Elemental perturbation in Arabidopsis thaliana under low temperature stress using ICP-MS based subcellular metallomics

Abstract

The mechanism of how plants respond to low temperature stress is very important for resistance improvement and yield increase. As far as we know, no research has reported a comprehensive analysis of elemental perturbation in plants under low temperature stress by metallomics at the subcellular level until now. In this study, a subcellular metallomics analytical method for Arabidopsis thaliana based on differential centrifugation-microwave digestion coupled with inductively coupled plasma mass spectrometry was developed. The correlation coefficients R² of 69 elements were all above 0.9928 in the corresponding linear ranges of 3 orders of magnitude. The limits of detection (LODs) ranged from 0.000005 to 1.535 μg g⁻¹, and limits of quantification (LOQs) ranged from 0.00002 to 5.118 μg g⁻¹. Forty elements in 5 subcellular fractions could be reasonably determined with a repeatability that the relative standard deviations (RSDs) of elemental contents below 30% reached 66.8%. The method accuracy was validated by a certified reference material (CRM) (GBW10028). Under low temperature stress, the absolute contents of 26 elements in 51 subcellular fractions changed significantly with fold changes ranging from 0.18–3.16 between the low temperature group and the control group. Three main trends of significant elemental perturbation in subcellular components under cold stress were found: the contents of some elements (Co, Fe, Rb and W) increased in chloroplasts; the contents of elements Eu, Nb, Th, Ti, Dy, Lu, Y, Cs, Si and Yb increased in cell wall components; the contents of elements Ba, K, Mg, Mn, P, Ca, Sr, Mo and Zn decreased in the nuclear component but increased in the chloroplast and mitochondrial components. The method was proven to be sufficiently accurate, stable and reliable with wide elemental coverage, high throughput and high sensitivity, and it could serve as a good technical reference for obtaining multi-elemental characteristics at the subcellular level in plants.