Phosphorus nutrition-mediated effects of arbuscular mycorrhiza on leaf morphology and carbon allocation in perennial ryegrass

• Published in: The New phytologist 2005-11, Vol.168 (2), p.435-444
• Main Authors: Grimoldi, Agustín A., Kavanová, Monika, Lattanzi, Fernando A., Schnyder, Hans
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; allocation; arbuscular mycorrhizal fungus (AMF); Average linear density; Biological and medical sciences; Biological Transport, Active; Biomass; carbon; Carbon - metabolism; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Glomus; Glomus hoi; grasses; Kinetics; Leaf area; leaf mass per area; Lolium - anatomy & histology; Lolium - growth & development; Lolium - metabolism; Lolium - microbiology; Lolium perenne; Lolium perenne (perennial ryegrass); Mass ratio; microbial colonization; Mycorrhizae - growth & development; Mycorrhizae - metabolism; Mycorrhizal fungi; nutrient uptake; Parasitism and symbiosis; Phosphorus; Phosphorus - metabolism; phosphorus nutrition; physiological transport; Plant growth; Plant Leaves - anatomy & histology; Plant Leaves - growth & development; Plant Leaves - metabolism; Plant morphology; plant nutrition; plant physiology; Plant physiology and development; Plant roots; Plants; soil nutrients; structural carbon; Symbiosis; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); vesicular arbuscular mycorrhizae; water‐soluble carbohydrates
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2005.01500.x

• The aim of this work was to disentangle phosphorus status-dependent and -independent effects of arbuscular mycorrhizal fungus (AMF) on leaf morphology and carbon allocation in perennial ryegrass (Lolium perenne). • To this end, we assessed the P-response function of morphological components in mycorrhizal and nonmycorrhizal plants of similar size. • AMF (Glomus hoi) stimulated relative P-uptake rate, decreased leaf mass per area (LMA), and increased shoot mass ratio at low P supply. Lower LMA was caused by both decreased tissue density and thickness. Variation in tissue density was almost entirely caused by variations in soluble C, while that in thickness involved structural changes. • All effects of AMF were indistinguishable from those mediated by increases in relative P-uptake rate through higher P-supply rates. Thus the relationships between relative P-uptake rate, leaf morphology and C allocation were identical in mycorrhizal and nonmycorrhizal plants. No evidence was found for AMF effects not mediated by changes in plant P status.