Crassulacean acid metabolism (CAM) supersedes the turgor loss point (TLP) as an important adaptation across a precipitation gradient, in the genus Clusia.

Publisher: CSIRO Pub Country of Publication: Australia NLM ID: 101154361 Publication Model: Print Cited Medium: Internet ISSN: 1445-4416 (Electronic) Linking ISSN: 14454416 NLM ISO Abbreviation: Funct Plant Biol Subsets: MEDLINE

Original Publication: Collingwood, VIC, Australia : CSIRO Pub., c2002-

Clusia*; Crassulacean Acid Metabolism ; Ecosystem ; Photosynthesis ; South America

As future climates continue to change, precipitation deficits are expected to become more severe across tropical ecosystems. As a result, it is important that we identify plant physiological traits that act as adaptations to drought, and determine whether these traits act synergistically or independently of each other. In this study, we assessed the role of three leaf-level putative adaptations to drought: crassulacean acid metabolism (CAM), the turgor loss point (TLPΨ) and water storage hydrenchyma tissue. Using the genus Clusia as a model, we were able to explore the extent to which these leaf physiological traits co-vary, and also how they contribute to species' distributions across a precipitation gradient in Central and South America. We found that CAM is independent of the TLPΨ and hydrenchyma depth in Clusia. In addition, we provide evidence that constitutive CAM is an adaptation to year-long water deficits, whereas facultative CAM appears to be more important for surviving acute dry seasons. Finally, we find that the other leaf traits tested did not correlate with environmental precipitation, suggesting that the reduced transpirational rates associated with CAM obviate the need to adapt the TLPΨ and hydrenchyma depth in this genus.

Date Created: 20210305 Date Completed: 20210630 Latest Revision: 20210630

20240105

10.1071/FP20268

33663679