Reactive oxygen species and nitric oxide are involved in polyamine-induced growth inhibition in wheat plants

RECALDE L; VÁZQUEZ A; GROPPA MD; BENAVIDES MP

PROTOPLASMA

SPRINGER WIEN

Lugar: Viena; Año: 2018

0033-183X

Polyamines (PAs) produce H2O2 and nitric oxide (NO) during their normal catabolism and modulate plant growthand development. To explore the biochemical basis of PAs-induced growth inhibition in Triticum aestivum L seedlings, we examined the role of O2·-, H2O2 or NO in shoot and root development. Although all PA treatmentsresulted in a variable reduction of root and shoot elongation, spermine (Spm) caused the greater inhibition in asimilar way to that observed with the NO donor, sodium nitroprusside (SNP). In both cases, O2·- production wascompletely blocked whereas H2O2 formation was high in the root apex under SNP or Spm treatments. Catalaserecovered root and shoot growth in SNP but not in Spm-treated plants, revealing the involvement of H2O2 in SNProot length reduction. The addition of the NO scavenger, cPTIO, restored root length in SNP- or Spm-treated plants,respectively, and partially recovered O2·- levels, compared to the plants exposed to PAs or SNP without cPTIO. Astrong correlation was observed between root growth restoration and O2·- accumulation after treating roots with SNP+ aminoguanidine, a diamine oxidase inhibitor, and with SNP + 1,8-diaminoctane, a polyamine oxidase inhibitor,confirming the essential role of O2·- formation for root growth and the importance of the origin and level of H2O2.The differential modulation of wheat growth by PAs through reactive oxygen species or NO is discussed.