Patterns of activities of root phosphomonoesterase and phosphodiesterase in wetland plants as a function of macrophyte species and ambient phosphorus regime

Abstract

Summary• Phosphorus (P)-limited plants produce higher amounts of root phosphatases, but research has mostly focused on phosphomonoesterases (PMEs). Because phosphate diesters can form a significant proportion of organic P in wetlands, we aimed to determine whether wetland plants produce both root PMEs and root phosphodiesterases (PDEs), and, if so, what factors influence activities of these enzymes.• We measured the activities of root PMEs and PDEs colorimetrically in a wide range of macrophytes from natural and P-enriched wetlands. Hydrolyzable P in sediments was analyzed using commercially available PMEs and PDEs.• In all species, both root PMEs and PDEs were always present, and their activities were closely correlated. Sedges and broadleaved emergents had the highest activity of both enzymes, while those of floating-leaved plants were the lowest. Redundancy analysis revealed close association between root enzymes and the proportion of monoesterase-and diesterase-hydrolyzable dissolved unreactive P. Both enzymes were positively correlated with root tissue N : P ratio.• Both plant and sediment traits were important when explaining differences in enzyme activities. Although the activities are related to ambient P regime, the relationship was not close enough to use root enzymes as reliable predictors of dissolved unreactive P that is hydrolyzed by sediment phosphomono-and diesterases.

Legumes have a higher root phosphatase activity than other forbs, particularly under low inorganic P and N supply

“…and the lichen Cladonia portentosa (Dufour) Coem. indicates that PDE activity is five to ten times lower than PME activity (Asmar and GisselNielsen 1997;Chen et al 2002;Hogan et al 2010), but a recent study with various wetland plants in Belize showed that the difference between PME and PDE activity can be smaller than that (Rejmánková et al 2011). Also the role that mycorrhizae might play in PME activity for legumes and other plants under various soil N and P conditions is worth investigating.…”

Characterization of biogenic phosphorus in outflow water from constructed wetlands

“…The enzymatic activities in natural ecosystems are several orders of magnitude lower than in Pant et al's enzymatic assay. Nevertheless, relatively effective DOP retention has indeed been observed in periphyton and cattail dominated cells (Gu and Dreschel, 2008;Piccone et al, 2013) and especially P limitation may lead to increased utilization of DOP (Kuhn et al, 2002;Newman et al, 2003) which can be observed in increased activity of phosphatase and diesterase (Newman et al, 2003;Rejmánková et al, 2011). Our measurement of the enzymatic activity does also show some tendencies to an increased enzymatic activity from the inflow to the outflow in wetlands were the SRP concentration is low e.g.…”

The role of macrophytes in wetland ecosystems

“…However, despite different classification schemes and terminologies there is no single commonly accepted functional type classification useful for all studies whether they are concerned with wetland or terrestrial plants (Sieben et al 2010). It seems that plant functional groups are being de novo defined for each individual study depending on the study aims (Rejmánková et al 2011).…”