Laboratório de Cultura de Células e Tecidos Vegetais, UFPel, Instituto de Biologia, Depto. Botânica, Campus Universitário S/N., CEP 96160-000, Capão do Leão, RS, Brazil.
J Plant Physiol. 2011 Nov 15;168(17):2056-62. doi: 10.1016/j.jplph.2011.06.003. Epub 2011 Jul 12.
Iron (Fe) is an essential nutrient for plant growth and development. In plant tissues, approximately 80% of Fe is found in photosynthetic cells. This study was carried out to determine the effect of different iron concentrations on the photosynthetic characteristics of sweet potato plants. The fluorescence transient of chlorophyll a (OJIP), chlorophyll index and gas exchange were measured in plants grown for seven days in Hoagland solution containing an iron concentration of 0.45, 0.90, 4.50 or 9.00 mM Fe (as Fe-EDTA). The initial and maximum fluorescence increased in the plants receiving 9.00 mM Fe. In the analysis of the fluorescence kinetic difference, L- and K-bands appeared in all of the treatments, but the amplitude was higher in plants receiving 4.50 or 9.00 mM Fe. In plants grown in 9.00 mM Fe, the parameters of the JIP-Test indicated a better efficiency in the capture, absorption and use of light energy, and although the chlorophyll index was higher, the net photosynthesis was lower. The overall data showed that sweet potato plants subjected to high iron concentrations may not exhibit the toxicity symptoms, but the light reactions of photosynthesis can be affect, which may result in a declining net assimilation rate.
铁（Fe）是植物生长和发育所必需的营养物质。在植物组织中，大约 80%的铁存在于光合细胞中。本研究旨在确定不同铁浓度对甘薯植物光合作用特性的影响。在含有 0.45、0.90、4.50 或 9.00 mM Fe（以 Fe-EDTA 计）的 Hoagland 溶液中培养 7 天的植物中测量叶绿素 a（OJIP）的荧光瞬变、叶绿素指数和气体交换。在接受 9.00 mM Fe 的植物中，初始和最大荧光增加。在荧光动力学差异分析中，所有处理都出现了 L-和 K-带，但在接受 4.50 或 9.00 mM Fe 的植物中，振幅更高。在 9.00 mM Fe 中生长的植物中，JIP-Test 的参数表明在捕获、吸收和利用光能方面具有更高的效率，尽管叶绿素指数较高，但净光合作用较低。总体数据表明，受到高浓度铁处理的甘薯植物可能不会表现出毒性症状，但光合作用的光反应可能会受到影响，这可能导致净同化率下降。
