title: Altered Phenylpropanoid Metabolism in the Maize Lc-Expressed Sweet Potato (Ipomoea batatas) Affects Storage Root Development.
abstract: There is no direct evidence of the effect of lignin metabolism on early storage root development in sweet potato. In this study, we found that heterologous expression of the maize leaf color (Lc) gene in sweet potato increased anthocyanin pigment accumulation in the whole plant and resulted in reduced size with an increased length/width ratio, low yield and less starch content in the early storage roots. RT-PCR analysis revealed dramatic up-regulation of the genes involved in the lignin biosynthesis pathway in developing storage roots, leading to greater lignin content in the Lc transgenic lines, compared to the wild type. This was also evidenced by the enhanced lignification of vascular cells in the early storage roots. Furthermore, increased expression of the β-amylase gene in leaves and storage roots also accelerated starch degradation and increased the sugar use efficiency, providing more energy and carbohydrate sources for lignin biosynthesis in the Lc transgenic sweet potato. Lesser starch accumulation was observed in the developing storage roots at the initiation stage in the Lc plants. Our study provides experimental evidence of the basic carbohydrate metabolism underlying the development of storage roots, which is the transformation of lignin biosynthesis to starch biosynthesis.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, Shanghai 200032, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Wang
authors.affiliation: Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Plant Science Research Center, Chinese Academy of Science, Shanghai Chenshan Botanical Garden, Shanghai 201602, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, Shanghai 200032, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, Shanghai 200032, China.
authors.forename: Weijuan
authors.initials: W
authors.lastname: Fan
authors.affiliation: Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet Dagan 50250, Israel.
authors.forename: Nurit
authors.initials: N
authors.lastname: Firon
authors.affiliation: Department of Plant and Soil Science, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Sitakanta
authors.initials: S
authors.lastname: Pattanaik
authors.affiliation: Department of Plant and Soil Science, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Yuan
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, Shanghai 200032, China.|Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Plant Science Research Center, Chinese Academy of Science, Shanghai Chenshan Botanical Garden, Shanghai 201602, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
mesh_terms: D053898:Biosynthetic Pathways; D050260:Carbohydrate Metabolism; D005419:Flavonoids / Q000096:biosynthesis; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D027723:Ipomoea batatas / Q000235:genetics* / Q000378:metabolism*; D008031:Lignin / Q000096:biosynthesis; D010641:Phenotype; D010788:Photosynthesis; D018515:Plant Leaves / Q000502:physiology; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D030821:Plants, Genetically Modified; D020005:Propanols / Q000378:metabolism*; D013213:Starch / Q000378:metabolism; D003313:Zea mays / Q000235:genetics*
chemical_list: D005419:Flavonoids; D020005:Propanols; C439395:1-phenylpropanol; D013213:Starch; D008031:Lignin