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Indoleacetic Acid (indoleacetic + acid)
Selected AbstractsEffects of light quality on the reproduction and morphology of sporophytes of Laminaria japonica (Phaeophyceae)AQUACULTURE RESEARCH, Issue 12 2007Hiroyuki Mizuta Abstract Responses of the sporophytes of Laminaria japonica to blue, red and white lights were investigated using segments, discs and whole plants. The relative growth rate with regard to the blade's length and width showed no difference among the light conditions during 2 weeks of culturing. On the contrary, the elongation rates of the stipe and the holdfast were 1.7,2.5 times higher under red light than that under white light as a control. Callus formation in the segments was also promoted more under red light conditions than under white or blue light. Blue light irradiation resulted in a 48% and 12% decrease in the relative growth rate of the stipe and the holdfast, respectively, in comparison with the control. When sporophyte discs were cultured for 10 weeks, all discs formed zoosporangial sori 2,3 weeks earlier under blue light than under white light. However, red light inhibited the formation of zoosporangia. Indoleacetic acid (IAA) oxidase activity was about two-fold higher under blue light than under red light, suggesting that the difference in response between the blue and red light conditions is related to the internal IAA level of the tissues. The developmental, reproductive and morphological effects of blue and red lights will be useful for the artificial control of the life cycle of Laminaria plants and for the development of more efficient cultivation techniques. [source] Mechanism of insoluble phosphate solubilization by Pseudomonas fluorescens RAF15 isolated from ginseng rhizosphere and its plant growth-promoting activitiesLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2009K.-H. Park Abstract Aims:, To investigate the mechanism of insoluble phosphate (P) solubilization and plant growth-promoting activity by Pseudomonas fluorescens RAF15. Methods and Results:, We investigated the ability of Ps. fluorescens RAF15 to solubilize insoluble P via two possible mechanisms: proton excretion by ammonium assimilation and organic acid production. There were no clear differences in pH and P solubilization between glucose-ammonium and glucose-nitrate media. P solubilization was significantly promoted with glucose compared to fructose. Regardless of nitrogen sources used, Ps. fluorescens RAF15 solubilized little insoluble P with fructose. High performance liquid chromatography analysis showed that Ps. fluorescens RAF15 produced mainly gluconic and tartaric acids with small amounts of 2-ketogluconic, formic and acetic acids. During the culture, the pH was reduced with increase in gluconic acid concentration and was inversely correlated with soluble P concentration. Ps. fluorescens RAF1 showed the properties related to plant growth promotion: pectinase, protease, lipase, siderophore, hydrogen cyanide, and indoleacetic acid. Conclusion:, This study indicated that the P solubility was directly correlated with the organic acids produced. Significance and Impact of the Study:,Pseudomonas fluorescens RAF15 possessed different traits related to plant growth promotion. Therefore, Ps. fluorescens RAF15 could be a potential candidate for the development of biofertilizer or biocontrol agent. [source] Potential of bacterial indoleacetic acid to induce adventitious shoots in plant tissue cultureLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2007B. Ali Abstract Aims:, The main aim of this study was to investigate the possible role of indoleacetic acid (IAA) from bacteria to induce in vitro adventitious shoots in internodal explants of Brassica oleracea L. Methods and Results:, Culture supernatant of Halomonas sp. RE1 and Halomonas sp. HT1 that contain 21 and 40 ,g ml,1 IAA, respectively, was used to supplement Murashige and Skoog (MS) medium. Two combinations that were supplemented with bacterial supernatant (BS) are MS + BS and MS + BS + 10%CW (coconut water) while basal MS medium was used as control. The amounts of BS used in this experiment were 50, 100, 150 and 200 ,l in 5 ml MS medium in each combination. In vitro -grown internodal explants of B. oleracea were inoculated on these media combinations and incubated in a growth chamber at 25 ± 1°C and exposed to 16-h cool fluorescent light. After 5,6 weeks of incubation adventitious shoot induction was observed in all treatments that were supplemented with BS as compared with the controls where very low response was observed. The frequency of shoot induction was high in media that were supplemented with 10%CW in the presence of bacterial auxin. Conclusions:, It was concluded that IAA of microbial origin has the potential to induce adventitious shoots in internodal explants. Significance and Impact of the Study:, IAA from bacteria can be effectively used in plant tissue culture; especially a combination of MS + BS + 10%CW is very cost-effective as compared with synthetic phytohormones for in vitro studies. [source] Regeneration potential of CIMMYT durum wheat and triticale varieties from immature embryosPLANT BREEDING, Issue 4 2001N. E. Bohorova Abstract Twenty-five durum wheat elite advanced lines and released varieties, and five triticale varieties were evaluated for their ability to produce embryogenic callus using three different media. For callus initiation and maintenance there were basal Murashige and Skoog (MS) medium containing double strains of macroelements and 2.5 mg/l 2,4D (DW1), basal MS medium containing 2.0 mg/l 2,4D (DW2), or basal MS medium supplemented with 1.0 mg/l 2,4 D and coconut milk (DW3). Plant regeneration was achieved on basal MS medium with indoleacetic acid and 6-benzylaminopurine, and plants rooted on MS with 1-naphthale-neacetic acid. DW3 medium proved better than the other media tested for embryogenic callus initiation and maintenance. Regeneration rates varied widely with both genotype and initiation medium, with values ranging from no regeneration to 100% regeneration; the plantlets produced per embryo ranged from five to 20. Fourteen of the durum wheat genotypes showed 63,100% regeneration from DW3 callus formation medium, four lines from DW1 medium, and two lines from DW2. Four of the triticale varieties had regeneration of 48,100% from DW3 medium. After six subcultures, over a 6-month period, genotypes lost their ability to regenerate plants. Only 10 lines retained some plant regeneration potential but regeneration was at reduced levels. Successful regeneration of durum wheat and triticale varieties will be used as an integral part of the transformation process. [source] Prospective Evaluation of the Change of Predialysis Protein-Bound Uremic Solute Concentration With Postdilution Online HemodiafiltrationARTIFICIAL ORGANS, Issue 7 2010Natalie Meert Abstract Although protein-bound uremic compounds have been related to outcome in observational studies, few current dialysis strategies provide more removal of those compounds than standard hemodialysis. We evaluated the evolution of protein-bound uremic solutes after a switch from high-flux hemodialysis to postdilution hemodiafiltration (n = 13). We compared predialysis solute concentration at 4, 5, and 9 weeks versus baseline for several protein-bound compounds and water-soluble solutes, as well as for ,2 -microglobulin. After 9 weeks of postdilution hemodiafiltration, a significant decrease versus baseline could be detected for total concentration of protein-bound solutes: p-cresylsulfate (3.98 ± 1.51,3.17 ± 1.77 mg/dL, ,20%, P < 0.01) and 3-carboxyl-4-methyl-5-propyl-2-furanpropionic acid (0.72 ± 0.52,0.64 ± 0.46 mg/dL, ,11%, P < 0.01). For the other protein-bound solutes, hippuric acid, indoleacetic acid, and indoxylsulfate, no change in total concentration could be detected. The concentration of the middle molecule, ,2 -microglobulin, decreased as well after 9 weeks of postdilution hemodiafiltration (24.7 ± 9.3,18.1 ± 6.7 mg/L, ,27%, P < 0.01). For water-soluble compounds, no significant change of concentration was found. Postdilution hemodiafiltration in comparison to high-flux hemodialysis provided significant reduction of predialysis concentration of protein-bound compounds, especially those with the highest protein binding, and of ,2 -microglobulin, by ,11 to ,27% in 9 weeks. 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