Identification and Expression Analysis of Tubulin Gene Family in Upland Cotton

Abstract

Background: Upland cotton (Gossypium hirsutum) is one of the important cash crops. Therefore, improving fiber quality of upland cotton, is one of the current important research directions. Cotton fibers are single-celled extensions of the seed epidermis, which is important pattern material of research cytoskeleton. Tubulin genes act an important role in the synthesis of the microtubules (MT), which is core element of the cytoskeleton. Some tubulin genes in cotton ovule and fiber development are were reported, while the systematic study of its family genes has not yet in cotton. Therefore, identification and expression analyses of G. hirsutum tubulin genes provide pivotal targets for molecular manipulation in cotton breeding.Result: In this study, we investigated all tubulin genes from seven varies plant species, and identified 98 tubulin genes in G. hirsutum. Phylogenetic analysis showed that tubulin family genes were classified into three subfamilies. The protein motifs and gene structure of α, β-tubulin genes are more conservative comparing with γ-tubulin genes. Most tubulin genes are located at the proximate ends of the chromosomes. Spatiotemporal expression pattern by transcriptome and qRT-PCR analysis revealed that 12 α-tubulin and 7 β-tubulin genes are specific expression in different stages of fiber development. However, Gh.A03G027200, Gh.D03G169300 and Gh.A11G258900 had clear express pattern at distinct stages of fiber development in J02508 and ZRI015.Conclusion: In this study, evolutionary analysis showed that the tubulin genes were divided into 3 clades. The genetic structures and molecular functions were highly conserved in different plants. Three candidate genes of Gh.A03G027200, Gh.D03G169300 and Gh.A11G258900 may play key roles during length and strength in fiber development with the expression analysis at different organizations.