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Besi tiba di sekitar akar maupun berbagai senyawa kimia organik kompleks, jarang sebagai unsur Fe. Besi dalam larutan tanah dapat dipindahkan ke akar tanaman sebagai komponen dalam larutan pori-pori tanah massal bergerak menuju root sebagai air diambil ke dalam tanaman untuk menggantikan yang hilang oleh aliran transpirasi atau digunakan dalam proses pertumbuhan. Besi juga dapat memindahkan ke akar dengan difusi dari daerah konsentrasi tinggi ke yang lebih rendah (pada permukaan akar sebagai Fe diambil oleh tanaman). Akar juga bisa mencegat Fe senyawa dalam tanah sebagai akar tumbuh dan berkembang ke dalam tanah tambahan volume. Akar kepadatan dan ekstensi adalah faktor yang sangat penting dalam kemampuan tanaman untuk memperoleh Fe.Iron uptake by the plant is not as simple as with other essential elements. Iron is taken up by plant roots in greatest amounts in the zone of the root between cell elongation and maturation, about 1 to 4 cm behind the root tip. Uptake of Fe by the plant is an active process, that is, energy is expended by the plant to take in Fe. Iron uptake is dependent on the plant’s ability to reduce Fe+++ to Fe++ and remove it from the complex or chelating compound. Research evidence shows this reduction occurs at the cell surface and that electrons from within the cell are used. The same 1- to 4-cm area behind the root tip where most Fe is absorbed also is the area of the root where most protons and reductants are released. The chelated Fe in the soil solution moves to the root by mass flow or by diffusion. At the root, Fe is reduced and removed from the chelating molecule and moved across the cell membrane. Iron uptake can be interfered with by other cations in the soil solution such as manganese (Mn) and calcium (Ca).In grasses, phytosiderophores (organic acids) are synthesized by the plant root and released into the rhizosphere, where they form complexes with Fe. The phytosiderophere-plus Fe complex is moved across the membrane in the root. Iron is absorbed into the rhizodermal (epidermal) cells and endodermal cells in the root (Figure 1). From the endodermis, Fe is loaded into the pericycle cells and then to the xylem. Most of the Fe transported to the shoots ends up in the shoot apoplast. From here it can be moved across the cell plasmalemma and into the cytoplasm and into organelles.Movement of Fe from one part of the shoot, particularly senescent leaves, to other shoot parts via the phloem does occur, however most scientists believe Fe is not easily re-translocated in plant shoots.
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