Abstract
A long-established ecological paradigm predicts a functional relationship determining vulnerability to cavitation: vulnerability increases with vessel hydraulic efficiency and vessel diameter. Even within a species, big vessels cavitate before small ones.
Some centrifuge methods for measuring vulnerability are prone to artifacts due to nano-particles seeding early embolism, as the particles are drawn into vessels during measurements. Both the Sperry and Cochard rotors are prone to early cavitation due to nano-particles drawn into long and wide vessels in Robinia pseudoacacia and Quercus acutissima, whereas extraction centrifuge methods produce vulnerability curves more resistant to cavitation.
Sufficient nano-particles pass through the stems to seed early embolism in all rotor designs. For several years, people have thought that early embolism is induced by nano-particles present in laboratory water. One new hypothesis is that the origin of nano-particles is from cut-open living cells but a much bigger study including many species is required to confirm this idea. This paper confirms the hypothesis in comparisons between short-vesselled Acer, and long-vesselled Robinia, and Quercus. Our new results and a review of old results justifies bigger study.
Hypothetical nano-particles might explain why different methods for measuring vulnerability curves cause different T50 = tensions causing 50% loss of hydraulic conductivity. Hence the hypothesis for future research should be that the open-vessel artifact is consistent with ‘long’ vessels surrounded by cut open living cells.
One sentence Summary Nano-particles induced early cavitation in species with vessel lengths about ¼ the stem length used in all centrifuge rotors, and the origin of nano-particles might be from living cells nearby vessels
Footnotes
Responsibilities of the author for contact, The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (https://academic.oup.com/plphys/pages/General-Instructions) is Dongmei Yang
Finding information, This research was supported by grants of the National Natural Science Foundation of China (No. 31770647), the Natural Science Foundation of Zhejiang Provincial (China) (LY19C150007).