Water and nutrient uptake capacity of leaf-absorbing trichomes vs. roots in epiphytic tank bromeliads

• Published in: Environmental and experimental botany Vol. 163; pp. 112 - 123
• Main Authors: Leroy, Céline, Gril, Eva, Si Ouali, Lynda, Coste, Sabrina, Gérard, Bastien, Maillard, Pascale, Mercier, Helenice, Stahl, Clément
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2019; Elsevier
• Subjects: 15N labelling; Aechmea; Biodiversity; Biodiversity and Ecology; Botanics; carbohydrates; carbon; Carbon metabolism; Ecology, environment; Ecosystems; Environmental Sciences; epiphytes; growth traits; leaves; Life Sciences; malates; Nutrient uptake; photosynthesis; Plant performance; roots; stable isotopes; synergism; Systematics, Phylogenetics and taxonomy; Tank bromeliad; trichomes; uptake mechanisms; Vegetal Biology; water content; Water status; Carbon metabolism; Tank bromeliad; Water status; Nutrient uptake; 15N labelling; Plant performance; French Guiana
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/j.envexpbot.2019.04.012

•Lutheria splendens and Aechmea aquilega are epiphytic tank bromeliad.•Leaf absorbing trichomes and roots have different functions in resource uptake in the two species.•The root system of L. splendens only plays a negligible role in resources uptake.•The root system of A. aquilega does contribute to water and nutrient uptake. The water and nutrient uptake mechanisms used by vascular epiphytes have been the subject of a few studies. While leaf absorbing trichomes (LATs) are the main organ involved in resource uptake by bromeliads, little attention has been paid to the absorbing role of epiphytic bromeliad roots. This study investigates the water and nutrient uptake capacity of LATs vs. roots in two epiphytic tank bromeliads Aechmea aquilega and Lutheria splendens. The tank and/or the roots of bromeliads were watered, or not watered at all, in different treatments. We show that LATs and roots have different functions in resource uptake in the two species, which we mainly attributed to dissimilarities in carbon acquisition and growth traits (e.g., photosynthesis, relative growth rate, non-structural carbohydrates, malate), to water relation traits (e.g., water and osmotic potentials, relative water content, hydrenchyma thickness) and nutrient uptake (e.g., 15N-labelling). While the roots of A. aquilega did contribute to water and nutrient uptake, the roots of L. splendens were less important than the role played by the LATs in resource uptake. We also provide evidenced for a synergistic effect of combined watering of tank and root in the Bromelioideae species. These results call for a more complex interpretation of LATs vs. roots in resource uptake in bromeliads.