changes in plasmid profile of several indiginous pseudomonas fluorescent isolates, as affected by different levels of zn and cd

نویسندگان

حسینعلی علیخانی

دانشیار پردیس کشاورزی و منابع طبیعی دانشگاه تهران پویان شهیدی صادقی

دانشجوی کارشناسی ارشد، پردیس کشاورزی و منابع طبیعی دانشگاه تهران باقر یخچالی

دانشیار پژوهشگاه ملی مهندسی ژنتیک و زیست فناوری هوشنگ علیزاده

استادیار پردیس کشاورزی و منابع طبیعی دانشگاه تهران

چکیده

the species of pseudomonas genus show different levels of resistance to soil's heavy metals pollution. since, there exists is a relationship between heavy metal resistance and plasmid profile of bacteria, in this study, plasmid profile of plant growth promoting rhizobacteria (pgpr) pseudomonas fluorescence isolates were studied in the presence of cadmium and zinc. the bacteria were initially isolated from soybean rhizosphere and characterized as based on biochemical and biological properties. then, different concentrations of zn and cd, in the h.e.p.e.s and m.e.s solid mediums, were employed to evaluate the resistance of the isolates to these heavy metals. based on the growth in the presence of zn and cd, the isolates were classified into 4 groups. two isolates taken from each group were exposed to different concentrations of zn and cd for a period of 2 months. then, the isolates were sub-cultured and their plasmids isolated using alkaline lysis procedure. the plasmid profile of isolates indicated that the toxic effect of the cadmium was higher than that of zinc even when at lower concentrations. at concentrations of cadmium, all the isolates lost their plasmids. three isolates also showed multiple resistances to heavy metals.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

an investigation of accuracy and complexity across different proficiency levels in written narrative task

abstract this quasi-experimental study was aimed at examining the impact of storyline complexity on the grammatical accuracy and complexity of advanced and intermediate efl learners. a total of 65 advanced and intermediate efl learners were selected from iran language institute (ili). an intact group including 35 intermediate participants and another intact group with 30 advanced participants ...

the role of application of dynamic assessment approach in improvement of iranian efl writing performance at different language proficiency levels

the present study sought to investigate the role of dynamic assessment (da) in improvement of iranian efl writing performance at different language proficiency levels. to this end, after conducting the quick placement test, 60 iranian efl learners were assigned to two groups with different language proficiency levels. in both groups each participant wrote two compositions, one before and one af...

: the effect of sericin levels (silk glue protein) on rate of in vitro maturation, fertilization and culture of sheep oocytes

هدف از آزمایش اول بررسی اثر سطوح مختلف سریسین [0 (control), 0.1, 0.5, 1.0, 2.5 %] افزوده شده به محیط , ivm بر cumulus cell expansion، بلوغ هسته و توسعه متوالی جنین، در گوسفندان نژاد سنجابی در فصل تولید مثلی می باشد. از سرگیری میوز به وسیله خارج شدن اولین پولار بادی اندازه گیری و هم چنین درصد رسیدن جنین های دو سلولی به مرحله کلیواژ و بلاستوسیت نیز به عنوان نشانه ای از میزان شایستگی توسعه اولیه ج...

the effect of task cognitive complexity and time limit on the performance of the learners with different proficiency levels in second language writing skill

this study investigated the effects of manipulating the cognitive complexity of tasks along +/- few elements and the time limits on l2 learners writing performance. to conduct the study, 60 iranian efl learners with two levels of proficiency, low and high intermediate, were selected and assigned to three groups based on the time devoted to task completion. the participants performed both a simp...

15 صفحه اول

Changes in weed seed banks and the potato yield as affected by different amounts of nitrogen and crop residue

In order to evaluate the impact of crop residues (zero, 25 and 50%) and nitrogen (zero, 125 and 250 kg ha) on weed seed bank and potato yield, two-years research was conducted as a split plot arranged in randomized complete block design in Rozveh Agriculture Research Station, Freidan-Esfahan. Numbers of weed species in seed bank, aboveground, and both seed bank and aboveground were 1, 2 and...

متن کامل

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید


عنوان ژورنال:
تحقیقات آب و خاک ایران

جلد ۴۴، شماره ۱، صفحات ۶۹-۸۰

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023