Copper is a redox-active transition element with roles in photosynthesis, respirations, C and N metabolism, and protection against oxidative stress.Like Fe, it forms highly stable complexes and participates in electron transfer reactions. Divalent is reduced readily to monovalent Cu which is unstable.
铜是具有氧化还原活性的过渡元素，在光合作用，呼吸作用，碳氮代谢和抗氧化应激反应等方面起着重要的作用。与铁一样，形成高度稳定的络合物,并参与电子转移反应。 二价态容易还原成不稳定的一价铜。
Most of the functions of Cu as a plant nutrient are based on enzymatically bound Cu which catalyses redox reaction. In redox reactions of terminal oxidases, Cu enzymes react directly with molecular oxygen. Terminal oxidation in living cells therefore catalysed by Cu and by Fe.
Cu作为植物营养物的大部分功能是基于酶促结合的铜，催化氧化还原反应。 在末端氧化酶的氧化还原反应中，Cu酶直接与分子氧反应。 活细胞中的末端氧化因此由Cu和Fe催化。
Copper has a high affinity for peptide and sulphhydryl groups, and thus to cysteine-rich proteins,as well as also for carboxylic and phenolic groups. Therefore, more than 98% of the Cu in plants is present in complexed forms and the concentritions of free Cu2 and Cu is extremely low in the cytoplasm.
铜对肽和巯基具有高亲和力，因此对富含半胱氨酸的蛋白质以及羧基和酚基团都具有高亲和力。 因此，植物中超过98％的铜以复合形式存在，并且游离态的Cu2 和Cu 浓度在细胞质中极低。
There has been rapid progress in understanding Cu transport into cells and organelles in recent years . Within the Cu transport (COPT) protein family, of which there are six members in Arabidopsis, COPT is thought to mediate uptake of Cu into cells, whereas other members may mediate intracellular transport. Zn/Fe permeases (ZIPs) may also be involved in divalent Cu2 transport at the plasma mebrane, alongside P1B-TYPE ATPase (HMA) transporters on organelle and plasma membrances which are selective for both monovalent and divalent Cu foems. Yellow Stripe Like (YSL) transporters are likely to mediate Cu2 -nicotianamine transport at the plasma membrane,. In addition to transport, several at Cu chaperones have a central role in cellular Cu homeostasis.
近年来对Cu向细胞和细胞器转运的研究快速进展。 在铜转运（COPT）蛋白家族中，拟南芥中有6个成员，认为COPT介导Cu摄入细胞，而其他成员可能介导细胞内转运。 Zn / Fe通透酶（ZIP）也可能参与质膜上的二价Cu2 的转运，以及对细胞器和细胞器上的P1B型ATP酶（HMA）转运蛋白的转运，这些转运蛋白对单价和二价铜都有选择性。 黄色条纹样（YSL）转运蛋白很可能介导Cu2 - 烟酰胺在质膜上的转运。 除了运输之外，几个铜伴侣在细胞铜平衡中具有核心作用。
Copper deficiency is often observed in plants growing on soils either low in total Cu (e.g., ferrallitic and ferrginous coarse textured soils, or calcareous soils derived from chalk ) and on soils high in organic matter where Cu is complexed with organic substances. As mentioned above, high N availability can also lead to Cu deficiency.
在Cu总量较低的土壤（例如，铁铝土和铁质粗质地土壤，或来自石灰岩的钙质土壤）以及Cu与有机物质复合的富含有机质的土壤中生长的植物中经常观察到铜缺乏。 如上所述，高氮利用率也会导致铜缺乏。
The critical deficiency concentration of Cu in vegetative plant parts is generally in the range of 1-5 μg/g dw, depending on plant species, plant organ, developmental stage and N supply with the critical deficiency concentration in the youngest emerged leaf being less affected by environmental factors than that of older leaves.Plant species differ considerably in sensitivity to Cu deficiency: wheat, oats and spinach are more sensitive than, for example, pea, rye and oilseed rape. Stunted growth, distortion of young leaves, chlorosis/necrosis starting at the apical meristem entending down the leaf margins, and bleaching of young leaves ('white tip' or 'reclamation disease' of cereals grown in organic soils ), and /or 'summer dieback' in trees are typical visible symptoms of Cu deficiency. Enhanced formation of tillers in cereals and auxiliary shoots in dicotyledons are secondary symptoms caused by necrosis of the apical meristem.Wilting in young leaves, also characteristic of Cu-dificient plants, is either the result of impaired water transport due to insufficient lignification of the xylem vessels or of structural weaknesses in the cell wall system rather than the result of a low water content per se . According to Yreula the molecular responses to Cu deficiency are increased expression of metal reductases and transporters, and prioritizing Cu to essential enzymatic pathways including compensatory increases in FeSOD and MnSOD in places of CuzNSOD.
植物营养器官中Cu的临界缺乏浓度一般在1-5μg/ g 干重范围内，取决于植物种类，植物器官，发育阶段和氮供应，在最新出现的叶片中临界缺乏浓度受环境因素的影响比老叶片小。植物物种对铜缺乏的敏感性差异很大：小麦，燕麦和菠菜比豌豆，黑麦和油菜更敏感。生长发育迟缓，幼叶扭曲，从顶端分生组织开始并蔓延向叶缘的萎黄/坏死，幼叶漂白（在有机土壤中生长的谷物的“白尖”或“复垦病”），和/或“夏季树木中的“枯死”是典型的缺铜症状。增强禾谷类的分蘖形成和双子叶植物的辅助枝条是由顶端分生组织坏死引起的次生症状。幼叶萎蔫，也是缺Cu植物的特征，是由于木质部导管的木质化不足而导致水输送受损或者细胞壁系统结构弱化的结果，而不是由于水分含量低本身。根据Yreula的报道，对Cu缺乏的分子反应是增加金属还原酶和转运蛋白的表达，并优先将Cu转化为必需的酶途径，包括CuzNSOD位置上FeSOD和MnSOD的补偿性增加。
The vailability of Cu can be low in many soils and this can be corrected by soil or foliar applications.Soil applications of inorganic copper as CuSO4 or oxide forms, or slow-release metal compounds, sewage sludges or manures are often appropriate for long-term effects. Foliar applications of Cu in the form of inorganic salts, oxides, or chelates can be used to rapidly correct Cu deficiency in soil grown plants. The use of Cu-containing fertilizers can be used to increase the Cu concentration of the edible portions of humans and livestock. However, Cu fertilization must be managed appropriately since high Cu concentrations can be toxic to plants and animals. Selecting genotypes which are highly efficient in Cu uptake, translocation from the roots to the shoots and re-translocation within the shoot is a promising longer-term approach to the prevention of Cu deficiency.
在许多土壤中，Cu的有效性可能很低，这可以通过土壤或叶面施加来校正。土壤施用诸如CuSO4或氧化铜形式的无机铜，或缓释金属化合物，污水污泥或粪肥通常适用于长期效果。 以无机盐，氧化物或螯合物形式的叶面施用Cu可以用于迅速纠正土壤生长植物中的Cu缺乏。 含Cu肥料的使用可以用来增加人类和牲畜可食用部分的Cu浓度。然而，铜的施肥必须适当管理，因为高铜浓度可能对植物和动物有毒。 选择高效吸收Cu的基因型，从根到地上的转运及在地上部的再转移是预防Cu缺乏症的有前景的长期方法。
英文内容摘自《Marschners Mineral Nutrition of Hihger Plants》
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