Bioactive compounds derived from plant natural compounds have proven to be valuable sources of metabolites which can seldom be obtained from other sources. Plants belonging to the genus Zanthoxylum have been valued ac...Bioactive compounds derived from plant natural compounds have proven to be valuable sources of metabolites which can seldom be obtained from other sources. Plants belonging to the genus Zanthoxylum have been valued across various cultures for their curative properties. Zanthoxylum armatum DC., belonging to the family Rutaceae is extensively used in traditional practices in North-Eastern India and neighbouring regions including South-East Asia. However, the potential cytogenetic effects of Zanthoxylum armatum under in vivo conditions, and their causative mechanisms have not yet been studied in detail. The current study was undertaken to evaluate the cytotoxic and genotoxic potential of aqueous extracts of fruits of Z. armatum under in vivo conditions using the Allium test. Physiological and cellular data indicate that the extracts induce clumped chromosomes at metaphase stage of cell division coupled with mitotic arrest. Electron microscopy data reveal membrane damage of cellular organelles, chromatin condensation and chromatin marginalisation in cell of roots incubated in the extracts. The extracts also induce concentration dependent protein precipitation and genomic DNA degradation.展开更多
Nitric oxide （NO） is involved in diverse plant growth processes; however, little is known about pathways regulating NO levels in plants. In this study, we isolated a NO-overproducing mutant of tomato （Solanum lycop...Nitric oxide （NO） is involved in diverse plant growth processes; however, little is known about pathways regulating NO levels in plants. In this study, we isolated a NO-overproducing mutant of tomato （Solanum lycopersicurn） in which hyper-accumulation of NO, associated with increase in nitric oxide synthase （NOS）-Iike activity, caused diminished vegetative growth of plants and showed delayed flowering. The hyper-accumulation of NO caused drastic shortening of primary root （shr） in the seedlings, while the scavenging of NO restored root elongation in shr mutant. Inhibition of NOS- like activity reduced NO levels and stimulated root elongation in the shr mutant seedlings, while inhibition of nitrate reductase （NR） activity could not rescue shr phenotype. The stimulation of NO levels in shr mutant also conferred increased resistance to pathogen Pseudomonas syringae. Application of pharmacological inhibitors regulating ubiquitin-proteasome pathway reduced NO levels and NOS-like activity and stimulated shr root elongation. Our data indicate that a signaling pathway involving regulated protein degradation likely regulates NO synthesis in tomato.展开更多
文摘Bioactive compounds derived from plant natural compounds have proven to be valuable sources of metabolites which can seldom be obtained from other sources. Plants belonging to the genus Zanthoxylum have been valued across various cultures for their curative properties. Zanthoxylum armatum DC., belonging to the family Rutaceae is extensively used in traditional practices in North-Eastern India and neighbouring regions including South-East Asia. However, the potential cytogenetic effects of Zanthoxylum armatum under in vivo conditions, and their causative mechanisms have not yet been studied in detail. The current study was undertaken to evaluate the cytotoxic and genotoxic potential of aqueous extracts of fruits of Z. armatum under in vivo conditions using the Allium test. Physiological and cellular data indicate that the extracts induce clumped chromosomes at metaphase stage of cell division coupled with mitotic arrest. Electron microscopy data reveal membrane damage of cellular organelles, chromatin condensation and chromatin marginalisation in cell of roots incubated in the extracts. The extracts also induce concentration dependent protein precipitation and genomic DNA degradation.
文摘Nitric oxide （NO） is involved in diverse plant growth processes; however, little is known about pathways regulating NO levels in plants. In this study, we isolated a NO-overproducing mutant of tomato （Solanum lycopersicurn） in which hyper-accumulation of NO, associated with increase in nitric oxide synthase （NOS）-Iike activity, caused diminished vegetative growth of plants and showed delayed flowering. The hyper-accumulation of NO caused drastic shortening of primary root （shr） in the seedlings, while the scavenging of NO restored root elongation in shr mutant. Inhibition of NOS- like activity reduced NO levels and stimulated root elongation in the shr mutant seedlings, while inhibition of nitrate reductase （NR） activity could not rescue shr phenotype. The stimulation of NO levels in shr mutant also conferred increased resistance to pathogen Pseudomonas syringae. Application of pharmacological inhibitors regulating ubiquitin-proteasome pathway reduced NO levels and NOS-like activity and stimulated shr root elongation. Our data indicate that a signaling pathway involving regulated protein degradation likely regulates NO synthesis in tomato.
