Krizzia Mae R. Lumangaya | Joan Christine O. Adajar | Mannix S. Pedro | Karen B. Alviar
Several species of Bacillus are plant growth-promoting rhizobacteria that can produce the phytohormone Indole-3-acetic acid (IAA) which regulates plant growth and development, and in some species, protects the host plant from pathogen invasion. Previous studies reveal several pathways for IAA biosynthesis in various bacterial species including genes and enzymes that take part in the biosynthetic pathway. In this study, we aim to amplify dhaS, one of the component genes from the indole-3-pyruvic acid pathway (IPyA) for IAA synthesis, and to conduct 16S rRNA sequence analysis from two Bacillus spp. isolated from Fermented Plant Juice biofertilizer. Genomic DNA extraction was performed in isolate 1 (B. amyloliquefaciens) using CTAB method followed by dhaS gene amplification through polymerase chain reaction using designed gene-specific primers. Sequenced DNA was then analyzed and BLASTn results showed 98% identity with B. velezensis strain FJAT-45028 and a translated BLAST hit with an aldehyde dehydrogenase protein, having a percent identity of 96%. The secondary structure of the protein coded by dhaS gene in isolate 1 was also examined using Phyre2 and Protein Data Bank (PDB) displayed models of proline dehydrogenase and aldehyde dehydrogenase. Furthermore, 16s rRNA sequences from two Bacillus isolates were analyzed. 16S rRNA from Isolate 1 showed a top BLAST hit with Bacillus sp. strain 1CY1 (99.67%) while Isolate 2 showed a top BLAST hit with B.subtilis strain GX S-11 (95.65%). Phylogenetic trees were generated using the Maximum likelihood method to reveal the relationship of the two isolates to their top five BLAST hits. To further understand the potential roles of dhaS in the IPyA pathway for IAA synthesis, transcriptional responses to l-tryptophan and functional genomic studies must be done. These will help us further understand the physiological bases of biofertilizers towards sustainable agriculture in reducing problems associated with the use of chemicals fertilizers Poster Session - Agri-Fisheries
ISSN 2719-1990 (Print)
Philippine E-Journals
