IAA priming improves the germination and seedling growth in cotton (Gossypium hirsutum L.) via regulating the endogenous phytohormones and enhancing the sucrose metabolism

•It is the first study that IAA priming was applied on cotton seeds.•IAA priming improved the seed germination of cotton.•IAA priming promoted the seedling growth of cotton.•IAA priming functions by regulating the phytohormone and sucrose metabolism.•IAA priming technology had a potential in cotton production.