OBJECTIVE: The objective of this study was to examine the effect of endophytic bacteria from mangrove tree (Rhizophora apiculata Blume) for their efficacy in promoting seedling growth in rice.
MATERIALS AND METHODS: Eight endophytic bacterial isolates (EBIs) isolated from twig and petiole tissues of the mangrove were identified based on their 16S ribosomal ribonucleic acid (rRNA) gene sequence homology. Separately, surface sterilized paddy seeds were treated with cell-free broth and cell suspension of the EBIs. Rice seedlings were analyzed by various bioassays and data was recorded.
RESULTS: The gene sequences of the isolates were closely related to two genera namely, Bacillus and Pantoea. Inoculation of EBIs from R. apiculata with rice seeds resulted in accelerated root and shoot growth with significant increase in chlorophyll content. Among the isolates, Pantoea ananatis (1MSE1) and Bacillus amyloliquefaciens (3MPE1) had shown predominance of activity. Endophytic invasion was recognized by the non-host by rapid accumulation of reactive oxygen species (ROS) and was counteracted by the production of hydrogen peroxide (H2O2) and lipid peroxide. The results demonstrated that EBIs from mangrove tree can increase the fitness of the rice seedlings under controlled conditions.
CONCLUSION: These research findings could be useful to enhance the seedling growth and could serve as foundation in further research on enhancing the growth of the rice crop using endophytic bacteria.
MATERIALS AND METHODS: The mice were divided into four different groups and received the test extracts and the standard drug (aspirin) for 14 days via force-feeding. On day 15, the mice were injected with 5% acetic acid, and the number of abdominal constriction and elongation of hind limb (writhes) were counted for 20 min.
RESULTS: The numbers of writhes were counted starting after 5 min of the acetic acid injection. The N. sativa extracts significantly reduced the number of writhes as compared to the control group. Both of the extracts revealed a comparable result as referred to the aspirin effects in the mice.
CONCLUSIONS: These findings indicate that N. sativa and E. cottonii may possess protective active constituent that is effective in reducing the sensation of pain in mice.