Importance of amylases for physiological quality in maize seeds

Abstract

Seed quality is the result of the sum of genetic, physical, physiological and sanitary attributes that affect seed ability to perform vital functions related to germination, vigor, and longevity. The expression of genes associated with physiological quality can be assessed by means of germination and vigor analyses, as well as by transcript and protein analyses. The objective in this work was to review the relevance of amylase group enzymes to the physiological quality of maize seeds. Within this group, α-amylase (1,4-α-D-glucan glucanohydrolase E.C 3.2.1.1) plays an important role in starch hydrolysis, and is responsible for 90% of the amylolytic activity in maize seeds. It is responsible for starch conversion into sugars (e.g., destrin), which is used for embryo growth. β-amylase (1,4-α-D-glucan maltohydrolase E.C 3.2.1.2) catalyzes the release of maltose and dextrins from the non-reducing ends of starch. Research has shown that amylase enzymes are directly linked to physiological quality of maize seeds. Alpha- and beta-amylases are mainly involved in the germination process and seed heterosis, and can also be used as molecular markers associated with seed tolerance for drying.