Enhanced organic phosphorus assimilation promoting biomass and shoot P hyperaccumulations in Lolium multiflorum grown under sterile conditions.
Search for plant species - prodigious in P use - is important for both P-sufficient and -deficient conditions. Gulf and Marshall ryegrass (Lolium multiflorum), grown in sterile media containing different organic P substrates (AMP, ATP, GMP, and IHP), exhibited high rates of growth and shoot P concentrations. Growth increase in Gulf was significantly greater on IHP relative to other sources of organic P substrates. Growth was also dependent on an increasing concentration of IHP (0-20 mM) in this cultivar. P accumulations in Gulf exceeded 1% shoot dry weight from IHP, AMP, and ATP-equivalent to the P accrual from equimolar Pi source. Plants supplied with IHP had phytase activity in root extracts comparable to that in Pi-fed plants or control (no P). The extracellular phytase, however, increased by about 100% relative to that observed in root extracts- for both ryegrass cultivars, but there were no significant differences (P < 0.05) between plant groups grown on different substrates (IHP, Pi or control). No significant differences in phosphomonoesterase activities were evident between plant groups supplied with organic P (IHP, G1P) and inorganic source or control. This study establishes the high P-use efficiency in ryegrass, irrespective of P source.
Department of Biology, Western Kentucky University, Bowling Green, 1906 College Heights Boulevard, Kentucky 42101-1080, United States. nilesh.sharma@wku.edu
Nilesh C
NC
Sharma
Shivendra V
SV
Sahi
D001673:Biodegradation, Environmental; D008129:Lolium / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D018520:Plant Shoots / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D009943:Organophosphorus Compounds; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D010758:Phosphorus