Calcium modulates leaf cell-specific phosphorus allocation in Proteaceae from south-western Australia
Calcium modulates leaf cell-specific phosphorus allocation in Proteaceae from south-western Australia
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DOI：
10.1093/jxb/erz156
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发表时间：
2019-08-01
影响因子：
6.9
通讯作者：
Lambers, Hans
中科院分区：
文献类型：
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作者：
Hayes, Patrick E.;Clode, Peta L.;Lambers, Hans
超过650种山龙眼科植物分布在澳大利亚西南部，为该地区异常高的生物多样性做出了贡献。大多数Proteaceae只发生在严重营养贫乏的酸性土壤（离钙），而只有少数也发生在年轻的石灰质土壤（土壤中性），钙（Ca）和磷（P）较高。钙增强的P毒性，pueridine连接到叶细胞的Ca和P.分离这些元素的具体分配是必不可少的，以避免有害的沉淀的钙磷酸盐的石灰石石的习性的Proteaceae解释。我们用定量X-射线微区分析，以确定叶细胞特定的营养浓度的两个钙和两个土壤无关Proteaceae生长在水培在一定范围内的Ca和P浓度。在高磷条件下，钙促进了磷向栅栏叶肉细胞的优先分配，但对整个叶片无显著影响[P]。与土壤无关的物种相比，钙拮抗剂表现出更大的PM [P]，对应于它们更大的敏感性。这项研究提出了我们的机制的理解，钙增强磷毒性，支持所提出的模型，并证明其作用的Proteaceae的离钙分布。这进一步加深了我们对细胞水平营养相互作用的理解，并突出了其对植物功能的重要性。
Over 650 Proteaceae occur in south-western Australia, contributing to the region's exceptionally high biodiversity. Most Proteaceae occur exclusively on severely nutrient-impoverished, acidic soils (calcifuge), whilst only few also occur on young, calcareous soils (soil-indifferent), higher in calcium (Ca) and phosphorus (P). The calcifuge habit of Proteaceae is explained by Ca-enhanced P toxicity, putatively linked to the leaf cell-specific allocation of Ca and P. Separation of these elements is essential to avoid the deleterious precipitation of Ca-phosphate. We used quantitative X-ray microanalysis to determine leaf cell-specific nutrient concentrations of two calcifuge and two soil-indifferent Proteaceae grown in hydroponics at a range of Ca and P concentrations. Calcium enhanced the preferential allocation of P to palisade mesophyll (PM) cells under high P conditions, without a significant change in whole leaf [P]. Calcifuges showed a greater PM [P] compared with soil-indifferent species, corresponding to their greater sensitivity. This study advances our mechanistic understanding of Ca-enhanced P toxicity, supporting the proposed model, and demonstrating its role in the calcifuge distribution of Proteaceae. This furthers our understanding of nutrient interactions at the cellular level and highlights its importance to plant functioning.