Enzymes in the rhizosphere of plants growing in the vicinity of the Polish Arctowski Antarctic Station

Abstract

In maritime Antarctica soil enzymes have been little researched, mainly in the rhizosphere of the only two vascular plants that grow there: Colobanthus quitensis and Deschampsia antarctica. This study evaluated the activities of hydrolytic enzymes β-glucosidase, phosphatase and urease in the rhizospheric soils of C. quitensis and D. antarctica from three different sites in the Polish Arctowski Station in Antarctica. The sensitivity to temperature changes of the enzymes was also evaluated using two incubation temperatures (37 and 12 °C). The highest activities related to the C and P cycles, β-glucosidase and acid phosphatase, respectively, were detected in the rhizospheric soils at the site with the greatest variety of plant cover. Urease activity, related to the N cycle, was high in two of the three sites, and the lowest activity was detected at the site where only D. antarctica was found. The activity of the enzymes decreased when the temperature of incubation was reduced, but the magnitude of the decrease depended on the enzyme. β-glucosidase was the most sensitive to temperature change, whereas urease was least affected. Therefore, temperature changes in rhizospheric soils could lead to changes in substrate degradation rates and consequently in the availability of nutrients (C, N and P) for C. quitensis and D. antartica in maritime Antarctica.

In vitro sensitivity of forest soil enzymes to temperature increase in Western Patagonia

“…The activities of BG, and NGA in these forest soils are within the range -or higher than reported in other studies (García et al, 2003;Trasar-Cepeda et al, 2008), and slightly higher than soils from previously investigated Antarctic ecosystems (Machuca et al, 2015). This can be an indicator of a greater C and N decomposition activity in forest ecosystems of Patagonia compared to Antarctica ecosystem, and therefore, a signal of the applicability of the enzyme activities to study C, N transformation in the soil.…”

The biological activities of β-glucosidase, phosphatase and urease as soil quality indicators: a review

“…showing the effect of temperature on urease hydrolysis (Machuca et al, 2015). In addition, a grassland soil incubated over a range of temperatures (-2 to 21°C) showed a positive relationship between urease activity and temperature, with an activation energy (E a ) of 73.4 kJ mol −1 and temperature coefficient (Q 10 ) of 2.78 (Fraser et al, 2013).…”

“…Although urease may be constitutively synthesized in some organisms, its expression is usually under N regulation (Machuca et al, 2015). The synthesis of the enzyme is prevented when cells grow in the presence of NH 4 + as the preferred N source (Geisseler et al, 2010).…”

Activity and Thermodynamic Parameters of Urease Enzymes in Soils Treated with Some Heavy Metals Under Different Temperatures and Moisture Levels

“…Kumari & Rao (2017) reported that the activity of urease enzyme increased by increasing the temperature from 20 to 70°C and then decreased dramatically as the temperature increased to 90°C. Machuca et al (2015) and Al-Ansari (2000) stated that Urease activity increases with increasing temperature from 10 to 50°C. Fraser et al (2013) explained as well the significant correlation between urease activity and temperature with activation energy (Ea) of 73.4 kJmol -1 .…”