The CAAS Cotton Research Institute has created cotton with pink fibers by accumulating betalains in cotton fibers through genetic engineering. The related research results were published online in the open access journal Plant Biotechnology Journal. The study first performed codon optimization of three key genes associated with betalain synthesis to create a new cotton material rich in betalain. Driving a constitutive promoter resulted in pink coloration of cotton fibers and other tissues. The concentration of betalains in mature fibers decreased due to vacuolar degradation, resulting in a shallower color. Scientific researchers plan to conduct further studies on the mechanism that allows betalains to deposit without fading.