Gamma rays are known to induce random mutations, which are used to enhance the production of biofilms in bacteria. Therefore, to improve the activity of biofilm formation in wild Bacillus amyloliquefaciens (HM6), this bacterial strain was mutated using five doses of gamma irradiation. | Turkish Journal of Botany Turk J Bot (2018) 42: 673-686 © TÜBİTAK doi: Research Article Gamma irradiation enhancement of biofilm production in Bacillus amyloliquifaciens and effect of mutants’ inoculation on APX1 expression in salt-stressed Egyptian barley 1, 1 2 3 3 Reda GAAFAR * , Wedad KASIM , Rania ABOU-ALI , Mohamed OMAR , Heba HEWAIT 1 Department of Botany, Faculty of Science, Tanta University, Tanta, Egypt.
2 Department of Nucleic Acids and Protein Structures, Agricultural Genetic Engineering Research Institute, Agricultural Research Centre, Giza, Egypt. 3 Department of Microbiology, Soil, Water and Environment Research Institute, Agriculture Research Centre, Giza, Egypt. Received: Accepted/Published Online: Final Version: Abstract: Gamma rays are known to induce random mutations, which are used to enhance the production of biofilms in bacteria. Therefore, to improve the activity of biofilm formation in wild Bacillus amyloliquefaciens (HM6), this bacterial strain was mutated using five doses of gamma irradiation. Sixteen mutants and their wild strain B. amyloliquefaciens (HM6) were tested for biofilm formation under two different (250 and 350 mM) NaCl concentrations. Only six mutants exhibited a significant increase in biofilm formation under 350 mM NaCl. Inoculation of salt-stressed Giza123 barley seedlings with the two mutants (M1 and M7), which showed distinguishable rep-PCR patterns, and their wild strain significantly decreased MDA content. In addition, such inoculation inhibited POX and CAT activities, while AsA content was increased. The lowest POX and CAT activities, as well as the highest AsA content, were recorded with mutant M7. The full length cDNA of Giza123 APX1 was cloned, sequenced, and submitted to GenBank under accession number MF804856. In BLASTX analysis, its sequence exhibited 99% homology with the Hordeum vulgare peroxisome type .
