Cation uptake and allocation by red pine seedlings under cation-nutrient stress in a column growth experiment

• DOI: 10.1007/s11104-013-2016-2
• Publication Date: 2014-01-09T06:11:00Z
• Authors: Zhenqing Shi; Zsuzsanna Balogh-...; Michael Grant; James Harsh; Richard Gill; Linda Thomashow; Alice Dohnalkova; Daryl Stacks; Melissa Letourneau; C. Kent Keller
• Keywords: Plant Physiology; Anorthite; Limiting

Plant nutrient uptake is affected by environmental stress, but how plants respond to cation-nutrient stress is poorly understood. We assessed the impact of varying degrees of cation-nutrient stress on cation uptake in an experimental plant-mineral system. Column experiments, with red pine (Pinus resinosa Ait.) seedlings growing in sand/mineral mixtures, were conducted for up to 9 months. The Ca and K were supplied from both minerals and nutrient solutions with varying Ca and K concentrations. Cation nutrient stress had little impact on carbon allocation after 9 months of plant growth and K was the limiting nutrient for biomass production. Measurement of Ca/Sr and K/Rb ratios allowed independent estimation of dissolution incongruency and discrimination against Sr and Rb during cation uptake processes. The fraction of K in biomass from biotite increased with decreasing K supply from nutrient solutions. The mineral anorthite was consistently the major source of Ca, regardless of nutrient treatment. Red pine seedlings exploited more mineral K in response to more severe K deficiency. This did not occur for Ca since Ca was not limiting plant growth. Plant discrimination factors must be carefully considered to accurately identify nutrient sources using cation tracers.