Differences in photorespiration, glutamine synthetase and polyamines between fragmented and closed stands of Phragmites australis

László Erdei, Ferenc Horváth, Irma Tari, Attila Pécsváradi, Zsolt Szegletes, Sándor Dulai

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Physiological processes related to C and N metabolism were investigated in closed healthy, and fragmented die-back stands of Phragmites australis (Cav.) Trin. ex Steudel along the shores of Lake Balaton, Hungary. In the leaves, similar concentrations of total N and P, K+, Na+, Ca2+ and Mg2+ were found. However, higher concentrations of soluble proteins in the fragmented stand indicated alterations in N metabolism. In both types of stands, nitrate reductase (NR) activity was detectable only in the period of vegetative growth and it was higher in the fragmented than in the closed stands. Glutamine synthetase (GS) activity showed three-fold higher activities in the leaves from the fragmented stands compared to those in closed stands, indicating high substrate (NH3/NH4 +) availability. Polyamine concentrations were 4-10-fold higher in the leaves of the fragmented stands than in those of closed stands. Photosynthetic activity was nearly equal in both stands, however, photorespiration was about two-fold higher in the fragmented than in the closed stands. A linear correlation between photorespiration and GS activity indicated a causal relationship (R2 = 0.86). Stomatal conductance data suggest that the higher photorespiration in the fragmented stands could be the consequence of disturbed stomatal regulation. It is concluded that fragmented stands of Phragmites possess an altered C/N metabolism, due to high photorespiration and intensive N metabolism. The primary reason of the cascade of events is still not clear but apparently, these metabolic malfunctions accompany an accelerated die-back of Phragmites around Lake Balaton.

Original languageEnglish
Pages (from-to)165-176
Number of pages12
JournalAquatic Botany
Volume69
Issue number2-4
DOIs
Publication statusPublished - Jan 1 2001

Keywords

  • Die-back
  • Nitrate reductase
  • Photorespiration
  • Photosynthesis
  • Phragmites australis
  • Polyamines
  • Stomatal conductance

ASJC Scopus subject areas

  • Aquatic Science
  • Plant Science

Fingerprint Dive into the research topics of 'Differences in photorespiration, glutamine synthetase and polyamines between fragmented and closed stands of Phragmites australis'. Together they form a unique fingerprint.

  • Cite this