Final answer:
In tissue culture, hormones like auxins, cytokinins, and gibberellins are critical for promoting growth and differentiation. Auxins aid in root and fruit development, cytokinins stimulate cell division and differentiation, and gibberellins are important for shoot elongation and seed germination.
Step-by-step explanation:
In tissue culture, multiple hormones are utilized to stimulate growth and differentiation of plant cells. The main hormones include:
- Auxins: These hormones, especially Indole-3-acetic acid (IAA), are used to encourage cell elongation, root development, and fruit growth. They are essential for regulating phototropism and gravitropism and also play a critical role in vascular tissue differentiation.
- Cytokinins: These promote cell division and are vital in delaying leaf senescence, stimulating mitosis, and activating meristem differentiation in shoots and roots. Cytokinins work in conjunction with auxins to regulate various aspects of plant development such as apical dominance.
- Gibberellins: A group of hormones that increase shoot elongation, trigger seed germination, and aid in fruit and flower maturation.
Other hormones like brassinosteroids also play a significant role in regulating cell division at the plant's root tips. While auxin is actively transported between cells, brassinosteroids have limited transport.