title: Molecular structural differences between maize leaf and endosperm starches.
abstract: The morphology, whole molecular size distribution and chain-length distribution of maize leaf starch have been characterized and compared to its endosperm starch, to better understand differences between leaf and endosperm starch structure, and the relationship with the functions of starch in these organs. Leaf starch is found to have amylopectin with much shorter chains (virtually none with a degree of polymerization, DP, above 70) than the endosperm amylopectin, which has significant numbers of chains with DP up to ∼120, and has much smaller molecular size (and is present at a much lower amount) than endosperm starch. It is postulated that these pronounced differences arise from the distinct starch synthesis pathways in these organs, and are consistent with the starches' distinct botanical functions: short-term storage requiring relatively rapid degradation for leaf starch, and high crystallinity and high energy density requiring slow degradation for endosperm starch.
authors.affiliation: Yangzhou University, College of Bioscience and Biotechnology, Yangzhou, Jiangsu 225009, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agricultural and Food Innovation, Brisbane, QLD 4072, Australia.
authors.forename: Shiyao
authors.initials: S
authors.lastname: Yu
authors.affiliation: Huazhong Agriculture University, National Key Laboratory of Crop Genetic Improvement, Wuhan, Hubei 430070, China.
authors.forename: Fangdong
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Yangzhou University, College of Bioscience and Biotechnology, Yangzhou, Jiangsu 225009, China. Electronic address: cheng.li1@uqconnect.edu.au.
authors.forename: Cheng
authors.initials: C
authors.lastname: Li
authors.affiliation: Yangzhou University, College of Bioscience and Biotechnology, Yangzhou, Jiangsu 225009, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agricultural and Food Innovation, Brisbane, QLD 4072, Australia. Electronic address: b.gilbert@uq.edu.au.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Gilbert
mesh_terms: D000687:Amylopectin / Q000737:chemistry; D056625:Endosperm / Q000737:chemistry*; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D003313:Zea mays
chemical_list: D013213:Starch; D000687:Amylopectin
keywords: Leaf starch; Molecular size distribution; Structural characterization