A plastidic ATP/ADP transporter gene, lbAATP, increases starch and amylose contents and alters starch structure in transgenic sweetpotato

作者：Wang Yan-nan; Li Yan; Zhang Huan; Zhai Hong; Liu Qing-chang; He Shao-zhen^*

来源：Journal of Integrative Agriculture, 2016, 15(9): 1968-1982.

DOI：10.1016/S2095-3119(15)61192-3

• sweetpotato
• lbAATP
• starch content and composition
• starch granule size
• starch structure
• pasting properties

A plastidic adenosine triphosphate (ATP)/adenosine diphosphate (ADP) transporter (AATP) is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids. In this study, a gene encoding the AATP protein, named lbAATP, was isolated from sweetpotato (lpomoea batatas (L.) Lam.). Transcripts of lbAATP were predominantly detected in the storage roots and leaves and were induced by exogenous sucrose and subjected to circadian rhythm. Transient expression of lbAATP in tobacco and onion epidermal cells revealed the plastidic localization of lbAATP. The overexpression of lbAATP in sweetpotato significantly increased the starch and amylose contents and led to enlarged starch granules. The lbAATP-overexpressing plants showed altered fine structure of amylopectin, which contained an increased proportion of chains with a degree of polymerization (DP) of 10-23 and a reduced number of chains with a DP of 5-9 and 24-40. In addition, starch from the transgenic plants exhibited different pasting properties. The transcript levels of starch biosynthetic genes, including lbAGP, lbGBSSI, lbSSI-IV, and lbSBE, were differentially regulated in the transgenic plants. These results revealed the explicit role of lbAATP in the starch biosynthesis of sweetpotato and indicated that this gene has the potential to be used to improve starch content and quality in sweetpotato and other plants.

• 出版日期2016
• 单位中国农业大学