ABSTRACT
Understanding the mechanism of information processing in plants remains a challenging task even in the era of machine learning and artificial neural networks. Sir J.C. Bose had demonstrated through his experiments that the various modes of stimulation which effectively initiated nervous impulse in animals led to impulse generation in the excitable plant Mimosa pudica as well. In order to localize the tissue responsible for conduction of excitation in the petiole of Mimosa, Bose had constructed a specialized ‘Electric Probe’ (glass tip electrode). From this experiment, Bose found that there were different intensities of transmitted excitation in different tissue layers of the petiole. In this backdrop, an experimental research has been conducted to comparatively study the pattern of spatial voltage distribution across different tissue layers in both, a non-excitable plant Alternanthera philoxeroides (in stem) and an excitable plant Mimosa pudica (in petiole), by following experimental principles similar to that of Sir J. C. Bose. For the present experimental study, the electrical probes (glass tip electrode), similar to the one designed by J.C. Bose and the whole experimental setup has been constructed and developed completely in the laboratory. The results indicated a striking difference in the spatial voltage distribution pattern between the non-excitable and the excitable plant. Since Mimosa is an excitable plant having specialized mechanoreceptor cells, the change in spatial voltage distribution in the different layers of petiole, following excitation (uniform electrical stimuli) of a sub-petiole has been also studied, as an additional segment of the present research. In the present study a notable difference in the intensities of the transmitted excitation was also found upon electrical stimulation of one of the sub-petioles of the excitable plant M. pudica.
ABSTRACT
A manipulação da concentração dos microelementos no meio de cultura representa uma boa estratégia para aumentar a produção de metabólitos secundários em cultura de tecidos. Este trabalho teve por objetivo demonstrar a influência do sulfato de cobre na produção de betacianina e na multiplicação de plantas de Alternanthera philoxeroides (erva-de-jacaré) cultivadas in vitro. Segmentos nodais, obtidos de plantas pré-estabelecidas e após três subcultivos, foram inoculados em meio MS, com diferentes concentrações de CuSO4 (0; 25; 75; 125; 175; 200µM). O delineamento experimental utilizado foi inteiramente casualizado, com seis concentrações de CuSO4 e cinco repetições representadas por um frasco contendo quatro explantes. Os resultados foram submetidos à análise de variância, à regressão polinomial e a análises de correlação entre as variáveis morfológicas e a produção de betacianina. Concentrações acima de 75µM diminuíram a altura das plantas, o número de brotos e gemas e o crescimento radicular, enquanto que, na concentração de 125µM, houve a maior produção de massa fresca. A produção de betacianina aumentou 60 por cento em relação ao controle com 175µM de CuSO4. Ocorreu crescimento das plantas em todas as concentrações de CuSO4 testadas, com exceção de 200µM, sendo esta considerada tóxica.
The manipulation of concentration of trace elements in the culture medium represents a good strategy to increase the production of secondary metabolites in tissue culture. This study aimed to demonstrate the influence of copper sulphate in the production of betacyanin and the multiplication of plants of Alternanthera philoxeroides (alligator weed) cultured in vitro. Nodal segments, obtained from plants pre-stablished and after three subcultures, were inoculated in basic MS with different concentrations of CuSO4 (0, 25, 75, 125, 175, 200µM). The results were subjected to analysis of variance, polynomial regression and correlation analysis between the morphological variables and the production of betacyanin. The experimental design was completely randomized with six concentration of CuSO4 and five replicates represented by a bottle containing four explants. Concentrations above 75µM decreased the height of the plant, number of shoots and buds and root growth, while the concentration of 125µM resulted in the highest fresh mass production. Betacyanin production increased 60 percent over control with 175µM CuSO4. Plant growth occurred in all tested concentrations of CuSO4, with the exception of 200µM which was toxic.
ABSTRACT
Objective To investigate the anti-HBV constituents from Alternanthera philoxeroides.Methods The constituents were isolated with silica gel and gel permeation chromatography,and purified by HPLC.Their structures were elucidated by spectroscopy.The antivirus effects of the isolated compounds were tested by ELISA method in vitro.Results Ten compounds were isolated and elucidated as followings:oleanolic acid(Ⅰ),oleanolic acid 3-O-?-D-glucuronopyranoside(Ⅱ),oleanolic acid 28-O-?-D-glucopyranoside(Ⅲ),chikusetsusaponin Ⅳ a methyl ester(Ⅳ),4,5-dihydroblumenol(Ⅴ),N-trans-feruloyl 3-methyldopamine(Ⅵ),N-trans-feruloyl tyramine(Ⅶ),3?-hydroxystigmast-5-en-7-one(Ⅷ),24-methylenecycloartanol(Ⅸ),and cycloeucalenol(Ⅹ).The values of inhibition percent of compounds Ⅰ-Ⅲ,Ⅴ-Ⅶ revealed a significant distinction compared to the control group.Compounds Ⅱ and Ⅴ showed significant inhibition against HepG2 cells transected with cloned hepatitis B virus DNA,their inhibitive ratios were 85.38% and 87.37% at 50 ?g/mL,respectively.Conclusion Compounds Ⅳ-Ⅶ are isolated from this plant for the first time and phenolic amides have been determined as the new structure type from the plants of Alternanthera Forsk.Compounds Ⅱ and Ⅴ from A.philoxeroides show the more significant anti-HBV activities.
ABSTRACT
0.05) was found between the dechlorinated water group and the extract of A.philoxeroides group in the activities of LDH and SDH after 12 h or 20 h of exposure.Conclusion The extract of A.philoxeroides rapidly inhibits ChE,and then the activity of Mg2+-ATPase,which may suppress the release and utilization of ATP in the Oncomelania snails and finally causes death of snails.