Inhibition of abscisic acid biosynthesis affects carotenoid accumulation in satsuma mandarin fruit

Fruit coloration is one of the important factors determining the fruit quality in satsuma mandarin (Citrus unshiu Marc.). We investigated the effects of an abscisic acid (ABA) biosynthesis inhibitor, i.e., nordihydroguaiaretic acid (NDGA), on the endogenous levels of ABA, total chlorophyll, total carotenoids, and sugars in satsuma mandarin fruits. ‘Miyagawa-wase’ fruits on the tree were sprayed with 1 mM NDGA at 145 days after full bloom.
This NDGA treatment significantly reduced the endogenous ABA content at 5 days after treatment (DAT). The total carotenoid content in the NDGA-treated fruit was significantly increased at 11, 21, and 33 DAT. No significant differences between the NDGA-treated and untreated controls were observed for the total chlorophyll and sugar contents.
These results suggest that treating satsuma mandarin fruit with NDGA may promote carotenoid accumulation by inhibiting the biosynthesis of ABA without affecting the fruit’s chlorophyll and sugar levels.

XV International Citrus Congress

H. Tomiyama, M. Shingu, J. Abe, H. Fujisawa

satsuma mandarin, carotenoid, chlorophyll, ABA, NDGA

https://doi.org/10.17660/ActaHortic.2026.1448.47