Therapeutic efficacy in BALB/C mice of extract from marine alga <Emphasis Type="Italic">Canistrocarpus cervicornis</Emphasis> (Phaeophyceae) against herpes simplex virus type 1

Studies with diterpenes from marine brown alga Canistrocarpus cervicornis showed the antiviral potential of the products from this alga in controlling the replication of HSV-1 and maintaining low cytotoxicity. Hence, the aim of this work was to evaluate the anti-herpetic efficacy of C. cervicornis extract ointment in BALB/c mice. To test the anti-herpetic efficacy in vivo, four groups of BALB/c mice (n?=?5) were used: 1—untreated, 2—extract ointment (2 % or 0.4 mg cm^?2 dose^?1), 3—Acyclovir cream (5 % or 1.0 mg cm^?2 dose^?1), and 4—ointment base. The right midflank of each mouse was clipped and depilated with a chemical depilatory. After 2 days, the skin area was scratched and inoculated with HSV-1. The ointments and cream were applied three times a day over a 16-day period, beginning 1 h after virus inoculation. The development of skin lesions was continuously monitored and scored. To evaluate the effect of C. cervicornis topical treatment on biochemical parameters and on body weight, two uninfected groups were formed: an untreated group and a group treated with ointment C. cervicornis extract (2 %). The signs of infection appeared from the second day after infection, while on the 10th day of the experiment, the ointment base and untreated groups had significantly more severe lesions than did the groups that were treated with extract (p?<?0.05) or acyclovir (p?<?0,01). The topical application of extract ointment did not change body weight, hepatic, or renal function suggesting that the extract has a low toxicity in this route of administration. These results suggest that the extract may be useful in reducing the severity of HSV-1 cutaneous lesions.     

Physiological and Biochemical Mechanisms Preventing Cd Toxicity in the New Hyperaccumulator <Emphasis Type="Italic">Abelmoschus manihot</Emphasis>

Abelmoschus manihot, an ornamental plant, was examined for phytoremediation purposes in accordance with the ability to accumulate cadmium and physiological mechanisms of cadmium tolerance. A net photosynthetic rate (A _N) glasshouse experiment for 60 days was conducted to investigate the influence of different cadmium amounts (0–100 mg kg^?1) on the growth, biomass, photosynthetic performance, reactive oxygen species (ROS) production, antioxidative enzyme activities, Cd uptake and accumulation of A. manihot. Exposure to cadmium enhanced plant growth even at 100 mg kg^?1, without showing symptoms of visible damage. The cadmium concentration of shoots (stems or leaves) and roots was more than the critical value of 100 mg kg^?1 and reached 126.17, 185.26 and 210.24 mg kg^?1, respectively. BCF values of A. manihot plants exceeded the reference value 1.0 for all the Cd treatments, and TF values were greater than 1 at 15–60 mg kg^?1 Cd treatment. The results also showed that cadmium concentrations of 60 mg kg^?1 or less induced a significant enhancement in plant net photosynthetic rate (A _N), stomatal conductance (G _s), transpiration rate (T _r), photosynthetic pigments and F _v/F _m. These parameters were slightly decreased at the higher concentration (100 mg kg^?1). The ROS production (O₂ ^?, H₂O₂) and antioxidative response including SOD, CAT and POD were significantly enhanced by increasing cadmium. These results suggest that A. manihot can be considered as a Cd-hyperaccumulator and the hormetic effects may be taken into consideration in remediation of Cd contamination soil.     

Extraction of sterols in brown macroalgae from Antarctica and their identification by liquid chromatography coupled with tandem mass spectrometry

This study reports for the first time the extraction and quantification of sterols in six species of brown macroalgae from Antarctica: Adenocystis utricularis, Ascoseira mirabilis, Cystosphaera jacquinotii, Desmarestia anceps, Desmarestia antarctica, and Himantothallus grandifolius. Ultrasound irradiation was used as a promotor to extract sterols from algal biomass. The extracts were analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for sterol quantization (ergosterol, brassicasterol, fucosterol, β-sitosterol, campesterol, cholesterol, and stigmasterol). In general, fucosterol was the most abundant (6.60 to 48.13 mg kg^?1), followed by β-sitosterol (5.29 to 16.49 mg kg^?1), stigmasterol (2.69 to 14.84 mg kg^?1) in five of the six examined algae. The sterol campesterol was found in lower concentrations (0.07 to 0.15 mg kg^?1) in all studied samples.     

Accumulation and tolerance characteristics of lead in <Emphasis Type="Italic">Althaea rosea</Emphasis> Cav. and <Emphasis Type="Italic">Malva crispa</Emphasis> L.

Two ornamental plants of Althaea rosea Cav. and Malva crispa L. were exposed to various concentrations of lead (Pb) (0, 50, 100, 200 and 500 mg·kg^?1) for 70 days to evaluate the accumulating potential and the tolerance characteristics. The results showed that both plant species grown normally under Pb stress, and A. rosea had a higher tolerance than M. crispa, while M. crispa had a higher ability in Pb accumulation than A. rosea. Besides, lower Pb concentration (50 mg·kg^?1) stimulated the shoot biomass in both plant species. Pb accumulation in plants was consistent with the increase of Pb levels, and the main accumulation sites were the roots and the older leaves. In addition, the photosynthetic pigments content and chlorophyll fluorescence parameters were influenced by Pb stress. In such case, both of the plants could improve the activities of antioxidant enzymes of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX), and the contents of the total soluble sugar and soluble protein, which reached the highest value at Pb 100 mg·kg^?1, as well as the accumulation of the total thiols (T-SH) and non-protein thiols (NP-SH) to adapt to Pb stress. Thus, it provides the theoretical basis and possibility for ornamental plants of A. rosea and M. crispa in phytoremediation of Pb contaminated areas.     

Promotion of shoot regeneration of <Emphasis Type="Italic">Swertia chirata</Emphasis> by biosynthesized silver nanoparticles and their involvement in ethylene interceptions and activation of antioxidant activity

A complete protocol for the in vitro induction of Eclipta alba tetraploids has been optimized to enhance the wedelolactone content, an anti-cancerous compound. The effects of different concentrations of colchicine (0, 0.01, 0.05, 0.1, 0.2 and 0.3%; w/v) along with treatment durations (12, 24, 36 and 48 h) were investigated on shoot tip (ST) and nodal segment (NS). The treated explants were then incubated on Murashige and Skoog (MS) medium having 1.5 mg L^?1 N⁶-benzylaminopurine and 0.5 mg L^?1 α-napthalene acetic acid for shoot regeneration and afterward root was induced on 1.0 mg L^?1 indole-3-acetic acid enriched ½MS medium. The tetraploids of E. alba were proficiently induced by the treatment of 0.1% colchicine for 24 h. The highest tetraploid induction efficiency was obtained from ST (30.56%) in comparison to the NS (22.22%). Analysis by spectrophotometry and flow cytometry showed that colchicine treated plants contained higher quantity of DNA than diploid plants. Cytological studies demonstrated doubled the chromosome number in tetraploids (2n?=?4x?=?44) than diploids (2n?=?2x?=?22). The ploidy level enhancement lead to alteration of other traits, like increased plant height, stem diameter, leaf size, stomatal size and chlorophyll content. As determined through high performance thin-layer chromatography, the ultimate achievement of this technique is the higher accumulation of wedelolactone in tetraploid plants (300.32 µg g^?1 dry weight) in evaluation to in vitro diploid (131.31 µg g^?1 dry weight) and in vivo diploid mother plants (93.26 µg g^?1 dry weight), thus improving the pharmaceutical value of E. alba.     

Micropropagation, <Emphasis Type="Italic">in vitro</Emphasis> flowering,and tuberization in <Emphasis Type="Italic">Brachystelma glabrum</Emphasis> Hook.f., an endemic species

Brachystelma glabrum Hook.f. is an endemic plant species of Eastern Ghats, India. In this study, efficient protocols for in vitro micropropagation, flowering, and tuberization of this plant were developed. Sterilized shoot tip and nodal explants were cultured on Murashige and Skoog (MS) medium supplemented with different plant growth regulators (PGRs) and additives for shoot induction and multiplication. Both shoot tip and nodal explants showed the best response (90 and 100%, respectively) on MS medium supplemented with thidiazuron (TDZ) at 1.0 mg L^?1. The microshoots multiplied best on MS + TDZ (1.0 mg L^?1) in combination with α-naphthaleneacetic acid (NAA) at 0.5 mg L^?1 and coconut water (CW) at 25%. The highest number of in vitro flowers (4.0 flowers per microshoot) was observed on MS medium supplemented with a combination of N6-benzyladenine (BA) and indole-3-butyric acid (IBA), each at 1.5 mg L^?1. In vitro-derived shoots produced aerial tubers on MS + TDZ (2.0 mg L^?1) + IBA (0.5 mg L^?1) and basal tubers on MS + TDZ at 2.0 mg L^?1. In vitro shoots were best rooted on half-strength (½) MS + NAA at 0.5 mg L^?1. The rooted plantlets were successfully acclimatized in pots with 70% survival after a hardening period of 1 mo. This protocol provides an effective method for the conservation of this endemic plant species.     

Effect of over-expression of <Emphasis Type="Italic">Linum usitatissimum</Emphasis> PINORESINOL LARICIRESINOL REDUCTASE (<Emphasis Type="Italic">LuPLR</Emphasis>) gene in transgenic <Emphasis Type="Italic">Phyllanthus amarus</Emphasis>

Shoot tip explants of Phyllanthus amarus were cocultivated with Agrobacterium tumefaciens strain LBA 4404 carrying plasmid pCAMBIA 2301 harbouring genes coding for betaglucuronidase (gus), kanamycin (kan), and neomycin phosphotransferase II (nptII) along with a gene coding for Linum usitatissimum PINORESINOL LARICIRESINOL REDUCTASE (Lu-PLR). Transformed shoot tip explants were maintained in a Murashige and Skoog (MS) medium containing TDZ 1.54 mg l^?1, kan 50 mg l^?1 and cephotaxime 62.5 mg l^?1. The optimum medium for regeneration of multiple shoots was MS supplemented with TDZ 1.54 mg l^?1, kan 50 mg l^?1. Efficient and effective rooting of plantlets was achieved by culturing the in vitro regenerated shoots on liquid ½ MS medium containing 0.7 mg l^?1 indole 3-butyric acid (IBA) and 5 mg l^?1 kan. Rooted plants were acclimatized in the mixtures of vermiculite and soil. The transformation of kan-resistant plantlets regenerated from shoot-tip explants was confirmed by GUS and polymerase chain reaction (PCR) analysis. Southern blot and reverse transcribed PCR (RT-PCR) analysis confirmed successful integration and expression of Lu-PLR gene. Quantitative analysis of phyllanthin performed on transgenic and wild plants using high-performance liquid chromatography (HPLC) revealed that transgenic lines contained higher phyllanthin content (0.3–0.81% w/w) than wild plants (0.09% w/w). The highest yield of phyllanthin was detected in transgenic lines was up to 1.16, 1.22 and 1.23 folds higher than that of wild plant. This report highlights the transgenic approach to enhance the contents of phyllanthin and hypophyllanthin.     

Phycoremediation potential,physiological, and biochemical response of <Emphasis Type="Italic">Amphora subtropica</Emphasis> and <Emphasis Type="Italic">Dunaliella</Emphasis> sp. to nickel pollution

Metal pollution can produce many biological effects on aquatic environments. The marine diatom Amphora subtropica and the green alga Dunaliella sp. possess a high metal absorption capacity. Nickel (Ni) removal by living cells of A. subtropica and Dunaliella sp. was tested in cultures exposed to different Ni concentrations (100, 200, 300, and 500 mg L^?1). The amount of Ni removed by the microalgae increased with the time of exposure and the initial Ni concentration in the medium. The metal, which was mainly removed by bioadsorption to Dunaliella sp. cell surfaces (93.63% of total Ni (for 500 mg Ni L^?1) and by bioaccumulation (80.82% of total Ni (for 300 mg Ni L^?1) into Amphora subtropica cells, also inhibited growth. Exposure to Ni drastically reduced the carbohydrate and protein concentrations and increased total lipids from 6.3 to 43.1 pg cell^?1, phenolics 0.092 to 0.257 mg GAE g^?1 (Fw), and carotenoid content, from 0.08 to 0.59 mg g^?1 (Fw), in A. subtropica. In Dunaliella sp., total lipids increased from 26.1 to 65.3 pg cell^?1, phenolics from 0.084 to 0.289 mg GAE g^?1 (Fw), and carotenoid content from 0.41 to 0.97 mg g^?1 (Fw). These compounds had an important role in protecting the algae against ROS generated by Ni. In order to cope with Ni stress shown by the increase of TBARS level, enzymatic (SOD, CAT, and GPx) ROS scavenging mechanisms were induced.     

An ethanol extract from the phaeophyte <Emphasis Type="Italic">Undaria pinnatifida</Emphasis> improves learning and memory impairment and dendritic spine morphology in hippocampal neurons

Learning and memory are closely related to synaptic plasticity in neurons, associated with robust spine density and classical morphological patterns. Here, we investigated the effects of Undaria pinnatifida ethanol extract (UPE) on learning and spatial memory in mice. For behavioral studies, the passive avoidance test and radial-arm maze paradigm were used. With oral administration of UPE at an optimal concentration of 2 mg g^?1 body weight, the latency time in the passive avoidance test was increased significantly (on average, 143 and 116 s on days 1 and 2, respectively; P < 0.01) versus the scopolamine induced memory impairment group (25 and 23 s on days 1 and 2, respectively). The working errors and latency time in the radial-arm maze decreased to 0.6 errors and 56 s (P < 0.05) compared with scopolamine-administered mice (1.0 error and 113 s) on day 2, respectively. Dendritic spine morphology of hippocampal neurons in the UPE-administered group (2 mg g^?1 body weight) was analyzed using Golgi-impregnated tissue sections; the number of dendritic spines increased significantly (1.4-fold, versus control). Numbers of large mushroom and stubby spines also increased (1.8- and 1.7-fold, respectively, versus control). These findings indicate that U. pinnatifida has repairing effects on memory and behavioral disorders, probably through restoring spine density and morphology, and may thus have beneficial effects in the treatment of neurodegeneration.     

Mixotrophic cultivation of <Emphasis Type="Italic">Chlorococcum</Emphasis> sp. under non-controlled conditions using a digestate from pig manure within a biorefinery

A number of business opportunities may arise from microalgae and wastewater treatment becoming an integrated system, as biofuels and high-added value products could be obtained simultaneously. This study, performed under controlled and non-controlled conditions, aimed at cultivating Chlorococcum sp. using a digestate from pig manure as culture medium and assessing its growth and biochemical composition for further applications. Under controlled conditions, cultures of Chlorococcum sp. were established testing various digestate dilutions (v/v). It was found that all tested dilutions (up to 8% v/v) promoted a higher biomass density, compared to the control culture in modified Bold’s Basal Medium (modified BBM). Under non-controlled conditions, it was found that the biomass productivity using the digestate diluted 5.6% v/v (23.4 mg L^?1 day^?1) was statistically similar to the one obtained using modified BBM (26.4 mg L^?1 day^?1). The volatile fatty acids contained in the digestate might have allowed mixotrophic growth for Chlorococcum sp. The intracellular lipid content in Chlorococcum sp. remained constant throughout the experiments in both, treatment and control cultures, while carbohydrates increased from 20 to 45% of the cell dry weight in the treatment and from 20 to 42% in the control one. It was concluded that conditions of nitrogen starvation and fluctuating irradiance and temperature benefit carbohydrate accumulation in this strain, since intracellular carbohydrate content increased nearly two-fold during this period. Additionally, the obtained biomass has the potential to be used as feedstock for bioethanol production. This system can meet the concept of a microalgae-based biorefinery, in which biofuels and high-added value products are produced from microalgae and wastewater.     

Integrated control of tobacco black shank by combined use of riboflavin and <Emphasis Type="Italic">Bacillus subtilis</Emphasis> strain Tpb55

We investigated the effect of riboflavin on the biocontrol activity of Bacillus subtilis Tpb55 against Phytophthora nicotianae (Pn), which causes tobacco black shank. Riboflavin (0.2 mg ml^?1) significantly improved the biocontrol activity of Tpb55 (2.0 × 10⁸ cfu ml^?1). Riboflavin (0.02–0.5 mg ml^?1) alone could not significantly inhibit Pn growth. However, it enhanced the B. subtilis population, both in vitro and in tobacco roots and significantly increased the activity of defense enzymes, peroxidase, catalase, superoxide dismutase, and β-1,3-glucanase, in the roots of B. subtilis-treated tobacco seedlings. Our results indicate that riboflavin can stimulate the growth of B. subtilis Tpb55 and induce resistance to Pn in tobacco plants. These findings should boost the prospects for practical application of B. subtilis Tpb55 as a biocontrol agent against black shank of tobacco.     

Iron homeostasis in tropical <Emphasis Type="Italic">indica</Emphasis> rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) cultivars having contrasting grain iron concentration

Iron homeostasis was studied in two tropical indica rice cultivars viz. Sharbati (high Fe) and Lalat (low Fe) having contrasting grain Fe concentration. Plants were hydroponically grown with 5 concentrations of Fe (0.05, 2, 5, 15, 50 mg L^?1) till maturity. The effect of incremental Fe treatment on the plant was followed by analyzing accumulation of ferritin protein, activities of aconitase enzyme, enzymes of anti-oxidative defense and accumulation of hydrogen peroxide and ascorbic acid. Plant growth was adversely affected beyond 15 mg L^?1 of Fe supplementation and effects of Fe stress (both deficiency and excess) were more apparent on the high Fe containing cultivar Sharbati than the low Fe containing Lalat. Level of ferritin protein and aconitase activity increased up to 5 mg L^?1 of Fe concentration. Lalat continued to synthesize ferritin protein at much higher Fe level than Sharbati and the cultivar also had higher activities of peroxidase, superoxide dismutase and glutathione reductase. It was concluded that the tolerance of Lalat to Fe stress was because of its higher intrinsic ability to scavenge free radicals of oxidative stress for possessing higher activity of antioxidative enzymes. This, together with its capacity to sequester the excess Fe in ferritin protein over a wider range of Fe concentrations made it more tolerant to Fe stress.     

Silicon Alleviates Cadmium Toxicity in Two Cypress Varieties by Strengthening the Exodermis Tissues and Stimulating Phenolic Exudation of Roots

The aim of this work was to investigate the effect of silicon (Si) on phenolic exudation of plant roots and cadmium (Cd) bioavailability in rhizospheres. For this purpose, pot experiments with two cypress varieties, Juniperus chinensis and Platycladus orientalis, each subjected to 100 mg kg^?1 Cd and/or 400 mg kg^?1 Si for 220 days, were conducted using a rhizobag technique. The results showed that P. orientalis accumulated a higher amount of Cd, hence caused higher growth inhibition on the leaves compared with J. chinensis. Si alleviated the growth inhibition induced by Cd toxicity on both varieties, but the mechanisms involved were species specific. For J. chinensis, Si did not affect the root exudation but enhanced the Cd retention of the roots by strengthening the exodermis tissues, restraining Cd translocation from the roots to the shoots. For P. orientalis, Si exposure significantly elevated the phenolic exudation (for example, ferulic acid, catechin, and gallic acid) of the roots, which caused greater Cd mobility in the rhizosphere and enhancement of Cd accumulation in the shoots compared with Cd treatment alone. These results suggest that Cd-chelating with the Si-induced phenolics in the rhizosphere is involved in the Cd detoxification in P. orientalis.     

<Emphasis Type="Italic">Pseudomonas</Emphasis> spp. increases root biomass and tropane alkaloid yields in transgenic hairy roots of <Emphasis Type="Italic">Datura</Emphasis> spp.

Transgenic hairy roots of Datura spp., established using strain A4 of Agrobacterium rhizogenes, are genetically stable and produce high levels of tropane alkaloids. To increase biomass and tropane alkaloid content of this plant tissue, four Pseudomonas strains, Pseudomonas fluorescens P64, P66, C7R12, and Pseudomonas putida PP01 were assayed as biotic elicitors on transgenic hairy roots of Datura stramonium, Datura tatula, and Datura innoxia. Alkaloids were extracted from dried biomass, and hyoscyamine and scopolamine were quantified using liquid chromatography-tandem mass spectrometry analysis. D. stramonium and D. innoxia biomass production was stimulated by all Pseudomonas spp. strains after a 5-d treatment. All strains of P. fluorescens increased hyoscyamine yields compared to untreated cultures after both 5 and 10 d of treatment. Hyoscyamine yields were highest in D. tatula cultures exposed to a 5-d treatment with C7R12 (16.633 + 0.456 mg g^?1 dry weight, a 431% increase) although the highest yield increases compared to the control were observed in D. stramonium cultures exposed to strains P64 (511% increase) and C7R12 (583% increase) for 10 d. D. innoxia showed the highest scopolamine yields after elicitation with P. fluorescens strains P64 for 5 d (0.653 + 0.021 mg g^?1 dry weight, a 265% increase) and P66 for 5 and 10 d (5 d, 0.754 + 0.0.031 mg g^?1 dry weight, a 321% increase; 10 d 0.634 + 0.046 mg g^?1 dry weight, a 277% increase). These results show that the Pseudomonas strains studied here can positively and significantly affect biomass and the yields of hyoscyamine and scopolamine from transgenic roots of the three Datura species.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation,micromorphological studies and <Emphasis Type="Italic">ex vitro</Emphasis> rooting of cannon ball tree (<Emphasis Type="Italic">Couroupita guianensis</Emphasis> aubl.): a multipurpose threatened species

In vitro propagation methods using seeds and nodal segments of a 21-year old Couroupita guianensis - a medicinally important but threatened tree have been developed. Hundred percent of the seeds germinated on half strength Murashige and Skoog (MS) medium with 2.0 mg l^?1 indole-3 butyric acid (IBA). Nodal segments were found most suitable for the establishment of cultures. About 90 % explants responded and 4.1 ± 0.23 shoots per node were induced after five weeks of inoculation on MS medium +4.0 mg l^?1 6-benzylaminopurine (BAP). Further shoot multiplication was achieved by repeated transfer of mother explants and subculturing of in vitro produced shoots on fresh medium. Maximum number (8.2 ± 0.17) of shoots were regenerated on MS medium with 1.0 mg l^?1 each of BAP and Kinetin (Kin) + 0.5 mg l^?1 α-naphthalene acetic acid (NAA) with additives (50 mg l^?1 of ascorbic acid and 25 mg l^?1 each of adenine sulphate, L-arginine and citric acid). The multiplied shoots rooted (4.3 ± 0.26 roots/shoot) on half strength MS medium with 2.5 mg l^?1 IBA. All the shoots were rooted ex vitro when pulse treated with 400 mg l^?1 of IBA for five min with an average of 7.3 ± 0.23 roots per shoot. Nearly 86 % of these plantlets were acclimatized within 7–8 weeks and successfully transferred in the field. Biologically significant developmental changes were observed during acclimation particularly in leaf micromorphology in terms of changes in stomata, veins and vein-islets, and trichomes. This study helps in understanding the response by the plants towards outer environmental conditions during acclimatization. This is the first report on micropropagation of C. guianensis, which could be used for the large-scale multiplication, restoration and conservation of germplasm of this threatened and medicinally important tree.     

Quercetin and silver nitrate modulate organogenesis in <Emphasis Type="Italic">Carissa carandas</Emphasis> (L.)

An in vitro organogenesis protocol for Carissa carandas L. was developed using an auxin transport inhibitor (quercetin) and silver nitrate (AgNO₃), an inhibitor of ethylene action, in association with cytokinins in the culture medium. This protocol produced the maximum number of shoots from aseptic seedling-derived shoot apex explants of C. carandas. The highest rate of shoot multiplication was recorded on MS medium containing 2.0 mg L^?1 6-benzylaminopurine; 0.5 mg L^?1 kinetin, and 0.75 mg L^?1 quercetin at after 4 wk of culture. Similar results were obtained when MS medium fortified with 2.0 mg L^?1 BAP, 0.5 mg L^?1 kinetin, and 1.5 mg L^?1 AgNO₃ was used. However, successful rooting was achieved on quarter strength MS medium with 0.5 mg L^?1 indole-3-acetic acid. In this study, an inhibitor of auxin transport and ethylene action maximized shoot multiplication in medium fortified with cytokinins. The established rapid micropropagation method could be used to conserve elite genotypes of C. carandas.     

Biomass and terpenoids produced by mutant strains of <Emphasis Type="Italic">Arthrospira</Emphasis> under low temperature and light conditions

The filamentous Cyanobacterium Arthrospira is commercially produced and is a functional, high-value, health food. We identified 5 low temperature and low light intensity tolerant strains of Arthrospira sp. (GMPA1, GMPA7, GMPB1, GMPC1, and GMPC3) using ethyl methanesulfonate mutagenesis and low temperature screening. The 5 Arthrospira strains grew rapidly below 14?°C, 43.75 μmol photons m^?2 s^?1 and performed breed conservation at 2.5?°C, 8.75 μmol photons m^?2 s^?1. We used morphological identification and molecular genetic analysis to identify GMPA1, GMPA7, GMPB1 and GMPC1 as Arthrospira platensis, while GMPC3 was identified as Arthrospira maxima. Growth at different culture temperatures was determined at regular intervals using dry biomass. At 16?°C and 43.75 μmol photons m^?2 s^?1, the maximum dry biomass production and the mean dry biomass productivity of GMPA1, GMPB1, and GMPC1 were 2057?±?80 mg l^?1, 68.7?±?2.5 mg l^?1 day^?1, 1839?±?44 mg l^?1, 60.6?±?1.8 mg l^?1 day^?1, and 2113?±?64 mg l^?1, 77.7?±?2.5 mg l^?1 day^?1 respectively. GMPB1 was chosen for additional low temperature tolerance studies and growth temperature preference. In winter, GMPB1 grew well at mean temperatures <10?°C, achieving 3258 mg dry biomass from a starting 68 mg. In summer, GMPB1 grew rapidly at mean temperatures more than 28?°C, achieving 1140 mg l^?1 dry biomass from a starting 240 mg. Phytonutrient analysis of GMPB1 showed high levels of C-phycocyanin and carotenoids. Arthrospira metabolism relates to terpenoids, and the methyl-d-erythritol 4-phosphate pathway is the only terpenoid biosynthetic pathway in Cyanobacteria. The 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) gene from GMPB1 was cloned and phylogenetic analysis showed that GMPB1 is closest to the Cyanobacterium Oscillatoria nigro-viridis PCC711. Low temperature tolerant Arthrospira strains could broaden the areas suitable for cultivation, extend the seasonal cultivation time, and lower production costs.     

Optimization of continuous-flow solid-phase denitrification via coupling carriers in enhancing simultaneous removal of nitrogen and organics for agricultural runoff purification

Coupling of biodegradable corncob and plastic carrier was optimized in continuous-flow solid-phase denitrification systems for enhancing simultaneously removal of nitrogen and organics in agricultural runoff. In compared with preposition of plastic carriers and mixed distribution method, it was demonstrated that the preposition of corncobs simultaneously enhanced nitrate (6.64 ± 1.35 mg L^?1 day ^?1) and organics removal (6.33 ± 1.44 mg L^?1 day^?1) at a hydraulic retention time (HRT) of 6 h. The operation performance could be further enhanced with extension of HRT to 12 h. The dominant genera found in corncob were denitrifiers for nitrate reduction (Bosea, Simplicispira, Desulfovibrio, Klebsiella, etc.) and fermentative bacteria (Pleomorphomonas, Actinotalea, Opitutus, Cellulomonas, Bacteroides, etc.) responsible for corncob degrading to simple organics for other denitrifiers. However, much lower and different denitrifiers abundances (Bradyrhizobium, Acinetobacter, Bacillus, etc.) exhibited on plastic filler than those of corncob. It well explained that the biofilm on plastic carrier was mainly related with organics removal while the biofilm on corncobs inclined to effectively remove nitrate, and simultaneous removal of nitrogen and organics could be achieved in coupling carriers system with preposition of biodegradable corncob.     

A rapid and efficient in vitro shoot regeneration protocol using cotyledons of London plane tree (<Emphasis Type="Italic">Platanus acerifolia</Emphasis> Willd.)

A rapid, prolific and reproducible protocol for in vitro shoot regeneration from mature cotyledons of Platanus acerifolia has been developed. The influences of different plant growth regulator (PGR) combinations and donor seedling ages on shoot regeneration were investigated. The results showed that the application of BA in conjunction with NAA was the most effective PGR combination for the induction of shoot regeneration. When cotyledon explants of 5-day-old seedlings were incubated on MS basal medium supplemented with 4.0 mg L^?1 BA and 0.2 mg L^?1 NAA, 67.6?±?4.9% of the cotyledon segments produced adventitious shoots. These regenerated shoots were initially formed as stunted rosette cluster forms and were encouraged to elongate to produce distinct shoots by transfer onto MS medium containing 0.5 mg L^?1 BA and 0.05 mg L^?1 NAA; the resulting mean number of adventitious shoots per explant was 5.81?±?0.36. The elongated shoots were readily induced to root (i.e. 89.3% of shoots) by incubation on ½-strength MS medium supplemented with 0.1 mg L^?1 IBA. This is the first report of an efficient in vitro shoot regeneration protocol for P. acerifolia through direct organogenesis using cotyledon explants. Hence, this provides a more efficient basis for the Agrobacterium-mediated genetic transformation of Platanus than previously available.     

Alterations in photosynthetic pigments,protein, and carbohydrate metabolism in a wild plant <Emphasis Type="Italic">Coronopus didymus</Emphasis> L. (Brassicaceae) under lead stress

Coronopus didymus has been emerged as a promising wild, unpalatable plant species to alleviate lead (Pb) from the contaminated soils. This work investigated the hypothesis regarding various metabolic adaptations of C. didymus under lead (Pb) stress. In pot experiments, we assessed the effect of Pb at varied concentrations (500–2900 mg kg^?1) on growth, photosynthetic pigments, alteration of macromolecular (protein and carbohydrate) content, and activities of enzymes like protease, α-and β-amylase, peroxidase (POX), and polyphenol oxidase (PPO) in C. didymus for 6 weeks. Results revealed that Pb exposure enhanced the growth, protein, and carbohydrate level, but decreased the leaf pigment concentration and activities of hydrolytic enzymes. The activities of POX and PPO in roots increased progressively by ~337 and 675%, respectively, over the control, at 2900 mg kg^?1 Pb treatment. Likewise, contemporaneous findings were noticed in shoots of C. didymus, strongly indicating its inherent potential to cope Pb-induced stress. Furthermore, the altered plant biochemical status and upregulated metabolic activities of POX and PPO indulged in polyphenol peroxidation elucidate their role in allocating protection and conferring resistance against Pb instigated stress. The current work suggests that stress induced by Pb in C. didymus stimulated the POX and PPO activities which impart a decisive role in detoxification of peaked Pb levels, perhaps, by forming physical barrier or lignifications.