Expression of BASI during barley germination and its relation with nitrogen content

P. CODÓ; P. PRYSTUPA; J. ZAVALA; R. WOLOSIUK; E. PAGANO

Potrero de los Funes

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2011

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Plant seeds have a large number of proteinaceous inhibitors which act on α-amylase and proteases. Among Kunitz-type inhibitors there is one of endogenous α-amylase in barley named BASI (Barley α-Amylase Subtilisn Inhibitor). BASI is synthesized during grain filling and is an abundant protein of the mature seed. Thioredoxin h (Trx h), a ubiquitous protein containing a redox-active disulfide group, reduce storage proteins and inactivate various inhibitor proteins. The aim of this work is to determine the response to nitrogen content in Trx h and BASI expression during germination of barley. To this end, an experiment of nitrogen fertilization was conducted in barley. The resulting seeds were germinated and were measured both expression of Trx and BASI. The complete sequence of BASI was sequenced in cDNA synthesized from RNA of 48-hour-germination seeds. It was confirmed that the inhibitor is expressed in germinating seeds. Both Trx and inhibitor were greater in seeds with high nitrogen content than in seeds with lower nitrogen content. The understanding of these biochemical relationships will help to understand the relation between grain composition and the mechanisms of starch degradation during germination.