title: Characters related to higher starch accumulation in cassava storage roots.
abstract: Cassava (Manihot esculenta) is valued mainly for high content starch in its roots. Our understanding of mechanisms promoting high starch accumulation in the roots is, however, still very limited. Two field-grown cassava cultivars, Huanan 124(H124) with low root starch and Fuxuan 01(F01) with high root starch, were characterised comparatively at four main growth stages. Changes in key sugars in the leaves, stems and roots seemed not to be strongly associated with the final amount of starch accumulated in the roots. However, when compared with H124, F01 exhibited a more compact arrangement of xylem vascular bundles in the leaf axils, much less callose around the phloem sieve plates in the stems, higher starch synthesis-related enzymatic activity but lower amylase activity in the roots, more significantly up-regulated expression of related genes, and a much higher stem flow rate (SFR). In conclusion, higher starch accumulation in the roots results from the concurrent effects of powerful stem transport capacity highlighted by higher SFR, high starch synthesis but low starch degradation in the roots, and high expression of sugar transporter genes in the stems. A model of high starch accumulation in cassava roots was therefore proposed and discussed.
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources; Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering; College of Life Science and Technology, Guangxi University; 100 Daxue Road, Nanning, Guangxi 530004, P. R. China.
authors.forename: You-Zhi
authors.initials: YZ
authors.lastname: Li
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources; Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering; College of Life Science and Technology, Guangxi University; 100 Daxue Road, Nanning, Guangxi 530004, P. R. China.
authors.forename: Jian-Yu
authors.initials: JY
authors.lastname: Zhao
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources; Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering; College of Life Science and Technology, Guangxi University; 100 Daxue Road, Nanning, Guangxi 530004, P. R. China.
authors.forename: San-Min
authors.initials: SM
authors.lastname: Wu
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources; Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering; College of Life Science and Technology, Guangxi University; 100 Daxue Road, Nanning, Guangxi 530004, P. R. China.
authors.forename: Xian-Wei
authors.initials: XW
authors.lastname: Fan
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources; Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering; College of Life Science and Technology, Guangxi University; 100 Daxue Road, Nanning, Guangxi 530004, P. R. China.
authors.forename: Xing-Lu
authors.initials: XL
authors.lastname: Luo
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources; Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering; College of Life Science and Technology, Guangxi University; 100 Daxue Road, Nanning, Guangxi 530004, P. R. China.
authors.forename: Bao-Shan
authors.initials: BS
authors.lastname: Chen
mesh_terms: D050260:Carbohydrate Metabolism; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D002365:Manihot / Q000235:genetics / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D017440:Photoperiod; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*; D018547:Plant Stems / Q000378:metabolism; D013213:Starch / Q000378:metabolism*
chemical_list: D013213:Starch