Changes in the phosphorus composition of seeds of Hakea sericea (Proteaceae) during germination under low phosphorus conditions

• Published in: The New phytologist Vol. 96; no. 2; pp. 239 - 247
• Main Authors: Mitchell, D.T, Allsopp, N
• Format: Journal Article
• Language: English
• Published: Oxford, UK Academic Press 01-02-1984; Blackwell Publishing Ltd; Blackwell
• Subjects: Acid soils; Biological and medical sciences; Cotyledons; Fundamental and applied biological sciences. Psychology; Germination; Germination and dormancy; Hakea sericea; Phosphates; Phosphorus; phytic acid; plant biochemistry; plant physiology; Plant physiology and development; RNA; Seedlings; Seeds; Soil biochemistry; Sowing; Seeds; Dicotyledones; Germination; Angiospermae; Phosphorus; Proteaceae; Spermatophyta; Inorganic element
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.1984.tb03560.x

Seeds of Hakea sericea Schrad. belonging to the subfamily Grevilleoideae of the Proteaceae contain greater P reserves than those belonging to the Proteoideae indigenous to South Africa. The main P-containing compounds in seeds of H. sericea are phytic acid with smaller proportions consisting of lipid-P, RNA, DNA, protein-P, polyphosphate and orthophosphate. Hakea sericea grew on sterile acid washed sand for up to 125 d after sowing before signs of mineral deficiency symptoms appeared. Proteoid roots were produced by seedlings grown in Clovelly sand from 60 d after sowing and their numbers appeared to be related to the accumulation of P in the seedling. It is concluded that the P reserves of seeds of H. sericea may provide a competitive advantage over those of the Proteoideae for establishment and growth in the acidic sandy soils of the south-western Cape, South Africa.