The red alga, Porphyra yezoensis is used for laver farming. In red algae including P. yezoensis, the most abundant pigments are phycobilins bound to phycobilisomes, light-harvesting complexes in chloroplast (Fig. 1). It is known that nutrient-deficiency induces the phycobilisome degradation, resulting bleaching (Fig. 2).

To develop stress resistant strains of in P. yezoensis, two research projects are proceeded in our laboratory.

• (1) To know molecular mechanism of laver bleaching, we are studying the expression of genes involved in phycobilisome degradation in P. yezoensis.
• (2) In seed plants, activation of some retrotransposons was successfully used for isolation of mutants and gene analysis.
  To develop a new genetic engineering tool of laver farming, we have isolated retrotransposons from P. yezoensis and are studying their expression regulatory mechanism.

We are also studying the regulation of the expression of genes involved in oxidative stress responses and secondary metabolite biosynthesis, using marine algae, moss plants and seed plants.