Protein patterns associated with Pisum sativum somatic embryogenesis

M. Griga, J. Horáček, H. Klenotičová

Biologia plantarum 51:201-211, 2007 | DOI: 10.1007/s10535-007-0041-9

Total protein patterns were studied in the course of development of pea somatic embryos using simple protocol of direct regeneration from shoot apical meristems on auxin supplemented medium. Protein content and total protein spectra (SDS-PAGE) of somatic embryos in particular developmental stages were analysed in Pisum sativum, P. arvense, P. elatius and P. jomardi. Expression of seed storage proteins in somatic embryos was compared with their accumulation in zygotic embryos of selected developmental stages. Pea vegetative tissues, namely leaf and root, were used as a negative control not expressing typical seed storage proteins. The...

High efficient transgenic plant regeneration from embryogenic calluses of Citrus sinensis

Y. X. Duan, W. W. Guo, H. J. Meng, N. G. Tao, D. D. Li, X. X. Deng

Biologia plantarum 51:212-216, 2007 | DOI: 10.1007/s10535-007-0043-7

Transformation and high efficient regeneration of transgenic plants from embryogenic calluses of Bingtang sweet orange [Citrus sinensis (L.) Osbeck] was reported. Embryogenic calluses were inoculated with Agrobacterium tumefaciens strain EHA105, harboring the binary Ti plasmid pROK II and carrying a neomycin phosphotransferase II (NPTII) gene, an intron β-glucuronidase (GUS) gene and the Arabidopsis APETALA1 (AP1) gene. Transformation treatment was with inoculation time of 30 min, co-culture of 3 d at 23 °C and supplementation of the co-culture medium with 2 mg dm^-3 acetosyringone (AS). Kanamycin (50 mg dm^-3)...

Effects of benzylaminopurine and irradiance on cytokinin contents, α-tubulin gene expression and cucumber cotyledon expansion

Y. L. Li, Q. H. Ma

Biologia plantarum 51:217-222, 2007 | DOI: 10.1007/s10535-007-0044-6

The fluctuation of endogenous cytokinins was determined in the excised cucumber (Cucumis sativa L.) cotyledons incubated with benzylaminopurine (BA) under irradiance or in darkness. The data indicated that light stimulated the cotyledon expansion compared with dark and BA further enhanced the expansion of cotyledons. However, only BA treatment markedly increased the contents of endogenous cytokinins and induced α-tubulin gene expression. Actinomycin D, a well-known inhibitor of gene transcription, strongly inhibited both light-and BA-induced cotyledon expansions and increase of endogenous cytokinin contents and α-tubulin gene expression....

Embryogenesis and plant regeneration from unpollinated ovary culture of Psoralea corylifolia

S. Chand, A. K. Sahrawat

Biologia plantarum 51:223-228, 2007 | DOI: 10.1007/s10535-007-0045-5

Embryogenesis and plant regeneration was achieved from callus cultures derived from unpollinated ovaries of Psoralea corylifolia L. Callus was initiated from unpollinated ovaries on Murashige and Skoog (MS) medium supplemented with 2.2 µM N ⁶-benzyladenine (BA) and various concentrations of α-naphthaleneacetic acid (NAA (2.7 to 10.7 µM) or 2,4-dichlorophenoxyacetic acid (2,4-D (2.3 to 9 µM) alone or in combination. Highly organized embryogenic callus induction, embryo development, proliferation and maturation were achieved on transfer of callus clumps to MS medium supplemented with NAA (0.27 µM)...

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 | DOI: 10.1007/s10535-007-0046-4

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 K_m 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...

Ginsenoside production, growth and cytogenetic characteristics of sustained Panax japonicus var. Repens cell suspension culture

I. N. Smolenskaya, O. V. Reshetnyak, A. V. Nosov, S. E. Zoriniants, A. L. Chaiko, Y. N. Smirnova, A. M. Nosov

Biologia plantarum 51:235-241, 2007 | DOI: 10.1007/s10535-007-0047-3

Cytophysiological and cytogenetic characteristics of cell suspension culture of Panax japonicus var. repens were studied in relation to the accumulation of ginsenosides (GSs). The minimal time of cell number doubling was 1.3 ± 0.1 d and cell number increased 7 to 8-fold during growth cycle. The cell culture can be considered as aneuploid with about tetraploid (46-60 chromosomes) modal class. Upon long-term cultivation, the total content of GSs considerably increased and maximal concentration of GSs was 2.2 %(d.m.). The ratio of seven major GSs only slightly altered both over each and different subcultures. The overall amount of...

Agrobacterium-mediated transformation of Cry1C, Cry2A and Cry9C genes into Gossypium hirsutum and plant regeneration

X. Guo, C. Huang, S. Jin, S. Liang, Y. Nie, X. Zhang

Biologia plantarum 51:242-248, 2007 | DOI: 10.1007/s10535-007-0048-2

Three constructs harbouring novel Bacillus thuringiensis genes (Cry1C, Cry2A, Cry9C) and bar gene were transformed into four upland cotton cultivars, Ekangmian10, Emian22, Coker201 and YZ1 via Agrobacterium-mediated transformation. With the bar gene as a selectable marker, about 84.8 % of resistant calli have been confirmed positive by polymerase chain reaction (PCR) tests, and totally 50 transgenic plants were regenerated. The insertions were verified by means of Southern blotting. Bioassay showed 80 % of the transgenic plantlets generated resistance to both herbicide and insect. We optimized conditions for improving...

Identification and sequence analysis of cDNA fragments relative to ovary development of Cymbidium hybridium after pollination

X. Q. Chen, C. G. Wang, Y. Zhang, W. Q. Song, R. Y. Chen

Biologia plantarum 51:249-256, 2007 | DOI: 10.1007/s10535-007-0050-8

In this study, seven cDNA fragments of genes, differentially expressed in ovaries after pollination in Cymbidium hybridium, were identified and characterized by mRNA differential display reverse transcription polymerase chain reaction (DDRT-PCR). Four (CDD-313, CDD-272, CDD-265, CDD-243) among these seven cDNA fragments showed no significant homology with ESTs or genes in the databases of NCBI; another three (CDD-193, CDD-218, CDD-470) showed significant homologies with sequences encoding components of an ABC-type transporter, a GTPase and 40S ribosomal S3 proteins (RPS3), respectively. The differential expression patterns of them were confirmed...

Expression pattern of the AHP gene family from Arabidopsis thaliana and organ specific alternative splicing in the AHP5 gene

J. Hradilová, B. Brzobohatý

Biologia plantarum 51:257-267, 2007 | DOI: 10.1007/s10535-007-0051-7

Histidine-containing phosphotransmitters (AHPs) transfer a phosphoryl group from membrane receptors to effectors in the nucleus. Five AHP genes have been identified in Arabidopsis. Real-time reverse transcription polymerase chain reaction (RT-PCR) was employed to quantify contents of individual transcripts in Arabidopsis leaves, roots, stems, flowers and siliques. High organ specificity of gene expression was found in AHP1, AHP2, AHP4 while expression of AHP3 and AHP5 appears more ubiquitous. We detected two AHP5 specific PCR products (AHP5 and AHP5L). Out of the five AHP5 introns,...

Production of human papillomavirus type 16 E7 oncoprotein fused with β-glucuronidase in transgenic tomato and potato plants

J. Bříza, D. Pavingerová, J. Vlasák, V. Ludvíková, H. Niedermeierová

Biologia plantarum 51:268-276, 2007 | DOI: 10.1007/s10535-007-0053-5

The human papillomavirus type 16 (HPV 16) oncogene E7 fused with the gene for β-glucuronidase (gus) was used in plant transformation experiments. The E7 gene modified for lower cancerogenicity and fused with the 5' end of the gus in cassettes with cauliflower mosaic virus 35S promoter and transcription terminator produced high contents of fusion proteins in potato protoplasts. Expression vectors harbouring E7 fusion cassettes were used for Agrobacterium tumefaciens LBA4404 mediated transformation of either potato (Solanum tuberosum L. cv. Bintje) or tomato (Lycopersicon esculentum Mill. cv. Moneymaker)....

Improvement of protein quality in transgenic soybean plants

H. A. El-Shemy, M. M. Khalafalla, K. Fujita, M. Ishimoto

Biologia plantarum 51:277-284, 2007 | DOI: 10.1007/s10535-007-0055-3

Glycinin is one of the abundant storage proteins in soybean seeds. A modified Gy1 (A1aB1b) proglycinin gene with a synthetic DNA encoding four continuous methionines (V3-1) was connected between the hpt gene and the modified green fluorescent protein sGFP(S65T) gene, and a resultant plasmid was introduced into soybean by particle bombardment in order to improve nutritional value of its seeds. After the selection with hygromycin, the efficiency of gene introduction was evaluated. More than 60 % of the regenerated plants tolerant to hygromycin yielded the hpt and V3-1 fragment by polymerase chain reaction (PCR) analysis,...

Two calcium mobilizing pathways implicated within abscisic acid-induced stomatal closing in Arabidopsis thaliana

A. Cousson

Biologia plantarum 51:285-291, 2007 | DOI: 10.1007/s10535-007-0057-1

The present study investigated whether, depending on the abscisic acid (ABA) concentration, phospholipase C (PLC) would be implicated within a Ca²⁺ mobilizing pathway that would regulate stomatal aperture under standard watering conditions. Among Al sensitive mutants the als1-1 mutant of Arabidopsis thaliana (L.) Heynh. (Columbia-4 ecotype) was selected for a pharmacological approach of stomatal closing in leaf epidermal peels induced by 3, 20 or 30 µM ABA. Comparison with the wild type (WT) revealed that, exclusively in the als1-1 mutant, the stomatal response to 3 or 20 µM ABA was inhibited by about 40...

Water status indicators of lemon trees in response to flooding and recovery

M. F. Ortuño, J. J. Alarcón, E. Nicolás, A. Torrecillas

Biologia plantarum 51:292-296, 2007 | DOI: 10.1007/s10535-007-0058-0

Potted 2-year-old lemon trees [Citrus limon (L.) Burm. fil, cv. Verna] grafted on sour orange (C. aurantium L.) rootstock were subjected to flooding for 3 d. Control plants were irrigated daily to field capacity. Continuously (sap flow, trunk diameter fluctuations) and discretely (predawn and midday leaf water potential, leaf conductance) measured plant-based water status indicators were compared. The sensitivity of the maximum daily trunk shrinkage signal intensity to flooding and its behaviour during the recovery period demonstrated that this indicator is more feasible than the others for use in automatic irrigation. The responses to...

The relationship between respiration rate and peroxidase activities in maize root mitochondria

V. Hadži-Tašković Šukalović, M. Vuletić

Biologia plantarum 51:297-302, 2007 | DOI: 10.1007/s10535-007-0059-z

In the present study we provide the evidence of different respiration rates and peroxidase activities in maize (Zea mays L.) mitochondria isolated from germinated seeds and roots of 2-week-old seedlings. The negative relationships between mitochondrial respiration rate measured with NADH as substrate and activities of peroxidases that oxidized NADH in both oxidative and peroxidative cycles were found. The possible role of peroxidase in the regulation of reactive oxygen species metabolism in expense of NADH oxidation was hypothesized.

Organ-dependent responses of the african rice to short-term iron toxicity: Ferritin regulation and antioxidative responses

V. Majerus, P. Bertin, V. Swenden, A. Fortemps, S. Lobréaux, S. Lutts

Biologia plantarum 51:303-312, 2007 | DOI: 10.1007/s10535-007-0060-6

Hydroponically grown African rice (Oryza glaberrima) was exposed for 72 h to a high Fe²⁺ concentration (500 mg dm^-3) to identify the first steps of iron toxicity response in various organs. Iron accumulated in all plant parts analysed and had only a limited impact on absorption and translocation of other nutrients. The content of the iron-storage protein ferritin increased as a consequence of transcription stimulation or increase in mRNA stability and culminated after 48 h of treatment in laminae and to a lesser extent in sheaths but was not detected in roots. Although endogenous iron concentrations were similar in sheaths...

Effects of elevated ozone on chlorophyll a fluorescence in symptomatic and asymptomatic leaves of two tomato genotypes

E. Degl'Innocenti, L. Guidi, G. F. Soldatini

Biologia plantarum 51:313-321, 2007 | DOI: 10.1007/s10535-007-0061-5

Two different genotypes of Lycopersicon esculentum Mill. (cv. Cuor di Bue, O₃-sensitive and line 93.1033/1, O₃-resistant) were treated with a single dose of ozone (150 mm³ m^-3 for 3 h). The PS 2 activity was examined by measurements of chlorophyll a fluorescence on symptomatic and asymptomatic leaves. Symptoms were evident on the 4^th leaves from the bottom, in both genotypes, while the 2^nd leaves of the line 93.1033/1 were asymptomatic. In these leaves, the net photosynthetic rate (P_N) did not change even if the F_v/F_m ratio significantly...

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

W. Maksymiec, Z. Krupa

Biologia plantarum 51:322-326, 2007 | DOI: 10.1007/s10535-007-0062-4

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...

An elicitor-and pathogen-induced cdna from potato encodes a stress-responsive cyclophilin

I. A. Dubery

Biologia plantarum 51:327-332, 2007 | DOI: 10.1007/s10535-007-0063-3

Differential mRNA display was used to identify pathogen-responsive, stress-related genes in potato cell suspensions treated with salicylic acid and a cell wall-derived elicitor from Phytophthora infestans. Among the positive clones identified, one was found to be expressed at a significantly higher level in elicited cells than in control cells. DNA sequencing of this amplicon revealed high homology and identified it as a potato cyclophilin cDNA. The maximum amount of the cyclophilin mRNA was found 9 to 12 h after elicitation. Cyclophilin (CyP) mRNA synthesis was also up-regulated from 12 to 24 h in potato leaves locally infected with zoospores...

Resistance of transgenic papaya plants to Papaya ringspot virus

S. Kertbundit, N. Pongtanom, P. Ruanjan, D. Chantasingh, A. Tanwanchai, S. Panyim, M. Juříček

Biologia plantarum 51:333-339, 2007 | DOI: 10.1007/s10535-007-0065-1

The coat protein gene isolated from Papaya ringspot virus, Thai isolate, was used to generate transgenic papayas. A binary vector containing the coat protein gene under the control of a 35S promoter, was constructed and transformed into somatic embryos of papaya cultivar Khak Dum by microprojectile bombardment. Eight transgenic lines were identified from 1980 bombarded calli of papaya somatic embryos under kanamycin selection. Integration of the transferred genes into kanamycin resistant papaya calli was verified by PCR amplification of the coat protein gene, GUS assays and Southern blot hybridization. Although the coat protein gene was detected...

Singh, R.J., Jahuar, P.P. (ed.): Genetic Resources, Chromosome Engineering, and Crop Improvement. Cereals. Vol. 2

J. Vagera

Biologia plantarum 51:211, 2007 | DOI: 10.1007/s10535-007-0042-8

Farineau, J., Morot-Gaudry, J.-F.: La Photosynthèse. Processus Physiques, Moléculaires et Physiologiques. [Photosynthesis. Physical, Molecular and Physiological Processes.]

L. Nátr

Biologia plantarum 51:248, 2007 | DOI: 10.1007/s10535-007-0049-1

Sharma, C.P.: Plant Micronutrients

J. Pospíšilová

Biologia plantarum 51:267, 2007 | DOI: 10.1007/s10535-007-0052-6

Wang, K. (ed.): Agrobacterium Protocols. 2^nd Ed. Volume 1

J. Bříza

Biologia plantarum 51:276, 2007 | DOI: 10.1007/s10535-007-0054-4

Lal, R., Cerri, C.C., Bernoux, M., Etchevers, J., Cerri, E. (ed.): Carbon Sequestration in Soils of Latin America

L. Nátr

Biologia plantarum 51:284, 2007 | DOI: 10.1007/s10535-007-0056-2

Cassells, A.C., Gahan, P.B.: Dictionary of Plant Tissue Culture

J. Pospíšilová

Biologia plantarum 51:332, 2007 | DOI: 10.1007/s10535-007-0064-2

Loyola-Vargas, V.M., Vázquez-Flota, F.: Plant Cell Culture Protocols (Second Edition)

R. Podlipná

Biologia plantarum 51:339, 2007 | DOI: 10.1007/s10535-007-0066-0

Price, W.C., Rana, N., Sample, V.A. (ed.): Plantations and Protected Areas in Sustainable Forestry

L. Nátr

Biologia plantarum 51:350, 2007 | DOI: 10.1007/s10535-007-0070-4

Rieger, M.: Introduction to Fruit Crops

J. Tupý

Biologia plantarum 51:362, 2007 | DOI: 10.1007/s10535-007-0074-0

Schekman, R., Goldstein, L., Rossant, J. (ed.): Annual Review of Cell and Developmental Biology. Volume 22

T. Gichner

Biologia plantarum 51:366, 2007 | DOI: 10.1007/s10535-007-0076-y

Saito, K., De Kok, L.J., Stulen, I., Hawkesford, M.J., Schnug, E., Sirko, A., Rennenberg, H. (ed.): Sulfur Transport and Assimilation in Plants in the Post Genomic Era

O. Gašparíková

Biologia plantarum 51:385, 2007 | DOI: 10.1007/s10535-007-0081-1

Teixeira da Silva, J.A. (ed.): Floriculture, Ornamental and Plant Biotechnology: Advances and Topical Issues. Volumes I-IV

J. Pospíšilová

Biologia plantarum 51:390, 2007 | DOI: 10.1007/s10535-007-0083-z

Merchant, S., Briggs, W.R., Chandler, V.L. (ed.): Annual Review of Plant Biology. Volume 57, 2006.-Annual Reviews

Z. Šesták

Biologia plantarum 51:399-400, 2007 | DOI: 10.1007/s10535-007-0086-9

Transgenic rice tolerant to high temperature with elevated contents of dienoic fatty acids

S. O. Sohn, K. Back

Biologia plantarum 51:340-342, 2007 | DOI: 10.1007/s10535-007-0067-z

Transgenic rice plants in which the content of dienoic fatty acids was increased as a result of co-suppression of fatty acid desaturase were more tolerant to high temperatures than untransformed wild-type plants, as judged by growth rate and chlorophyll content. When untransformed wild-type and transgenic rice seedlings were incubated at 35 °C, seedlings of the transgenic rice lines showed approximately 1.6 and 2.1 times the growth of untransformed wild-type seedlings, as assayed by shoot and root mass, respectively. The chlorophyll content of the transgenic leaves after 9 d at 35 °C was also higher than that of wild-type rice. The maximum photochemical...

Effects of microwave treatment on growth, photosynthetic pigments and some metabolites of wheat

E. A. M. Hamada

Biologia plantarum 51:343-345, 2007 | DOI: 10.1007/s10535-007-0068-y

Wheat (Triticum aestivum L. Sakha 61) grains were exposed to microwave radiation of a wavelength 2.85 cm and frequency 10.525 GHz for 15, 45, or 75 min. The exposed grains were germinated and then harvested after 7 and 14 d. While 15-and 45-min exposure of the grains stimulated seedling shoot length and fresh and dry masses, the exposure for 75 min had no pronounced effects. 15 and 75-min irradiation increased succulence and pigment contents in 7-and 14-d-old seedlings. While the ratios chlorophyll (Chl) a/b, carotenoids (Car)/Chl were higher in 7-d-old seedlings than in the control ones for all doses, they decreased in 14-d-old seedlings....

Plant regeneration through direct somatic embryogenesis from leaf explants of Dendrobium

H. H. Chung, J. T. Chen, W. C. Chang

Biologia plantarum 51:346-350, 2007 | DOI: 10.1007/s10535-007-0069-x

A protocol for induction of direct somatic embryogenesis, secondary embryogenesis and plant regeneration of Dendrobium cv. Chiengmai Pink was developed. Thidiazuron (TDZ) at 0.3, 1 and 3 mg dm^-3 induced 5-25 % of leaf tip segments of in vitro grown plants to directly form embryos after 60 d of culture, and 1 mg dm^-3 TDZ was the best treatment. Somatic embryos mostly formed from leaf surfaces near cut ends, and occasionally found on leaf tips. Higher frequency of embryogenesis was obtained in light than in darkness. During subculture, secondary embryos developed from outer cell layers of primary embryos. All combinations...

Proline accumulation induced by excess nickel in detached rice leaves

Y. C. Lin, C. H. Kao

Biologia plantarum 51:351-354, 2007 | DOI: 10.1007/s10535-007-0071-3

The regulation of proline accumulation in detached rice leaves exposed to excess NiSO₄ was investigated. NiSO₄ treatment increased proline and Ni contents but had no effect on relative water content, indicating that proline accumulation in Ni-exposed detached rice leaves was due to Ni uptake per se, rather than to water stress. Proline accumulation caused by NiSO₄ was related to protein hydrolysis, a decrease in proline dehydrogenase activity, and a decrease in proline utilization. It seems that an increase in the content of ammonia and an increase in the activities of Δ¹-pyrroline-5-carboxylate reductase...

Effects of brassinosteroid infiltration prior to cold treatment on ion leakage and pigment contents in rape leaves

A. Janeczko, G. Gullner, A. Skoczowski, F. Dubert, B. Barna

Biologia plantarum 51:355-358, 2007 | DOI: 10.1007/s10535-007-0072-2

The effect of 24-epibrassinolide (BR₂₇) on cold resistance of rape seedlings was studied by ion leakage and photosynthetic pigment degradation measurements. Aqueous solutions of BR₂₇ were injected into cotyledons or primary leaves of rape plants and these plants were incubated at 2 °C or 20 °C. Cold treatment (2 °C) without BR₂₇ injection elevated the membrane permeability in both primary leaves and cotyledons significantly. Surprisingly, injection of leaves with water or 0.467 % aqueous ethanol solution led to a massive increase in membrane permeability after cold stress at 2 °C. The synergistic effect of leaf infiltration...

Freezing sensitivity in the gigantea mutant of Arabidopsis is associated with sugar deficiency

S. Q. Cao, Y. Q. Song, L. Su

Biologia plantarum 51:359-362, 2007 | DOI: 10.1007/s10535-007-0073-1

The freezing sensitivity in the gi-3 mutant (an allele of the gigantea mutant) was associated with a constitutive reduction in soluble sugar content. Although sugar accumulation was evident in wild-type plants in response to cold treatment, the gi-3 mutant showed a constitutive reduction in soluble sugar content. There were no significant differences in the proline content and the transcript levels of cold-responsive gene RD29A and abscisic acid-responsive gene RAB18 between the wild type and the gi-3 mutant in response to cold treatment. These results suggest that freezing sensitivity in the gi-3 mutant...

Localization of cadmium in the root cells of Allium cepa by energy dispersive x-ray analysis

D. Liu, I. Kottke, D. Adam

Biologia plantarum 51:363-366, 2007 | DOI: 10.1007/s10535-007-0075-z

Allium cepa L. roots were exposed to 0.1 and 1.0 mM Cd for 6, 24 and 48 h and the localization of Cd in the root tissue was investigated. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA) were performed on frozen-dried tissues of roots. No Cd was detected in the roots treated with only 0.1 mM Cd, while after exposure to higher Cd concentration (1.0 mM) Cd was observed in cell wall and in cytoplasm in the epidermis, cortex and vascular tissues in the roots.

Soapwort oxidoreductase is involved in trinitrotoluene detoxification

R. Podlipná, A. Nepovím, P. Soudek, M. Vágner, T. Vaněk

Biologia plantarum 51:367-371, 2007 | DOI: 10.1007/s10535-007-0077-x

Plant enzymes participating in degradation of nitroaromatic compounds have not been biochemically characterized in details so far. From suspension culture of soapwort (Saponaria officinalis L.) we isolated a novel plant oxidoreductase involved in degradation of trinitrotoluene (TNT). The enzyme catalyses first steps of reduction of TNT nitro groups in the presence of NAD(P)H under anaerobic conditions. The enzyme is monomeric with molecular mass 29 kDa, its two isoforms have pI 4.8 and 5.1. According to the spectral and activation analysis the enzyme contains flavinmono-nucleotide as a prosthetic group. The structure properties suggest an evolutional...

Methyl salicylate fumigation increases monoterpene emission rates

J. Peñuelas, J. Llusià, I. Filella

Biologia plantarum 51:372-376, 2007 | DOI: 10.1007/s10535-007-0078-9

We aimed to assess the potential effects of fumigation by methyl salicylate (MeSA) on plant monoterpene production and emissions. We evaluated monoterpene production and emissions both by chromatographic and proton transfer reaction mass spectrometry at the whole plant-and leaf-scales, in MeSa-fumigated (ca. 60 mm³ m^-3 in air) and control (without MeSa fumigation) holm oak (Quercus ilex L.) plants exposed to temperatures ranging from 25 to 50 °C. The MeSa-fumigated plants showed ca. 3-4-fold greater leaf monoterpene concentrations and emission rates than the control plants between the temperatures of 25 to 45 °C.

Influence of cytokinins and novel cytokinin antagonists on the senescence of detached leaves of Arabidopsis thaliana

I. Sergiev, D. Todorova, M. Somleva, V. Alexieva, E. Karanov, E. Stanoeva, V. Lachkova, A. Smith, M. Hall

Biologia plantarum 51:377-380, 2007 | DOI: 10.1007/s10535-007-0079-8

Cytokinins N⁶-benzyladenine (BA) and 1-(2-chloropyridin-4-yl)-3-phenylurea (4PU-30) delayed the senescence of detached leaves (3^rd to 7^th leaf node) of wild and ethylene insensitive eti5 mutant of Arabidopsis thaliana. The novel anticytokinins, structural analogues of purine and phenylurea cytokinins also affected the senescence of detached rosette leaves of A. thaliana. They diminished to a significant extent the cytokinin-induced delay of chlorophyll destruction, but without a considerable difference in their action against both types of cytokinins. These results correlated with changes observed...

Low night temperature effects on photosynthetic performance on two grapevine genotypes

M. Bertamini, L. Zulini, K. Muthuchelian, N. Nedunchezhian

Biologia plantarum 51:381-385, 2007 | DOI: 10.1007/s10535-007-0080-2

The functional activities of the photosynthetic apparatus of two grapevine genotypes (Vitis vinifera L. cvs. Müller-Thurgau and Lagrein) were investigated after low night temperature (LNT) treatment for 7 d. LNT caused important reductions of the net photosynthetic rate (P_N) of Lagrein plants due to non-stomatal components. These non-stomatal effects were not evident in Müller-Thurgau. At LNT treatment, the contents of photosynthetic pigments decreased significantly in Lagrein, but in Müller-Thurgau the contents of chlorophyll (Chl) remained unchanged whereas the contents of carotenoids (Car) increased. An increase and decrease of...

Effect of osmotic stress and sodium nitroprusside pretreatment on proline metabolism of wheat seedlings

Y. Lei, C. Yin, J. Ren, C. Li

Biologia plantarum 51:386-390, 2007 | DOI: 10.1007/s10535-007-0082-0

Effect of osmotic stress and sodium nitroprusside (SNP, NO donor) pretreatment on growth and proline metabolism of wheat seedlings was investigated. Polyethylene glycol 6000 treatment for 2, 4 and 6 d could be termed as mild, moderate and severe stress, respectively, according to decrease in the relative water content. Severe osmotic stress significantly decreased the growth and photochemical efficiency, and increased proline content due to activation of its synthesis. 0.2 mM SNP pretreatment enhanced growth of wheat seedlings, increased variable to maximum fluorescence ratio (F_v/F_m) and fluorescence yield, while decreased proline...

Activity of secreted cell wall-modifying enzymes and expression of peroxidase-encoding gene following germination of Orobanche ramosa

C. Veronesi, E. Bonnin, S. Calvez, P. Thalouarn, P. Simier

Biologia plantarum 51:391-394, 2007 | DOI: 10.1007/s10535-007-0084-y

Radicle growth of germinated seed of the root parasite O. ramosa is shown to be rapidly accompanied by secretion of proteins including pectinolytic enzymes, polygalacturonase and rhamnogalacturonase. These secretions peaked between 4 to 8 d after induction of germination and remained constant for some further days in the case of polygalacturonases. After 6 d, germinated seeds secreted proteins which exhibit peroxidase activity. The latter may be correlated with expression of OrPOX1, a putative gene encoding for secreted peroxidase. The involvement of these enzymes in host root attack and haustorium formation by the parasite is discussed.

Changes in spectral reflectance of a foliar lichen Umbilicaria hirsuta during desiccation

J. Gloser, V. Gloser

Biologia plantarum 51:395-398, 2007 | DOI: 10.1007/s10535-007-0085-x

Water potential (ψ_w) and water saturation deficit (WSD), and several reflectance (R) indexes were assessed in an aerophytic lichen Umbilicaria hirsuta (Sw. ex Westr.) Hoffm. The water index (WI, R₉₀₀/_R970) and normalized difference vegetation index, NDVI [(R₉₀₀-R₆₈₀)/(R₉₀₀+R₆₈₀)] were strongly correlated both with the ψ_w and the WSD of lichen thalli. No significant changes during desiccation were found in structural independent pigment index, SIPI [(R₈₀₀-R₄₄₅)/(R₈₀₀-R₆₈₀)]. Sensitivity of the spectral detection...