High levels of expression of multiple enzymes in the Smirnoff-Wheeler pathway are important for high accumulation of ascorbic acid in acerola fruits

ABSTRACT

Acerola fruits contain abundant ascorbic acid (AsA). The gene expression levels of three upstream enzymes in the primary AsA biosynthesis pathway were correlated with AsA contents in the fruits of two acerola cultivars. Multiple overexpression of the enzymes increased AsA contents, suggesting their high expression is important for high AsA accumulation in acerola fruits and the breeding of AsA-rich plants.

Abbreviations: AsA: ascorbic acid; PMI: phosphomannose isomerase; PMM: phosphomannomutase; GMP: GDP-d-mannose pyrophosphorylase; GME: GDP-d-mannose 3ʹ,5ʹ-epimerase; GGP: GDP-l-galactose phosphorylase; GPP: l-galactose-1-phosphate phosphatase; GDH: l-galactose dehydrogenase; GLDH: l-galactono-1,4-lactone dehydrogenase

KEYWORDS:

• acerola
• ascorbic acid
• multiple expressions
• the Smirnoff-Wheeler pathway

Acknowledgments

This work was supported by [The Ministry of Education, Culture, Sports, Science and Technology] under Grant-in-Aid for Scientific Research (C) [15K07394 and 18K05620]. We thank to Dr. M. Yamamoto at Kagoshima University for providing acerola fruits.

Author contribution

M. Suekawa performed the experiments and wrote the paper. A. Inoue performed the experiments. E. Uchida and T. Koizumi conceived the original idea. Y. Fujikawa and T. Kondo and M. Esaka designed research and gave the advice of paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Ministry of Education, Culture, Sports, Science and Technology Grant-in-Aid for Scientific Research (C) [15K07394 and 18K05620].