), then transferred to a rooting medium and finally transplanted to
pots and acclimatized in a greenhouse. For genetic transformation, a binary vector carrying P5CSF129A and uidA genes, both under control of the 35SCaMV promoter, was used. Leaves were co-cultured with Agrobacterium tumefaciens in the dark on CI medium for 5 d. The explants were transferred to the selective callogenesis inducing medium (SCI) containing
kanamycin and cefotaxime. Calli developed shoots that were cultured on an elongation medium for 14 d and finally multiplied.
The presence of the transgene in the plant genome was demonstrated by PCR and confirmed by Southern blot analysis. Proline
content in the leaves was four times higher in transformed than in untransformed plants while the proline content in the roots
was similar in both types of plants. 相似文献
10.
Lenaldo Muniz de Oliveira Renato Paiva José Raniere Ferreira de Santana Eduardo Alves Rairys Cravo Nogueira Flávia Dionísio Pereira 《In vitro cellular & developmental biology. Plant》2008,44(2):128-135
The role of cytokinins in the differentiation of the photosynthetic apparatus in micropropagated plants and their effect on
the plant’s ability to transition from a heterotrophic to an autotrophic condition during acclimatization was investigated.
Annona glabra L. shoots were cultured on woody plant medium supplemented with sucrose and different cytokinins to evaluate leaf tissue
for chloroplast development, chloroplast numbers, photosynthetic pigmentation, total photosynthetic potential, and soluble
sugar content. Plants were transferred to the rooting medium in the presence or absence of sucrose and then acclimatized.
Kinetin and benzyladenine (BAP) stimulated chloroplast differentiation. Inclusion of zeatin in the medium induced the formation
of greater numbers of chloroplasts in the leaves, while plants cultivated in the presence of only kinetin and BAP demonstrated
greater chlorophyll a and carotenoid content. The use of kinetin and BAP during in vitro culture promoted accumulation of dry matter during the acclimatization phase, especially in plants rooted under autotrophic
conditions (without sucrose). Kinetin and BAP promoted development of more leaf area and greater plant survival rates in plant
acclimatization on both autotrophic and heterotrophic media. The inhibitory effects of thidiazuron on the differentiation
of chloroplasts, accumulation of chlorophyll a, and photosynthetic potential were examined. 相似文献
11.
T. K. Golovko I. V. Dalke I. G. Zakhozhiy O. V. Dymova G. N. Tabalenkova 《Russian Journal of Plant Physiology》2011,58(4):549-559
Morphological and functional characteristics of Plantago media L. leaves were compared for plants growing at different light regimes on limestone outcrops in Southern Timan (62°45′N, 55°49′E).
The plants grown in open areas under exposure to full sunlight had small leaves with low pigment content and high specific
leaf weight; these leaves exhibited high photosynthetic capacity and elevated water use efficiency at high irradiance. The
maximum photochemical activity of photosystem II (F
v/F
m) in leaves of sun plants remained at the level of about 0.8 throughout the day. The photosynthetic apparatus of sun plants
was resistant to excess photosynthetically active radiation, mostly due to non-photochemical quenching of chlorophyll fluorescence
(qN). This quenching was promoted by elevated deepoxiation of violaxanthin cycle pigments. Accumulation of zeaxanthin, a photoprotective
pigment in sun plant leaves was observed already in the morning hours. The plant leaves grown in the shade of dense herbage
were significantly larger than the sun leaves, with pigment content 1.5–2.0 times greater than in sun leaves; these leaves
had low qN values and did not need extensive deepoxidation of violaxanthin cycle pigments. The data reveal the morphophysiological
plasticity of plantain plants in relation to lighting regime. Environmental conditions can facilitate the formation of the
ecotype with photosynthetic apparatus resistant to photoinhibition. Owing to this adjustment, hoary plantain plants are capable
of surviving in ecotopes with high insolation. 相似文献
12.
The responses of tobacco plants over-expressing trans-zeatin O-glucosyltransferase gene under constitutive or senescence-inducible promoter (35S:ZOG1 and SAG12:ZOG1) and of wild type (WT) plants to water stress and subsequent rehydration were compared. In plants sufficiently supplied with
water, both transgenics have higher net photosynthetic rate (PN) in upper and middle leaves and higher stomatal conductance (gs) in middle leaves than WT. Water use efficiency (WUE = PN/E) was higher in both transgenics than in WT. During prolonged water stress, both PN and E declined to a similar extent in both transgenics and WT plants. However, 7 d after rehydration PN in SAG:ZOG (upper and middle leaves) and 35S:ZOG (upper leaves) was higher than that in WT plants. Increased content of endogenous CKs in 35S:ZOG plants did not prevent their response to ABA application and the results obtained did not support concept of CK antagonism
of ABA-induced stomatal closure. The chlorophyll (Chl) a+b content was mostly higher in both transgenics than in WT. During water stress and subsequent rehydration it remained unchanged
in upper leaves, decreased slightly in middle leaves only of WT, while rapidly in lower leaves. Total degradation of Chl,
carotenoids and xanthophyll cycle pigments (XCP) was found under severe water stress in lower leaves. Carotenoid and XCP contents
in middle and upper leaves mostly increased during development of water stress and decreased after rehydration. While β-carotene
content was mostly higher in WT, neoxanthin content was higher in transgenics especially in 35S:ZOG under severe stress and after rehydration. The higher content of XCP and degree of their deepoxidation were usually found
in upper and middle leaves than in lower leaves with exception of SAG:ZOG plants during mild water stress. 相似文献
13.
14.
Zagorska NA Shtereva LA Kruleva MM Sotirova VG Baralieva DL Dimitrov BD 《Plant cell reports》2004,22(7):449-456
We present data on the morphological, cytological, biochemical and genetic characteristics of tomato regenerants obtained through anther culture. As a result of induced androgenesis, more than 6,000 rooted regenerants were developed that differed both from the donor plants and among each other with respect to habitus and leaf, flower and inflorescence morphology. Cytological analysis revealed a great variability in chromosome number in the cells of the regenerated plants. While most of the regenerants were mixoploid, the majority of the cells had a haploid chromosome number. R1 and R2 progenies were tested for their resistance to Clavibacter michiganense subsp. michiganense (Cmm 7). Some of the regenerants were resistant to the pathogen. A biochemical analysis of fruit from R3 and R4 plants showed a higher content of dry matter, sugars and vitamin C in the regenerant plants obtained from the hybrids than in those from the cultivars and control plants. The values of the parameters of hybrid regenerants grown in the greenhouse were about 1.5-fold higher than those of the hybrid regenerants grown in the field, and this trend is clearly expressed in all of the hybrid regenerants. The results obtained suggest that induced androgenesis and gametoclonal variation may be used as an additional tool to create a large range of new forms. The application of the latter in breeding programs would accelerate the development of tomato lines and varieties that would be more productive, disease-resistant, highly nutritive and flavour-acceptable.Abbreviations
BAP
N6-Benzylaminopurine
-
Cmm
Clavibacter michiganense subsp. michiganense
-
cfu
Colony-forming units
-
GA
3
Gibberellic acid
-
IBA
Indole-3-butyric acid
-
ms
Male sterility
-
PDA
Potato dextrose agar
Communicated by H. Lörz 相似文献
15.
Summary Cell cultures of freshwater wetland monocots were regenerated, plants were grown in the greenhouse, and then established and
evaluated in wetlands. Typha (cattail), Juncus (rushes), Scirpus (bulrushes), and Carex (sedges) were studied because they are common, dominant, high biomass wetland-adapted plants, tolerant of chemically diverse
ecosystems. The goal was to define micropropagation and wetland establishment protocols. Tissue culture systems defined for
numerous monocot crop species can be readily applied to wetland plants, with a few modifications. Issues addressed were selection
of explant material, shoot and root regeneration conditions, culture age verses regenerability, greenhouse acclimatization
needs, plant uniformity and requirements for wetland establishment. In vitro-germinated seedlings were an excellent source of pathogen-free regenerable tissue. T. latifolia, T. angustifolia, and J. accuminatus were regenerated from callus induced in the dark with picloram, then transferred to medium with benzyladenine in the light
to promote shoot organogenesis. J. effusus, S. polyphyllus, and C. lurida could not be regenerated from callus, which turned black. They could be regenerated directly by culturing intact seedlings
directly on cytokinin media in the light. Shoots rooted with little or no auxin. J. effusus rooting was promoted by the addition of charcoal to the medium. Covering plants for the first 2 wk with plastic facilitated
greenhouse establishment. There were high rates of greenhouse and wetland survival. No abnormal plants were observed. These
regeneration systems could be utilized for the production of wetland plants for potential application in habitat restoration
and wetland creation, and would provide an alternative to field collection. 相似文献
16.
Summary A protocol has been developed for high-frequency shoot regeneration and plant establishment of Tylophora indica from petiole-derived callus. Optimal callus was developed from petiole explants on Murashige and Skoog basal medium supplemented
with 10μM2,4-dichlorophenoxyacetic acid +2,5μM thidiazuron (TDZ). Adventitious shoot induction was achieved from the surface of the callus after transferring onto shoot
induction medium. The highest rate (90%) of shoot multiplication was achieved on MS medium containing 2.5μM TDZ. Individual elongated shoots were rooted best on halfstrength MS medium containing 0.5μM indole-3-butyric acid (IBA). When the basal cut ends of the in vitro-regenerated shoots were dipped in 150μM IBA for 30 min followed by transplantation in plastic pots containing sterile vermiculite, a mean of 4.1 roots per shoot
developed. The in vitro-raised plantlets with well-developed shoot and roots were successfully established in earthen pots containing garden soil
and grown in a greenhouse with 100% survival. Four months after transfer to pots, the performance of in vitro-propagated plants of T. indica was evaluated on the basis of selected physiological parameters and compared with ex vitro plants of the same age. 相似文献
17.
Tobacco (Nicotiana tabacum L.) plants were cultured in vitro photoautotrophically at three levels of irradiance (PAR 400–700 nm): low (LI, 60 μmol m−2 s−1), middle (MI, 180 μmol m−2 s−1) and high (HI, 270 μmol m−2 s−1). Anatomy of the fourth leaf from bottom was followed during leaf development. In HI and MI plants, leaf area expansion started
earlier as compared to LI plants, and both HI and MI plants developed some adaptations of sun species: leaves were thicker
with higher proportion of palisade parenchyma to spongy parenchyma tissue. Furthermore, in HI and MI plants palisade and spongy
parenchyma cells were larger and relative abundance of chloroplasts in parenchyma cells measured as chloroplasts cross-sectional
area in the cell was lower than in LI plants. During leaf growth, chloroplasts crosssectional area in both palisade and spongy
parenchyma cells in all treatments considerably decreased and finally it occupied only about 5 to 8 % of the cell cross-sectional
area. Thus, leaf anatomy of photoautotrophically in vitro cultured plants showed a similar response to growth irradiance as in vivo grown plants, however, the formation of chloroplasts and therefore of photosynthetic apparatus was strongly impaired. 相似文献
18.
Agroinfiltration was used to express transiently cre recombinase from bacteriophage P1 in planta. Activation of gfp expression after cre-mediated excision of a bar intervening sequence served as a marker to monitor site-specific recombination events in lox-target N. benthamiana plants. Gfp expressing regenerants from A. tumefaciens infiltrated leaves were obtained with an efficiency of about 34%. In 20% of the regenerants bar gene excision was due to the expression of stably integrated cre gene, whereas in 14% of plants site-specific recombination was a consequence of transient cre expression. Phenotypic and molecular data indicated that the recombined state has been transferred to the T1 generation. These results demonstrate the suitability of agroinfiltration for the expression of cre recombinase in vivo. 相似文献
19.
J. A. Bunce 《Photosynthetica》2008,46(4):517-524
Plants differ in how much the response of net photosynthetic rate (P
N) to temperature (T) changes with the T during leaf development, and also in the biochemical basis of such changes in response. The amount of photosynthetic acclimation
to T and the components of the photosynthetic system involved were compared in Arabidopsis thaliana and Brassica oleracea to determine how well A. thaliana might serve as a model organism to study the process of photosynthetic acclimation to T. Responses of single-leaf gas exchange and chlorophyll fluorescence to CO2 concentration measured over the range of 10–35 °C for both species grown at 15, 21, and 27 °C were used to determine the
T dependencies of maximum rates of carboxylation (VCmax), photosynthetic electron transport (Jmax), triose phosphate utilization rate (TPU), and mesophyll conductance to carbon dioxide (g’m). In A. thaliana, the optimum T of P
N at air concentrations of CO2 was unaffected by this range of growth T, and the T dependencies of VCmax, Jmax, and g’m were also unaffected by growth T. There was no evidence of TPU limitation of P
N in this species over the range of measurement conditions. In contrast, the optimum T of P
N increased with growth T in B. oleracea, and the T dependencies of VCmax, Jmax, and g’m, as well as the T at which TPU limited P
N all varied significantly with growth T. Thus B. oleracea had much a larger capacity to acclimate photosynthetically to moderate T than did A. thaliana. 相似文献
20.
Two rice chlorophyll (Chl) b-less mutants (VG28-1, VG30-5) and the respective wild type (WT) plant (cv. Zhonghua No. 11) were analyzed for the changes
in Chl fluorescence parameters, xanthophyll cycle pool, and its de-epoxidation state under exposure to strong irradiance,
SI (1 700 μmol m−2 s−1). We also examined alterations in the chloroplast ultrastructure of the mutants induced by methyl viologen (MV) photooxidation.
During HI (0–3.5 h), the photoinactivation of photosystem 2 (PS2) appeared earlier and more severely in Chl b-less mutants than in the WT. The decreases in maximal photochemical efficiency of PS2 in the dark (Fv/Fm), quantum efficiency of PS2 electron transport (ΦPS2), photochemical quenching (qP), as well as rate of photochemistry (Prate), and the increases in de-epoxidation state (DES) and rate of thermal dissipation of excitation energy (Drate) were significantly greater in Chl b-mutants compared with the WT plant. A relatively larger xanthophyll pool and 78–83 % conversion of violaxanthin into antheraxanthin
and zeaxanthin in the mutants after 3.5 h of HI was accompanied with a high ratio of inactive/total PS2 (0.55–0.73) and high
1–qP (0.57–0.68) which showed that the activities of the xanthophyll cycle were probably insufficient to protect the photosynthetic
apparatus against photoinhibition. No apparent difference of chloroplast ultrastructure was found between Chl b-less mutants and WT plants grown under low, LI (180 μmol m−2 s−1) and high, HI (700 μmol m−2 s−1) irradiance. However, swollen chloroplasts and slight dilation of thylakoids occurred in both mutants and the WT grown under
LI followed by MV treatment. These typical symptoms of photooxidative damage were aggravated as plants were exposed to HI.
Distorted and loose scattered thylakoids were observed in particular in the Chl b-less mutants. A greater extent of photoinhibition and photooxidation in these mutants indicated that the susceptibility to
HI and oxidative stresses was enhanced in the photosynthetic apparatus without Chl b most likely as a consequence of a smaller antenna size. 相似文献