Background : Obvious applications of aloe (Aloe vera) and their rapid intake make it crucial to evaluate their biological impacts to aquatic organisms. Methods and Results : In this study, we investigated the possible effects of aloe extract on zebrafish embryos (Danio rerio) by assessing teratogenic properties including survival rate, hatching success, heart rate and morphological changes for 96hpf (hours post fertilization). We noticed that exposure to aloe extracts (0.1, 10, 50, 100 and 150 μl/ml in embryo medium) to zebrafish embryos showed no alterations in survival and morphological changes when compared to control embryos. In contrast, embryos exposed to 150 μl/ml of aloe extract shows delayed hatching rate at 72hpf when compared to lower concentrations. Similarly, aloe extract at 150 μl/ml exposed embryos elicited significantly reduced heart rate (132 ± 1 beats/min) at 48hpf when compare to control embryos. Conclusion : Based on the above findings, we speculate the teratogenic effect of aloe extract on zebrafish embryos.

Wild rice might have previously unidentified genes important for disease resistance and stress tolerance in response to biotic and abiotic stresses. A set of subtractive library was constructed both from leaves of wild rice plants, Oryza grandiglumis (CCDD, 2n=48), treated with fungal elicitor and from wounded leaves. A partial fragment that was homologous to PR10 genes from other plant species was identified via suppression subtractive hybridization and cDNA macroarray. The obtained full-length cDNA sequence (OgPR10) contains an open reading frame of 480 bp nucleotide, encoding 160 amino acids with a predicted molecular mass of 16.944 kDa and an isoelectric point (pI) of 4.91. The multiple alignment analyses showed the higher sequence homology of OgPR10 with PR10 genes identified in rice plants at amino acid level. The OgPR10 mRNA was not expressed by treatment with wounding, jasmonic acid, and salicylic acid, but markedly expressed in leaves treated with protein phosphatase inhibitors cantharidin and endothall, and yeast extract. In addition, the expression of OgPR10 mRNA was induced within 72 h after treatment with probenazole, one of well-known chemical elicitors, and reached the highest level at 144 h. Heterologous expression of OgPR10 caused growth inhibition and seedling lethality in E. coli and Arabidopsis, respectively. Chemically induced OgPR10 expression with glucocorticoid-mediated transcriptional induction system further reconfirmed its lethality on Arabidopsis seedling. In addition, OgPR10-expressing rice plants, Oryzae sativar were resistant against the infection of rice blast fungus, Magnaporthe grisea. These results indicate that OgPR10 is involved in probenazole- and microbe associated molecular patterns-mediated disease resistance responses in plants and is a potential gene for developing disease resistance crop plants.