title: Differences between the Bud End and Stem End of Potatoes in Dry Matter Content, Starch Granule Size, and Carbohydrate Metabolic Gene Expression at the Growing and Sprouting Stages.
abstract: Potatoes usually have the tuber bud end dominance in growth during tuber bulking and in tuber sprouting, likely using carbohydrates from the tuber stem end. We hypothesized that the tuber bud end and tuber stem end coordination in carbohydrate metabolism gene expression is different between the bulking dominance and sprouting dominance of the tuber bud end. After comparing the growing tubers at harvest from a green vine and the stage that sprouts just started to emerge after storage of tubers at room temperature, we found the following: (1) Dry matter content was higher in the tuber stem end than the tuber bud end at both stages. (2) The starch granule size was larger in the tuber bud end than in the tuber stem end. (3) The tuber bud end had higher gene expression for starch synthesis but a lower gene expression of sucrose transporters than the tuber stem end during tuber growing. (4) The tuber stem end at the sprouting stage showed more active gene expression in both starch degradation and resynthesis, suggesting more active export of carbohydrates, than the tuber bud end. The results indicate that the starch accumulation mechanism in the tuber bud end was different between field growing and post-harvest sprouting tubers and that tubers already increased dry matter and average starch granule sizes in the tuber bud end prior to the rapid growth of sprouts.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University , Yangling, Shaanxi 712100, People's Republic of China.|Potato Research Centre, Agriculture and Agri-Food Canada , 850 Lincoln Road, Post Office Box 20280, Fredericton, New Brunswick E3B 4Z7, Canada.|Gansu Provincial Key Laboratory of Arid Land Crop Science, Gansu Key Laboratory of Crop Genetic and Germplasm Enhancement, Gansu Agricultural University , Lanzhou, Gansu 730070, People's Republic of China.
authors.forename: Bailin
authors.initials: B
authors.lastname: Liu
authors.affiliation: Gansu Provincial Key Laboratory of Arid Land Crop Science, Gansu Key Laboratory of Crop Genetic and Germplasm Enhancement, Gansu Agricultural University , Lanzhou, Gansu 730070, People's Republic of China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Potato Research Centre, Agriculture and Agri-Food Canada , 850 Lincoln Road, Post Office Box 20280, Fredericton, New Brunswick E3B 4Z7, Canada.
authors.forename: Agnes
authors.initials: A
authors.lastname: Murphy
authors.affiliation: Potato Research Centre, Agriculture and Agri-Food Canada , 850 Lincoln Road, Post Office Box 20280, Fredericton, New Brunswick E3B 4Z7, Canada.
authors.forename: David
authors.initials: D
authors.lastname: De Koeyer
authors.affiliation: Potato Research Centre, Agriculture and Agri-Food Canada , 850 Lincoln Road, Post Office Box 20280, Fredericton, New Brunswick E3B 4Z7, Canada.
authors.forename: Helen
authors.initials: H
authors.lastname: Tai
authors.affiliation: Potato Research Centre, Agriculture and Agri-Food Canada , 850 Lincoln Road, Post Office Box 20280, Fredericton, New Brunswick E3B 4Z7, Canada.
authors.forename: Benoit
authors.initials: B
authors.lastname: Bizimungu
authors.affiliation: Gansu Provincial Key Laboratory of Arid Land Crop Science, Gansu Key Laboratory of Crop Genetic and Germplasm Enhancement, Gansu Agricultural University , Lanzhou, Gansu 730070, People's Republic of China.
authors.forename: Huaijun
authors.initials: H
authors.lastname: Si
authors.affiliation: Potato Research Centre, Agriculture and Agri-Food Canada , 850 Lincoln Road, Post Office Box 20280, Fredericton, New Brunswick E3B 4Z7, Canada.
authors.forename: Xiu-Qing
authors.initials: XQ
authors.lastname: Li
mesh_terms: D018506:Gene Expression Regulation, Plant; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D035281:Plant Tubers / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011198:Solanum tuberosum / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013213:Starch / Q000737:chemistry* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D013213:Starch
keywords: Solanum tuberosum L.; dry matter; gene expression; potato sprouting; real-time quantitative polymerase chain reaction; starch granules; starch metabolism; tuber ends; tuber growth