Activities of enzymes involved in starch synthesis in grains of large and small kernel type wheat (Triticum aestivum L.).

摘要

Characterization of changing activities of key enzymes during grain filling in 2 kernel type winter wheat cultivars was carried out. Results showed that starch accumulation rate (SAR) and activities of ADP-glucose pyrophosphorylase (AGPase), soluble starch synthase (SSS), granule-bound starch synthases (GBSS) and starch branching enzyme (SBE) in large kernel types were significantly higher than those in small kernel types. Simulation with Richards' equation showed that it was accumulation duration and SAR that determined starch accumulation in large kernel types. Compared with small kernel types, plants of large kernel types maintained longer filling duration, higher SAR and greater activities of related enzymes during mid and late grain-filling. These observations may suggest stronger sink activities in large kernel types at a later stage of development. Consequently, it is suggested that large kernel types may have advantages over small kernel types in terms of amount of starch accumulation at the mid and late stages.