Free radical production in roots of Phaseolus vulgaris subjected to phosphate deficiency stress

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• 作者：Malusà ; Eligio ; Laurenti ; Enzo ; Juszczuk ; Izabela ; Ferrari ; Rosa Pia ; Rychter ; Anna M.
• 关键词：Bean roots ; Free radicals ; Hydrogen peroxide ; Phenolics ; Phosphate deficiency ; AOS ; active oxygen species ; DMPO ; 5 ; 5-dimethyl-L-pyrroline-N-oxide ; ESR ; electron spin resonance ; POX ; peroxidase
• 刊名：Plant Physiology and Biochemistry
• 出版年：2002
• 出版时间：November, 2002
• 年：2002
• 卷：40
• 期：11
• 页码：963-967
• 全文大小：117 K

文摘

We subjected bean plants (Phaseolus vulgaris L. cv. ‘Zlota Saxa’) to phosphate deficiency stress and studied free radical production in whole root extracts. Starting from the 12th day of growth a carbon-centred free radical was detected, by means of electron spin resonance (ESR) after spin trapping with 5,5-dimethyl-L-pyrroline-N-oxide (DMPO), only in phosphate-deficient plants. The simulated hyperfine coupling constants of this spectrum (a_N = 16.2 G; a_H = 23.6 G) are consistent with an aliphatic or an aromatic carbon-centred radical; this species could derive from lipid peroxidation or phenol oxidation processes, respectively. Hydrogen peroxide production was also enhanced. Production of both H₂O₂ and DMPO adduct were related to the length of growth on the phosphate-deficient medium. Roots from phosphate-deficient plants showed increased content of phenols and a redox state of ascorbate similar to the control. These results indicate that phosphate starvation imposes a mild oxidative stress.