Gene Expression Studies Reveal the Role of Major Genes Regulate the High Quality of Egyptian Cotton Fibers

The aim of the present study was the development of a gene candidate platform through bioinformatics work for filtering candidate genes are highly correlated to cotton fiber-quality. Thereafter, gene expression analyses were performed to validate the function of genes participate in fiber development. The expression analyses of each gene were performed at elongation stage (5, 10, 15 and 20 DPA; days postanthesis) in different genotypes; the Egyptian cotton cv. Giza 70 (Gossypium barbadense), the Upland cotton cv. Tamcot (G. hirsutum) in addition to the developed Hybrids; Hybrid A (Giza 70, female x Tamcot) and Hybrid B (Tamcot, female x Giza 70). The results of bioinformatics analyses were used to determine the candidate genes which are highly correlated to cotton fiber quality. Twenty four candidate genes belonging to 21 families were determined in this study. Thus, semi-quantitative RT-PCR and Real-time quantitative RT-PCR (qRT-PCR) analyses were performed for each gene. The results of gene expression analyses revealed that these candidate genes were highly expressed in fiber cells of Giza 70 followed by a relatively high expression in the two hybrids A&B compared to the lowest level of expression which was detected in Tamcot. These results confirmed the functional role of these genes in the development of fiber cells during the elongation stage. Thus, these genes are participating in superior fiber quality of Egyptian cotton and represent potential targets for further improvement of Egyptian cotton through an integrated metabolic engineering strategy to develop high-yield Egyptian cotton with more proper industrial added-value.