Water status and macronutrient concentrations, but not carbon status, of Viscum album ssp. album are determined by its hosts: a study across nine mistletoe-host pairs in central Switzerland

Ao Wang; Arun K Bose; Marco M Lehmann; Andreas Rigling; Arthur Gessler; Longfei Yu; Maihe Li

doi:10.3389/fpls.2023.1142760

Water status and macronutrient concentrations, but not carbon status, of Viscum album ssp. album are determined by its hosts: a study across nine mistletoe-host pairs in central Switzerland

Front Plant Sci. 2023 May 8:14:1142760. doi: 10.3389/fpls.2023.1142760. eCollection 2023.

Authors

Ao Wang^{1

2

3}, Arun K Bose^{2

4}, Marco M Lehmann², Andreas Rigling^{2

3}, Arthur Gessler^{2

3}, Longfei Yu¹, Maihe Li^{2

5

6}

Affiliations

¹ Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China.
² Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse Birmensdorf, Switzerland.
³ Institute of Terrestrial Ecosystems ITES, Swiss Federal Istitute of Technology, ETH Zürich, Universitätstrasse 16 Zurich, Switzerland.
⁴ Forestry and Wood Technology Discipline, Khulna University, Khulna, Bangladesh.
⁵ Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, Jilin, China.
⁶ College of Life Science, Hebei University, Baoding, Hebei, China.

Abstract

Introduction: European mistletoe, Viscum album L., is a hemiparasite that can infect various tree species, yet our understanding of its physiological interactions with host species is limited.

Methods: Nine mistletoe-host pairs (i.e. V. album ssp. album growing on nine different broadleaf tree species) under different growth conditions in central Switzerland were selected to examine the carbon, water and nutrient relationships between mistletoe and its hosts. We measured leaf morphological traits, isotopic compositions (δ13C and δ15N), concentrations of non-structural carbohydrates (NSC) and specific compounds (i.e. mobile sugars and starch), and macronutrients (i.e. N, P, K, Ca, Mg, S) in leaf and xylem tissues of both mistletoe and its hosts.

Results and discussion: There were only non-significant relationships between NSC concentrations in mistletoe and in its host species across the nine mistletoe-host pairs, suggesting the carbon condition of V. album ssp. album is determined by both the heterotrophic carbon transfer and self-photosynthetic capacity among different mistletoe-host pairs. However, mistletoe leaf morphological traits (single leaf area and mass, and leaf mass per unit leaf area) did not change across the nine mistletoe-host pairs, and mistletoe leaf δ13C, water content and macronutrient concentrations were linearly correlated with those in the host leaves. Macronutrients showed accumulations in mistletoe across the nine pairs. Further, tissue N concentrations were significantly higher in mistletoe grown on N-fixing hosts than on non-N-fixing hosts. Finally, leaf N:P in mistletoe was significantly correlated with the ratio in the host across the nine mistletoe-host pairs. Overall, our results indicate strong relationships between mistletoe and its hosts for water- and nutrient-related traits, but not for carbon-related traits, which demonstrates that V. album ssp. album can adjust its physiology to survive on different deciduous tree species hosts and under different site conditions.

Keywords: Viscum album ssp. album; macronutrient; mistletoe-host pair; non-structural carbohydrate (NSC); water availability.

Grants and funding

The study was financially supported by the Chinese Scholarship Council (No. 201706510023) and WSL. MML was supported by a Swiss National Science Foundation Ambizione grant (No. 179978). And the open access publication fees is funded by the Swiss Federal Institute for Forest, Snow and Landscape Research, WSL. Open access funding by Swiss Federal Institute for Forest, Snow and Landscape Research (WSL).