Calcium oxalate druse crystals and other inclusions in seed protein bodies: Eucalyptus and jojoba

Abstract

Druse crystals of Ca oxalate are known to occur in some protein bodies of some plant seeds. Observations on crystals, and other contents, of protein bodies of E. erythrocorys and Simmondsia chinensis (jojoba) were presented. Results are presented from thin section studies of glutaraldehyde-OsO4 fixed, dehydrated and embedded tissue; freeze-fracture studies; energy dispersive X-ray (EDX) analysis studies of freeze-dried tissue powders (Eucalyptus only); and chemical analysis studies of P, Mg, K and Ca content (Eucalyptus only). Many Eucalyptus protein bodies contained large druse crystals rich in Ca but devoid of P, K and Mg, and an occasional protein body from jojoba contained some dispersed crystals. Eucalyptus seeds were exceptionally high in Ca content. EDX analysis results provide evidence favoring the phytin-rich nature of globoid crystals in the 2 spp. Structural variation in the globoid crystals was great, especially in jojoba. Eucalyptus, whose protein bodies contained very large globoid crystals rich in P, Mg and K, had higher levels of these elements than most species investigated to date.