Immune Priming Triggers Cell Wall Remodeling and Increased Resistance to Halo Blight Disease in Common Bean

Abstract

The cell wall (CW) is a dynamic structure extensively remodeled during plant growth and under stress conditions, however little is known about its roles during the immune system priming, especially in crops. In order to shed light on such a process, we used the Phaseolus vulgaris-Pseudomonas syringae (Pph) pathosystem and the immune priming capacity of 2,6-dichloroisonicotinic acid (INA). In the first instance we confirmed that INA-pretreated plants were more resistant to Pph, which was in line with the enhanced production of H2O2 of the primed plants after elicitation with the peptide flg22. Thereafter, CWs from plants subjected to the different treatments (non- or Pph-inoculated on non- or INA-pretreated plants) were isolated to study their composition and properties. As a result, the Pph inoculation modified the bean CW to some extent, mostly the pectic component, but the CW was as vulnerable to enzymatic hydrolysis as in the case of non-inoculated plants. By contrast, the INA priming triggered a pronounced CW remodeling, both on the cellulosic and non-cellulosic polysaccharides, and CW proteins, which resulted in a CW that was more resistant to enzymatic hydrolysis. In conclusion, the increased bean resistance against Pph produced by INA priming can be explained, at least partially, by a drastic CW remodeling.

Plant Cell Wall Plasticity under Stress Situations

“…These modifications affect not only water retention in the cell wall but also its defense capacity against fungal pathogens. In line with this study, the fourth paper [ 4 ] demonstrates how the cell wall composition of Phaseolus vulgaris L. affects its enzymatic degradation, which ultimately has an effect on the host’s susceptibility to Pseudomonas syringae pv. phaseolicola .…”

With a Little Help from My Cell Wall: Structural Modifications in Pectin May Play a Role to Overcome Both Dehydration Stress and Fungal Pathogens

“…Given the large number of PMEs, it is highly plausible that only specific PMEs interact with MPs. The ability for the cell wall to remodel in response to viral pathogens is another critical component in defense, as it increases the strength of the cell wall [93]. This process has been found to be an important mechanism of defense against a variety of viral pathogens including halo blight disease in common bean, and Potato virus [93][94][95].…”

“…The ability for the cell wall to remodel in response to viral pathogens is another critical component in defense, as it increases the strength of the cell wall [93]. This process has been found to be an important mechanism of defense against a variety of viral pathogens including halo blight disease in common bean, and Potato virus [93][94][95]. PMEI and PME have both been found to mediate cell wall remodeling [96,97].…”

Transcriptome Responses of Wild Arachis to UV-C Exposure Reveal Genes Involved in General Plant Defense and Priming

“…Moreover, when challenged by stressful conditions, plants protect themselves by altering cell wall properties and remodeling the architecture of its components, being certain changes specific to one type of stress [ 97 ]. The plant cell wall is a complex matrix of polysaccharides, structural glycoproteins, and secondary metabolites that dynamically react to pathogen attack and environmental changes and, therefore, emerges as an essential component of defense priming [ 98 , 99 ].…”