Plants (Nov 2022)

ROS and RNS Alterations in the Digestive Fluid of <i>Nepenthes</i> × <i>ventrata</i> Trap at Different Developmental Stages

  • Agnieszka Wal,
  • Pawel Staszek,
  • Barbara Pakula,
  • Magdalena Paradowska,
  • Urszula Krasuska

DOI
https://doi.org/10.3390/plants11233304
Journal volume & issue
Vol. 11, no. 23
p. 3304

Abstract

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The carnivorous pitcher plant, Nepenthes × ventrata (Hort. ex Fleming = N. ventricosa Blanco × N. alata Blanco), produces passive traps containing digestive fluid. Although reactive oxygen species (ROS) in the fluid were detected in some pitcher plants, the participation of reactive nitrogen species (RNS) in the digestion process has not yet been examined. The aim of this work was to investigate the production of superoxide anion (O2•−), nitric oxide (NO) and peroxynitrite (ONOO−) levels in the digestive fluid of traps throughout organ development. We revealed the ROS and RNS occurrence in the digestive fluid, linked to the ROS-scavenging capacity and total phenolics content. In digestive fluid from the fed traps, NO emission was higher than in the fluid from the developed unfed pitcher. The concentration of nitrite (NO2−) decreased in the fluid from the fed traps in comparison to the unfed ones, pointing at NO2− as the key source of NO. The enhanced emission of NO was associated with lowered content of ONOO− in the fluid, probably due to lower production of O2•−. At the same time, despite a decline in total phenolics, the maximum ROS scavenging capacity was detected. In addition, ROS and RNS were noted even in closed traps, suggesting their involvement not only in digestion per se but also their action as signaling agents in trap ontogeny.

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