Overexpression of adenosine 5′-monophosphate deaminase increased umami substance—Inosine 5′- mononucleotide and promoted Neopyropia yezoensis quality

Abstract

Precision molecular breeding technology plays an important role in improving the yield and quality of cultivated marine crops. In this study, we aimed to improve the quality of Neopyropia yezoensis, one of the important economic seaweeds. We constructed overexpression (OE)-, co-suppression (Ci)-, and RNAi (Ri)-type mutants of Nyampd (AMP deaminase of N. yezoensis), which could catalyze the decomposition of AMP into the umami substance inosine 5′- mononucleotide (IMP) through the genetic transformation system of N. yezoensis. Our results showed that the IMP content and growth rate of OE strain were significantly higher than those of wild type. In addition, in knockdown strains (Ci/Ri), a phenomenon similar to genetic compensation in knockout research occurred, i.e., the expression of Nyampd2 (isozyme of Nyampd) was significantly upregulated in Ri/Ci strains, and the IMP content increased in Ci/Ri strains. These results provide important knowledge for precise molecular breeding and genetic transformation research of N. yezoensis.