Investigation of The Roles of Hydrogen Peroxide and NADPH Oxidase in The Regulation of Polyamine Metabolism in Maize Plants under Drought Stress Conditions

OpenAlex İngilizce

The relationship between hydrogen peroxide and polyamine metabolism and the role of NADPH oxidase (NOX) in this relationship under drought conditions has not yet been clarified. To reveal the relationship, expression levels of the genes in polyamine metabolism, such as arginine decarboxylase (ADC), agmatine aminohydrolase (AIH), spermidine synthase (SPDS), S-adenosyl methionine decarboxylase (SAMDC), diamine oxidase (DAO) and polyamine oxidase (PAO) were determined by RT PCR under drought stress combined with exogenous hydrogen peroxide (H2O2) and diphenyleneiodonium chloride (DPI) treatments in maize seedlings. Also, some basic stress parameters (leaf water potential, lipid peroxidation), polyamine levels (putrescine, spermidine, and spermine), and gene expression of NOX were measured under drought stress. Exogenous H2O2 induced polyamine contents by up-regulating polyamine-synthesizing genes and downregulating polyamine oxidizing genes. Moreover, when the NOX enzyme was inhibited by DPI, the polyamine metabolic pathway tended toward degradation rather than production. Exogenous H2O2 regulated polyamine metabolism to promote their synthesis, and NOX had a key role in this regulation.