Possible involvement of abscisic acid metabolism in endodormancy release in persimmon (Diospyros kaki)
Endodormancy in temperate-zone deciduous fruit trees is an important mechanism that allows trees to survive under unfavorable conditions during winter. There are two ecotypes of persimmon (Diospyros kaki); one adapted to the subtropical zone and the other adapted to the temperate zone. These ecotypes could serve as useful models to understand the physiological changes and genetic regulation of endodormancy in fruit trees. Firstly, we investigated the seasonal changes in the contents of abscisic acid (ABA) and its catabolites in dormant buds of two different persimmon genotypes, 'Taiwanshoshi' and 'Jiro', grown in the Japanese temperate climate. 'Taiwanshoshi' is a non-dormant Japanese persimmon adapted to the Taiwanese sub-tropical climate and 'Jiro' is a dormant-type Japanese persimmon. The results showed that 'Taiwanshoshi' did not enter endodormancy whereas 'Jiro' was endodormant in November and then released from endodormancy at the end of December. The ABA levels in both genotypes decreased from November to spring, with lower concentrations in 'Taiwanshoshi' than in 'Jiro' at all time points. The content of the ABA catabolite phaseic acid (PA) increased during endodormancy release of 'Jiro', while the PA content was lower during the same period in 'Taiwanshoshi'. These results suggested that ABA catabolic activity was enhanced during endodormancy release in the process of persimmon adaptated to the temperate zone. Taken together, these results indicate that ABA metabolism could be involved in endodormancy release in Diospyros spp.
Iwasa, H., Yamane, H., Gao-Takai, M., Oikawa, A. and Tao, R. (2018). Possible involvement of abscisic acid metabolism in endodormancy release in persimmon (Diospyros kaki). Acta Hortic. 1208, 287-290
ABA, bud break, dormancy, LC-MS/MS, phaseic acid (PA)