Evaluation of Siderophore Production Capacity by Isolated Cyanobacteria from Paddy Fields

Siderophores are low molecular weight organic chelators which mostly expressed under iron deficiency to chelate Fe (III) metal ions in order to regulate iron based activities. Cyanobacteria, which are Gram-negative photoautotrophic prokaryotic organisms, hydroxamate type of siderophore predominates. The objective of this investigation was to determine the potentials of some indigenous cyanobacteria for siderophore production in Tabarestan Biotechnology Institute in 2014. For this purpose, 30 strains of cyanobacteria were isolated from Guilan paddy field. Potentials of these strains for siderophore production were evaluated by chrome azorel-S assay (CAS-agar) through color change. Pot experiment was performed to evaluate the application of selected top strains of cyanobacteria on growth and yield of rice plant (cv. Tarom Hashemi). Cyanobacter inoculation treatment was selected with the top seven strains and control treatment without inoculation with three replications was performed in a randomized complete block design in the greenhouse. The results of this study showed that the highest rate of siderophore production in CAS- agar Chroococcus sp. GGuCy-34 and Anabaena sp. GGuCy-49, 4.19 and 4.08 respectively and in spectrophotometer method strains of Anabaena sp. GGuCy-21 and Nostoc sp. GGuCy-47, 6.69 and 5.75 (µmol/L.day) respectively. Anabaena sp. GGuCy-42 highest grain yield (8.27 g pot-1) Chroococcus sp. GGuCy-34 showed the highest iron uptake (2.31 mg pot-1) and Cylendrospermum sp. GGuCy-25 the highest N (81.3 mg pot-1) and P (11.7 mg pot-1) uptake in pot experiment in rice plant. The results of the evaluation of siderophore production of cyanobacteria in CAS- agar with the results of the pot experiment were more consistent. Increased iron uptake can be attributed to the effect of siderophore strains on plant iron availability. Due to the fact that cyanobacteria capable of producing siderophore can also be used as stimulants of plant growth.