Betacyanin accumulation in the leaves of C3 halophyte Suaeda salsa L. is induced by watering roots with H2O2

Seeds, 5-day and 10-day-old seedlings of C3 halophyte Suaeda salsa were watered, sprayed and infiltrated with 0, 0.10%, 0.33% and 1.00% hydrogen peroxide (H2O2) solution to examine whether H2O2 is involved in the betacyanin accumulation. H2O2 treatments led to the most significant betacyanin accumulation in the shoots of Suaeda salsa seedlings when seeds were watered with H2O2 solution. The increase of betacyanin content was the highest and that of H2O2 content was the lowest in leaves, while the increase of betacyanin content was the lowest and that of H2O2 content was the highest in roots of seedlings obtained from seeds watered with H2O2 solution. When leaves of 5-day and 10-day-old seedlings were sprayed and infiltrated with H2O2 solution, the H2O2 content was enhanced significantly, but the increase of betacyanin content was not notable in leaves, and the content of betacyanin and H2O2 was also at a lower level in roots. The H2O2 content in organs of Suaeda salsa seedlings was not proportional to betacyanin content, and the betacyanin accumulation in leaves was correlated with the H2O2 production in roots rather than that in leaves and stems. These results suggested that the oxidative stress signal leading to betacyanin production in H2O2 treatments may be perceived by roots initially, then the signal was transferred to leaves; the signal transduction was performed and betacyanin accumulation was induced in leaves of Suaeda salsa.