EGU22-8437, updated on 28 Mar 2022
https://doi.org/10.5194/egusphere-egu22-8437
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Effect of warming on β-glucosidase activity and root exudates depends on soil moisture: Combining Zymography with glucose imaging and enzyme kinetic

Seyed Sajjad Hosseini1,2, Sayeda Rabia Sultan2, Mehdi Rashtbari2, Amir Lakzian1, and Bahar S. Razavi2
Seyed Sajjad Hosseini et al.
  • 1Department of Soil Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran,
  • 2Department of Soil and Plant microbiome, Institute for phytopathology, University of Kiel , Germany

Temperature and soil moisture strongly affect plant root exudates and enzyme activities. Global warming may stimulate root exudation and enzyme activities while drought can drop releasing of root exudates and inhibit enzyme activities. However, how the interaction of warming and drought regulate these processes in the rhizosphere is poorly known. To clarify these interactions, wheat plants were grown for one month at 20 and 30 ºC in drought (30% WHC) and optimum (70% WHC) condition. To investigate the pattern of root exudates releasing and enzyme activities, we combined β-glucosidase zymography with glucose imaging and enzyme kinetic.

Drought significantly decreased hotspots of glucose in compare to optimum condition at both temperatures. Releasing of glucose by wheat at 30 ºC was 53% lower than at 20 ºC in optimum condition. Hotspots of β-glucosidase activity in drought was 52% and 37.7% lower than in optimum at 20 and 30 ºC, respectively. β-glucosidase hotspot at 30 ºC was 12.2% lower than at 20 ºC in optimum condition. The results of enzyme kinetic (Vmax and Km) showed that drought decreased β-glucosidase activity in compare to optimum condition at both temperatures. β-glucosidase activity at 30 ºC was 2 times higher that at 20 ºC in optimum condition. On the contrary, it was 56% lower than at 20 ºC in drought condition. Drought increased Km at 20 ºC while decreased it at 30 ºC in compare to optimum condition. The affinity of β-glucosidase for substrates in optimum condition was not affected by temperature. Km value at 30 ºC was lower than at 20 ºC in drought condition. According to these results, the warming in optimum condition (high labile carbon availability) decreased enzyme production and substrates release and did not change the affinity of enzyme for substrates. While warming in drought condition (low labile carbon availability) produced an enzyme pool with high efficiencies and did not change enzyme production and substrates release.

How to cite: Hosseini, S. S., Sultan, S. R., Rashtbari, M., Lakzian, A., and Razavi, B. S.: Effect of warming on β-glucosidase activity and root exudates depends on soil moisture: Combining Zymography with glucose imaging and enzyme kinetic, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8437, https://doi.org/10.5194/egusphere-egu22-8437, 2022.

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