Induction of Fe(III)-Chelate Reductase Activity by Ethylene and Salicylic Acid in Iron-Deficient Peach Rootstock Explants

Abstract The possible involvement of ethylene in the regulation of the root plasma-membrane Fe(III)-chelate reductase was investigated, using explants from three peach rootstock [GF-677 (Prunus amygdalus × P. persica), Cadaman (P. persica × P. davidiana) and Myrobolan 29C (Prunus cerasifera)] grown in Murashige and Skoog (MS) medium deprived of iron (Fe). Two ethylene inhibitors, AgNO3 and salicylic acid (1, 10, and 20 μM), and two ethylene promotors, methionine and ethephon (1, 10, and 100 μM) were added in the culture medium. The AgNO3 (20 μM) inhibited ethylene production, whereas salicylic acid (20 μM), methionine, and ethephon enhanced it. Explants cultured in the MS medium containing Fe (+Fe) produced less ethylene than those grown without Fe (−Fe). With the exception of the 100 μM ethephon-treated explants the increase in ethylene production was accompanied by an increase in root Fe(III)-chelate reductase activity. Conversely, exposure to AgNO3 and salicylic acid (1 and 10 μM) had no effect on Fe(I...