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Growth and ion uptake in Annona muricata and A. squamosa subjected to salt stressV. M. Passos, N. O. Santana, F. C. Gama, J. G. Oliveira, R. A. Azevedo, A. P. VitóriaBiologia plantarum 49:285-288, 2005 | DOI: 10.1007/s10535-005-5288-4 The effects of treatment with NaCl (3, 100 and 300 mM) for 1, 2, 3 and 7 d on plant growth and ion accumulation were analyzed in 2-week and 8-week-old Annona muricata and A. squamosa plants. Fresh mass and root growth inhibition were directly related to the increase in salinity, particularly for A. squamosa. Two-weeks old seedlings were sensitive to 100 and 300 mM NaCl particularly after 7 d, whereas 8-week-old plants were shown to be more resistant to NaCl even at 300 mM NaCl. Na+ and Cl- mostly accumulated in young leaves. Our results suggest that A. squamosa is more sensitive than A. muricata to salt stress and that older seedlings of both species are more tolerant than younger seedlings. |
Transcription factors in plants and ABA dependent and independent abiotic stress signallingP. K. Agarwal, B. JhaBiologia plantarum 54:201-212, 2010 | DOI: 10.1007/s10535-010-0038-7 Plants face variable environmental stresses that negatively affect plant growth and productivity. The multiplicity of responses is an important aspect of the complexity of stress signalling. Abscisic acid (ABA) is a broad-spectrum phytohormone involved not only in regulating stomatal opening, growth and development but also in coordinating various stress signal transduction pathways in plants during abiotic stresses. The both ABA-dependent and ABA-independent signal transduction pathways from stress signal perception to gene expression involve different transcription factors such as DREB, MYC/MYB, AREB/ABF, NAM, ATAF1,2, CUC and their corresponding cis-acting elements DRE, MYCRS/MYBRS, ABRE, NACRS. Genetic analysis of ABA mutants has given insight that ABA-dependent and ABA-independent pathways for osmotic stress and cold stress interact and converge. This review focuses on ABA-dependent and ABA-independent transcriptional components and cascades, their specificity and crosstalk in stress gene regulation. |
Hairy roots formation in recalcitrant-to-transform plant Chenopodium rubrumS. Dmitroviæ, N. Mitiæ, S. Zdravkoviæ-Koraæ, B. Vinterhalter, S. Ninkoviæ, L. J. ÆulafiæBiologia plantarum 54:566-570, 2010 | DOI: 10.1007/s10535-010-0101-4 Susceptibility of C. rubrum to Agrobacterium-mediated transformation was demonstrated by inoculating the petioles of in vitro grown plants with A. rhizogenes strain A4M70GUS. Hairy roots were produced in 8 % of explants. They were isolated and maintained on plant growth regulator-free solid or liquid half-strength Murashige and Skoog medium for two years. Hairy root fresh mass increased 30 - 90 folds when grown in liquid medium, which was superior to solid medium, where most of the hairy roots produced calli. When these calli were grown on medium supplemented with 0.5 mg dm-3 thidiazuron, embryo-like structures were obtained. Transgenic status of long-term callus and hairy root cultures was confirmed by histochemical GUS assay, by PCR specific to the uidA, rolA&B and ags genes and by Southern hybridization. |
Photosynthetic and anatomic responses of peanut leaves to zinc stressG. R. Shi, Q. S. CaiBiologia plantarum 53:391-394, 2009 | DOI: 10.1007/s10535-009-0074-3 In this study, photosynthetic performance, pigment content, chlorophyll a fluorescence, and leaf anatomy in peanut (Arachis hypogaea) subjected to zinc (Zn) stress were investigated. Zn stress resulted in reduction of photosynthetic and transpiration rates, pigment contents and root biomass. Zn-induced xerophyte structure in peanut leaves (i.e. thick lamina, upper epidermis, and palisade mesophyll, as well as abundant and small stomata) also contributed to decreased transpiration rate and stomatal conductance. This in turn, partially contributed to the limitation of photosynthesis. |
The influence of thidiazuron on shoot regeneration from leaf explants of fifteen cultivars of RhododendronD. PavingerováBiologia plantarum 53:797-799, 2009 | DOI: 10.1007/s10535-009-0147-3 The influence of cytokinin thidiazuron (TDZ) and auxin indole-3-acetic acid (IAA) on in vitro shoot organogenesis of fifteen Rhododendron genotypes was investigated and a protocol for high frequency adventitious shoot regeneration from leaf explants was developed. High genotypic variation was observed and regeneration frequencies ranged from 0 to 100 %. Genotype Ovation had the highest number of shoots (26.4 per explant) after 12 weeks on medium with 0.57 µM IAA and 1.20 µM TDZ, but only 65 % of explants regenerated. Catawbiense Grandiflorum had 17.7 shoots per explant and 75 % regeneration on medium with 5.70 µM IAA and 0.45 µM TDZ and Van Werden Poelman had 14.3 shoots per explant and 100 % regeneration on medium with 0 57 µM IAA and 0.45 µM TDZ. |
Characterization of the antioxidant system during the vegetative development of pea plantsP. Díaz-Vivancos, G. Barba-Espín, M. J. Clemente-Moreno, J. A. HernándezBiologia plantarum 54:76-82, 2010 | DOI: 10.1007/s10535-010-0011-5 The antioxidative system was studied during the development of pea plants. The reduced glutathione (GSH) content was higher in shoots than in roots, but a greater redox state of glutathione existed in roots compared with shoots, at least after 7 d of growth. The 3-d-old seedlings showed the highest content of oxidised ascorbate (DHA), which correlated with the ascorbate oxidase (AAO) activity. Also, the roots exhibited higher DHA content than shoots, correlated with their higher AAO activity. The activities of antioxidant enzymes were much higher in shoots than in roots. Ascorbate peroxidase (APX) activity decreased during the progression of growth in both shoots and roots, whereas peroxidase (POX) activity strongly increased in roots, reflecting a correlation between POX activity and the enhancement of growth. Catalase activity from shoots reached values nearly 3 or 4-fold higher than in roots. The monodehydroascorbate reductase (MDHAR) activity was higher in young seedlings than in more mature tissues, and in roots a decrease in MDHAR was noticed at the 11th day. No dehydroascorbate reductase (DHAR) was detected in roots from the pea plants and DHAR values detected in seedlings and in shoots were much lower than those of MDHAR. In shoots, GR decreased with the progression of growth, whereas in roots an increase was seen on the 9th and 11th days. Finally, superoxide dismutase (SOD) activity increased in shoots during the progression of growth, but specific SOD activity was higher in roots than in shoots. |
Chlorophyll fluorescence in micropropagated Rhododendron ponticum subsp. baeticum plants in response to different irradiancesM. L. Osório, J. Osório, A. RomanoBiologia plantarum 54:415-422, 2010 | DOI: 10.1007/s10535-010-0076-1 The aim of this study was to investigate acclimation of micropropagated plants of Rhododendron ponticum subsp. baeticum to different irradiances and recovery after exposure to high irradiance. Plants grown under high (HL) or intermediate (IL) irradiances displayed higher values of maximum electron transport rate (ETRmax) and light saturation coefficient (Ek) than plants grown under low irradiance (LL). The capacity of tolerance to photoinhibition (as assessed by the response of photochemical quenching, qp) varied as follows: HL > IL > LL. Thermal energy dissipation (qN) was also affected by growth irradiance, with higher saturating values being observed in HL plants. Light-response curves suggested a gradual replacement of qp by qN with increasing irradiance. Following exposure to irradiance higher than 1500 μmol m-2 s-1, a prolonged reduction of the maximal photochemical efficiency of PS 2 (Fv/Fm) was observed in LL plants, indicating the occurrence of chronic photoinhibition. In contrary, the decrease in Fv/Fm was quickly reverted in HL plants, pointing to a reversible photoinhibition. |
Tissue- and genotype-specific ascorbate peroxidase expression in sweet potato in response to salt stressK. H. Lin, S. F. PuBiologia plantarum 54:664-670, 2010 | DOI: 10.1007/s10535-010-0118-8 The aim of this work was to study the short-term effects of salt stress on the antioxidant system and ascorbate peroxidase (APX) expression in two salt sensitive sweet potato cultivars Tainung 57 (TN57) and Tainung 66 (TN66), and one salt-tolerant cultivar Hsusu 18 (HS18). Plants were grown in plastic pots in a greenhouse for 30 d followed by NaCl treatments (0, 150, 300, and 450 mM) for 0, 24 and 48 h in a growth chamber. Young, fully expanded leaves of each treatment and period of time were clipped for enzyme activity measurements. In addition, different tissues (leaves, stems, and roots) were also harvested to analyze the tissue-specific APX gene expression using semiquantitative reverse-transcription polymerase chain reaction (RT-PCR). Three degenerated primers of APX isoforms from cytosol, peroxisomes and chloroplasts were used to amplify the APX complementary DNA of these cultivars. Our results show higher increase in APX activity at 24 and 48 h of salinity (450 mM of NaCl) in salt-stress tolerant genotype than in saltsensitive ones. The expression of APX isoforms in response to salinity was tissue specific and also dependent on stress duration. |
Multifunctional genes: the cross-talk among the regulation networks of abiotic stress responsesX. J. Hu, Z. B. Zhang, P. Xu, Z. Y. Fu, S. B. Hu, W. Y. SongBiologia plantarum 54:213-223, 2010 | DOI: 10.1007/s10535-010-0039-6 Unfavourable environment brings many kinds of stresses to plants. To survive such stresses, efficient resistance is required for the plants. Multifunctional genes enable the cross-talk among the various abiotic stress resistance systems. This paper reviews the action mechanisms of multifunctional genes. These genes can be classified into three groups: genes encoding diverse proteins through mRNA splicing (e.g. AOX in rice); genes like BADH, P5CS and HAV that control drought, salinity, osmotic and heat stress resistance; and a gene family, for example AQP, controlling transport of many compounds including water and nutrients. These genes participate in signal sensing and transduction, transcriptional regulation and functional gene activation during stress resistance induction. Furthermore, it should be noted that, under abiotic stresses, the regulation cascades are mutually interdependent and there also exists a close correlation between those cascades and normal plant growth and development. |
Responses to drought stress in two poplar species originating from different altitudesF. Yang, X. Xu, X. Xiao, C. LiBiologia 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 (POD), ascorbate peroxidase (APX) and glutathione reductase (GR). Compared with P. cathayana with greater leaf area, P. kangdingensis with greater root/shoot ratio exhibited lower MDA and H2O2 contents, higher soluble sugar and free proline contents, and higher activities of CAT, SOD, POD, APX and GR. These results suggested that P. kangdingensis was more drought tolerant than P. cathayana. |
Effects of Boron on Growth, and Chlorophyll and Mineral Contents of Shoots of the Apple Rootstock MM 106 cultured in vitroG.N. Mouhtaridou, T.E. Sotiropoulos, K.N. Dimassi, I.N. TheriosBiologia plantarum 48:617-619, 2004 | DOI: 10.1023/B:BIOP.0000047169.13304.67 The in vitro cultures of apple rootstock MM 106 produced the highest fresh mass (FM) when 0.1 mM B was included in the culture medium. By increasing B concentration of the culture medium from 0.1 to 6.0 mM, FM and contents of B, P, Ca, and Mg in explants increased, whereas K, Fe, Mn, and Zn contents decreased. SPAD units of leaves characterizing chlorophyll contents declined as B concentration of the culture medium increased from 0.1 to 6.0 mM. |
Over-expression of heat shock protein gene hsp26 in Arabidopsis thaliana enhances heat toleranceY. Xue, R. Peng, A. Xiong, X. Li, D. Zha, Q. YaoBiologia plantarum 54:105-111, 2010 | DOI: 10.1007/s10535-010-0015-1 In the yeast Saccharomyces cerevisiae, the molecular chaperone HSP26 has the remarkable ability to sense increases in temperature directly and can switch from an inactive to a chaperone-active state. In this report, we analyzed the effect of expression of HSP26 in Arabidopsis thaliana plants and their response to high temperature stress. The hsp26 transgenic plants exhibited stronger growth than wild type plants at 45 °C for 16 h. The chlorophyll content and chlorophyll fluorescence decreased much more in wild type than in transgenic plants. Moreover, the transgenic plants had higher proline and soluble sugar contents, and lower relative electrical conductivity and malondialdehyde contents after high temperature stress. Furthermore, we found that over-expression of HSP26 in Arabidopsis increased the amount of free proline, elevated the expression of proline biosynthetic pathway genes and therefore enhanced Arabidopsis tolerance to heat stress. |
Effect of abiotic stresses on the activity of antioxidative enzymes and contents of phytohormones in wild type and AtCKX2 transgenic tobacco plantsZ. Mýtinová, V. Motyka, D. Haisel, A. Gaudinová, Z. Lubovská, N. WilhelmováBiologia plantarum 54:461-470, 2010 | DOI: 10.1007/s10535-010-0082-3 The responses of antioxidant enzymes (AOE) ascorbate peroxidase (APX), glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT) in soluble protein extracts from leaves and roots of tobacco (Nicotiana tabacum L. cv. Samsun NN) plants to the drought stress, salinity and enhanced zinc concentration were investigated. The studied tobacco included wild-type (WT) and transgenic plants (AtCKX2) harbouring the cytokinin oxidase/dehydrogenase gene under control of 35S promoter from Arabidopsis thaliana (AtCKX2). The transgenic plants exhibited highly enhanced CKX activity and decreased contents of cytokinins and abscisic acid in both leaves and roots, altered phenotype, retarded growth, and postponed senescence onset. Under control conditions, the AtCKX2 plants exhibited noticeably higher activity of GR in leaves and APX and SOD in roots. CAT activity in leaves always decreased upon stresses in WT while increased in AtCKX2 plants. On the contrary, the SOD activity was enhanced in WT but declined in AtCKX2 leaves. In roots, the APX activity prevailingly increased in WT while mainly decreased in AtCKX2 in response to the stresses. Both WT and AtCKX2 leaves as well as roots exhibited elevated abscisic acid content and increased CKX activity under all stresses while endogenous CKs and IAA contents were not much affected by stress treatments in either WT or transgenic plants. |
Involvement of arabinogalactan proteins in the control of cell proliferation of Cucurbita pepo suspension culturesA. Ben Amar, P. Cobanov, A. Ghorbel, A. Mliki, G. M. ReustleBiologia plantarum 54:321-324, 2010 | DOI: 10.1007/s10535-010-0055-6 Arabinogalactan proteins (AGPs) secreted by zucchini squash (Cucurbita pepo L.) cell cultures into the medium are implicated in cell proliferation. Conditioned medium derived from cell suspensions of squash cultivar Dundoo could enhance multiplication rate of slow-growing cell line Cx3005. To examine the role of AGPs, a precipitation assay was performed using Yariv reagent which binds selectively to AGPs. This AGP precipitation as well as proteinase application arrested cell division. However, chitinase treatment successfully increased embryogenic callus mass. A growth promotion was also obtained by arabinogalactan addition to the culture medium. Immunoblotting analysis using the MAC 207 anti-AGP monoclonal antibody showed high AGP expression in Dundoo cell cultures. |
UV-B radiation and cadmium induced changes in growth, photosynthesis, and antioxidant enzymes of cyanobacterium Plectonema boryanumS. M. Prasad, M. ZeeshanBiologia plantarum 49:229-236, 2005 | DOI: 10.1007/s10535-005-0236-x UV-B (0.4 W m-2) irradiation and cadmium (2 and 8 μM) treatments separately inhibited the survival, growth, pigment content, and photosynthetic electron transport in Plectonema boryanum. Phycocyanin was the main target to UV-B and Cd and it was followed by chlorophyll a and carotenoids. UV-B and Cd caused strong inhibition on activities of photosystem 2 (PS2) and the whole electron transport chain, whereas photosystem 1 (PS1) was the least affected. UV-B and Cd treatment accelerated respiration, lipid peroxidation, and the activities of superoxide dismutase and catalase. However, enhancement in catalase activity was considerably less (5 - 50 %) as compared to SOD activity. As compared to individual treatment, the effect of their combination (UV-B + Cd) was more detrimental to the above parameters. A synergistic interaction of UV-B and Cd is probably due to increased cadmium uptake as a result of increased membrane permeability caused by lipid peroxidation in P. boryanum after UV-B exposure. |
Morphological and anatomical observations of abnormal somatic embryos from anther cultures of Citrus reticulataC. Benelli, M. A. Germanà, T. Ganino, D. Beghè, A. FabbriBiologia plantarum 54:224-230, 2010 | DOI: 10.1007/s10535-010-0040-0 A morphological and anatomical study of regenerants obtained from mandarin anther culture was carried out. Beside morphologically normal somatic embryos, abnormal structures were originated in the course of somatic embryogenesis. Anatomical anomalies can be found at several growth stages, causing the formation of slender stems, stubby structures, non-functional leaves. When too long, some structures are subject to shedding, with the formation of various abscission zones. Most of them are subject to degeneration, although many are capable of further, localized, morphogenesis. A thorough knowledge of morphology and anatomy of normal and abnormal regenerants could make possible to select and subculture the lines considered most suitable for conversion into plantlets. |
Morpho-histological study of direct somatic embryogenesis in endangered species Frittilaria meleagrisA. Subotiæ, M. Trifunoviæ, S. Jevremoviæ, M. PetriæBiologia plantarum 54:592-596, 2010 | DOI: 10.1007/s10535-010-0107-y Direct somatic embryogenesis of Frittilaria meleagris L. was induced using leaf base explants excised from in vitro grown shoots. Somatic embryos occurred at the basal part of leaf explants 4 weeks after culture on a Murashige and Skoog (MS) medium supplemented with various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) or kinetin (KIN). The highest number of somatic embryos (SEs) were formed (9.74) from leaf explant on MS medium supplemented with 0.1 mg dm-3 2,4-D after 4 weeks of culture initiation. An initial exposure to a low concentration of KIN in the medium also enhanced SEs induction. Our observations by light and scanning electron microscopy revealed that SEs originate directly from the epidermal and subepidermal layers of leaf explant. The developmental stages of somatic embryogenesis from the first unequal cell division through the meristematic clusters, multi-cellular globular somatic embryos to the fully formed cotyledonary embryos were determined. After 4 weeks on MS medium without plant growth regulators, SEs developed into bulblets. |
Leaf morphological and physiological responses to drought and shade in two Populus cathayana populationsX. Huang, X. Xiao, S. Zhang, H. Korpelainen, C. LiBiologia 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 traits were more pronounced in the dry climate population, which suggested that the dry climate population was more light-demanding. In addition, moderate shade alleviated the drought stress of P. cathayana not only by improving the leaf RWC but also by maintaining the positive carbon balance. In contrast, severe shade aggravated drought stress as indicated by a pronounced decrease in leaf size, carbon and nitrogen contents, maximum PN, free proline content and antioxidative enzyme activities. |
Exogenously-supplied trehalose protects thylakoid membranes of winter wheat from heat-induced damageY. Luo, F. Li, G. P. Wang, X. H. Yang, W. WangBiologia 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. |
Direct somatic embryogenesis and shoot organogenesis from leaf explants of Primulina tabacumG. H. Ma, C. X. He, H. Ren, Q. M. Zhang, S. J. Li, X. H. Zhang, B. EricBiologia plantarum 54:361-365, 2010 | DOI: 10.1007/s10535-010-0064-5 An efficient propagation system via somatic embryogenesis and shoot organogenesis and plant regeneration system for endangered species Primulina tabacum Hance was established. Thidiazuron (TDZ) was the key plant growth regulator for inducing somatic embryogenesis and kinetin (KIN) and 6-benzylaminopurine (BAP) were the key cytokinins for inducing shoot organogenesis from leaf explants. TDZ combined with BAP or KIN in the induction Murashige and Skoog medium induced both somatic embryos and adventitious shoots. Leaf explants with abaxial site in contact with the medium induced less somatic embryos or adventitious shoots compared to inversely placed leaf explants and the optimum pH was 6.5-7.0. Secondary somatic embryos or adventitious shoot could be induced from primary somatic embryos using TDZ and BAP. Shoots developed adventitious roots on rooting medium containing 0.5 μM indole-3-butyric acid and 0.2 % activated carbon. Over 90 % of plantlets survived following acclimatization and transfer to potting mixture (sand:Vermiculite:limestone; 1:2:1). |
High efficiency organogenesis and analysis of genetic stability of the regenerants in Solanum melongenaY. Xing, Y. Yu, X. Luo, J. -N. Zhang, B. Zhao, Y. -D. GuoBiologia 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. |
Factors affecting in vitro propagation and field establishment of Chlorophytum borivilianumA. Kumar, D. Aggarwal, P. Gupta, M. S. ReddyBiologia 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. |
Effects of different N-sources on growth, nutritional status, chlorophyll content, and photosynthetic parameters of shoots of the apple rootstock MM 106 cultured in vitroT. E. Sotiropoulos, G. N. Mouhtaridou, T. Thomidis, V. Tsirakoglou, K. N. Dimassi, I. N. TheriosBiologia plantarum 49:297-299, 2005 | DOI: 10.1007/s10535-005-7299-6 The effects of five different N-sources (KNO3 + NH4NO3 = control, KNO3, NH4NO3, NH4H2PO4, L-alanine) on growth, nutritional status, chlorophyll (Chl) content, and photosynthetic parameters of the apple rootstock MM 106 shoots cultured in vitro were investigated. In comparison to all the other treatments, control explants grown on a MS medium containing KNO3 + NH4NO3 had the highest fresh mass, Chl content, net photosynthetic rate, transpiration rate, and stomatal conductance. |
Waterlogging induced oxidative stress and antioxidant activity in pigeonpea genotypesD. Kumutha, K. Ezhilmathi, R. K. Sairam, G. C. Srivastava, P. S. Deshmukh, R. C. MeenaBiologia plantarum 53:75-84, 2009 | DOI: 10.1007/s10535-009-0011-5 The objective of this study was to examine the role of antioxidant enzymes in waterlogging tolerance of pigeonpea (Cajanus cajan L. Halls) genotypes ICP 301 (tolerant) and Pusa 207 (susceptible). Waterlogging resulted in visible yellowing and senescence of leaves, decrease in leaf area, dry matter, relative water content and chlorophyll content in leaves, and membrane stability index in roots and leaves. The decline in all parameters was greater in Pusa 207 than ICP 301. Oxidative stress in the form of superoxide radical, hydrogen peroxide and thiobarbituric acid reactive substances (TBARS) contents initially decreased, however at 4 and 6 d of waterlogging it increased over control plants, probably due to activation of DPI-sensitive NADPH-oxidase. Antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, glutathione reductase and catalase also increased under waterlogging. The comparatively greater antioxidant enzyme activities resulting in less oxidative stress in ICP 301 could be one of the factor determining its higher tolerance to flooding as compared to Pusa 207. This study is the first to conclusively prove that waterlogging induced increase in ROS is via NADPH oxidase. |
Organogenesis and Agrobacterium tumefaciens-mediated transformation of Eucalyptus saligna with P5CS geneR. Dibax, C. Deschamps, J. C. Bespalhok Filho, L. G. E. Vieira, H. B. C. Molinari, M. K. F. De Campos, M. QuoirinBiologia plantarum 54:6-12, 2010 | DOI: 10.1007/s10535-010-0002-6 The purpose of this research was Eucalyptus saligna in vitro regeneration and transformation with P5CSF129A gene, which encodes Δ1-pyrroline-5-carboxylate synthetase (P5CS), the key enzyme in proline biosynthesis. After selection of the most responsive genotype, shoot organogenesis was induced on leaf explants cultured on a callus induction medium (CI) followed by subculture on a shoot induction medium (SI). Shoots were subsequently cultured on an elongation medium (BE), then transferred to a rooting medium and finally transplanted to pots and acclimatized in a greenhouse. For genetic transformation, a binary vector carrying P5CSF129A and uidA genes, both under control of the 35SCaMV promoter, was used. Leaves were co-cultured with Agrobacterium tumefaciens in the dark on CI medium for 5 d. The explants were transferred to the selective callogenesis inducing medium (SCI) containing kanamycin and cefotaxime. Calli developed shoots that were cultured on an elongation medium for 14 d and finally multiplied. The presence of the transgene in the plant genome was demonstrated by PCR and confirmed by Southern blot analysis. Proline content in the leaves was four times higher in transformed than in untransformed plants while the proline content in the roots was similar in both types of plants. |
In vitro propagation of Drosera intermedia in a single stepT. Grevenstuk, N. Coelho, S. Gonçalves, A. RomanoBiologia plantarum 54:391-394, 2010 | DOI: 10.1007/s10535-010-0071-6 A simple and efficient protocol for the micropropagation of Drosera intermedia, using cultures initiated from in vitro produced seedlings, is described. Shoot proliferation was significantly influenced by Murashige and Skoog (MS) macronutrient concentration, showing higher multiplication rates for 1/4 MS (the lowest concentration), but was not affected by the addition of 0.1 mg dm-3 kinetin. In all cases a multiplication percentage above 90 % was recorded. High rooting percentages (up to 100 %) were obtained in multiplication phase on 1/4 MS medium without growth regulators. In average 15.8 plantlets per initial shoot was produced after 8 weeks of culture. All plantlets were successfully acclimatized to ex vitro conditions, exhibiting normal development. |
Importance of glucose-6-phosphate dehydrogenase in taxol biosynthesis in Taxus chinensis culturesL. J. Yu, W. Z. Lan, C. Chen, Y. Yang, Y. P. SunBiologia plantarum 49:265-268, 2005 | DOI: 10.1007/s10535-005-5268-8 The roles of glucose-6-phosphate dehydrogenase (G6PDH) in paclitaxel production were investigated in cell suspension cultures of Taxus chinensis. In the normal cultures, the trend of G6PDH activity was similar to that of cell growth. Addition of glutamate increased G6PDH activity, while dehydroepiandrosterone (DHEA) decreased G6PDH activity. In elicitor-treated cultures, cell growth was depressed, while G6PDH activity and taxol production were enhanced compared with the control. Glutamate recovered the depression of cell growth, and resulted in further increase in G6PDH activity and taxol production. Contrarily, DHEA exacerbated the depression of cell growth, and decreased G6PDH activity and taxol production induced by fungal elicítor. The results indicated that G6PDH played a critic role of taxol production by affecting cell viability. |
Cadmium Toxicity: The effect on Macro- and Micro-Nutrient Contents in Soybean SeedlingsG. Dra¾iæ, N. Mihailoviæ, Z. StojanoviæBiologia plantarum 48:605-607, 2004 | DOI: 10.1023/B:BIOP.0000047160.79306.b7 The effect of Cd (10, 100, and 200 μM) on tissue contents of macronutrients (N, P, K, Ca, Mg) and micronutrients (Fe, Zn, Cu, Mn) was investigated in hydroponically grown soybean (Glycine max) seedlings. Concentration changes of analysed elements observed against increasing Cd accumulation indicated that acute Cd-phytotoxic effect monitored through chlorophyll content was not a consequence of nutrient deficiency. |
Pigment Diverse Mutants of Pseudomonas sp.: Inhibition of Fungal Growth and Stimulation of Growth of Cicer arietinumA.K. Goel, S.S. Sindhu, K.R. DadarwalBiologia plantarum 43:563-569, 2000 | DOI: 10.1023/A:1002877917537 A Pseudomonas strain MRS16 inhibited growth of different pathogenic fungi (Aspergillus sp., Fusarium oxysporum, Pythium aphanidermatum and Rhizoctonia solani) in vitro. Larger inhibition zones were obtained on nutrient agar and King's B media compared to potato dextrose agar and pigment production media. Mutants altered in production of fluorescent pigment were derived by nitrosoguanidine mutagenesis. The pigment overproducer mutant MRS16M-1 was more inhibitory whereas nonproducer mutant MRS16M-5 was less inhibitory than parent strain on nutrient agar medium. Addition of iron (100 µM FeCl3) in the medium decreased inhibition of fungal growth, suggesting the involvement of siderophores and other antifungal secondary metabolites. Seed bacterization of two cultivars of chickpea (Cicer arietinum cvs. H8618 and C235) differing in susceptibility to wilt caused initial root and shoot stunting at 5 d of growth followed by proliferation of secondary root growth at 10 d. Coinoculation of chickpea with Pseudomonas strain MRS16 or mutants and Rhizobium sp. Cicer strain Ca181 enhanced nodulation, nitrogen fixation and plant dry mass as compared to single inoculation with Rhizobium strain under sterile conditions. |
Improvement of Biomass Partitioning, Flowering and Yield by Triadimefon in UV-B Stressed Vigna radiata (L.) WilczekK. Rajendiran, M.P. RamanujamBiologia plantarum 48:145-148, 2004 | DOI: 10.1023/B:BIOP.0000024293.31266.a2 Elevated UV-B radiation (12.2 kJ m-2 d-1) as against the ambient level of 10 kJ m-2 d-1 affected flowering, productivity and biomass partitioning of green gram [Vigna radiata (L.) Wilczek cv. KM-2]. UV-B stress delayed flowering initiation and achievement of 50 % flowering, reduced flower retention by 25 %, potential yield by 18 % and all yield attributes such as pod number (25 %), pod mass (41 %), seed number (32 %) and seed mass (45 %). Harvest index and shelling percentage were also reduced by 31 and 7 %, respectively. Application of triadimefon (20 mg dm-3) to unstressed plants accelerated flowering and enhanced flower retention (21 %), potential yield (15 %) and yield attributes (7 to 44 %). The partitioning of biomass between plant parts also showed improvement over the control plants. In UV-B-stressed plants, triadimefon treatment compensated the inhibitions to varying extents. |


