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LOCALIZATION OF STARCH BIOSYNTHETIC AND DEGRADATIVE ENZYMES IN MAIZE LEAVES
Author(s) -
Echeverria Edgardo,
Boyer Charles D.
Publication year - 1986
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1986.tb08517.x
Subject(s) - starch , starch synthase , vascular bundle , biology , enzyme , glycogen phosphorylase , biochemistry , chloroplast , amylase , glycogen branching enzyme , glycogen debranching enzyme , botany , amylopectin , amylose , gene
The cellular distribution of the starch biosynthetic and degradative enzymes in protoplasts prepared from maize leaf mesophyll and bundle sheath cells was investigated. In conformity with the cellular distribution of starch, starch biosynthetic enzymes (soluble starch synthase, ADPglucose pyrophosphorylase, branching enzyme and starch Phosphorylase) were exclusively localized in the bundle sheath cells. In contrast, starch degradative enzymes (α‐amylase, β‐amylase and debranching enzyme) were present in both types of leaf cells. Isolated chloroplasts from bundle sheath cells were shown to contain 100% of the starch biosynthetic enzymes. However, approximately 60% of the activity of degradative enzymes and 67% of the activity of starch Phosphorylase was localized in bundle sheath chloroplasts.