Meta-topolin: Advantages and Disadvantages for In Vitro Propagation

Discoveries of new plant growth regulators are significantly enriching the range of tools used by researchers in plant tissue culture. Meta-topolin (mT, 6-(3-hydroxybenzylamino) purine), firstly isolated from poplar leaves, is a highly active natural aromatic cytokinin successfully used over the last two decades in many different biological fields. The main criteria of its efficiency in plant micropropagation are high multiplication rate, shoot health, good rooting, and acclimatization ability. The absence of abnormalities and somaclonal variation are further advantages. For this reason, mT is examined in various regeneration systems in comparison with isoprenoid, aromatic, as well as phenylurea derivatives with cytokinin-like activity. This chapter will review the advantages and disadvantages of mT application as an inducer of different morphogenetic pathways of plant regeneration in vitro, including axillary shoot proliferation, de novo organogenesis, and somatic embryogenesis.