Fig. 1

Primary vascular tissue of cotton hypocotyl is the primary target of Agrobacterium infection. a Agrobacterium-mediated genetic transformation and plant regeneration via somatic embryogenesis with cotton hypocotyls as explants, including callus induction, embryogenic callus induction, and plant regeneration via somatic embryogenesis. b The left picture shows etiolated cotton seedling under dark culture. Scale bar, 1 cm. The right picture shows the tissue types in the cross-section of cotton hypocotyl. Scale bar, 500 μm. c The comparison of three major types of stem cells in plants, including SAM, RAM, and cambium in vascular bundles. The vascular bundle of dicotyledons is cyclic annular and consists of xylem, phloem, and cambium. The vascular bundles of monocotyledons are scattered without cambium. d Specific expression of green fluorescent protein and far-red fluorescent protein driven by CaMV 35S promoter in primary vascular tissue (indicated by yellow arrow) after Jin668 and TM-1 hypocotyls infected with Agrobacterium for 48 h. Scale bar, 500 μm