Changes in endogenous auxins during winter dormancy in tea (Camellia sinensis L.) O. Kuntze

Changes in endogenous auxin (IAA) were determined in tea shoots with the onset of winter dormancy (30 October) and subsequent to dormancy release (15 April). Very low levels of free IAA were detected in dormant shoots when they were still in deep dormancy. The levels increased after 30 January and reached highest value after dormancy release. Conjugated IAA levels increased with onset of dormancy reaching its maximum value when free IAA levels were lowest. With increase in free IAA levels, the conjugated IAA levels decreased in shoots prior to dormancy release suggesting of metabolic inter-conversion of IAA during these periods. The possible roles of free and conjugated IAA in dormancy and following its release are discussed in relation to winter dormancy in tea shoots.