Cotton fibre is the most used natural fibre globally. Australia is one of the top exporters of cotton fibres and Australian cotton industry is dedicated to supply the most environmentally and socially responsible cotton to the world. However, the available technologies for tracing Australian cotton fibres are still limited and sometimes it is extremely difficult to track the source of the fibres due to the dispersed supply chain and the lack of transparency.

My award project Traceable Cotton Fibres aims to explore a plant-based technology-option for cotton fibre traceability by using genetic manipulation (GM) cotton germplasms derived from our CSIRO Synthetic Biology (SynBio) FSP: Novel Synthetic Plant Fibres Project (The closure report of the CSIRO Synthetic Biology FSP Project, 2022; related patent PCT number is PCT/AU2023/050436). These cotton germplasms can synthesize foreign proteins which are fluorescent with specific excitation and emission wavelengths of light. The approach was to use different methods to detect the proteins and their fluorescence in various plant tissues including fibres at different developmental stages to assess where it is most stable. Two GM proteins were used: amilGFP and mCherry.

During the progress of this award project, it was found that the fluorescence of the amilGFP protein in the fibre is highly similar to the autofluorescence range of cotton fibre. Therefore, another set of GM cotton germplasm with the mCherry protein was used. mCherry is also fluorescent, and the excitation and emission wavelength are more distinctive in contrast to the high autofluorescence range of cotton fibre. In addition, the Enzyme-Linked Immunosorbent Assay (ELISA) was employed to detect the presence of mCherry protein in fibres as there is a commercially available kit with antibodies which detect mCherry. The results enabled evaluation of the possibility of using such germplasms to develop plant-based techniques for the traceability of cotton fibres across key stages of the value chain.