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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 CO 2 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 CO 2 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., (© 2022 The Authors. American Journal of Botany published by Wiley Periodicals LLC on behalf of Botanical Society of America.)

Premise: Because of its broad range in the neotropical rainforest and within tree canopies, the tank bromeliad Guzmania monostachia was investigated as a model of how varying leaf hydraulic conductance (K leaf ) could help plants resist and recover from episodic drought. The two pathways of K leaf , inside and outside the xylem, were also examined to determine the sites and causes of major hydraulic resistances within the leaf., Methods: We measured leaf hydraulic conductance for plants in the field and laboratory under wet, dry, and rewetted conditions and applied physiological, anatomical, and gene expression analysis with modeling to investigate changes in K leaf ., Results: After 7 d with no rain in the field or 14 days with no water in the glasshouse, K leaf decreased by 50% yet increased to hydrated values within 4 d of tank refilling. Staining to detect embolism combined with modeling indicated that changes outside the xylem were of greater importance to K leaf than were changes inside the xylem and were associated with changes in intercellular air spaces (aerenchyma), aquaporin expression and inhibition, and cuticular conductance., Conclusions: Low values for all conductances during drying, particularly in pathways outside the xylem, lead to hydraulic resilience for this species and may also contribute to its broad environmental tolerances., (© 2019 The Authors. American Journal of Botany is published by Wiley Periodicals, Inc. on behalf of the Botanical Society of America.)

Fabry's disease is an X-linked hereditary disorder resulting in accumulation of a glycolipid (galactosylgalactosyl glucosylceramide) due to deficiency of alpha-galactosidase A. The diagnosis can be made by histopathologic examination of skin biopsy, low activity of alpha-galactosidase in leucocytes and genetic examination. Treatment is symptomatic. We want to stress the multidisciplinary collaboration necessary to deal with this condition, in order to prevent acceleration of symptoms.