Key message

Ca²⁺ induces adaptive response to low P stress through increased root growth and expansion, but plays minor or no role in remobilization of P in leaf tissues or in maintaining membrane integrity.

Abstract

The role of calcium (Ca²⁺) in signaling environmental stress has been demonstrated; however, its role in signaling low phosphorus (P) stress and subsequent adaptive responses in trees are largely unexplored. The aim of this study was to examine the effects of Ca²⁺ application on root growth and expansion, seedling growth, remobilization of P, and maintaining membrane integrity in leaf tissues. Thus, a sand culture experiment was set up with five Ca²⁺ concentrations (0, 1, 3, 5, and 10 mmol/L Ca(NO₃)₂·4H₂O) under two P treatments (0.0 and 1.0 mmol/L KH₂PO₄). After 4 months, growth attributes, P and Ca²⁺ accumulations, and biochemical responses were determined. Results showed that (1) low P seedlings supplied with 5 mmol/L Ca²⁺ produced longer roots, larger root surface area, higher root diameter, and larger root volume than the control; (2) seedling height and root collar diameter were positively affected by addition of 3 and 5 mmol/L Ca²⁺ into the growing media, and whole plant biomass of low P seedlings supplied with 5 mmol/L Ca²⁺ was significantly higher than the control; (3) whole plant P accumulation was higher in 3 and 5 mmol/L Ca²⁺ treatments in low P seedlings, whereas whole plant Ca²⁺ accumulation increased linearly with increasing Ca²⁺ concentration; and (4) the effects of Ca²⁺ on malondialdehyde and soluble protein contents and acid phosphatase activity did not show consistent trend with increasing or decreasing Ca²⁺ concentration. In conclusion, Ca²⁺ induces adaptive response to low P stress through increased root growth and expansion, but plays minor or no role in remobilization of P in leaf tissues or in maintaining membrane integrity.

中文翻译：

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钙介导的杉木低磷胁迫适应性反应

关键信息

Ca ²⁺通过增加根的生长和扩张而诱导对低磷胁迫的适应性反应，但在叶片组织中的磷转运或维持膜完整性方面起着很小的作用或没有作用。

抽象

已经证明了钙（Ca ²⁺）在环境压力信号中的作用。然而，它在信号低磷（P）胁迫和随后的树木适应性反应中的作用尚未得到充分的探索。这项研究的目的是研究施用Ca ²⁺对根组织生长和扩展，幼苗生长，磷的迁移以及维持叶片组织中膜完整性的影响。因此，在两个P处理（0.0和1.0 mmol / L ）下，建立了五个浓度为Ca ²⁺（^{0、1、3、5}和10 mmol / L Ca（NO ₃）₂ ·4H ₂ O）的砂培养实验。L KH ₂ PO ₄）。4个月后，生长属性P和Ca ²⁺积累，并确定了生化反应。结果表明：（1）与对照相比，提供5 mmol / L Ca ^2+的低磷幼苗的根系更长，根系表面积更大，根系直径更大，根系体积更大；（2）在生长培养基中添加3和5 mmol / L Ca ²⁺对幼苗高度和根颈直径有积极的影响，低磷苗中提供5 mmol / L Ca ^2+的整株植物生物量显着高于控制；（3）整个植物P累积在3和5毫摩尔更高/ L的Ca ²⁺的治疗在低磷苗，而整个植物的Ca ²⁺积累随钙线性增加²⁺浓度; （4）Ca ²⁺对丙二醛，可溶性蛋白质含量和酸性磷酸酶活性的影响没有随Ca ²⁺浓度的增加或减少呈现一致的趋势。总之，Ca ²⁺通过增加根的生长和扩张而诱导对低磷胁迫的适应性反应，但在叶片组织中磷的迁移或维持膜完整性方面起着很小的作用或没有作用。