Role of Meta-topolin on in Vitro Shoot Regeneration: An Insight

Meta-topolin [6-(3-hydroxybenzylamino)purine)] is an aromatic cytokinin bearing a benzyl ring substituted by a hydroxyl group at meta-position. It was first isolated from the leaves of poplar tree. Meta-topolin (mT) has immense potential for shoot regeneration. Its other beneficial attributes include delaying senescence, preventing shoot-tip necrosis, and evading the effects of hyperhydricity. The concise results obtained from different studies, conducted over the past one decade, distinctively show that the effects of mT basically include in vitro shoot induction, shoot proliferation, and increase in shoot length. When used in combination with auxins, it exhibits an ability to induce regenerative callus. Based on all the beneficial attributes of mT, it can be regarded as a potent aromatic cytokinin that can be utilized in micropropagation. Considering its significant application in plant tissue culture, the present chapter intricately describes the nature, usage, and advantages of mT on shoot regeneration, in particular.