North GB, Brinton EK, Kho TL, Fukui K, Maharaj FDR, Fung A, Ranganath M, Shiina JH. Acid waters in tank bromeliads: Causes and potential consequences.
AMERICAN JOURNAL OF BOTANY 2023;
110:e16104. [PMID:
36571428 PMCID:
PMC10107723 DOI:
10.1002/ajb2.16104]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 06/17/2023]
Abstract
PREMISE
The consequences of acidity for plant performance are profound, yet the prevalence and causes of low pH in bromeliad tank water are unknown despite its functional relevance to key members of many neotropical plant communities.
METHODS
We investigated tank water pH for eight bromeliad species in the field and for the widely occurring Guzmania monostachia in varying light. We compared pH changes over time between plant and artificial tanks containing a solution combined from several plants. Aquaporin transcripts were measured for field plants at two levels of pH. We investigated relationships between pH, leaf hydraulic conductance, and CO2 concentration in greenhouse plants and tested proton pump activity using a stimulator and inhibitor.
RESULTS
Mean tank water pH for the eight species was 4.7 ± 0.06 and was lower for G. monostachia in higher light. The pH of the solution in artificial tanks, unlike in plants, did not decrease over time. Aquaporin transcription was higher for plants with lower pH, but leaf hydraulic conductance did not differ, suggesting that the pH did not influence water uptake. Tank pH and CO2 concentration were inversely related. Fusicoccin enhanced a decrease in tank pH, whereas orthovanadate did not.
CONCLUSIONS
Guzmania monostachia acidified its tank water via leaf proton pumps, which appeared responsive to light. Low pH increased aquaporin transcripts but did not influence leaf hydraulic conductance, hence may be more relevant to nutrient uptake.
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