Salicylic acid may indirectly influence the photosynthetic electron transport |
| |
Authors: | Janda Katalin Hideg Eva Szalai Gabriella Kovács László Janda Tibor |
| |
Affiliation: | Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, 6701 Szeged, POB 521, Hungary. |
| |
Abstract: | Salicylic acid (SA) is a phenolic phytohormone with important roles in plant development, transpiration, endogenous signaling and defense against pathogens. One of the pathways of SA biosynthesis is located in the chloroplasts. The aim of the present work was to investigate the possible regulatory effects of SA on photosynthetic electron transport processes. Here we show that SA also affects leaf photosynthesis, via inducing stomatal closure and also by slowing down Photosystem II (PS II) electron transport. Photosynthetic CO? incorporation and stomatal conductivity (measured with an infrared gas analyzer) were much lower in SA-infiltrated tobacco leaves than in untreated or water-infiltrated controls. PS II electron transport (calculated from PAM chlorophyll fluorescence data) was more sensitive to SA than Photosystem I (PS I) (measured with far red absorption). Direct probing of PS II charge separation and stabilization (measured with thermoluminescence), however, showed that these events were less affected in isolated thylakoid membranes than in leaves, suggesting that the effect of SA on PS II is indirect and different from similar effects of phenolic herbicides. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|