Investigating the physiological role of conglutin γ in plant tissues

Conglutin γ is an abundant oligomeric lupin seed glycoprotein of still unknown function, that has been considered for a long time as a storage protein. However, conglutin γ displays unique properties of its own, since its sequence does not match any canonical legume protein family and it is not proteolytically degraded during seed germination. Other several unusual features make this protein an interesting one to investigate both from the molecular and functional point of view. Conglutin γ-like proteins have been detected in either monocotyledonous and dicotyledonous plants, including various legumes, tomato, pears, grape, carrot and wheat. It has been found accumulated in the seeds or expressed in other tissues under different physiological or stress conditions. However, the bibliographic data are heterogeneous and often conflicting, thus not allowing an univocal function for this protein. In this communication, the results of several experimental approaches aimed to evidence the expression and presence of conglutin γ during the germination of lupin seeds and during the first stages of the life of the seedlings, will be shown. Moreover, a meta-analysis of all the expression patterns obtained from model plants, such as Medicago truncatula and Arabidopsis thaliana, will be presented. By and large, the results will help to elucidate the physiological role of this protein