Different cellulose synthase genes are prominently expressed during fiber elongation in Gossypium arboreum and G. hirsutum

摘要

Quantitative expression analysis of three cellulose synthases/subunits encoding genes (cesAl, cesAlb, and cesA2) during three fibre development stages [3, 15 and 35 days post anthesis (dpa)] in Gossypium arboreum, G. anomalum, and G. hirsutum was undertaken. Exceptionally high expression was observed in G. hirsutum at 15 dpa stage for cesAl and cesA2 (6.5 and 7.7 magnitude increase over (3 tubulin) genes, which might be responsible for longer fibre in G. hirsutum. Moderately high expression of cesAl gene was recorded in G. arboreum (at 15 dpa), and in G. anomalum (at 3 and 15 dpa). However cesAl gene expression was negligible in G. arboreum, and G. hirsutum at 3 dpa and in all three species at 35 dpa. Strong increase in expression levels of cesAlb gene (6.4 magnitude increase over (3 tubulin) was observed in G. arboreum at 15 dpa stage. Expression levels of cesAlb gene were moderate in G. hirsutum (at 3 and 15 dpa) and in G. anomalum (at 15 dpa); while its expression was low to negligible in rest of the samples. The cesA2 gene expressed at moderate to low levels at 3 dpa in G. anomalum and G. hirsutum; at 15 dpa in G. arboreum and G. anomalum; and at 35 dpa in all three species. During fibre initiation, expression of all three cellulose synthase genes was negligible in G. arboreum. In fuzzy fibred G. anomalum expression of all three ces genes was low (nil for cesAl at 3 dpa) at all the stages. These results indicate that different cellulose synthase genes, cesA1 and cesA2 (in G. hirsutum) and cesAlb (in G. arboreum) play a predominant role in fibre development.