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Pressure–volume curves: revisiting the impact of negative turgor during cell collapse by literature review and simulations of cell micromechanics
Author(s) -
Ding Yiting,
Zhang Yanxiang,
Zheng QuanShui,
Tyree Melvin T.
Publication year - 2014
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.12829
Subject(s) - turgor pressure , micromechanics , osmotic pressure , cell size , temperate climate , mathematics , botany , chemistry , biology , materials science , composite material , composite number , microbiology and biotechnology
Summary The Scholander–Hammel pressure chamber has been used in thousands of papers to measure osmotic pressure, π c , turgor pressure, P t , and bulk modulus of elasticity, ε , of leaf cells by pressure–volume ( PV ) curve analysis. PV analysis has been questioned in the past. In this paper we use micromechanical analysis of leaf cells to examine the impact on PV curve analysis of negative turgor in living cells ( P t ). Models predict negative P t (−0.1 to −1.8 MP a) depending on leaf cell size and shape in agreement with experimental values reported by J. J. Oertli. Modeled PV curves have linear regions even when P t is quite negative, contrary to the arguments of M.T. Tyree. Negative P t is totally missed by PV curve analysis and results in large errors in derived π c and P t but smaller errors in ε . A survey of leaf cell sizes vs habitat (arid, temperate, and rainforest), suggests that the majority of published PV curves result in errors of 0.1–1.8 MP a in derived π c and P t , whereby the error increases with decreasing cell size. We propose that small cell size in leaves is an ecological adaptation that permits plants to endure negative values of water potential with relatively little water loss.