The phytotoxicity of non-protein amino acids beta-N-methylamine-L-alanine and meta-tyrosine against cyanobacteria and microalgae

Abstract

Algae and cyanobacteria synthesize various non-protein amino acids, whose biological functions and mechanisms of action still remain insufficiently studied. Some non-protein amino acids synthesized by plants and microalgae such as beta‑N‑methylamino‑L‑alanine (BMAA) and meta‑tyrosine (m‑tyrosine) exhibit strong allelopathic effects on the growth and development of plants, algae, and cyanobacteria. The phytotoxicity of these amino acids has attracted attention toward them as potential bioherbicides. Proteomics, transcriptomics, and biophysical methods used in photosynthesis research have enabled the identification of key biological effects of BMAA and m‑tyrosine on cyanobacterial and microalgal cells. Both amino acids alter the expression of proteins involved in photosynthesis, ribosomal proteins, amino acid metabolism enzymes, oxidative stress related proteins, chaperones, cell division proteins, and numerous other proteins whose function remains unknown. Research on the specific mechanisms of action of these molecules on various stages of photosynthesis is still in its infancy. This review aim is to draw attention of algologists, microbiologists, and biophysicists to the phytotoxic effect of non–protein amino acids on cyanobacteria and microalgae cells in order to encourage further in-depth experimental study of their mechanisms of action.