biologia plantarum

International journal on Plant Life established by Bohumil Němec in 1959

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Results 721 to 750 of 2229:

Nitrogen nutrition of rice plants under salinity

E. M. Abdelgadir, M. Oka, H. Fujiyama

Biologia plantarum 49:99-104, 2005 | DOI: 10.1007/s10535-005-0104-8

Two rice (Oryza sativa L.) cultivars, Koshihikari and Pokkali, were grown in solution culture at three concentrations of NaCl or Na2SO4 [0 (S0), 50 (S1), and 100 (S2) mmol dm-3] and three N contents [0.7 (N1), 7 (N2) and 14 (N3) mmol dm-3]. Salinity significantly decreased dry matter of both cultivars. Pokkali had better growth than Koshihikari under both saline and non-saline conditions. Applications of N enhanced development of shoot dry mass under S0 and S1 treatments up to N2. Under S2, N application had no effect on shoot dry mass of both cultivars. Root dry mass of both cultivars decreased with increasing N application at S1 and S2. Shoot and root NO3-N content in both rice cultivars increased with increasing N concentration in the nutrient solutions. The absorption of NO3-N was less in Koshihikari than Pokkali plants, and also was much less in Cl- than SO4 2- salinity suggesting the antagonism between Cl- and NO3 -. In addition a significant negative correlation between concentrations of NO3-N and Cl- in the shoots or roots was observed in both cultivars

Cytogenetic analysis of hybrids derived from wheat and Tritipyrum using conventional staining and genomic in situ hybridization

G. Mirzaghaderi, G. Karimzadeh, H. S. Hassani, M. Jalali-Javaran, A. Baghizadeh

Biologia plantarum 54:252-258, 2010 | DOI: 10.1007/s10535-010-0044-9

The new salt tolerant cereal, Tritipyrum (2n=6x=42, AABBEbEb) offers potential to introduce desirable characters for wheat improvements. This study was aimed to generate a segregating population from Iranian local wheat cultivars (2n=6x=42, AABBDD) and Tritipyrum crosses, study of the meiotic behaviour in F2 hybrids and identification of Eb chromosomes in F3 individuals. Results showed meiotic abnormalities in F2 plants and different pairing frequency in the meiosis among F2 plants. Genomic in situ hybridization revealed that total and Eb chromosome number of F3 seeds ranged from 39 to 45 and 0 to 10, respectively. A significant prevalence of hyper-aneuploidy was observed among F3 genotypes. C-banding patterns identified Eb chromosomes in Tritipyrum, indicating that it also can be useful to study wheat-Tritipyrum derivatives.

Factors affecting in vitro propagation and field establishment of Chlorophytum borivilianum

A. Kumar, D. Aggarwal, P. Gupta, M. S. Reddy

Biologia plantarum 54:601-606, 2010 | DOI: 10.1007/s10535-010-0109-9

The effect of plant growth regulators (PGRs), gelling agents, sucrose and heat shock on shoot multiplication, shoot growth, rooting and subsequent survival of Chlorophytum borivilianum Sant. et Fernand was evaluated. Benzyladenine (BA) was found to be better cytokinin over kinetin (KIN) for shoot multiplication. Sucrose concentrations from 116-290 mM in the basal medium (BM) promoted shoot multiplication. Heat shock (50 °C, 1 h) also promoted shoot multiplication at these sucrose concentrations on both BM medium and BM supplemented with 5.0 μM BA. Beneficial effect of sucrose was also observed on rooting of shoots on BM as well as BM supplemented with 5.0 μM indole-3-butyric acid (IBA). Phytagel as a gelling agent was found to be more effective for shoot proliferation and growth compared to agar. Amongst various soil mixtures tested, higher survival of plants was observed in soil containing Vermicompost. It was interesting to note that a maximum plant survival (> 95 %) was observed when plants were directly transferred to net-house (irradiance reduced to 50 % with green net, without humidity and temperature control) than poly-house (with humidity and temperature control). Random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) analysis of regenerated plants showed genetic similarity to mother plant.

Leaf morphology and anatomy of transgenic cucumber lines tolerant to downy mildew

M. Szwacka, T. Tykarska, A. Wisniewska, M. Kuras, H. Bilski, S. Malepszy

Biologia plantarum 53:697-701, 2009 | DOI: 10.1007/s10535-009-0125-9

The objective of the present paper was to investigate the reason of increased tolerance to the pathogenic fungus Pseudoperonospora cubensis found in transgenic cucumber (Cucumis sativus L.) lines 210 and 212 bearing 35S:cDNA preprothaumatin II gene construct. The tolerance investigation was accomplished by comparing the morphological and anatomical structure of plant leaves. The results obtained demonstrate that leaves of both lines exhibited some anatomical and morphological characteristics (e.g. wax load and composition, cuticle ultrastructure, ultrastructure of secondary wall, arrangement of mesophylll cells) which may be responsible for enhanced tolerance.

Direct somatic embryogenesis and plant regeneration from immature explants of chickpea

S. Kiran Ghanti, K. G. Sujata, M. Srinath Rao, P. B. Kavi Kishor

Biologia plantarum 54:121-125, 2010 | DOI: 10.1007/s10535-010-0018-y

A protocol for plant regeneration via somatic embryogenesis was developed in two chickpea (Cicer arietinum L.) cultivars ICCV-10 and Annigeri. Somatic embryos were induced from immature cotyledons on Murashige and Skoog's (MS) medium supplemented with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), α-naphthaleneacetic acid (NAA) and picloram alone or in combination with 0.5 - 2.0 mg dm-3 N6-benzylaminopurine (BA) or kinetin (KIN). NAA was better for somatic embryo induction compared to other auxins. The well formed, cotyledonary shaped embryos germinated into plantlets with 36.6 % frequency on MS medium supplemented with 2.0 mg dm-3 BA + 0.5 mg dm-3 abscisic acid (ABA). The frequency of embryogenesis and plantlet regeneration was higher in cv. ICCV-10 as compared to cv. Annigeri. Regenerated plants were transferred to soil (40 % survival) and grown to maturity. Histological studies of explants at various developmental stages of somatic embryogenesis reveled that somatic embryos developed directly from the cotyledon cells and they were single cell origin.

Exogenously-supplied trehalose protects thylakoid membranes of winter wheat from heat-induced damage

Y. Luo, F. Li, G. P. Wang, X. H. Yang, W. Wang

Biologia plantarum 54:495-501, 2010 | DOI: 10.1007/s10535-010-0087-y

The effects of trehalose pretreatment on thylakoid membranes of winter wheat were investigated under heat stress. Under normal growth conditions, the winter wheat synthesized 502 μg g-1(f.m.) trehalose, which increased to 1250 μg g-1(f.m.) under heat stress and to 1658 μg g-1(f.m.) in trehalose-pretreated seedlings. Under heat stress, proteins in the thylakoid membranes and the photosynthetic capacity were protected by trehalose pretreatment. Moreover, the electrolyte leakage, contents of malondialdehyde, superoxide anion and hydrogen peroxide, and lipoxygenase activity in trehalose-pretreated seedlings were lower than in the non-pretreated plants.

Efficient Regeneration of Tetraploid Isatis indigotica Plants via Adventitious Organogenesis from Hypocotyl Explants

L. Zhang, G. Kai, T. Xu, Y. Pi, H. Zhang, X. Sun, K. Tang

Biologia plantarum 48:121-124, 2004 | DOI: 10.1023/B:BIOP.0000024287.23065.e8

An efficient in vitro plant regeneration system via hypocotyl segments of tetraploid Isatis indigotica Fort. was established. Murashige and Skoog's (MS) and Gamborg's (GB5) media were found to be superior to White medium for promoting shoot regeneration. The highest shoot regeneration (92 %) was achieved from hypocotyls cultured on MS medium containing 8.9 μM benzyladenine (BA) and 2.7 μM naphthaleneacetic acid (NAA), with an average of 4.2 shoots developed per explant. Plant regeneration was also improved when the explants were cultured in MS basal medium containing 3 % (m/v) sucrose and grown under a 12-h photoperiod. The developed shoots were well rooted in a half-strength MS medium supplemented with 0.5 μM indole-3-butyric acid (IBA) and were morphologically normal after transfer to soil.

Plasma membrane localization of soybean matrix metalloproteinase differentially induced by senescence and abiotic stress

C.-W. Cho, E. Chung, K. Kim, H.-A. Soh, Y. K. Jeong, S.-W. Lee, Y.-C. Lee, K.-S. Kim, Y.-S. Chung, J.-H. Lee

Biologia plantarum 53:461-467, 2009 | DOI: 10.1007/s10535-009-0086-z

We isolated and characterized a stress-inducible gene, designated as Slti114, encoding matrix metalloproteinase (MMP) in soybean. The derived amino acid sequences of Slti114 show the 69 % homology with MMP2 from Glycine max (AAL27029). The size of the full-length cDNA of Slti114 is 1194 bp with open reading frame comprised of 394 amino acids. RNA expression of Slti114 was induced by low temperature or wounding. During early stage, Slti114 RNA level was extremely high, but Slti114 RNA was not detectable just after cotyledons became yellowish. Green fluorescent protein fusion expression system confirmed that Slti114-smGFP and H+-ATPase-RFP were co-localized to the plasma membrane. Purified glutathione-S-transferase (GST)-Slti114 protein was shown to digest myelin basic protein (MBP) in vitro, but not gelatin. This report provides strong evidence that plasma membrane MMP, Slti114 protein may play a critical role during abiotic stress and senescence in plant.

Gibberellin retards chlorophyll degradation during senescence of Paris polyphylla

J. R. Li, K. Yu, J. R. Wei, Q. Ma, B. Q. Wang, D. Yu

Biologia plantarum 54:395-399, 2010 | DOI: 10.1007/s10535-010-0072-5

Chlorophyll (Chl) degradation was found to be related to the endogenous gibberellin (GA) content in shoots during senescence in the perennial plant Paris polyphylla var. yunnanensis (Franch.). Treatment with gibberellic acid (GA3) significantly increased the content of endogenous GAs (GA4 + GA7), retarded the senescence of shoots, and the degradation of proteins and Chl. Chlorophyllase, Mg-dechelation and peroxidase activities increased more in control plants than in those treated with GA3. GA3 treatment also protected lipoxygenase activity, which decreased significantly in control plants.

Tobacco transcription factor WRKY4 is a modulator of leaf development and disease resistance

X.-J. Ren, W -D. Huang, W.-Z. Li, D.-Q. Yu

Biologia plantarum 54:684-690, 2010 | DOI: 10.1007/s10535-010-0121-0

The role of tobacco transcription factor WRKY4 in leaf development and biotic stress tolerance was studied using RNAi suppressed transgenic plants. The leaves were more numerous and wider in NtWRKY4 RNAi suppressed transgenic lines compared to the vector control, while the levels of miRNA166 and miRNA396 were reduced in suppressed lines. NtWRKY4 expression was markedly induced in response to salicylic acid (SA), but not to abiotic stresses. When infected by tobacco mosaic virus (TMV), the leaves of the transgenic plants were more twisted and displayed a more obvious mosaic pattern compared to those of vector-transgenic plants. Less TMV viral RNA accumulated in vector-transformed plants than in transgenic plants. The results indicate that NtWRKY4 is involved in leaf morphogenesis and antiviral defense, which is seldom seen in WRKY family members.

Proteomic analysis of bacterial blight defence signalling pathway using transgenic rice overexpressing thaumatin-like protein

T. Mahmood, A. Jan, S. Komatsu

Biologia plantarum 53:285-293, 2009 | DOI: 10.1007/s10535-009-0052-9

Rice overexpressed thaumatin-like protein gene and the proteins from the leaf blades of 2-week-old transgenic rice seedlings were fractionated into cytosolic and membrane fractions, and separated by two-dimensional polyacrylamide gel electrophoresis and stained with Commassie brilliant blue. Among of 440 detected proteins, 5 proteins were up-regulated and 5 proteins were down-regulated by the overexpression of thaumatin-like protein. In the sense thaumatin-like protein transgenic rice and/or in rice inoculated with Xanthomonas oryzae pv. oryzae (Xo7435), 2-cys peroxiredoxin, thaumatin-like protein and glycine cleavage H protein were up-regulated, while oxygen evolving complex protein 2 was down-regulated. These results suggest that thaumatin-like protein-mediated disease resistance of rice against bacterial blight disease is the results of changes in proteins related to oxidative stress and energy metabolism in addition to changes in proteins related to defence.

Effects of short-term soil flooding on stomata behaviour and leaf gas exchange in barley plants

R. Y. Yordanova, A. N. Uzunova, L. P. Popova

Biologia plantarum 49:317-319, 2005 | DOI: 10.1007/s10535-005-7319-6

Exposure of barley plants (Hordeum vulgare L.) to soil flooding for 2 to 24 h reduced the net photosynthetic rate and transpiration rate. Stomatal conductance also decreased in flooded plants. Stomatal closure started within 2 - 6 h and stomata remained closed up to 24 h of treatment.

Antioxidative system in maize roots as affected by osmotic stress and different nitrogen sources

M. Vuletić, V. Hadľi-Taąković ©ukalović, K. Marković, J. Dragiąić Maksimović

Biologia plantarum 54:530-534, 2010 | DOI: 10.1007/s10535-010-0093-0

The activities of antioxidative enzymes and contents of proline and total phenolics were assayed in roots of two maize (Zea mays L.) genotypes grown in a medium containing nitrate (NO3 -) or both nitrogen forms, nitrate and ammonium (NH4 +/NO3 -). An increase in the activities of class III peroxidases (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX), ascorbate oxidase (AO) and proline content, and decrease in phenolic content were observed in NH4 +/NO3 - in comparison with NO3 - grown plants. When polyethylene glycol (PEG) was added to both nitrogen treatments, the content of total phenolics and proline was increased, especially in NH4 +/NO3 - treatment. The PEG treatment decreased enzyme activities in NH4 +/NO3 - grown plants, but in NO3 - grown plants activities of POD and SOD were increased, opposite to decreased APX and AO. Isoelectric focusing demonstrated increased activities of acidic POD isoforms in PEG treated NO3 - grown plants, and lower activities of both, acidic and basic isoforms in NH4 +/NO3 -grown plants.

Clonal propagation of Zephyranthes grandiflora using bulbs as explants

M. Gangopadhyay, D. Chakraborty, S. Dewanjee, S. Bhattacharya

Biologia plantarum 54:793-797, 2010 | DOI: 10.1007/s10535-010-0145-5

Zephyr lily (Zephyranthes grandiflora), an important ornamental plant has been micropropagated in vitro after controlling microbial contamination by a pretreatment with 0.2 % Bavistin and 0.1 % Pantomycin for 4 h before final sterilization with 0.1 % mercuric chloride. In 67 % of the sterile cultures, 11 shoots on average were regenerated directly from basal half of bulb scales in Murashige and Skoog (MS) medium containing 3 % sucrose and 2 mg dm-3 benzylaminopurine (BAP). Shoots emerged in bunches on a basal achlorophyllous bulbous part. Combination of 2 mg dm-3 BAP with 1 mg dm-3 gibberellic acid (GA3) enhanced shoot growth. Stout roots (maximum of 5-6 per shoot) were developed in presence of 1 mg dm-3 indole-3-butyric acid (IBA). Micro-bulbs showed potential of regeneration and could be used as secondary explants. The morphologically identical plants derived by in vitro propagation were genetically identical as shown by PCR based ISSR marker analysis of genomic DNA.

Secondary embryogenesis and transient expression of the β-glucuronidase gene in hypocotyls of rapeseed microspore-derived embryos

M. R. Abdollahi, A. Moieni, A. H. Salmanian, A. Mousavi

Biologia plantarum 53:573-577, 2009 | DOI: 10.1007/s10535-009-0104-1

Secondary embryogenesis from rapeseed microspore-derived embryos (MDEs) was studied in three Brassica napus L. cultivars Global, PF704 and Option. The best results in terms of secondary embryogenesis percentage obtained in cultures of Global and PF704 MDEs (75.88 and 65.97 %, respectively) and PF704 produced the highest number of secondary embryos per each primary embryo (14.91 ± 2.18). After optimization of physical parameters, rapeseed hypocotyls of MDEs were bombarded with microcarriers coated with a plasmid containing GUS reporter gene. The highest levels of transient GUS expression were obtained using bombardment with gold particles of 1.6 µm, at helium pressure of 9.3 MPa, a bombardment distance of 9 cm, chamber vacuum pressure of 7.1 × 10-6 kPa and single bombardment in bombardment medium containing 0.4 M mannitol.

Molecular cloning and characterization of a novel microsomal oleate desaturase gene DiFAD2 from Davidia involucrata Baill

N. Lei, S. Peng, B. Niu, J. Chen, J. Zhou, L. Tang, Y. Xu, S. Wang, F. Chen

Biologia plantarum 54:41-46, 2010 | DOI: 10.1007/s10535-010-0006-2

In the conversion of oleic acid to linoleic acid, δ12-fatty acid desaturase (δ12-FAD) is involved. Based on the conserved oligo amino acid residues of the FAD2 genes from other plants, a new full-length cDNA (DiFAD2) encoding a δ12-FAD was cloned from Davidia involucrata Baill. Sequence analysis indicated that the DiFAD2 gene had an open reading frame (ORF) of 1 149 bp, coding for 382 amino acids residues of 44.3 kDa, pI of the deduced protein was 8.8. The deduced amino acid sequence of the cloned DiFAD2 showed high identities to those genes of other plant δ12-FAD. RT-PCR showed that DiFAD2 was expressed in all tissues and expression was abundant in young stems. Expression of DiFAD2 is not enhanced by low temperature and the altered polyunsaturated fatty acid content in leaves treated with low temperature may be due to the post-transcriptional regulation of the DiFAD2 gene or the other FAD2 gene family regulation.

Expression of Rhizobium pydA-pydB fusion gene in Nicotiana tabacum confers resistance to the toxic aromatic compound 3-hydroxy-4-pyridone

S. Jube, J. Awaya, D. Borthakur

Biologia plantarum 53:355-359, 2009 | DOI: 10.1007/s10535-009-0066-3

The toxic aromatic compound 3-hydroxy-4-pyridone (HP) is an intermediate in both synthesis and degradation of mimosine, which is produced by the tree legume Leucaena leucocephala. The L. leucocephala root-nodule symbiont Rhizobium TAL1145 contains a dioxygenase (pydA) and a hydrolase (pydB) gene that produce enzymes necessary for the degradation of HP. In order to coordinately express both genes in plant tissues under a single promoter, three different pydA-pydB fusion constructs (G0, G3, and G7) with varying glycine linkers between the two genes were developed. Prior to transferring the fusion constructs into L. leucocephala, which is highly recalcitrant to genetic transformation, we tested the expression and activity of the hybrid proteins in Nicotiana tabacum, a model plant system that can be easily transformed and analyzed. Seven independent transgenic tobacco lines were generated by Agrobacterium-mediated transformation, and stable integration and expression of pydA-pydB in these transgenic lines were confirmed by polymerase chain reaction (PCR), reverse transcriptase PCR (RT-PCR) and Western analysis. Only one of the fusion constructs, G3, containing a 9-nucleotide linker between pydA and pydB, provided significant levels of resistance to 3 mM HP, indicating that the hybrid protein produced by this fusion construct could degrade HP.

Cold tolerance, water relations and accumulation of osmolytes in Bituminaria bituminosa

D. J. Walker, P. Romero, E. Correal

Biologia plantarum 54:293-298, 2010 | DOI: 10.1007/s10535-010-0051-x

We determined the cold (freezing) tolerance of five Spanish populations of the perennial shrub Bituminaria bituminosa (L.) C.H. Stirton (Fabaceae), as the temperature at which 50 % of leaf electrolytes are released (LT50) using leaves of field-grown plants, obtained in two winters and one spring. The freezing tolerance was greater in winter and reflected the minimum temperatures at the original sites from which the populations were obtained. Tolerance in vitro was related to osmotic adjustment in the leaves; more negative osmotic potential values and more positive pressure potential values (MPa) were associated with greater tolerance. Tolerance and osmotic potential were not related to leaf cation contents but to leaf amino acids, soluble sugar and proline contents.

Genetic variability in the endemic Leucojum valentinum

A. Jordán-Pla, E. Estrelles, M. Boscaiu, P. Soriano, O. Vicente, I. Mateu-Andrés

Biologia plantarum 53:317-320, 2009 | DOI: 10.1007/s10535-009-0057-4

The genetic variability of Leucojum valentinum Pau (Amaryllidaceae), a vulnerable endemic species restricted to a small area in the region of Valencia (Eastern Spain), has been studied using random amplified polymorphic DNA (RAPD) markers. A total of 197 individuals from eleven populations were studied using 13 RAPD primers. Our results show high variability for the species, low differentiation among populations and uncorrelated levels of genetic variability and population size. Four groups in which three populations (SAG, PUG and COL) are separated from all the others were found, but without connection to geographical location.

High efficiency organogenesis and analysis of genetic stability of the regenerants in Solanum melongena

Y. Xing, Y. Yu, X. Luo, J. -N. Zhang, B. Zhao, Y. -D. Guo

Biologia plantarum 54:231-236, 2010 | DOI: 10.1007/s10535-010-0041-z

A novel protocol for plant regeneration from cotyledon explants of eggplant (Solanum melongena) reducing concentration of sucrose was established. The most efficient bud induction medium consisted of Murashige and Skoog (MS) medium supplemented with 2.0 mg dm-3 zeatin, 0.1 mg dm-3 indoleacetic acid and 10 g dm-3 sucrose. After 15 d, the shoot buds were fragmented and transferred to the shoot elongation MS supplemented with 1.0-2.0 mg dm-3 gibberellic acid and 4.0-8.0 mg dm-3 AgNO3, which promoted shoots elongation. The genetic stability of the regenerated plants was analyzed by flow cytometry, RAPD and SSR molecular markers. The results indicated that almost no somaclonal variation was detected among the regenerants.

Using morphological diagnosis and molecular markers to assess the clonal fidelity of micropropagated Echinacea purpurea regenerants

S. J. Chuang, C. L. Chen, J. J. Chen, J. M. Sung

Biologia plantarum 54:539-542, 2010 | DOI: 10.1007/s10535-010-0095-y

Both morphological characteristics and amplified fragment length polymorphism (AFLP) markers were used to validate the genetic fidelity of 1 080 field-grown Echinacea purpurea plants regenerated from leaf explants of donor T5-9. Morphological diagnosis revealed that 1 067 out of 1 080 regenerants were normal, while 13 regenerants were aberrant. AFLP analysis was further performed to assess DNA variations among donor, 43 sampled normal regenerants and all 13 aberrant regenerants. Seven primer combinations generated 471 fragments among donor and normal regenerants, of which 9 fragments were polymorphic. The same primer pairs generated 484 fragments for aberrant regenerants, of which 417 fragments were polymorphic. UPGMA clustering indicated that 42 normal regenerants and donor fell into same cluster at similarity scale of > 0.99, while all 13 aberrant regenerants and one morphologically normal regenerant comprised the other clusters. AFLP analysis indicated that these 14 regenerants are off-types.

The promoter-elements of some abiotic stress-inducible genes from cereals interact with a nuclear protein from tobacco

A. Roychoudhury, D. N. Sengupta

Biologia plantarum 53:583-587, 2009 | DOI: 10.1007/s10535-009-0106-z

In this communication, we report the binding of abscisic acid responsive elements (ABREs) of rice Osem, namely motif A and motif B, with a cognate trans-acting factor present in the nuclear extract of tobacco leaf. The binding is specific as both the complexes were disrupted with an excess of homologous non-radioactive DNA like motif A or motif B themselves or with cis-elements of rice Rab16A, motif I (ABRE) and motif IIa (non-ACGT ABRE-like sequences). Four tandem repeats of ABRE from wheat Em (4X ABRE) or two tandem repeats of Em ABRE, plus two copies of coupling element (CE1) from barley HVA22 (2X ABRC), also showed specific complexes, that were competed out by an excess of homologous competitors like motif I, motif IIa, motif A, motif B, 4X ABRE and 2X ABRC, but not by the unrelated 4X DRE sequence. Elution of the protein from all the complexes showed a single 26 kDa polypeptide band. Introgression of two of the above synthetic promoters 4X ABRE and 2X ABRC, each fused with minimal promoter of cauliflower mosaic virus 35S (CaMV 35S), could induce the expression of the reporter gene β-glucuronidase (gus) in transgenic tobacco in response to high NaCl concentration, dehydration or abscisic acid, but not at the constitutive level, proving that they can be used as efficient stress-inducible promoters. Our work shows both in vivo and in vitro activity of the promoters from monocot genes in the model dicot plant tobacco.

Changes in key enzymes of viral-RNA biosynthesis in chloroplasts from PVY and TMV infected tobacco plants

M. ©indelářová, L. ©indelář, N. Wilhelmová, D. Procházková

Biologia plantarum 49:471-474, 2005 | DOI: 10.1007/s10535-005-0032-7

Effects of the infection with tobacco mosaic virus (TMV) and potato virus Y (PVY) on chloroplasts from susceptible tobacco plants were determined. Changes in ribonucleases (RNases), phosphomonoesterase (PME), phosphodiesterase (PDE), glucose-6-phosphate dehydrogenase (G6P DH), 6-phosphogluconate dehydrogenase (6PG DH), glucokinase (GK), and fructokinase (FK) activities in thylakoid/envelope and stroma fractions were studied. Slight increase in the activities of PME, PDE, G6P DH and 6PG DH of thylakoid/envelope fraction as well as of RNases, PME, PDE, G6P DH, 6PG DH, GK and FK of stroma fraction was found in chloroplasts isolated from leaf tissues infected with PVY. Infection with TMV produced higher increase in enzymes activities in chloroplasts; especially, PME, G6P DH and 6PG DH in fraction of thylakoid/envelope, and RNases, PME, PDE, G6P DH, 6PG DH, and GK in stroma fraction.

Photosynthetic performance and acclimation of Incarvillea delavayi to water stress

Y. -F. Cai, S. -B. Zhang, H. Hu, S. -Y. Li

Biologia plantarum 54:89-96, 2010 | DOI: 10.1007/s10535-010-0013-3

The photosynthetic performance and related leaf traits of Incarvillea delavayi Bur. et Franch were studied at different water regimes to assess its capacity for photosynthetic acclimation to water stress. The initial response of I. delavayi to water stress was the closure of stomata, which resulted in down-regulation of photosynthesis. The stomatal limitation (SL) represented the main component to photosynthetic limitations but non-stomatal limitation (NSL) increased quickly with the increasing water stress, and had similar magnitude to SL under severe water stress (soil moisture 25-30 % of field capacity). Chlorophyll (Chl) a fluorescence parameters characterizing photosystem (PS) 2 photochemical efficiency (ΦPS2), electron transport rate (J) and photochemical quenching (qP) decreased with the increasing water stress, indicating impaired photosynthetic apparatus. However, the water-stressed plants had a increased mesophyll CO2 diffusional conductance, Chl a/b ratio, leaf nitrogen partitioning in RuBPCO and bioenergetics in later grown parts, indicating that I. delavay had a substantial physiological plasticity and showed a good tolerance to water stress.

The effect of 5-azacytidine on wheat seedlings responses to NaCl stress

L. Zhong, Y. H. Xu, J. B. Wang

Biologia plantarum 54:753-756, 2010 | DOI: 10.1007/s10535-010-0135-7

The effect of 5-azacytidine (5-azaC) on the alleviation of damaging effects of NaCl treatment was studied in two wheat (Triticum aestivum L.) cultivars differing in salt tolerance (salt-tolerant Dekang-961 and sensitive Lumai-15). The plants were pre-treated or not with 50 μM 5-azaC and then subjected to salt stress induced by 100 or 150 mM NaCl. Salinity caused reduction in biomass accumulation and increase in malondialdehyde content in root tissues in both cultivars, but less in pre-treated seedlings. The activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in the roots of both cultivars increased during salt stress, but the rate of increase was higher in Dekang-961. Plants treated with 5-azaC had higher root SOD, CAT and POD activities under salt stress than untreated plants. Content of 5-methylcytosine (5mC) decreased in both cultivars under salt stress, and the level of demethylation was higher in Dekang-961 than that in Lumai-15. Moreover, the degree of methylation was lower in both cultivars under salt stress after 5-azaC application compared to only salt-treated groups. These findings suggested that 5-azaC could protect plants from salt stress.

Characterization of β-tubulin 4 regulated by gibberellins in rice leaf sheath

G. Yang, A. Jan, S. Komatsu

Biologia plantarum 53:422-428, 2009 | DOI: 10.1007/s10535-009-0081-4

Tubulins are basic components of microtubules and are encoded by a multigene family in eukaryotes. The expression of OsTUB4, one of eight β-tubulin isotypes identified in the rice genome, was characterized. OsTUB4 was expressed in root primodia and the shoot apical meristem in basal parts of the leaf sheath in rice seedlings. OsTUB4 transcript abundance in leaf sheath increased by treatment with gibberellic acid (GA3) in a dose- and time-dependent manner. OsTUB4 transcript levels in gibberellin (GA)-deficient mutants were less than those of wild type rice. An OsTUB4 promoter::GUS assay also confirmed the responsiveness of OsTUB4 to exogenous GA3, suggesting that OsTUB4 expression was regulated by GA and may be involved in GA-regulated leaf sheath growth. In addition, OsTUB4 could interact with different specific proteins in vitro as assayed by a yeast two-hybrid system, indicating that OsTUB4 may have diverse functions through interaction with different proteins.

Effect of zinc and cadmium on physiological and production characteristics in Matricaria recutita

M. Kummerová, ©. Zezulka, K. Kráµová, E. Masarovičová

Biologia plantarum 54:308-314, 2010 | DOI: 10.1007/s10535-010-0053-8

Effects of zinc (12-180 μM) alone and in mixtures with 12 μM Cd on metal accumulation, dry masses of roots and shoots, root respiration rate, variable to maximum fluorescence ratio (FV/FM), and content of photosynthetic pigments were studied in hydroponically cultivated chamomile (Matricaria recutita) plants. The content of Zn in roots and shoots increased with the increasing external Zn concentration and its accumulation in the roots was higher than that in the shoots. While at lower Zn concentrations (12 and 60 μM) the presence of 12 μM Cd decreased Zn accumulation in the roots, treatment with 120 and 180 μM Zn together with 12 μM Cd caused enhancement of Zn content in the root. Presence of Zn (12-120 μM) decreased Cd accumulation in roots. On the other hand, Cd content in the shoots of plants treated with Zn + Cd exceeded that in the plants treated only with 12 μM Cd. Only higher Zn concentrations (120 and 180 μM) and Zn + Cd mixtures negatively influenced dry mass, chlorophyll (Chl) and carotenoid content, FV/FM and root respiration rate. Chl b was reduced to a higher extent than Chl a.

Effect of arsenic on some physiological parameters in bean plants

N. Stoeva, M. Berova, Z. Zlatev

Biologia plantarum 49:293-296, 2005 | DOI: 10.1007/s10535-005-3296-z

The objective of the study was to investigate the effect of different arsenic concentrations on some physiological parameters of bean (Phaseolus vulgaris L.) cultivars Plovdiv 10 and Prelom in the early growth phases. Seedlings, grown in sand with Hoagland-Arnon nutrient solution in a climatic box, were treated with 0, 2, 5 mg(As) dm-3 as Na3AsO4 (pH 5.5). After 5 d of As treatment, the changes in leaf gas-exchange, water potential, chlorophyll and protein contents, peroxidase activity and lipid peroxidation in roots were recorded. Physiological analysis showed a minor negative effect of arsenic at concentration 2 mg(As) dm-3, but at the higher dosage of 5 mg(As) dm-3 growth, leaf gas-exchange, water potential, protein content and biomass accumulation were reduced in both cultivars. The peroxidase activity and lipid peroxidation increased considerably at 5 mg(As) dm-3, which is a typical reaction of the plants to a presence of oxidative stress.

Ex vitro acclimatization of plantain plantlets micropropagated in temporary immersion bioreactor

C. Aragón, L. Carvalho, J. González, M. Escalona, S. Amâncio

Biologia plantarum 54:237-244, 2010 | DOI: 10.1007/s10535-010-0042-y

Plantain (Musa ABB CEMSA 3/4) plantlets were micropropagated in temporary immersion bioreactors (TIB) or in gelled medium (GM). After ex vitro transfer ROS accumulation was determined by infiltrating leaves with nitroblue tetrazolium (NBT) and 3,3'-diaminobenzidine (DAB). Stomatal cells were more stained with NBT and DAB in GM plants than in TIB plants, but the difference disappeared at the end of acclimatization. At the end of the in vitro phase, GM plantlets showed higher activities of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and glutathione reductase (GR), while activities of catalase (CAT), superoxide dismutase (SOD) and glutathione transferase (GT) were higher in TIB grown plantlets. At the end of acclimatization GT, SOD, CAT and MDHAR stabilized at low values of activity in plantlets derived from both treatments. Concerning the correspondent genes, GM plantlets showed higher expression of all transcripts with the exception of CuZnSOD. The immunobloting of peroxiredoxins (PRXs) showed that chloroplast-located PRXs were expressed at higher levels in TIB plantlets, some showing polymerization. In conclusion, TIB grown plantlets had an improved anti-oxidative response when compared with GM.

ISSR marker based analysis of micropropagated plantlets of Nothapodytes foetida

M. Chandrika, V. Ravishankar Rai, Thoyajaksha

Biologia plantarum 54:561-565, 2010 | DOI: 10.1007/s10535-010-0100-5

A DNA-based, inter simple sequence repeat (ISSR) markers were used to monitor genetic stability in micropropagated plantlets of Nothapodytes foetida. A total of 146 clear and distinct bands were produced using 26 primers resulting in 3 212 fragments. Out of 146, 135 bands (92.4 %) were monomorphic and 11 bands (7.53 %) were polymorphic which ranged from 200 to 21 226 bp in size. The number of bands per each primer varied from 1 to 11 with an average of 5.6 bands per primer. The banding pattern for each primer was uniform and comparable to mother plant from which the cultures had been established. The dendrogram based on the unweighted pair-group method with arithmetic averaging (UPGMA) depicted about 97 % homology between the mother plant and micropropagated plants. An attempt was made to reintroduce the micropropagated plants in the natural habitat and over 500 plants were successfully established.

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