کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2025346 1069992 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The fate and toxicity of the flavonoids naringenin and formononetin in soil
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش خاک شناسی
پیش نمایش صفحه اول مقاله
The fate and toxicity of the flavonoids naringenin and formononetin in soil
چکیده انگلیسی

The flavonoid class of plant secondary metabolites play a multifunctional role in below-ground plant–microbe interactions with their best known function as signals in the nitrogen fixing legume–rhizobia symbiosis. Flavonoids enter rhizosphere soil as a result of root exudation and senescence but little is known about their subsequent fate or impacts on microbial activity. Therefore, the present study examined the sorptive behaviour, biodegradation and impact on dehydrogenase activity (as determined by iodonitrotetrazolium chloride reduction) of the flavonoids naringenin and formononetin in soil. Organic carbon normalised partition coefficients, log Koc, of 3.12 (formononetin) and 3.19 (naringenin) were estimated from sorption isotherms and, after comparison with literature log Koc values for compounds whose soil behaviour is better characterised, the test flavonoids were deemed to be moderately sorbed. Naringenin (spiked at 50 μg g−1) was biodegraded without a detectable lag phase with concentrations reduced to 0.13±0.01 μg g−1 at the end of the 96 h time course. Biodegradation of formononetin proceeded after a lag phase of ∼24 h with concentrations reduced to 4.5±1% of the sterile control after 72 h. Most probable number (MPN) analysis revealed that prior to the addition of flavonoids, the soil contained 5.4×106 MPN g−1 (naringenin) and 7.9×105 MPN g−1 (formononetin) catabolic microbes. Formononetin concentration had no significant (p>0.05) effect on soil dehydrogenase activity, whereas naringenin concentration had an overall but non-systematic impact (p=0.045). These results are discussed with reference to likely total and bioavailable concentrations of flavonoids experienced by microbes in the rhizosphere.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Soil Biology and Biochemistry - Volume 40, Issue 2, February 2008, Pages 528–536
نویسندگان
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