Measuring calcium content in plants using NEXAFS spectroscopy

Frontiers in Plant Science

Plant Science

Cheng Wang¹  William J. Barnes²  Oskar Siemianowski²  Charles T. Anderson²  Joshua T. Del Mundo³  Sintu Rongpipi³  Esther W. Gomez⁴  Enrique D. Gomez⁵  Guillaume Freychet⁶  Mikhail Zhernenkov⁶ 

[1] Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, United States;Department of Biology, The Pennsylvania State University, University Park, PA, United States;Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, United States;Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, United States;Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, United States;Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, United States;Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA, United States;National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, United States;

关键词: primary cell wall;    inductively coupled plasma mass spectrometry;    transmission NEXAFS;    fluorescence yield NEXAFS;    onion epidermis;    Arabidopsis hypocotyl;   

DOI  :  10.3389/fpls.2023.1212126

 received in 2023-04-25, accepted in 2023-07-20,  发布年份 2023

来源: Frontiers

【 摘 要 】

Calcium is important for the growth and development of plants. It serves crucial functions in cell wall and cell membrane structure and serves as a secondary messenger in signaling pathways relevant to nutrient and immunity responses. Thus, measuring calcium levels in plants is important for studies of plant biology and for technology development in food, agriculture, energy, and forest industries. Often, calcium in plants has been measured through techniques such as atomic absorption spectrophotometry (AAS), inductively coupled plasma–mass spectrometry (ICP-MS), and electrophysiology. These techniques, however, require large sample sizes, chemical extraction of samples or have limited spatial resolution. Here, we used near-edge X-ray absorption fine structure (NEXAFS) spectroscopy at the calcium L- and K-edges to measure the calcium to carbon mass ratio with spatial resolution in plant samples without requiring chemical extraction or large sample sizes. We demonstrate that the integrated absorbance at the calcium L-edge and the edge jump in the fluorescence yield at the calcium K-edge can be used to quantify the calcium content as the calcium mass fraction, and validate this approach with onion epidermal peels and ICP-MS. We also used NEXAFS to estimate the calcium mass ratio in hypocotyls of a model plant, Arabidopsis thaliana, which has a cell wall composition that is similar to that of onion epidermal peels. These results show that NEXAFS spectroscopy performed at the calcium edge provides an approach to quantify calcium levels within plants, which is crucial for understanding plant physiology and advancing plant-based materials.

【 授权许可】

Unknown   
Copyright © 2023 Rongpipi, Barnes, Siemianowski, Del Mundo, Wang, Freychet, Zhernenkov, Anderson, Gomez and Gomez