Search bioRxiv⌕ Search

Biology subjects

Valentova, O.

Publications and source records attributed to Valentova, O..

2 recordsLinked to original sources

Influence Of Salt Stress On The flg22 Induced ROS Production In Arabidopsis thaliana Leaves

In their natural habitats, plants have to cope with multiple stress factors triggering respective response pathways, leading to mutual interference. Our work aimed to study the effect of salt stress in combination with immune response triggered by microbe-associated molecular pattern (MAMP) in Arabidopsis thaliana Col-0 plants. We measured ROS production after treatment with flg22 and the influence of concomitant salt stress (NaCl and Na2CO3).The maximum combined effect of NaCl solution and flg22 on ROS production was achieved at 6 mM salt, which was almost 2 times higher than the single effect of MAMP. A similar maximum combined effect with Na2CO3 was observed at 10 mM concentration. High concentration of NaCl and Na2CO3 was accompanied with declining of ROS production, which was completely inhibited at 150 mM of NaCl and at 50 mM of Na2CO3.The immediate and long term (24 h) effect of NaCl on leaf tissue of Arabidopsis thaliana showed that the impact of salt stress on flg22induced ROS production probably did not affect the genetic aspects of the tissue response, but was associated with ionic and osmotic stresses. Experiments with mannitol, KCl and CaCl2 allowed to conclude that the observed effect was due to the ionic stress of the salt rather than the osmotic one.

physiology↗

Can Actin Depolymerization Actually Result In Increased Plant Resistance To Pathogens?

Introductory paragraphThe integrity of the actin cytoskeleton is essential for plant immune signalling1. Consequently, it is generally assumed that actin disruption reduces plant resistance to pathogen attack2-4. However, in a previous study, it was shown that actin depolymerisation triggers the salicylic acid (SA) signalling pathway5, which is interesting because increased SA is associated with enhanced plant resistance to pathogen attack6,7. Here, we attempt to resolve this seeming inconsistency by showing that the relationship between actin depolymerization and plant resistance is more complex than currently thought. We investigate the precise nature of this relationship using two completely different plant pathosystems: i) a model plant (Arabidopsis thaliana) and a bacterial pathogen (Pseudomonas syringae), and ii) an important crop (Brassica napus) and a fungal pathogen (Leptosphaeria maculans). We demonstrate that actin depolymerization induces a dramatic increase in SA levels and that the increased SA is biosynthesized by the isochorismate synthase pathway. In both pathosystems, this phenomenon leads to increased plant resistance.

plant biology↗