Paraveinal Mesophyll of Soybean Leaves in Relation to Assimilate Transfer and Compartmentation

Abstract

Immunohistochemical staining was used to determine the cellular distribution of two glycosylated polypeptides (molecular weights of 27 and 29 kilodaltons) which are normally present at low levels in soybean (Glycine max var `Wye') leaves but which markedly accumulate after depodding. These polypeptides, which comprise a substantial portion of the total leaf soluble protein of depodded plants, were exclusively located in the vacuoles of paraveinal mesophyll and associated bundle sheath cells. These results support the unique role of the soybean leaf paraveinal mesophyll in the transport and spatial compartmentation of nitrogen reserves in relation to seed filling.