
TY  - JOUR
A1  - Barrett, Damian J. 
A1  - Richardson, Alan E. 
A1  - Gifford, Roger M. 
T1  - Elevated atmospheric CO<sub>2</sub> concentrations increase wheat root phosphatase activity when growth is limited by phosphorus
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 1998
VL  - 25
IS  - 1
SP  - 87
EP  - 94
KW  - 
UR  - https://doi.org/10.1071/PP97045 
N2  - Wheat seedlings were grown in solution culture under adequate and limited phosphorus treatments at current ambient and elevated (approximately 2&#xd7; ambient) CO2 concentrations. Acid phosphomonoesterase (&#x2018;phosphatase&#x2019;) activity of root segments was measured using p-nitrophenyl phosphate as substrate. When plant growth was P-limited, elevated CO2 concentrations increased phosphatase activity more than at ambient CO2. This result (1) was evident when expressed on a unit root dry weight or root length basis, indicating that increased root enzyme activity was unlikely to be associated with CO2-induced changes in root morphology; (2) occurred when plants were grown aseptically, indicating that the increase in phosphatase activity originated from root cells rather than root- associated microorganisms; (3) was associated with shoot P concentrations below 0.18%; (4) occurred only when wheat roots were grown under P deficiency but not when a transient P deficiency was imposed; and (5) suggest that a previously reported increase in phosphatase activity at elevated CO2 by an Australian native pasture grass (Gifford, Lutze and Barrett 1996; Plant and Soil 187, 369&#x2013;387) was also a root mediated response. The observed increase in phosphatase activity by plant roots at elevated CO2, if confirmed for a wide range of field pasture and crop species, is one factor which may increase mineralisation of soil organic P as the anthropogenic increase of atmospheric CO2 concentrations continues. But, whether a concomitant increase in plant uptake of P occurs will depend on the relative influence of root and microbial phosphatases, and soil geochemistry in determining the rate of mineralisation of soil organic P for any given soil. 
ER  -

