Leaf initiation and development in soybean under phosphorus stress.
Experiments investigated changes in leaf development in young soybean plants progressing into P stress. The apical meristem and leaf structure were examined anatomically to evaluate the involvement of cell division and cell expansion in the restriction of leaf number and individual leaf size. Seedlings were deprived of P for 32 d following germination. Leaf initiation rates declined noticeably after about 2 weeks, even though the apical dome was of similar size and had a similar number of cells as controls. Primordia appeared morphologically similar also. Expansion of primary and the first three trifoliolate leaves of -P plants was severely reduced, and expansion of each leaf ceased, uniformly, when an area of about 40 cm(2) was obtained. Leaf epidermal cell size in the lateral plane was unaffected. The results indicate that expansion of leaves under P stress was limited by the number of cell divisions, which would imply control of cell division by a common regulatory factor within the leaf canopy.
Chiera
Joseph
J
Department of Botany, North Carolina State University, Raleigh, NC 27695-7612, USA
Thomas
Judith
J
Rufty
Thomas
T
D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D018519:Meristem / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D010758:Phosphorus / Q000172:deficiency* / Q000378:metabolism / Q000494:pharmacology; D019441:Plant Epidermis / Q000187:drug effects / Q000254:growth & development*; D018515:Plant Leaves / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D013025:Glycine max / Q000187:drug effects / Q000254:growth & development*; D013997:Time Factors
D010758:Phosphorus