Effect of Phyllanthus niruri Linn. treatment on liver, kidney and testes in CCl4 induced hepatotoxic rats

Phyllanthus niruri extract is extensively used in treating liver ailments. Effects of aqueous extract of P. niruri on liver, kidney and testes of CCl4 induced hepatotoxic rats were studied. High levels of malondialdehyde (MDA) were observed in the CCl4 test group with significant reduction of MDA levels in all groups on P. niruri extract administration. Highest levels of glutathione (GSH) were found in P. niruri group. Activities of alanine transaminase, aspartate transaminase and alkaline phosphatase enzymes were significantly reduced in the curative group (P. niruri treatment after CCl4 injection). Histopathology of liver showed lesser degree of inflammation in all P. niruri treated groups while the renal and seminiferous tubules showed eosinophilic protein casts with signs of tubular damage and degeneration. Testes also showed decreased amount of mature spermatozoa. The results suggest that P. niruri has anti-oxidant and hepato-protective activity with associated deleterious effects on kidney and testes.     

Bromodeoxyuridine labelling and fluorescence‐activated cell sorting of polyamine‐transforming bacterioplankton in coastal seawater

Polyamines (PAs) are a group of nitrogen‐rich dissolved organic nitrogen (DON) compounds that are ubiquitously distributed in marine environments. To identify bacteria that are involved in PA transformations, coastal bacterioplankton microcosms were amended with a single PA model compound, i.e. putrescine (PUT) or spermidine (SPD), or with no addition as controls (CTRs). Bromodeoxyuridine (BrdU) was added to all the microcosms to label newly synthesized DNAs. Fluorescence‐activated cell sorting (FACS) analysis indicated significant increases in numbers of total cells and cells with both high and low levels of BrdU incorporation in the PUT and SPD microcosms, but not in the CTRs. 16S rDNA pyrotag sequencing of FACS‐sorted cells indicated that PUT‐ and SPD‐transforming bacteria were composed similarly of a diverse group of taxa affiliated with Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria (especially Roseobacter of its alpha lineage). Broad taxonomic distribution of PA‐transforming bacteria was also indicated by the abundance and distribution of PA transporter gene homologues in a survey of sequenced marine bacterial genomes. Our results suggest that PAs may be common DON substrates for marine bacterioplankton, in line with the hypothesis that bacterially mediated PA transformation accounts for an important proportion of marine DON flux.     

Seed priming for abiotic stress tolerance: an overview

Plants are exposed to any number of potentially adverse environmental conditions such as water deficit, high salinity, extreme temperature, submergence, etc. These abiotic stresses adversely affect the plant growth and productivity. Nowadays various strategies are employed to generate plants that can withstand these stresses. In recent years, seed priming has been developed as an indispensable method to produce tolerant plants against various stresses. Seed priming is the induction of a particular physiological state in plants by the treatment of natural and synthetic compounds to the seeds before germination. In plant defense, priming is defined as a physiological process by which a plant prepares to respond to imminent abiotic stress more quickly or aggressively. Moreover, plants raised from primed seeds showed sturdy and quick cellular defense response against abiotic stresses. Priming for enhanced resistance to abiotic stress obviously is operating via various pathways involved in different metabolic processes. The seedlings emerging from primed seeds showed early and uniform germination. Moreover, the overall growth of plants is enhanced due to the seed-priming treatments. The main objective of this review is to provide an overview of various crops in which seed priming is practiced and about various seed-priming methods and its effects.     

GABA/BABA priming: a means for enhancing abiotic stress tolerance potential of plants with less energy investments on defence cache

Abiotic stress is one of the major factors limiting plant growth and yield globally. Though substantial progress has been made in breeding and genetic manipulation of plants to enhance abiotic stress tolerance, the task remains as a challenge even today. Investigations on the priming activity of various chemicals in plants for enhancing abiotic stress tolerance have been undertaken over the past few years. Priming with γ-amino butyric acid (GABA) and β-amino butyric acid (BABA) gains greater attention, because priming with these non-protein amino acids equips the plants to resist abiotic stresses effectively without suffering costly energy investments in operating defence mechanisms. It is well documented that the protective effect of non-protein amino acids like BABA and GABA on plants is due to a potentiation of natural defence mechanisms against abiotic stresses but at the same time not activating the complete defence arsenal before the stress exposure. The exact mode of action of priming with GABA/BABA in plants is still a puzzle, though their importance as signaling molecules during stress is undoubtful. The better understanding of molecular, physiological, and ecological aspects of GABA/BABA priming might lead to the emergence of this technique as a successful strategy for enhancing the abiotic stress(es) tolerance potential of plants in the field, without compromising much on productivity.