Developing fiber specific promoter-reporter transgenic lines to study the effect of abiotic stresses on fiber development in cotton

Authors: Chen, Junping; Burke, John

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/12/2015
Publication Date: 6/1/2015
Citation: Chen, J., Burke, J.J. 2015. Developing fiber specific promoter-reporter transgenic lines to study the effect of abiotic stresses on fiber development in cotton. PLoS One. 10(6):1-17.

Interpretive Summary: Cotton yield and fiber quality are two primary factors determining the economic outcomes for cotton producers. Environmental stresses, such as drought, high temperature and combination of both, not only reduce the overall growth of cotton plants, but also greatly decrease cotton yield and fiber quality. However, the impact of environmental stresses on fiber development is poorly understood due to technical difficulties associated with the study of developing fiber tissues and lack of genetic materials to study fiber development. To address this important question and provide the need for scientific community, we have generated a set of fiber specific promoter-reporter transgenic lines for six cotton fiber specific genes, representing genes expressing at different fiber development stages. Characterization of transgenic lines showed that the reporter gene activity in transgenic cotton lines were similar to those of the native genes. Greenhouse study showed a correlation between the decrease in promoter activities under drought and heat stressed conditions and decrease in fiber length and increase in micronaire in mature fibers measured by standard HVI test. The results indicate the suitability of these newly created materials as much needed molecular tools to study the effects of abiotic stresses on fiber development and fiber quality traits.

Technical Abstract: Cotton is one of the most important cash crops in US agricultural industry. Environmental stresses, such as drought, high temperature and combination of both, not only reduce the overall growth of cotton plants, but also greatly decrease cotton lint yield and fiber quality. The impact of environmental stresses on fiber development is poorly understood due to technical difficulties associated with the study of developing fiber tissues and lack of genetic materials to study fiber development. To address this important question and provide the need for scientific community, we have generated transgenic cotton lines harboring cotton fiber specific (CFS) promoter-reporter constructs from six cotton fiber specific genes, representing genes that are expressed at different stages of fiber development. Individual CFSP::GUS or CFSP::GFP construct was introduced into Coker 312 via Agrobacterium mediated transformation. Transgenic cotton lines were evaluated phenotypically and screened for the presence of selectable marker, reporter gene expression, and insertion numbers. Quantitative analysis showed that the patterns of GUS reporter gene activity during fiber development in transgenic cotton lines were similar to those of the native genes. Greenhouse drought and heat stress study showed a correlation between the decrease in promoter activities and decrease in fiber length, increase in micronaire and changes in other fiber quality traits in transgenic lines grown under stressed condition. These newly developed materials provide new molecular tools for studying the effects of biotic and abiotic stresses on fiber development.