dizzlekush
Member
The following articles have been provided in completion in the attachments below. The abstract of each article has been posted for your viewing pleasure and for skim-ability. Enjoy.
Bioassay to detect Ascophyllum nodosum extract-induced cytokinin-like activity in Arabidopsis thaliana
Wajahatullah Khan & David Hiltz & Alan T. Critchley & Balakrishnan Prithiviraj
"Ascophyllum nodosum, a brown macroalga, is the most widely used seaweed in agriculture. We report a rapid method for the detection of cytokinin-like activity in plants treated with a commercial A. nodosum liquid concen- trate (Stimplex®) using a transgenic line of Arabidopsis carrying the ARR5 promoter fused to ß-glucuronidase (GUS) reporter gene. Based on GUS activity assay, an increase in cytokinin-like activity was detected in plants grown in vitro treated with 3 mL L−1 Stimplex®, whereas foliar spray treatments showed similar cytokinin-like activity at a concentration of 5 mL L−1. Histochemical staining showed Stimplex®-induced GUS activity in leaf as well as in the root tissues. Taken together, our results suggest that Stimplex® contains compounds that may elicit endogenous cytokinin-like activity. Furthermore, it is shown that this bioassay can be used for rapid screening of extracts that can stimulate cytokinin-like activities using Arabidopsis AAR5::GUS reporter transgenic plants."
Commercial extract from the brown seaweed Ascophyllum nodosum reduces fungal diseases in greenhouse cucumber
Jayaraj Jayaraman & Jeff Norrie & Zamir K. Punja
"This study examined the effects of StimplexTM, a marine plant extract formulation from Ascophyllum nodo- sum, on some common cucumber fungal pathogens. Greenhouse cucumber plants were sprayed and/or root drenched using StimplexTM at 0.5% or 1% concentration twice at 10-day intervals. Treatments also included appli- cation of fungicide (chlorothalonil, 2 g L−1) alternating with StimplexTM application. Treated plants were inoculated with four cucumber fungal pathogens including Alternaria cucumerinum, Didymella applanata, Fusarium oxysporum, and Botrytis cinerea. StimplexTM application resulted in a significant reduction in disease incidence of all the pathogens tested. The disease control effect was greater for Alternaria and Fusarium infection, followed by Didy- mella and Botrytis. Combined spray and root drenching with StimplexTM was more effective than either spray or root drenching alone. The alternation of one fungicide application, alternated with StimplexTM application, was highly effective and found to be the best treatment in reducing the disease ratings. Plants treated with Stim- plexTM showed enhanced activities of various defense-elated enzymes including chitinase, β-1,3-glucanase, peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, and lipoxygenase. Altered transcript levels of various defense genes, including chitinase, lipoxygenase, glucanase, peroxidase, and phenylalanine ammonia lyase were observed in treated plants. Cucumber plants treated with StimplexTM also accumulated higher level of phe- nolics compared to water controls. These results suggest that seaweed extracts enhance disease resistance in cucumber probably through induction of defense genes or enzymes."
Effect of seaweed concentrate on hydroponically grown spring barley
C.M. Steveni & J. Norrington-Davies & S.D. Hankins
"Spring barley (Hordeum vulgare cv. Triumph) was grown hydroponically over a 6-week period. Two treatments were incorporated either into the hydroponic solution or sprayed onto the plants at rates of 1 ml per 3 litres. The treatments applied were: (i) a seaweed concentrate prepared from Ascophyllum nodosum (L.) Le Jolis (marketed as Maxicrop Triple), (ii) a 'Trace element' treatment incorporating the micro and macro nutrients added to the seaweed extract base to produce the formulated product Maxicrop Triple and (iii) a control treatment. Irrespective of the mode of application, plants treated with Maxicrop Triple grew faster than plants under either of the two other treatments. Elevated growth rates were also found for the 'Trace element' treated plants when incorporated into the hydroponic solution. At the final harvest, plants with Maxicrop Triple incorporated into the hydroponic solution showed increases from 56-63% over the control treatment for the growth characteristics measured. 'Trace element'-treated plants produced increases of between 25-45 %. When the treatments were sprayed the effect was less pronounced. Maxicrop Triple increased growth characters by 35-38% and the 'trace element' treatment gave increases in the range of 2-13%."
Effect of seaweed extracts and plant growth regulators on high-frequency in vitro mass propagation of Lycopersicon esculentum L (tomato) through double cotyledonary nodal explant
S. Vinoth & P. Gurusaravanan & N. Jayabalan
"An efficient and reproducible two-step in vitro propagation system for tomato (Lycopersicon esculentum) was developed by using the combinations of seaweed biostimulant (Gracilaria edulis and Sargassum wightii) extracts and plant growth regulators (PGRs). Double cotyledonary nodal (DCN) explants of Co-3 cultivar were initially cultured on Murashige and Skoog (MS) and Gamborg’s medium (B5) containing thidiazuron (TDZ) and 6-benzylaminopurine (BA); the best responding cyto- kinin was tested in combinations with different auxins (NAA, IAA and IBA), and seaweed extracts (G. edulis and S. wightii) of about basal MS medium +10–70% was used for shoot proliferation. The best organogenic culture response was obtained on MS medium fortified with 1.5 mg L−1 TDZ and 1.5 mg L−1 IBA. Up to 24 shoots per explants were formed at an optimal duration of exposure to 35 days. Mini shoots of about 3–4 cm were transferred to medium supplemented with MS + iP, MS + zeatin, MS + G. edulis and MS + S. wightii at different concentrations. High frequency of shoot elongation was observed in the medium supplemented with 30% G. edulis (15.2 cm), and profuse rooting was observed in the medium supplemented with 50% S. wightii of about 16.1 cm. Shoot elongation and rooting were observed in the medium supplemented with seaweed extracts. The plantlets were transferred to the plant growth chamber (70% of relative humidity and 9 light cycles) and maintained in it for a week, and then they were transferred to a greenhouse condition. The plant growth chamber to green house transferred plantlets showed an increase in the survival rate from 70 to 85%. Thus a two-step regeneration protocol was developed in this study with a combination of seaweed extracts and PGRs, which provides a basis for the production of transgenics with high frequency and survivability of tomato plants."
Extracts of the marine brown macroalga, Ascophyllum nodosum, induce jasmonic acid dependent systemic resistance in Arabidopsis thaliana against Pseudomonas syringae pv. tomato DC3000 and Sclerotinia sclerotiorum
Sowmyalakshmi Subramanian & Jatinder Singh Sangha & Bruce A. Gray & Rudra P. Singh & David Hiltz & Alan T. Critchley & Balakrishnan Prithiviraj
"Abstract We studied the mechanism of Ascophyllum nodosum (a brown macroalga) induced resistance in Arabidopsis thaliana against Pseudomonas syringae pv. tomato DC3000. Root treatment of A. thaliana Col-0 plants with extracts of A. nodosum [aqueous (ANE), chloroform (C-ANE) and ethylacetate fractions, (E-ANE)] reduced the development of disease symptoms on the leaves. These extracts also induced resistance in salicylic acid deficient NahG and ics1 plants. However, the extracts did not elicit an effect on jar1 (jasmonic acid resistance 1) mutant. A. nodosum extract induced resistance to Pst DC3000 correlated with increased expression of jasmonic acid related gene transcripts PDF1.2 while PR1 and ICS1 expression were less affected. Additionally, pretreat- ment of Arabidopsis plants with ANE, protected the plants from a necrotroph, Sclerotinia sclerotiorum. The results suggest that the A. nodosum extracts can induce resistance in Arabidopsis to different patho- gens which is largely jasmonic acid dependent."
Lipophilic components of the brown seaweed, Ascophyllum nodosum, enhance freezing tolerance in Arabidopsis thaliana
Prasanth Rayirath · Bernhard Benkel · D. Mark Hodges · Paula Allan-Wojtas · Shawna MacKinnon · Alan T. Critchley · Balakrishnan Prithiviraj
"Extracts of the brown seaweed Ascophyllum nodosum enhance plant tolerance against environmental stresses such as drought, salinity, and frost. However, the molecular mechanisms underlying this improved stress tol- erance and the nature of the bioactive compounds present in the seaweed extracts that elicits stress tolerance remain largely unknown. We investigated the eVect of A. nodosum extracts and its organic sub-fractions on freezing tolerance of Arabidopsis thaliana. Ascophyllum nodosum extracts and its lipophilic fraction signiWcantly increased tolerance to freezing temperatures in in vitro and in vivo assays. Untreated plants exhibited severe chlorosis, tissue damage, and failed to recover from freezing treatments while the extract-treated plants recovered from freezing temperature of ¡7.5°C in in vitro and ¡5.5°C in in vivo assays. Electrolyte leakage measurements revealed that the LT50 value was lowered by 3°C while cell viability staining demon- strated a 30–40% reduction in area of damaged tissue in extract treated plants as compared to water controls. More- over, histological observations of leaf sections revealed that extracts have a signifcant effect on maintaining membrane integrity during freezing stress. Treated plants exhibited 70% less chlorophyll damage during freezing recovery as compared to the controls, and this correlated with reduced expression of the chlorphyllase genes AtCHL1 and AtCHL2. Further, the A. nodosum extract treatment modu- lated the expression of the cold response genes, COR15A, RD29A, and CBF3, resulting in enhanced tolerance to freezing temperatures. More than 2.6-fold increase in expression of RD29A, 1.8-fold increase of CBF3 and two- fold increase in the transcript level of COR15A was observed in plants treated with lipophilic fraction of A. nodosum at ¡2°C. Taken together, the results suggest that chemical components in A. nodosum extracts protect membrane integrity and aVect the expression of stress response genes leading to freezing stress tolerance in A. thaliana."
Rapid bioassays to evaluate the plant growth promoting activity of Ascophyllum nodosum (L.) Le Jol. using a model plant, Arabidopsis thaliana (L.) Heynh
Prasanth Rayorath & Mundaya N. Jithesh & Amir Farid & Wajahatullah Khan & Ravishankar Palanisamy & Simon D. Hankins & Alan T. Critchley & Balakrishnan Prithiviraj
"Ascophyllum nodosum extract products are used commercially in the form of liquid concentrate and soluble powder. These formulations are manufactured from sea- weeds that are harvested from natural habitats with inherent environmental variability. The seaweeds by themselves are at different stages of their development life-cycle. Owing to these differences, there could be variability in chemical composition that could in turn affect product consistency and performance. Here, we have tested the applicability of using Arabidopsis thaliana as a model to study the activity of two different extracts from A. nodosum. Three different bioassays: Arabidopsis root-tip elongation bio- assay, Arabidopsis liquid growth bioassay and greenhouse growth bioassay were evaluated as growth assays. Our results indicate that both extracts promoted root and shoot growth in comparison to controls. Further, using Arabidopsis plants with a DR5:GUS reporter gene con- struct, we provide evidence that components of the com- mercial A. nodosum extracts modulates the concentration and localisation of auxins which could account, at least in part, for the enhanced plant growth. The results suggestthat A. thaliana could be used effectively as a rapid means to test the bioactivity of seaweed extracts and fractions."
Significance of betaines in the increased chlorophyll content of plants treated with seaweed extract
C.A. Whapham & G. Blundenl & T. Jenkins & S.D. Hankins
"Seaweed extract, prepared by alkaline extraction of Ascophyllum nodosum (L.) Le Jol., applied either to the soil or to the foliage of tomato plants, produced leaves with higher chlorophyll levels than those of control plants. The effects on leaf chlorophyll content were investigated using a cucumber bioassay procedure devised for cytokinins. The seaweed extract was shown to increase the chlorophyll levels of the cucumber cotyledons, but 'peaks' of activity were obtained when widely different concentrations were used. The possibility that these effects were the result of betaines present in the extract was considered. Glycinebetaine, y-aminobutyric acid betaine and 6-aminovaleric acid betaine all produced significantly enhanced chlorophyll concentrations in the cotyledons. 'Peaks' of activity were observed for each be- taine: for glycinebetaine at 10-6 and between 10-4 and 10' mg 1-', for y-aminobutyric acid betaine at 10-6, between 10- 4 and 10- 1,and 10' mg - , and for 6-aininovaleric acid betaine between 10- 5and 10 mg 1- 1.It was concluded that the effects of enhancing chlorophyll levels produced by the seaweed extract were due, at least in part, to betaines."
Stimulating Orobanche ramosa Seed Germination with an Ascophyllum nodosum Extract
G. Economou & D. Lyra & K. Sotirakoglou & K. Fasseas & P. Taradilis
"Algit Super,an extract of Ascophyllum nodosum, was found to be an effective stimulant for the germination of Orobanche ramosa seeds. The biological activity of Algit Super| was tested at a wide range of concentrations from 2.5 v/v to 1.2x 10-3 v/v. The seed germination in all studied O. ramosa populations showed a concentration dependence, with an inhibitory effect at higher concentrations. The response of O. ramosa to Algit Super| resembled its response to the reference stimulant GR24. VariousO. ramosa populations demonstrated differential response to the stimulant."
Use of Acadian marine plant extract powder from Ascophyllum nodosum in tissue culture of Kappaphycus varieties
Anicia Q. Hurtado & Dianne Aster Yunque & Keneth Tibubos & Alan T. Critchley
"Three varieties of Kappaphycus alvarezii (Kapilaran, KAP), Tambalang purple (PUR), Adik-adik (AA), and one variety of Kappaphycus striatum var. sacol (green sacol (GS) were used to determine the efficiency of Acadian marine plant extract powder (AMPEP) as a culture medium at different concentrations, for the regeneration of young plants of Kappaphycus varieties, using tissue culture techniques for the production of seed stock for nursery and outplanting purposes for the commercial cultivation of carrageenophytes. A shorter duration for shoot formation was observed when the explant was treated with AMPEP + Plant Growth Regulator (PGR = PAA + zeatin at 1 mg L−1) compared to AMPEP when used singly. However, four explants responded differently to the number of days required for shoot formation. The KAP variety took 46 days to form shoots at 3–4 mg L−1 AMPEP + PGR; while PUR required 21 days at 3–5 mg L−1 AMPEP and 3–4 mg L−1 AMPEP + PGR. AA required 17 days at 3–5 mg L−1 AMPEP and AMPEP+PGR; and GS 25 days at 1 mg L−1 AMPEP+PGR. It was observed that among the four explants used, PUR and AA initiated shoot formation with the use of AMPEP only at higher concentrations (3–5 mg L−1) after a shorter period. Only PUR responded positively to ESS/2 for shoot initiation. The use of AMPEP alone and/or in com- bination with PGR as a culture medium in the propagation of microplantlets using tissue culture technique is highly encouraging."
Attachments
-
Bioassay to detect Ascophyllum nodosum extract-induced cytokinin-like activity in Arabidopsis th.pdf248.2 KB · Views: 132
-
Use of Acadian marine plant extract powder from Ascophyllum nodosum in tissue culture of Kappaph.pdf221.7 KB · Views: 111
-
Stimulating Orobanche ramosa Seed Germination with an Ascophyllum nodosum Extract.pdf600.8 KB · Views: 101
-
Significance of betaines in the increased chlorophyll content of plants treated with seaweed ext.pdf272.4 KB · Views: 141
-
Rapid bioassays to evaluate the plant growth promoting activity of Ascophyllum nodosum (L.) Le J.pdf168.9 KB · Views: 115
-
Lipophilic components of the brown seaweed, Ascophyllum nodosum, enhance freezing tolerance in A.pdf653.4 KB · Views: 108
-
Extracts of the marine brown macroalga, Ascophyllum nodosum, induce jasmonic acid dependent syst.pdf359 KB · Views: 119
-
Effect of seaweed extracts and plant growth regulators on high-frequency in vitro mass propagati.pdf435.1 KB · Views: 113
-
Effect of seaweed concentrate on hydroponically grown spring barley.pdf464.2 KB · Views: 146
-
Commercial extract from the brown seaweed Ascophyllum nodosum reduces fungal diseases in greenho.pdf378.6 KB · Views: 123
kind regards from guineapig 
