Cloning and Analysis of Xyloglucan Endotransglucosylase/ Hydrolase Gene in Cotton

Abstract

Xyloglucan endotransglucosylase/Hydrolase (XTH) can loosening cell wall by breaking and re-forming the xyloglucan-cellulose crosslinks. Therefore, XTHs in cotton are related to elongation of cotton fibers. To investigate the relation, two XTH genes were cloned, respectively named as GhXTH1（GenBank:AY189971）and GhXTH2（GenBank:JN968478）.GhXTH1 contained 885 nucleotides, encoding 289 aa. GhXTH2 consisted of 885 nucleotides, encoding 289 aa. GhXTH1 and GhXTH2 contained the conserved motif (DEIDFEFLG) , characteristic of XTH family. Bioinformatic analyses showed that they possessed a transmembrane helice and signal peptide respectively. Phylogenetic analysis suggested that GhXTH1 was orthologous gene to AtXTH6、AtXTH7.  GhXTH2 was orthologous gene to AtXTH9. In addition,we analysed the expression of GhXTH1 and GhXTH2, respectively in Gossypium hirsutum and Gossypium barbadense. The results showed that transcript levels were lower during cotton fiber development, and transcript level of GhXTH2 were higher than that of GhXTH1.