Abstract: In order to study the function of VTC2 gene in cotton fiber development and cell elongation, a GhVTC2 gene was identified from fast elongating fibers of cotton. Expression analysis showed that GhVTC2 accumulated significantly during the rapid elongation period of cotton fibers, suggesting its important role in cell growth and development. The plant overexpression vector 35S:GhVTC2 was constructed and transformed into tobacco BY2 suspension cells and Arabidopsis thaliana; compared with that of the non-transformed Arabidopsis plants and tobacco cells, the cell length was increased significantly in transgenic tobacco cells, and the elongation of main roots in transgenic Arabidopsis was significantly promoted. The contents of AsA in transgenic tobacco cells and Arabidopsis root were increased. The promoter of GhVTC2 gene was obtained by cloning, and sequence analysis showed that the promoter contained multiple ethylene responsive elements ERE. The 5′ deletion vectors of different promoter sequences with or without the ERE element were constructed and transformed into tobacco leaves treated by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC). The results showed that ACC significantly promoted the activity of ERE-containing promoters. An effective reference is provided for studying the function and regulatory mechanism of GhVTC2 gene in cell elongation and development.

Key words: cotton fiber, ascorbic acid, ethylene, cell elongation, tobacco suspension cell, Arabidopsis