Abstract:

Based on the transcriptome data of Colocasia esculenta（L.）Schott，full-length cDNA of ApS1（ADP-glucose pyrophosphorylase small subunit 1）gene was cloned from‘Jingjiang Xiangsha Taro’，which consisted of 1 596 bp and encoded a protein of 532 amino acids，and tentatively designated as CeApS1（NCBI：Colocasia KU288757，unreleased）. CeApS1 contained a NTP_transf_3 domain（Gly¹⁰⁴–Pro³⁰⁶）and a PbH1 domain（Gly⁴⁷³–Ser⁵¹⁵）. This gene encoded a small subunit of ADP-glucose pyrophosphorylase，and isoelectric point and molecular weight were 6.73 and 57.6 kD，respectively. Results displayed ApS1 existed in monocotyledons and dicotyledons. BlastX showed that ApS1 in Colocasia esculenta shared 83.4% identity with Landoltia punctate，and showed farther phylogenetic relationships with Fragaria ananassa（AAS00541.1），Medicago truncatula（XP_003617925.1），Oryza sativa（AAK27313.1）and Triticum aestivum（CAA46879.1）. The CeApS1 transcript widely presented in the main corm，lateral cormels，leaves，petioles and roots of Colocasia esculenta，and displayed higher expression levels in taro corms than those in leaves. The results indicated that there was a significantly positive correlation between CeApS1 transcript expression and starch contents in taro corms.

Key words: Colocasia esculenta, starch synthase, gene cloning, expression analysis