Protein Bodies of Germinating Seeds ofVicia faba: CHANGES IN FINE STRUCTURE AND BIOCHEMISTRY

Abstract

Changes in fine structure and starch, total nitrogen and soluble sugar contents were followed during the first 3 weeks of germination in Vicia faba cotyledons. Following hydration the reserves were mobilized and loss of protein from the cotyledons began after 4 days; concomitant fine structural changes included the swelling and coalescence of protein bodies, the disappearance of their contents, and the differentiation of the provascular tissue in the cotyledon within which ‘transfer cells’ developed. There was some development of rough endoplasmic reticulum during the early part of germination. A pattern of protein-body degradation appeared in the cotyledons during germination, those cells nearest to the vascular bundles and to the epidermis being the first to lose their reserves. After 3 weeks' growth the parenchyma cells of the cotyledon were very vacuolate and typical of senescent tissue, while the vascular bundle cells still retained their contents and remained active-looking.