A reduced role for water transport during the Cenozoic evolution of epiphytic Eupolypod ferns

© 2022 The Authors New Phytologist © 2022 New Phytologist Foundation..

The Cretaceous-Cenozoic expansion of tropical forests created canopy space that was subsequently occupied by diverse epiphytic communities including Eupolypod ferns. Eupolypods proliferated in this more stressful niche, where lower competition enabled the adaptive radiation of thousands of species. Here, we examine whether xylem traits helped shape the Cenozoic radiation of Eupolypod ferns. We characterized the petiole xylem anatomy of 39 species belonging to the Eupolypod I and Eupolypod II clades occupying the epiphytic, hemiepiphytic, and terrestrial niche, and we assessed vulnerability to embolism in a subset of species. The transition to the canopy was associated with reduced xylem content and smaller tracheid diameters, but no differences were found in species vulnerability to embolism and pit membrane thickness. Phylogenetic analyses support selection for traits associated with reduced water transport in Eupolypod 1 species. We posit that in Eupolypod epiphytes, selection favored water retention via thicker leaves and lower stomatal density over higher rates of water transport. Consequently, lower leaf water loss was coupled with smaller quantities of xylem and narrower tracheid diameters. Traits associated with water conservation were evident in terrestrial Eupolypod 1 ferns and may have predisposed this clade toward radiation in the canopy.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:237

Enthalten in:

The New phytologist - 237(2023), 5 vom: 09. März, Seite 1745-1758

Sprache:

Englisch

Beteiligte Personen:

Pittermann, Jarmila [VerfasserIn]
Baer, Alex [VerfasserIn]
Campany, Courtney [VerfasserIn]
Jansen, Steven [VerfasserIn]
Holmlund, Helen [VerfasserIn]
Schuettpelz, Eric [VerfasserIn]
Mehltreter, Klaus [VerfasserIn]
Watkins, James E [VerfasserIn]

Links:

Volltext

Themen:

059QF0KO0R
Embolism
Huber value
Hydraulic conductance
Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Sporophyte
Stomatal density
Tracheid
Water
Xylem

Anmerkungen:

Date Completed 03.02.2023

Date Revised 08.02.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/nph.18667

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM349964556