Synergid: a key link in fertilization of angiosperms

D. X. Li, M. Z. Lin, Y. Y. Wang, H. Q. Tian

Biologia plantarum 53:401-407, 2009 | DOI: 10.1007/s10535-009-0078-z  

In over 80 % of the angiosperms, the female gametophyte is comprised of seven cells, two of which are the synergid cells. These cells are considered pivotal in assuring successful fertilization. The synergid cells direct pollen tube growth toward the female gametophyte, and facilitate the entrance of the tube into the embryo sac. Once the pollen tube enters the synergid cell, its growth is arrested, the tip of the tube breaks, and two sperm cells are released. This sequence of events is also synergid dependent. In addition, separation of the cells of the male germ unit, orientation of the two sperm cells in the degenerating synergid, and fusion of...

Improvement of ginsenoside production by Panax ginseng adventitious roots induced by γ-irradiation

D. S. Kim, S. Y. Kim, I. Y. Jeong, J. -B. Kim, G. -J. Lee, S. -Y. Kang, W. Kim

Biologia plantarum 53:408-414, 2009 | DOI: 10.1007/s10535-009-0079-y  

In order to evaluate effects of γ-rays on adventitious root formation and ginsenoside production, embryogenic calli induced from cotyledon explants of Panax ginseng C.A. Meyer were treated with γ-rays of 0, 10, 30, 50, 70, and 100 Gy. The highest frequency of adventitious root formation of 75 % occurred at γ-irradiation of 30 Gy, which is considered adequate dosage for selecting mutant cell lines. Five mutated adventitious roots (MAR)3-lines out of the propagation of 142 adventitious root lines treated with 30 Gy were selected based a 100-fold increase in proliferation rate compared to control adventitious roots (CAR) and content...

Effect of sucrose application, minerals, and irradiance on the in vitro growth of Cistus incanus seedlings and plantlets

D. Mills

Biologia plantarum 53:415-421, 2009 | DOI: 10.1007/s10535-009-0080-5  

To study the effect of sucrose on the sink-source relationship in in vitro-grown plants, Cistus incanus seedlings and plantlets were grown horizontally in a two-compartment Petri dish (split dish), with the root system in one compartment and the shoot in the other. Shoots and roots were exposed to different sucrose concentrations (0-30 g dm^-3), two irradiance levels (25 and 160 µmol m^-2s^-1) and the presence or absence of a minimum medium containing minerals and vitamins (M medium). Root and shoot biomass of the seedlings was enhanced by an increase in irradiance when the growth medium was not supplemented...

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...

The involvement of an expansin geneTaEXPB23 from wheat in regulating plant cell growth

S. -C. Xing, F. Li, Q. -F. Guo, D. -R. Liu, X. -X. Zhao, W. Wang

Biologia plantarum 53:429-434, 2009 | DOI: 10.1007/s10535-009-0082-3  

Expansins, found in the cell wall, have the unique ability to induce immediate cell wall extension. In this study, a β-expansin gene (TaEXPB23) isolated from wheat (Triticum aestivum L.) coleoptiles was transformed to tobacco (Nicotiana tabacum) to investigate its role in plant growth and development. TaEXPB23 was preferentially expressed in wheat coleoptile and a close correlation between TaEXPB23 expression and coleoptile growth was observed. The over-expression of TaEXPB23 in tobacco also resulted in accelerating growth of leaves and internodes at earlier developmental stages, and it was involved in...

Molecular and cytological characterization of ZTL in Ipomoea nil

A. Zienkiewicz, D. J. Smoliñski, K. Zienkiewicz, P. Glaziñska, W. Wojciechowski, J. Kopcewicz

Biologia plantarum 53:435-443, 2009 | DOI: 10.1007/s10535-009-0083-2  

The ZEITLUPE (ZTL) protein is involved in the control of circadian period, hypocotyl elongation and flowering time in Arabidopsis thaliana. The aim of the present work was the identification of the InZTL gene and localization of its mRNA in the model short-day plant Ipomoea nil. The deduced InZTL protein of 622 amino acid residues contained a LOV domain at the N-terminal part, followed by an F-box domain and six carboxy terminal kelch repeats. Amino acid sequence of InZTL showed 84 % homology with Mesembryanthemum crystallinum ZTL (McZTL) and 83 % with Arabidopsis thaliana ZTL (AtZTL). Fluorescence in situ...

Identification of differentially expressed genes associated with 5-methyltryptophan resistance in rice mutants

D. S. Kim, C. S. Jang, J. -B. Kim, G. -J. Lee, S. -Y. Kang, W. Kim, Y. W. Seo

Biologia plantarum 53:444-450, 2009 | DOI: 10.1007/s10535-009-0084-1  

5-Methyltryptophan (5MT), a tryptophan analog, resistant M4 rice mutants with high free amino acid contents were obtained through in vitro mutagenesis. To evaluate the 5MT resistance mechanism, a cDNA library was constructed by using the leaves and roots of the 5MT resistant mutant plants. Expressed sequenced tags (ESTs) of 1 019 randomly selected clones were analyzed and then assembled 588 unigens. A total of 389 unigenes had significant homologies with known protein sequences at the NCBI database and the remaining 199 unigenes were designated unidentified genes. These unigens were grouped into 13 categories according to their putative functions....

A mutation affecting symbiosis in the pea line Risnod27 changes the ion selectivity filter of the DMI1 homolog

K. Novák, J. Felsberg, E. Biedermannová, J. Vondrys

Biologia plantarum 53:451-460, 2009 | DOI: 10.1007/s10535-009-0085-0  

After identifying regions of cDNA conserved between the symbiotic gene DMI1 of the model species Medicago truncatula and the homologous genomic region of Arabidopsis thaliana, universal primers were designed from 8 of 12 exons to allow the routine amplification of plant homologs. As an example, the complete homologous sequence from the pea (Pisum sativum L.) was amplified and sequenced, although the poorly conserved 5'-end and 5'-flanking region of the gene had to be amplified using a modified TAIL-PCR strategy. The identity of this amplified homolog with the SYM8 gene was independently confirmed by the presence of...

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...

Apomeiotic pollen mother cell development in the apomictic Boechera species

K. M. Taskin, K. Turgut, R. J. Scott

Biologia plantarum 53:468-474, 2009 | DOI: 10.1007/s10535-009-0087-y  

Pollen mother cell (PMC) development in the apomictic Boechera species B. holboellii, B. gunnisoniana and B. divaricarpa were investigated by various cytological methods. In prophase I, in triploid species B. holboellii and B. gunnisoniana the individual chromosomes condensed into long strands within the nucleus. Then, in metaphase I, each PMC formed a restitutional nucleus thereby bypassing the rest of the first meiotic division. This is interpreted as representing apomeiosis. Subsequently, the restitution nuclei underwent a single cytokinesis as evidenced by the production of dyads. The cells within each...

The influence of low-temperature on the photochemical activity of chloroplasts and activity of antioxidant enzymes in maize leaves

M. Koèová, D. Holá, N. Wilhelmová, O. Rothová

Biologia plantarum 53:475-483, 2009 | DOI: 10.1007/s10535-009-0088-x  

The effects of low growth temperature on the activities of photosystems (PS) 1 and 2 and antioxidant enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR) and catalase (CAT) in leaves of various maize inbred and hybrid genotypes (parental lines, F1 hybrids, F2 and backcross generations) were investigated. Considerable decrease of the PS 2 activity (contrary to the activity of PS 1) due to low-temperature stress was observed in the majority of genotypes/generations examined. The GR, APX and SOD activities markedly increased due to chilling, whereas the activity of CAT showed lesser changes which depended on the genotype/generation...

Regulation of the ALBINO3-mediated transition to flowering in Arabidopsis depends on the expression of CO and GA1

A. X. Wang, D. Y. Wang

Biologia plantarum 53:484-492, 2009 | DOI: 10.1007/s10535-009-0089-9  

ALBINO3, a homologue of PPF1 in Arabidopsis, encodes a chloroplast protein, and is essential for chloroplast differentiation. In the present study, ALBINO3(-) transgenic plants exhibited a significant decrease in both the number of rosette leaves at bolting and the days before bolting, suggesting the important roles of ALBINO3 in regulating flowering during non-inductive short-day photoperiods. ALBINO3 mRNA was apparently accumulated in shoot apical meristem and floral meristems around the shoot apical meristem in wild-type plants. ALBINO3 might be predominantly involved in inducing the floral repression pathway...

Waterlogging induced oxidative stress and antioxidant enzyme activities in pigeon pea

R. K. Sairam, D. Kumutha, K. Ezhilmathi, V. Chinnusamy, R. C. Meena

Biologia plantarum 53:493-504, 2009 | DOI: 10.1007/s10535-009-0090-3  

An experiment was conducted with two contrasting pigeon pea (Cajanus cajan L.) genotypes, ICPL 84023 (tolerant) and ICP 7035 (susceptible), to study the physiological and molecular basis of waterlogging tolerance in relation to oxidative stress and antioxidant enzyme activities. Waterlogging resulted in visible yellowing and premature senescence of leaves, and greater decline in relative water content, chlorophyll content, and membrane stability index in ICP 7035 than in ICPL 84023. Superoxide radical and hydrogen peroxide contents increased at day 4 and 6 of waterlogging probably due to activation of NADPH-oxidase. O₂ ^.-...

Water deficit-induced oxidative stress and the activation of antioxidant enzymes in white clover leaves

B. R. Lee, L. S. Li, W. J. Jung, Y. L. Jin, J. C. Avice, A. Ourry, T. H. Kim

Biologia plantarum 53:505-510, 2009 | DOI: 10.1007/s10535-009-0091-2  

The objective of this study was to determine the development of the antioxidant enzymes induced by drought stress in white clover (Trifolium repens L.) leaves. Water stress was imposed during 28 d by decreasing the daily irrigation. Leaf water potential (Φ_w) gradually decreased from -0.46 to -2.33 MPa. For the first 7 d, dry mass (DM), H₂O₂ and lipid peroxidation were not significantly affected by water deficit. From 14 d of treatment, water stress decreased dry mass and increased content of reactive oxygen species (O₂ ^.- and H₂O₂) and oxidative stress (malondialdehyde...

Responses to drought stress in two poplar species originating from different altitudes

F. Yang, X. Xu, X. Xiao, C. Li

Biologia plantarum 53:511-516, 2009 | DOI: 10.1007/s10535-009-0092-1  

Cuttings of Populus kangdingensis and Populus cathayana, originating from high and low altitudes in the eastern Himalaya, respectively, were examined during one growing season in a greenhouse to determine their responses to drought stress (soil moisture decreased from 100 to 55 or 25 % field capacity). Compared to control plants grown under 100 % field capacity, those poplars grown under 55 and 25 % field capacity possessed lower increases in height and stem diameter, and higher contents of soluble sugars, free proline, malondialdehyde (MDA) and hydrogen peroxide, and higher activities of catalase (CAT), superoxide dismutase (SOD), peroxidase...

Responses of photosynthetic parameters of Mikania micrantha and Chromolaena odorata to contrasting irradiance and soil moisture

L. L. Zhang, D. Z. Wen, S. L. Fu

Biologia plantarum 53:517-522, 2009 | DOI: 10.1007/s10535-009-0093-0  

Photosynthetic parameters were measured in two invasive weeds, Mikania micrantha and Chromolaena odorata, grown in soil under full, medium, and low irradiance and full, medium, and low water supply. Both species showed significantly higher net photosynthetic rate, quantum yield of PS 2 photochemistry and photochemical quenching coefficient under high than low irradiance. For M. micrantha, low irradiance caused decreased chlorophyll content (Chl), Chl a/b ratio and maximum photochemical efficiency of PS 2 (F_v/F_m), while drought decreased Chl content and F_v/F_m and increased...

Contractile roots are the most sensitive organ in Crocus sativus to salt stress

S. M. Rajaei, V. Niknam, S. M. Seyedi, H. Ebrahimzadeh, K. Razavi

Biologia plantarum 53:523-529, 2009 | DOI: 10.1007/s10535-009-0095-y  

Crocus sativus corms were grown in Perlite and watered by half-strength modified Hoagland nutrient solution containing 0, 50, 100, 150, 200 mM NaCl. Growth parameters and contents of proteins, proline, polyphenols, minerals and saccharides were studied in fibrous roots, contractile roots, corms and leaves. All plants remained alive and did not display any sign of foliar damage even at 200 mM NaCl. However, the salinity decreased growth, relative water content and increased contents of proline and Na⁺ in all organs. Total protein content was increased in corms and contractile roots but decreased in fibrous roots. Changes in...

Peroxidase, acid phosphatase, RNase and DNase activity and isoform patterns during in vitro rooting of Petunia × hybrida microshoots

M. Kotis, T. A. Yupsanis, T. D. Syros, A. S. Economou

Biologia plantarum 53:530-538, 2009 | DOI: 10.1007/s10535-009-0096-x  

Specific activities and isoform patterns of peroxidases, acid phosphatases, DNases and RNases were studied in relation to in vitro rooting of Petunia × hybrida microshoots in the presence of 4 µM indole-3-butyric acid (IBA). Specific activities of the above enzymes increased in the course of rooting. Rhizogenesis could be related with an increased specific activity of peroxidases during the initiation phase, in parallel with increased lignin content. Twelve peroxidases, six anionic (A1-A6) and six cationic (C1-C6), seven acid phosphatases (ACP1-ACP7), seven RNases (R1-R7) and four DNases (D1-D4) isoforms were detected following...

Effects of chilling on the root cell ultrastructure of two soybean cultivars

S. Gliñska, M. Gapiñska, B. Gabara, A. Mikiciñski, K. Szafrañska

Biologia plantarum 53:539-544, 2009 | DOI: 10.1007/s10535-009-0098-8  

Two soybean [Glycine max (L.) Merr.] cultivars: Aldana (more resistant) and Essor (less resistant to low temperature) were subjected to chilling at 5°C for 24 h, and then the ultrastructure of the root meristem cells was investigated. The ultrastructure of control root cells of the tested cultivars differed in the number of condensed mitochondria, plastids with phytoferritin, deformed vacuoles, as well as multivesicular bodies (MB) in cytoplasm and vacuoles. Chilling induced concentric endoplasmic reticulum (ER) arrangement in both soybean cultivars, while the circular Golgi apparatus (GA) occurred only in cv. Essor and MB in the cytoplasm of...

The role of salicylic acid in response of two rice cultivars to chilling stress

D. H. Wang, X. X. Li, Z. K. Su, H. X. Ren

Biologia plantarum 53:545-552, 2009 | DOI: 10.1007/s10535-009-0099-7  

Two rice (Oryza sativa L.) cultivars differing in chilling sensitivity, Changbaijiu (chilling-tolerant) and Zhongjian (chilling-sensitive) were pre-treated with 0.5, 1.0 and 2.0 mM salicylic acid (SA) for 24 h before chilling at 5°C for 1 d. Chilling induced SA accumulation, particularly conjugated SA in both leaves and roots of the two rice cultivars. After SA administration, SA accumulated in the roots of both cultivars at a concentration-dependent manner, whereas only a slight increase was observed in their leaves. Conjugated SA accounted for most of the increase. The beneficial effect of SA treatment on protecting rice seedlings from chilling...

Defence responses of chilli fruits to Colletotrichum capsici and Alternaria alternata

T. Anand, R. Bhaskaran, T. Raguchander, R. Samiyappan, V. Prakasam, C. Gopalakrishnan

Biologia plantarum 53:553-559, 2009 | DOI: 10.1007/s10535-009-0100-5  

The induction of defence compounds and enzymes involved in the phenylpropanoid pathway were studied in the ripe and green chilli fruits inoculated with Colletotrichum capsici and Alternaria alternata. Total phenols and the activity of phenylalanine ammonia lyase (PAL), peroxidase (PO), polyphenol oxidase (PPO) and catalase (CAT) increased in the inoculated ripe and green chilli fruits compared to the corresponding healthy fruits. Total phenols and the activities of the enzymes were at the maximum 2-3 d after inoculation and thereafter declined sharply in ripe chilli fruits, whereas slowly in green chilli fruits. In comparison with ripe...

Abscisic acid and auxin accumulation in Catasetum fimbriatum roots growing in vitro with high sucrose and mannitol content

L. E. P. Peres, A. Zsögön, G. B. Kerbauy

Biologia plantarum 53:560-564, 2009 | DOI: 10.1007/s10535-009-0101-4  

Endogenous contents of indolyl-3-acetic acid (IAA) and abscisic acid (ABA) were quantified in excised roots of Catasetum fimbriatum (Orchidaceae) cultured in vitro on solidified Vacin and Went medium with 1, 2, 4, 6, 8 and 10 % sucrose, as well as 2 % sucrose plus mannitol. Maximum root growth was observed in media with 4 % sucrose and 2 % sucrose plus 2.2 % mannitol, suggesting that a moderate water or osmotic stress promotes orchid root growth. Contents of both ABA and IAA increased in parallel to increasing sucrose concentration and a correlation between root elongation and the ABA/IAA ratio was observed. Incubating isolated...

Effect of esculetin on activities of pumpkin glutathione S-transferases and growth of pumpkin seedlings

M. D. Hossain, M. Fujita

Biologia plantarum 53:565-568, 2009 | DOI: 10.1007/s10535-009-0102-3  

The effect of esculetin and some related coumarins (coumarin, 7-hydroxycoumarin and scopoletin) on growth of pumpkin (Cucurbita maxima Duch.) seedlings and the activities of pumpkin glutathione S-transferases (GSTs) were investigated. Coumarin and esculetin affected the growth of seedlings. The hypocotyls of affected seedlings became weak and bent at the mid region, roots became very soft with brownish discoloration, and finally seedlings died. Among the compounds tested, only esculetin inhibited CmGSTU3 and CmGSTU2 activities measured with 1-chloro-2,4-dinitrobenzene (CDNB) and at a concentration of 22 µM, it inhibited...

Rapid in vitro propagation of Holarrhena antidysenterica using seedling cotyledonary nodes

K. Mallikarjuna, G. Rajendrudu

Biologia plantarum 53:569-572, 2009 | DOI: 10.1007/s10535-009-0103-2  

A rapid in vitro propagation of Holarrhena antidysenterica has been developed. Seedling cotyledonary nodes on Murashige and Skoog medium (MS) containing 2 mg dm^-3 N⁶-benzyladenine (BA) produced highest number of multiple shoots. The shoot numbers were increased further upon subculture on MS medium supplemented with 0.5 mg dm^-3 BA. By repeated subculture of derived shoots, a high multiplication rate was established. The excised shoots were rooted on MS basal medium without growth regulators. The in vitro formed shoots were also rooted ex vitro by dipping them in 2 mg dm^-3 of indole-3-butyric...

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...

Regeneration of transgenic citrus plants from the trimmed shoot/root region of etiolated seedlings

D. L. Li, B. Tan, Y. X. Duan, W. W. Guo

Biologia plantarum 53:578-582, 2009 | DOI: 10.1007/s10535-009-0105-0  

Transformation and high efficient regeneration of transgenic plants from the trimmed etiolated shoot/root region (TESRR) of Anliucheng sweet orange [Citrus sinensis (L.) Osb.] seedling was reported. A visual green fluorescent protein (GFP) marker gene was introduced to evaluate transformation efficiency by using the explants from TESRR and epicotyls. The transformation protocol was: infection 20 min, co-culture 3 d, selection culture 30 d, and rooting 15 d. Out of a total of 288 sprouted shoots obtained from TESRR, 34 shoots (11.8 %) yielded GFP expression. In contrast, only 2 (3.0 %) of the 67 sprouted shoots from epicotyl transformation yielded...

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...

Leaf morphological and physiological responses to drought and shade in two Populus cathayana populations

X. Huang, X. Xiao, S. Zhang, H. Korpelainen, C. Li

Biologia plantarum 53:588-592, 2009 | DOI: 10.1007/s10535-009-0107-y  

Cuttings from two contrasting Populus cathayana Rehder populations originating from Hanyuan (wet climate) and Ledu (dry climate) in western China were grown in a greenhouse to determine the effects of drought, shade and their interaction on the morphological and physiological traits of leaves. The dry climate population was more droughttolerant than the wet climate population, as indicated by smaller decreases in the leaf relative water content (RWC) and net photosynthetic rate (PN), as well as by greater increases in antioxidative enzyme activities and free proline content under drought. On the other hand, the negative effects of shade on leaf...

Chloroplast DNA polymorphism in different types of cytoplasmic male sterile rice

L. -J. Ou, G. -W. Huang, W. -J. Li, G. P. Kang, J. -L. Chen, S. Luan, L. -B. Chen

Biologia plantarum 53:593-596, 2009 | DOI: 10.1007/s10535-009-0108-x  

The lengths of open reading frame (ORF)100 and ORF29-TrnC^GCA, the intronic sequence of rps16 and the transcribed spacer of TrnT^UGU-TrnL^UAA in chloroplast from different lines of cytoplasmic male sterility (CMS) rice were studied using indica types, japonica types and common wild rice as controls. The results show that the lengths of ORF100 and ORF29-TrnC^GCA in CMS lines are similar to those of typical indica. The sequences of the rps16 intron and the TrnT^UGU-TrnL^UAA spacer in sporophyte sterile types (wild-abortive type, Yinshui type and K type) are...

Effect of increased alkalinity on Na⁺ and K⁺ contents, lipid peroxidation and antioxidative enzymes in two populations of Populus cathayana

S. Lu, S. Zhang, X. Xu, H. Korpelainen, C. Li

Biologia plantarum 53:597-600, 2009 | DOI: 10.1007/s10535-009-0109-9  

We compared two populations of Populus cathayana Rehder, originating from altitudes 2 840 m and 1 450 m, to determine whether trees from different altitudes exhibit different tolerance to alkalinity. The tree cuttings were exposed to nutrient solutions with pH 7.9, 8.8, 9.8 and 10.4 and the salt concentration 200 mM. Na⁺ and K⁺ contents, and Na⁺/K⁺ ratios in leaves and roots were greatly affected by pH values. At pH 10.4, the Na⁺/K⁺ ratios in both leaves and roots sharply dropped in the higher altitude population but were maintained at higher levels in the lower altitude population....

Understanding Bioinformatics

R. Podlipná

Biologia plantarum 53:522, 2009 | DOI: 10.1007/s10535-009-0094-z  

Sulfur Metabolism in Phototrophic Organisms

D. Sofrová

Biologia plantarum 53:538, 2009 | DOI: 10.1007/s10535-009-0097-9