نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم خاک، دانشکده کشاورزی، دانشگاه ارومیه، صندوق پستی: 165، ارومیه-ایران
2 گروه علوم خاک، دانشکده کشاورزی، دانشگاه تربیت مدرس، صندوق پستی: 336-14115، تهران-ایران
3 بخش تحقیقات بیولوژی خاک، مؤسسه تحقیقات خاک و آب، صندوق پستی: 6185-14155، تهران-ایران
4 پژوهشگاه علوم و فنون هستهای، سازمان انرژی اتمی ایران، صندوق پستی: 836-14395، تهران-ایران
کلیدواژهها
عنوان مقاله English
نویسندگان English
The objective of this investigation was to determine the potentials of some indigenous fluorescent Pseudomonads for siderophore production and their effects on 65Zn absorption in 2005. For this purpose, 201 strains of Pseudomonas putida, P. fluorescens, and P. aeruginosa were isolated from different locations representing rhizosphere of wheat (Triticum aestivum L.). The potentials of these strains for siderophore production were evaluated by chrome azorel-S assay (CAS blue agar) through color change. High siderophore producing super-strains were selected for the extraction of siderophores. These isolates were grown in SSM (standard succinate medium) for 72 hrs at 28°C. The bacterial cells
were removed by centrifugation (10000 g for 20 minutes) and the supernatant was filtered through filter membrane (0.22 μ) and used as the source of siderophore source. The evaluations of Zn uptake and translocation were carried out with the complexes of bacterial siderophores and 65Zn compared with the standard siderophore Desferrioxamine in a randomized complete block design with three replications. This experiment was conducted on two wheat genotypes different in Zn-efficiency under hydroponic condition. The results revealed that among the three most effective siderophores producing strains considered, the P. putida produced a siderophore complex that showed efficiencies of 83% compared with the standard siderophore (DFOB) in the uptake of Zn and was statistically in the same group as the control. The effect of bacterial siderophores in the uptake of labeled 65Zn by wheat was significant, indicating that the chemical structures of the siderophores from different strains were different. The effects of wheat variety on 65Zn translocation to shoots was also significant, where the efficient Tabasi variety contained 46% more Zn in shoots than the inefficient Yavarous variety. It was concluded that the siderophore complex from P. putida was the most effective in translocation Zn to shoots, particularly in efficient Tabasi genotype. Siderophore effectiveness in Zn availability decreased in the order of Sid-DFOB> Sid-P. putida>Sid-P. fluorescens> Sid-P. aeruginosa. Due to the availability of P. putida in absorbing Zn, the siderophores of this group of bacteria can be named as zincophore.
کلیدواژهها English
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