Neugebauer Konrad, Broadley Martin R, El-Serehy Hamed A, George Timothy S, McNicol James W, Moraes Milton F, White Philip J
Ecological Science Group, The James Hutton Institute, Dundee, DD2 5DA, UK.
Plant and Crop Sciences Division, University of Nottingham, Loughborough, LE12 5RD, UK.
Physiol Plant. 2018 Feb 7. doi: 10.1111/ppl.12700.
The ionome is defined as the elemental composition of a subcellular structure, cell, tissue, organ or organism. The subset of the ionome comprising mineral nutrients is termed the functional ionome. A 'standard functional ionome' of leaves of an 'average' angiosperm, defined as the nutrient composition of leaves when growth is not limited by mineral nutrients, is presented and can be used to compare the effects of environment and genetics on plant nutrition. The leaf ionome of a plant is influenced by interactions between its environment and genetics. Examples of the effects of the environment on the leaf ionome are presented and the consequences of nutrient deficiencies on the leaf ionome are described. The physiological reasons for (1) allometric relationships between leaf nitrogen and phosphorus concentrations and (2) linear relationships between leaf calcium and magnesium concentrations are explained. It is noted that strong phylogenetic effects on the mineral composition of leaves of angiosperm species are observed even when sampled from diverse environments. The evolutionary origins of traits including (1) the small calcium concentrations of Poales leaves, (2) the large magnesium concentrations of Caryophyllales leaves and (3) the large sulphur concentrations of Brassicales leaves are traced using phylogenetic relationships among angiosperm orders, families and genera. The rare evolution of hyperaccumulation of toxic elements in leaves of angiosperms is also described. Consequences of variation in the leaf ionome for ecology, mineral cycling in the environment, strategies for phytoremediation of contaminated land, sustainable agriculture and the nutrition of livestock and humans are discussed.
离子组被定义为亚细胞结构、细胞、组织、器官或生物体的元素组成。离子组中包含矿质养分的子集被称为功能离子组。本文给出了一种 “平均” 被子植物叶片的 “标准功能离子组”，它被定义为生长不受矿质养分限制时叶片的养分组成，可用于比较环境和遗传因素对植物营养的影响。植物的叶片离子组受其环境与遗传之间相互作用的影响。文中列举了环境对叶片离子组影响的实例，并描述了养分缺乏对叶片离子组的影响。解释了（1）叶片氮磷浓度之间的异速生长关系和（2）叶片钙镁浓度之间线性关系的生理原因。需要注意的是，即使从不同环境中采样，也能观察到被子植物叶片矿质组成存在强烈的系统发育效应。利用被子植物目、科和属之间的系统发育关系，追溯了包括（1）禾本目叶片钙浓度低、（2）石竹目叶片镁浓度高和（3）十字花目叶片硫浓度高在内的性状的进化起源。文中还描述了被子植物叶片中有毒元素超积累现象的罕见进化情况。讨论了叶片离子组变化对生态学、环境中矿质循环、污染土地植物修复策略、可持续农业以及牲畜和人类营养的影响。
