A non-proteinogenic amino acid, β-tyrosine, accumulates in young rice leaves via long-distance phloem transport from mature leaves.

Shunta Sakamoto,Takanori Yoshikawa,M. Teraishi,N. Yoshinaga,K. Ochiai,Masaru Kobayashi,E. Schmelz,Y. Okumoto,N. Mori

Published 2022 in Bioscience, biotechnology and biochemistry

ABSTRACT

Oryza sativa L. ssp. japonica cv. Nipponbare produces a non-proteinogenic amino acid (3R)-β-tyrosine from L-tyrosine by tyrosine aminomutase (OsTAM1). However, physiological, and ecological function(s) of β-tyrosine have remained obscure. Often an improved understanding of metabolite localization and transport can aid in design of experiments to test physiological functions. In the current study, we investigated the distribution pattern of β-tyrosine in rice seedlings and found that β-tyrosine is most abundant in the youngest leaves. Based upon observations of high TAM1 activity in mature leaves, we hypothesized that β-tyrosine is transported from mature leaves to young leaves. Patterns of predominant mature synthesis and young leaf accumulation was supported by stable isotope studies using labeled β-tyrosine and the removal of mature leaves. Stem exudate analyses was also consistent with β-tyrosine transport through phloem. Thus, we identify young leaves as a key target in efforts to understand the biological function(s) of β-tyrosine in rice.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-28 of 28 references · Page 1 of 1