biologia plantarum

International journal on Plant Life established by Bohumil Němec in 1959

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Results 1561 to 1590 of 6239:

Effects of freezing on plasma membrane H+-ATPase of the callus from Chorispora bungeana

J. M. Wu, Z. G. Zhao, H. Xing, H. P. Guo, W. X. Li, L. Z. An, S. J. Xu, T. Chen

Biologia plantarum 51:229-234, 2007

The influence of freezing treatment on plasma membrane (PM) H+-ATPase was investigated using plasma membrane vesicles isolated from calluses from Chorispora bungeana Fisch. & C.A. Mey. by the discontinuous sucrose gradient centrifugation. Freezing treatment (-4 °C) for 5 d resulted in significant increases in the ATPase activity and the activity of p-nitrophenyl phosphate (PNPP) hydrolysis, decreases in the Km for ATP hydrolysis and PNPP hydrolysis, and the shift of optimal pH from 6.5 to 7.0. Also, the activity PNPP hydrolysis was less sensitive to vanadate after freezing treatment compared to control, while the inhibition of ATP hydrolysis by hydroxylamine was more sensitive. In addition, freezing treatment also decreased the activation effects of trypsin on PNPP hydrolysis, but increased the activation effects of lysophosphatidylcholine on ATP hydrolysis. Taken together, these results suggested that PM H+-ATPase might play an important role during adaptation to freezing and enhancing the frost hardness in C. bungeana.

Effects of methyl jasmonate and excess copper on root and leaf growth

W. Maksymiec, Z. Krupa

Biologia plantarum 51:322-326, 2007

A short time effects of 25 and 150 µM Cu2+ or 50 µM methyl jasmonate (MJ) on growth of roots and leaves of Phaseolus coccineus, Allium cepa and Zea mays were investigated. Both Cu2+ and MJ inhibited root growth. Jasmonate synthesis inhibitors (ibuprofen, IB, salicylhydroxamic acid, SHAM, and propylgallate, PG) partially reversed the inhibitory effect of Cu2+ in P. coccineus, but in A. cepa this effect was not clear. Pretreatment with NADPH oxidase inhibitor (20 mM imidazole, IM), and especially ethylene inhibitor (silver thiosulphate, STS) mostly weakened Cu2+ effect on root growth in P. coccineus and A. cepa. The growth of P. coccineus leaves also slowed down by Cu2+ and this effect was partially ameliorated by IB, PG and IM, and completely by SHAM and STS. In Z. mays the effect of STS was considerably lower than that of PG and SHAM which reversed the effect of Cu2+. These results indicate that jasmonate, ethylene and NADPH oxidase activity may be involved in Cu2+ inhibitory action on the roots of dicotyledon plants, but in A. cepa only ethylene and NADPH oxidase are involved. However, leaf growth inhibition induced by excess Cu2+ is connected in Z. mays especially with jasmonate, and in P. coccineus with ethylene, NADPH oxidase and, to a minor degree, with jasmonate.

Genetic differentiation of Vigna species by RAPD, URP and SSR markers

H. K. Dikshit, T. Jhang, N. K. Singh, K. R. Koundal, K. C. Bansal, N. Chandra, J. L. Tickoo, T. R. Sharma

Biologia plantarum 51:451-457, 2007 | DOI: 10.1007/s10535-007-0095-8

Seventy genotypes belonging to 7 wild and cultivated Vigna species were genetically differentiated using randomly amplified polymorphic DNA (RAPD), universal rice primer (URP) and simple sequence repeat (SSR) markers. We identified RAPD marker, OPG13 which produced a species-specific fingerprint profile. This primer characterized all the Vigna species uniquely suggesting an insight for their co-evolution, domestication and interspecific relationship. The cluster analysis of combined data set of all the markers resulted in five major groups. Most of the genotypes belonging to cultivated species formed a specific group whereas all the wild species formed a separate cluster using unweighted paired group method with arithmetic averages and principle component analysis. The Mantel matrix correspondence test resulted in a high matrix correlation with best fit (r = 0.95) from combined marker data. Comparison of three-marker systems showed that SSR marker was more efficient in detecting genetic variability among all the Vigna species. The narrow genetic base of the V. radiata cultivars obtained in the present study emphasized that large germplasm collection should be used in Vigna improvement programme.

Direct plant regeneration from cucumber embryonal axis

A. Vasudevan, N. Selvaraj, A. Ganapathi, C. W. Choi, M. Manickavasagam, S. Kasthurirengan

Biologia plantarum 51:521-524, 2007 | DOI: 10.1007/s10535-007-0111-z

Embryonal axis explants from 2-d-old in vitro germinated seeds were used to induce multiple shoot production. The combination of 4.44 µM BA and 1.59 µM NAA in MS medium triggered the initiation of adventitious shoot buds. The explants with shoot buds produced maximum number of shoots (10.6 per explant) in MS medium supplemented with 4.44 µM BA and 0.065 mM L-glutamine in three successive transfers. The elongated shoots were rooted on MS medium with 4.92 µM IBA. Rooted plants were transferred to soil with a survival rate of 65 %.

Cytokinin oxidase/dehydrogenase activity as a tool in gibberellic acid/cytokinin cross talk

D. Todorova, I. Vaseva, J. Malbeck, A. Trávníčková, I. Macháčková, E. Karanov

Biologia plantarum 51:579-583, 2007 | DOI: 10.1007/s10535-007-0127-4

Changes in endogenous cytokinin (CK) content and cytokinin oxidase/dehydrogenase activity (CKX) in response to gibberellic acid (GA3) in two pea cultivars with different life span were assessed. The control leaves of cv. Scinado, which developed faster, had higher initial cytokinin content and lower CKX activity, while opposite trend was observed in cv. Manuela with longer life span. Increased CKX and decreased CK content were detected in leaves of cv. Scinado after treatments with 0.5, 1 and 5 µM GA3. Changes in CK content and CKX activity in GA3-treated cv. Manuela leaves were reciprocal to those in cv. Scinado. CK content and CKX activity in roots were not significantly influenced by the application of GA3. The slight repression of CKX activity in some of the root samples was accompanied by increased isopentenyladenine and isopentenyladenine riboside content. Obtained results suggest that CKX was responsible for the changes in endogenous cytokinin pool in GA3-treated plants and most probably this enzyme represents an important link in GA/cytokinin cross talk.

Ethylene is a modulator of gibberellic acid-induced antheridiogenesis in Anemia phyllitidis gametophytes

A. KaĽmierczak

Biologia plantarum 51:683-689, 2007 | DOI: 10.1007/s10535-007-0143-4

In fern (Anemia phyllitidis) gametophytes cellulose in the walls of the antheridial zone cells which was organized in clusters and spots was transformed via dispersed form to fibrillar arrangement (layered in oblique and perpendicular array in relation to the transverse direction of cell expansion) during antheridiogenesis induced by gibberellic acid (GA3) and/or enhanced by 1-aminocyclopropane-1-carboxylic acid (ACC). In the ACC-treated gametophytes, where antheridia were not induced, the cellulose was arranged in the same manner. Aminooxyacetic acid (AOA), which inhibits antheridiogenesis and development of fern gametophytes, produced in the cell walls both random and longitudinal type of organization of cellulose microfibrils, however, in the GA3/AOA-treated plants the oblique type was also observed. The total numbers of cells with perpendicular and/or oblique type of cellulose microfibrils in the GA3-, GA3/ACC-and GA3/AOA-treated gametophytes corresponded to the average number of antheridia formed. Moreover, it was found that the extracts from the gametophytes treated with GA3 or with the mixture of GA3 and ACC contained significantly less soluble sugars but more α-amylase-and endoglucanase-released sugars than the extracts from the gametophytes of the other series. Thin layer chromatography of the samples from the cell wall extracts hydrolyzed by endoglucanase contained xylose and cellobiose which suggested that these sugars built the xyloglucans, hemicellulose polymers responsible for tethering of walls of fern gametophyte cells like in higher plants.

Pepper seed germination assessed by combined X-radiography and computer-aided imaging analysis

A. Dell'Aquila

Biologia plantarum 51:777-781, 2007 | DOI: 10.1007/s10535-007-0159-9

A lot of pepper seeds having 87 % germination were subjected to X-ray inspection using a non lethal dose of radiation. Seeds with less than 2.7 % (on the basis of total seed area) of free space area, i.e. the spaces between embryo and endosperm, were classified as highly viable seeds (97-100 % germination) with the lowest level of abnormal seedlings. Seeds X-ray classified as good were subjected to a computerised image analysis to study seed imbibition and radicle elongation. The patterns of seed area increase, chosen as the most accurate indicator of seed swelling, resembled the triphasic curve of water uptake. The first phase was completed at 9 h followed by a second phase that varied widely in time until completion of germination between 52 and 96 h. The proportion of seeds with radicle protrusion between 52-56 h and 64-72 h assessed with the image analysis was significantly higher than that recorded using a conventional germination test. In addition, the rate of increase of seed area during the third phase of imbibition, mostly due to protrusion of the radicle tip and its growth, was highly correlated with the corresponding radicle elongation rate.

Kang, M.S. (ed.): Genetic and Production Innovations in Field Crop Technology: New Developments in Theory and Practice

L. Nátr

Biologia plantarum 50:799-800, 2006 | DOI: 10.1007/s10535-006-0139-5

Estimation of endogenous contents of phytohormones during internode development in Merremia emarginata

D. Patel, V. S. Thaker

Biologia plantarum 51:75-79, 2007 | DOI: 10.1007/s10535-007-0015-y

During the entire period of internode growth of Merremia emarginata contents of gibberellic acid (GA3), phenyl-acetic acid (PAA), indole-3-acetic acid (IAA, free and conjugated) and abscisic acid (ABA, free and conjugated) were estimated by ELISA using polyclonal antibodies raised against each hormones. At the time of internode elongation free auxin content was low and increased with the decrease in the rate of elongation. In contrast, conjugated IAA showed declining trend where free IAA content was remarkably high, suggesting thereby that conjugated IAA might have mobilized during the later phase of internode development. The endogenous GA3 contents were high as compared to other hormones; however, no significant role of GA3 was discernible in elongation growth. Conjugated ABA contents remained very low during the elongation growth and increased thereafter.

Elevated CO2 Reduces Vessel Diameter and Lignin Deposition in Some Legume Plants Grown in Mini-FACE Rings

L. Sanità di Toppi, A. Fabbri, M.A. Favali, T. Ganino, S. Grassi, A. Raschi

Biologia plantarum 46:243-249, 2003 | DOI: 10.1023/A:1022806812134

Studies on stem (and leaf) structure and histology of a semi-natural grassland community, permanently growing in mini-FACE rings under elevated concentrations of atmospheric CO2 (560 μmol mol-1) are presented. Histochemical analysis of stem sections from legume plants grown under high CO2 concentration revealed both a reduction of lignin deposition in spring vascular bundles of Trifolium repens L., and a decrease in size of the xylem vessels in Vicia hybrida L. and Vicia sativa L. Thus, the effects of elevated CO2 on the stem histology of the species investigated are rather species-specific and/or organ-specific, and of major account especially in the early phases of vegetative growth, in particular as regards lignin deposition mechanisms. In leaves, neither differences as to lignification nor any other anatomical structure modification were found under CO2 enrichment.

Growth and Enzyme Activity in Roots and Calli of Resistant and Susceptible Allium Lines as Influenced by Sterile Culture Filtrates of Phoma terrestris

D. Zappacosta, R. Delhey, N. Curvetto

Biologia plantarum 46:101-105, 2003 | DOI: 10.1023/A:1022322403283

Growth and activities of peroxidases, chitinases and glucanases were studied in order to evaluate the response of calli and roots of pink root-susceptible Allium cepa cvs. Valcatorce and T-412 and resistant A. fistulosum cv. Nogiwa Negi, to sterile culture filtrates of Phoma terrestris. Untreated calli and roots of A. fistulosum exhibited higher activity of peroxidases and glucanases than that of Valcatorce and T-412. Enzyme activities and growth of roots and calli were not affected in filtrate-treated A. fistulosum. The growth of calli and roots of A. cepa cultivars decreased significantly after exposure to P. terrestris filtrates while the peroxidase and glucanase activities increased. Peroxidase and glucanase activities were also enhanced in roots of Valcatorce bulbs grown in P. terrestris-inoculated soil as compared to healthy control plants. We conclude that a high constitutive activity of glucanases and perhaps chitinases might account for the resistance of A. fistulosum. The differential reaction (with respect to root growth) of pink root-susceptible and resistant materials to culture filtrates indicates that this in vitro-system might be useful for the screening of onion breeding lines.

Water Relations Only Partly Explain the Distributions of Three Perennial Plant Species in a Semi-arid Environment

F. Domingo, A.J. Brenner, L. Gutiérrez, S.C. Clark, L.D. Incoll, C. Aguilera

Biologia plantarum 46:257-262, 2003 | DOI: 10.1023/A:1022810913043

The water relations and stomatal conductances of three perennial plant species, Stipa tenacissima L., Anthyllis cytisoides L., and Retama sphaerocarpa (L.) Boiss., dominant on the upper slopes, mid-slopes and floor of a valley, respectively, in semi-arid south-east Spain, were investigated to test the hypothesis that differences in plant-soil water relations could account for the different distributions of each species in the catena. Diurnal measurements of water potential (Ψw), relative water content (RWC) and stomatal conductance (gs) of leaves were made over one year. Leaf temperature, air humidity, wind-speed and incident quantum flux density were measured concurrently. Soil water content was determined gravimetrically at 0 - 5 cm and 15 - 20 cm depths. Measurements of Ψw, RWC and gs were analysed according to meteorological conditions, based on the maxima for daily air temperature and atmospheric saturation water vapour deficit and on soil moisture content. The hypothesis that plant-soil water relations can explain the distribution of the three species along the catena from valley side to valley floor was rejected for Anthyllis and Stipa but confirmed for Retama.

Compensation heat-pulse measurements of sap flow for estimating transpiration in young lemon trees

J. J. Alarcon, M. F. Ortuno, E. Nicolas, R. Torres, A. Torrecillas

Biologia plantarum 49:527-532, 2005 | DOI: 10.1007/s10535-005-0046-1

Potted two-year-old lemon trees [Citrus limon (L.) Burm. f.], cv. Verna grafted on sour orange (C. aurantium L.) rootstock, growing in greenhouse, were subjected to drought for 33 d. Control plants were daily irrigated at field capacity. Values of sap flow (SF) were compared with transpiration (E) rates measured gravimetrically. The results underlined the robustness and high sensitivity of the compensation heat-pulse technique for estimating transpiration on a wide range of SF. Good direct correlations between E and SF rates on an instantaneous and daily basis were obtained in both treatments. On a daily basis, a common calibration curve can be used for both irrigation treatments. On an instantaneous basis, changes in SF were matches by similar changes in E in both treatments, although the relationships between these parameters presented different intercepts in each treatment. Sap flow rates were influenced by weather conditions in trees growing in non-limiting soil water conditions. This makes it possible to evaluate the significance of any sap flow measurement in relation to the reference value calculated for the vapour pressure deficit at the time the measurement was taken.

Chalcone synthase homologues from Humulus lupulus: some enzymatic properties and expression

P. Novak, K. Krofta, J. Matousek

Biologia plantarum 50:48-54, 2006 | DOI: 10.1007/s10535-005-0073-y

The enzymatic properties of four chalcone synthase homologues CHS_H1, VPS, CHS 2 and CHS 4 from Humulus lupulus L. were investigated after heterologous expression in Escherichia coli. It was found that both VPS and CHS_H1 can utilize isovaleryl-CoA and isobutyryl-CoA as substrates producing compounds with positions in thin layer chromatography characteristic for phloroisovalerophenone and phloroisobutyrophenone. These reactions are accompanied by the formation of associated byproducts. The formation of naringenin chalcone can be catalyzed primarily by CHS_H1. Comparatively the ability of VPS to perform chalcone synthase reaction is very limited. Since only CHS_H1 has true chalcone synthase activity, this enzyme can be considered a key enzyme in prenylflavonoid biosynthesis. Both CHS 2 and CHS 4 utilize isovaleryl-CoA and isobutyryl-CoA as substrates, but the reactions were prematurely terminated. In comparison with VPS and CHS_H1, the optimum pH of CHS 2 was shifted to lower value. High expression of chalcone synthase-like genes were found in maturating hop cones of cultivars with high bitter acid content (Agnus, Magnum, Target) by Northern and Western blotting using probes specific for vps, chs_H1, chs 4 and polyspecific serum risen against recombinant protein CHS4, respectively. It was also found that these cultivars maintained expression of CHS homologues for a longer period of time during cone development in contrast to time-limited expression of CHS homologues in cultivars with low bitter acids content.

Secretion of a chitinase-like protein in embryogenic suspension cultures of Dactylis glomerata L.

M. I. Tchorbadjieva, I. Y. Pantchev

Biologia plantarum 50:142-145, 2006 | DOI: 10.1007/s10535-005-0090-x

A chitinase-like 32 kDa acidic protein with a potential chitinase activity has been identified in the medium of embryogenic suspension cultures of Dactylis glomerata L. using an antiserum raised against endochitinase EP3 from Daucus carota L. The presence of this protein discriminates between Dactylis glomerata L. embryogenic and nonembryogenic suspension cultures and thus could be possibly used as a marker for embryogenic potential.

Jasmonic acid induced changes in protein pattern, antioxidative enzyme activities and peroxidase isozymes in peanut seedlings

G. J. Kumari, A. M. Reddy, S. T. Naik, S. G. Kumar, J. Prasanthi, G. Sriranganayakulu, P. C. Reddy, Chinta Sudhakar

Biologia plantarum 50:219-226, 2006 | DOI: 10.1007/s10535-006-0010-8

Protein pattern, ammonia content, glutamine synthetase activity, lipid peroxidation, superoxide dismutase, catalase, peroxidase and peroxidase isoforms were studied in the leaves and roots of 7-d-old peanut (Arachis hypogaea L. cv. JL-24) seedlings treated by 25, 100 and 250 μM jasmonic acid (JA). SDS-PAGE protein profile of leaves and roots after JA application showed a significant increase in 18, 21, 30, 45, 47 and 97.4 kDa proteins and significant decrease in 22 and 36 kDa proteins. Pathogenesis related PR-18 was specific in leaves at 250 μM JA and PR-21 have cross reacted differently with 21 and 30 kDa proteins in leaves and roots treated by all JA concentrations. Further, the immunoblot analysis with glutamine synthetase, GS-45 antibodies revealed a specific cross reaction with 45 and 47 kDa proteins of both control and JA treated leaves, however, higher at 100 and 250 μM JA treated leaves than control ones. Further, the malondialdehyde (MDA) content significantly increased in leaves and roots treated with JA, indicated membrane damage with JA treatments that led to the generation of peroxidation products. The peroxidase isozymic pattern showed two specific isoforms. Besides, the activities of SOD and catalase were significantly elevated in JA treated leaves.

Water relations, activities of antioxidants, ethylene evolution and membrane integrity of pigeonpea roots as affected by soil moisture

M. Jain, A. S. Nandwal, B. S. Kundu, B. Kumar, I. S. Sheoran, N. Kumar, A. Mann, S. Kukreja

Biologia plantarum 50:303-306, 2006 | DOI: 10.1007/s10535-006-0026-0

The plants of pigeonpea (Cajanus cajan L.) cv. H77-216 were subjected to moderate [soil moisture content (SMC) = 7.3 ± 0.5 %] and severe (SMC = 4.3 ± 0.5 %) drought by withholding the irrigation at vegetative stage (45 d after sowing). The control plants were maintained at SMC of 11.0 ± 0.5 %. Half of the stressed plants were re-irrigated and their recovery was studied after 2 d. Leaf water potential, osmotic potential, and relative water content of leaf and root decreased significantly while a sharp rise in proline and total soluble sugars contents were noticed. Drought induced a significant increase in 1-aminocyclopropane 1-carboxylic acid (ACC) content and ACC oxidase activity which caused a considerable increase in ethylene evolution. Malondialdehyde content and relative stress injury were increased under drought whereas reverse was true for ascorbic acid content. The membrane integrity of roots decreased during stress and recovered on rehydration. The specific activity of total superoxide dismutase, ascorbate peroxidase, glutathione reductase, and glutathione transferase decreased to 37 - 78 %, 17 - 62 %, 29 - 36 % and 57 - 79 % at moderate and severe drought, respectively. The increase in activity of catalase and peroxidase could not overcome the accumulation of H2O2 content in the roots.

Contrasting foliar responses to drought in Quercus ilex and Phillyrea latifolia

R. Ogaya, J. Penuelas

Biologia plantarum 50:373-382, 2006 | DOI: 10.1007/s10535-006-0052-y

Leaf morphology, longevity, and demography were examined in Quercus ilex and Phillyrea latifolia growing in a holm oak forest in Prades mountains (northeast Spain). Four plots (10 × 15 m) of this forest were submitted to an experimental drought during three years (soil moisture was reduced about 15 %). Leaf area, thickness and leaf mass per area ratio (LMA) were measured in sun and shade leaves of both species. Leaf longevity, the mean number of current-year shoots produced per previous-year shoot (Sn/Sn-1), the mean number of current-year leaves per previous-year shoot (Ln/Sn-1), and the percentage of previous-year shoots that developed new ones were measured once a year, just after leaf flushing. LMA and leaf thickness increased since leaf unfolding except in summer periods, when stomatal closure imposed low photosynthetic rates and leaves consumed their reserves. LMA, leaf area, and leaf thickness were higher in Q. ilex than in P. latifolia, but leaf density was higher in the latter species. Drought reduced the leaf thickness and the LMA of both species ca. 2.5 %. Drought also increased leaf shedding up to ca. 20 % in Phillyrea latifolia and decreased it up to ca. 20 % in Q. ilex. In the later species, Sn/Sn-1 decreased by 32 %, Ln/Sn-1 by 41 %, percentage of shoots developed new ones by 26 %, and leaf area by 17 %. Thus the decrease of leaf number and area was stronger in the less drought-resistant Q. ilex, which, under increasingly drier conditions, might lose its current competitive advantage in these Mediterranean holm oak forests.

Variation in seed protein and isoenzyme patterns in Cucurbita cultivars

T. Stoilova, N. Cholakova, M. Markova

Biologia plantarum 50:450-452, 2006 | DOI: 10.1007/s10535-006-0068-3

The genetic variability in the seed proteins and the enzyme alcohol dehydrogenase (ADH) in representative species of the genus Cucurbita was studied. The banding patterns were obtained by means of vertical block electrophoresis in polyacrylamide gel. A specific protein components and ADH isoenzymes were established in the polymorphic banding patterns which can be applied individually or in combination as potential biochemical markers for breeding purposes.

Regulations of granule-bound starch synthase I gene expression in rice leaves by temperature and drought stress

S. J. Wang, L. F. Liu, C. K. Chen, L. W. Chen

Biologia plantarum 50:537-541, 2006 | DOI: 10.1007/s10535-006-0085-2

Effects of temperature (15/10, 25/20, 30/25, and 35/30 °C) and drought stresses on the expression of granule-bound starch synthase I (GBSSI) gene were examined in rice (Oryza sativa L.) seedlings. The GBSSI expression was higher at the low temperature (15/10 °C), and the transcript level decreased at temperatures higher than 30 °C. Protein phosphorylation was involved in the low temperature-stimulated signal transduction of GBSSI regulation. The expression of GBSSI in rice seedling was reduced under a drought stress. Even though exogenous ABA played a role to reduce the GBSSI transcript accumulation under non-stress condition, the reducing of GBSSI expression by drought stress appeared to be mediated by an ABA-independent pathway.

Effect of nickel on antioxidative enzyme activities, proline and chlorophyll contents in wheat shoots

E. Gajewska, M. Skłodowska, M. Słaba, J. Mazur

Biologia plantarum 50:653-659, 2006 | DOI: 10.1007/s10535-006-0102-5

Effect of two Ni concentrations (10 and 200 μM) on growth, Ni accumulation, chlorophyll and proline contents, relative water content (RWC) as well as the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and glutathione S-transferase (GST) were studied in shoots of wheat plants. Treatments caused a considerable accumulation of Ni in the shoots. However, exposure of plants to 10 μM Ni did not lead to significant alterations in shoot growth except for a slight increase in fresh mass. The other parameters studied were not affected by treatment of plants with 10 μM Ni. In contrast, 200 μM Ni caused inhibition of shoot growth, a decline in RWC and chlorophyll content, accumulation of proline and occurrence of visible symptoms of Ni toxicity. The activities of SOD and CAT decreased in response to 200 μM Ni. Conversely, several-fold enhancements of POD and GST activities were observed following the 3rd day of 200 μM Ni treatment.

Rapid micropropagation of mature wild cherry

J. Ďurkovič

Biologia plantarum 50:733-736, 2006 | DOI: 10.1007/s10535-006-0118-x

Explants taken from the mature vigorous tree of wild cherry (Prunus avium L.) were assayed for their organogenic capacity under various phytohormonal treatments. The highest rate of adventitious shoot multiplication was recorded at a combination of 0.5 mg dm-3 6-benzylaminopurine (BAP) and 0.05 mg dm-3 thidiazuron (6.83 shoots per explant). No differences in multiplication rates were found among media supplemented with BAP, BAP + α-naphthaleneacetic acid (NAA) or BAP + indole-3-butyric acid (IBA). Shoot elongation was significantly affected by the concentration of BAP, regardless of auxin addition to medium. Up to 73 % of microshoots rooted after using 0.3 mg dm-3 IBA, otherwise the adventitious rooting occurred at reasonable frequencies in all auxin treatments. Regenerated plantlets were successfully hardened ex vitro and continued to grow after the transfer to soil. No morphological aberrations were observed in the regenerates.

Stress-induced changes in the free amino acid composition in transgenic soybean plants having increased proline content

L. Simon-Sarkadi, G. Kocsy, Á. Várhegyi, G. Galiba, J. A. De Ronde

Biologia plantarum 50:793-796, 2006 | DOI: 10.1007/s10535-006-0134-x

Following drought stress at supraoptimal temperature the increase in proline (Pro) content in transgenic (T) soybean [Glycine max (L.) Merr. cv. Ibis] plants overexpressing the gene coding for the last enzyme of Pro biosynthesis, L-Δ1-pyrroline-5-carboxylate reductase, was much greater than in wild type (W) plants (105-fold versus 19-fold after 7 d). Under control conditions arginine accounted for nearly 60 % of the total free amino acid content. After stress treatment the content of Pro was more than 50 % in both T and W genotypes, and at the end of recovery the γ-aminobutyrate content reached 27 and 53 % in the W and T plants, respectively. Without stress treatment there was only a 2-fold difference between T and W in the tyrosine content. However, during the stress period and the subsequent recovery a similar difference was found for many amino acids. The present results indicate that manipulating of the content of a single amino acid influences the whole free amino acid composition in soybean.

Plant telomere-binding proteins

M. Kuchar

Biologia plantarum 50:1-7, 2006 | DOI: 10.1007/s10535-005-0067-9

Telomere-binding proteins have recently been recognised not only as necessary building blocks of telomere structure, but namely as components which are of central importance to telomere metabolism being involved in regulation of telomere length as well as in protective (capping) function of telomeres. Although the knowledge on plant telomeric DNA-binding proteins lags behind that in human and yeast, recent data show both analogies and plant-specific features in the composition and interactions of telomeric proteins. This review focuses primarily on proteins with known amino acid sequence. These can be classified into following groups: 1) the family of proteins with Myb domain at C-terminus, 2) proteins with Myb domain at N-terminus, both binding double-stranded DNA of telomeric repeats TTTAGGG, 3) the single-stranded DNA-binding proteins, and 4) other proteins that act also in non-telomeric chromatin regions. Proteins with C-terminal Myb domain reported as IBP family were previously found in human, whereas Smh family representing proteins with Myb domain at N-terminus was identified only in plants. Also RRM family of the single-stranded DNA-binding proteins is likely to be plant specific.

In vitro organogenesis and plant formation in cucumber

N. Selvaraj, A. Vasudevan, M. Manickavasagam, A. Ganapathi

Biologia plantarum 50:123-126, 2006 | DOI: 10.1007/s10535-005-0085-7

In vitro organogenesis was achieved from callus derived from hypocotyl explants of Cucumis sativus L. cv. Poinsett 76. Calli were induced from hypocotyl explants excised from 7-d-old seedlings grown on Murashige and Skoog (MS) medium containing 87.64 µM sucrose, 0.8 % agar, 3.62 µM 2,4-dichlorophenoxy acetic acid and 2.22 µM 6-benzyladenine (BA). Regeneration of adventitious buds from callus (25 shoots explant-1) was achieved on MS medium supplemented with 8.88 µM BA, 2.5 µM zeatin and 10 % coconut water after two subcultures in the same medium at 30-d interval. Gibberellic acid (1.75 µM) favoured shoot elongation and indole 3-butyric acid (7.36 µM) induced rooting. Rooted plants were hardened and successfully established in soil.

Characterization of the Ferredoxin-Gogat gene (OsGog2 clone) expression in rice

M. Mattana, E. Biazzi, A. Bertani, I. Coraggio

Biologia plantarum 50:187-192, 2006 | DOI: 10.1007/s10535-006-0005-5

Ferredoxin-dependent glutamate synthase (Fd-Gogat; EC 1.4.7.1) in leaf and root plastids is the last enzyme involved in the pathway of nitrate assimilation in higher plants. Arabidopsis thaliana expresses two different genes: the first, light regulated, specific of green tissues and the second expressed in other tissues. In this work, we investigated whether in our clone, OsGog2 AC Y12595, this gene is up-regulated by light or it is expressed under darkness. Fd-Gogat specific activity, protein and mRNA increased after light treatment in rice shoots. In roots, the activity and the protein content remained constant, whereas the mRNA is repressed by light treatment. The results obtained using a specific probe, situated in the 3' untranslated region of the OsGog2 cDNA, indicated that OsGog2 gene is up-regulated by light and that its expression is tissue specific and suggested that a dark expressed Fd-Gogat gene could be present in rice similarly as in Arabidopsis.

Influence of brassinosteroids on initiation of the root gravitropic response in Pisum sativum seedlings

G. N. Amzallag, J. Vaisman

Biologia plantarum 50:283-286, 2006 | DOI: 10.1007/s10535-006-0021-5

In roots of Pisum sativum seedlings, the average lag-time required for initiation of the gravitropic response was reduced proportionally to the concentration of 24-epibrassinolide (EBL) added to the root solution (range of 10-13 to 10-8 M concentrations). A treatment with clotrimazole, a compound inhibiting steroid synthesis, prevents initiation of the gravitropic response. This effect was partly reverted by addition of EBL. From analysis of variability in the populations, it is suggested that BR conditions the root curvature through a gravitropic-induced change in sensitivity to the PGRs regulating cell elongation.

In vitro analysis of susceptibility to Agrobacterium rhizogenes in 65 species of Mexican cacti

M.C. González-Díaz, M.E. Pérez-Reyes, E. Pérez-Molphe-Balch

Biologia plantarum 50:331-337, 2006 | DOI: 10.1007/s10535-006-0077-2

Susceptibility of Mexican cacti to Agrobacterium rhizogenes was evaluated in 65 species of 22 genera. Stem discs taken from in vitro cultured plants were inoculated with Agrobacterium rhizogenes A4 agropine-type strain that contains the wild RiA4 plasmid and the binary vector pESC4 with the nptII and gus genes. Hairy roots were produced directly from wounds, or starting from calli generated on the wounded surface, in 34 of the evaluated species. The frequency of hairy roots formation, the number of roots per explant and its growth rates were variable among the tested species. In the 31 remaining species the production of transformed roots was not observed under the conditions used in these experiments. Histochemical detection of β-glucuronidase (GUS) activity demonstrated the expression of this foreign gene in the hairy roots. PCR analyses demonstrated the presence of the rolB and nptII genes in the DNA of the transformed roots. The patterns of alkaloid-like compounds obtained by thin layer chromatography in some of the tested species were qualitatively similar between the transformed and non-transformed roots.

Propagation of Ficus carica L. clones by in vitro culture

S. Hepaksoy, U. Aksoy

Biologia plantarum 50:433-436, 2006 | DOI: 10.1007/s10535-006-0063-8

This experiment is designed to determine the most suitable conditions and media for propagating three selected fig (Ficus carica L.) clones through tissue culture. The clone 37 displayed a higher performance than clones 50 and 82. As the multiplication medium, the Murashige and Skoog (MS) medium containing 1 mg dm-3 α-indole-3-butyric acid (IBA), 1 mg dm-3 gibberellic acid and 5 mg dm-3 6-benzyladenine were the best, whereas, MS medium complemented with 1.2 and 2.5 μM IBA or 1-naphthalene acetic acid (NAA) were better in respect to rooting. Peat followed by volcanic tuff gave the best performance for acclimatization to outdoor conditions.

In vitro culture of Gypsophila paniculata L. and random amplified polymorphic DNA analysis of the propagated plants

M. R. Rady

Biologia plantarum 50:507-513, 2006 | DOI: 10.1007/s10535-006-0080-7

A protocol is established for regeneration of the economically important cut flower plant, Gypsophila paniculata L., using shoot tips explants. Multiple shoots were obtained on Murashige and Skoog medium fortified with 0.5 mg dm-3 each of α-naphthaleneacetic acid and 6-benzyladenine. Addition of 10 g dm-3 agar promoted shoot proliferation and reduced the degree of shoot vitrification. Transfer to 3 mg dm-3 indole-3-butyric acid containing medium produced optimum root initiation and development. The produced plants as well as intact plants were subjected to the random amplified polymorphic DNA (RAPD) analysis. Using 9 primers, the total number of amplification products generated by polymerase chain reaction was 142 bands (15.7 bands per primer), of which 7.74 % showed polymorphism. The analysis of bands recorded, showed 92.25 % similarity. The results indicated that very low variation at the DNA level occurred during in vitro culture of Gypsophila.

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