Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan.
Biotechnology Center, National Chung-Hsing University, Taichung 40227, Taiwan.
J Exp Bot. 2017 Nov 2;68(18):5021-5027. doi: 10.1093/jxb/erx320.
The biological significance of iron (Fe) is based on its propensity to oscillate between the ferric and ferrous forms, a transition that also affects its phyto-availability in soils. With the exception of grasses, Fe3+ is unavailable to plants. Most angiosperms employ a reduction-based Fe uptake mechanism, which relies on enzymatic reduction of ferric iron as an obligatory, rate-limiting step prior to uptake. This system functions optimally in acidic soils. Calcicole plants are, however, exposed to environments that are alkaline and/or have suboptimal availability of phosphorous, conditions under which the enzymatic reduction mechanism ceases to work effectively. We propose that auxiliary, non-enzymatic Fe reduction can be of critical importance for conferring fitness to plants thriving in alkaline soils with low bioavailability of Fe and/or phosphorus.
铁（Fe）的生物学意义基于其在三价铁和二价铁形式之间振荡的倾向，这种转变也会影响其在土壤中的植物可用性。除了草类，三价铁对植物是不可用的。大多数被子植物采用基于还原的铁吸收机制，该机制依赖于酶促还原三价铁作为摄取之前的必需、限速步骤。该系统在酸性土壤中最佳发挥作用。然而，钙质植物暴露于碱性环境和/或磷的可用性不足的环境中，在这些条件下，酶促还原机制不再有效地发挥作用。我们提出，辅助的、非酶促的铁还原对于在碱性土壤中具有低生物利用度的铁和/或磷的情况下茁壮成长的植物的适应性具有至关重要的意义。
