Perspectives on developing natural colored cotton through carotenoid biofortification

Cotton is a fundamental component of the textile industry, dominating natural fiber production globally. Besides textiles, cotton plays diverse roles such as producing cooking oil, seed feed, and even medicinal applications. Naturally colored cotton (NCC), featuring pigments derived from phenylpropanoids, offers a spectrum of hues in brown and green categories, providing an environmentally friendly and dye-free option. Despite the advantages of NCC, challenges such as limited superior NCC germplasm, coupled with lower strength, yield, pigment instability, and color constraints, have hindered NCC cultivar development. Recent advancements include developing pink cotton through betalain pathway engineering, highlighting biotechnological avenues for enhancing NCC cultivars. Carotenoids, diverse natural pigments with distinctive yellow, orange, and reddish hues, are essential for photosynthesis and serve as attractants for pollination in plants. Additionally, they are indispensable for human health as precursors of vitamin A and potent antioxidants, revolutionizing nutrient fortification in numerous crops. This review underscores advancements in NCC and carotenoid biofortification in crops, advocating genetic engineering via carotenoid biofortification in fibers to expand NCC’s color spectrum and revolutionize fiber development.