Preparing to fight back: generation and storage of priming compounds

Abstract

Immune-stimulated plants are able to respond more rapidly and adequately to various biotic stresses allowing them to efficiently combat an infection. During the priming phase, plant are stimulated in absence of a challenge, and can accumulate and store conjugates or precursors of molecules as well as other compounds that play a role in defense. These molecules can be released during the defensive phase following stress. These metabolites can also participate in the first stages of the stress perception. Here, we report the metabolic changes occuring in primed plants during the priming phase. β-aminobutyric acid (BABA) causes a boost of the primary metabolism through the tricarboxylic acids (TCA) such as citrate, fumarate, (S)-malate and 2-oxoglutarate, and the potentiation of phenylpropanoid biosynthesis and the octodecanoic pathway. On the contrary, Pseudomonas syringae pv tomato (PstAvrRpt2) represses the same pathways. Both systems used to prime plants share some common signals like the changes in the synthesis of amino acids and the production of SA and its glycosides, as well as IAA. Interestingly, a product of the purine catabolism, xanthosine, was found to accumulate following both BABA- and PstAvrRpt2-treatement. The compounds that are strongly affected in this stage are called priming compounds, since their effect on the metabolism of the plant is to induce the production of primed compounds that will help to combat the stress. At the same time, additional identified metabolites suggest the possible defense pathways that plants are using to get ready for the battle.

The Proteasome Acts as a Hub for Plant Immunity and Is Targeted by Pseudomonas Type III Effectors

“…The mounting of SAR requires the generation of signal in locally infected leaves, which is transmitted subsequently to systemic tissue, where it is perceived and confers a primed state that enables a faster and stronger defense response upon a secondary infection (Conrath et al, 2015). The exact nature of the signal(s) involved in this process is currently up for debate; however, it is proposed that several hormonal pathways, such as SA, ethylene, auxin, and jasmonic acid, play roles in SAR (Pastor et al, 2014). Because of its involvement in nearly all aspects of hormonal signaling, it appears reasonable to assume that the proteasome could play a critical role for the execution of the different phases of priming.…”

Advances in induced resistance by natural compounds: towards new options for woody crop protection

“…Plants have the ability to perceive certain attacks and initiate responses accordingly (Pritchard and Birch, 2014). When a pathogen is recognized, the speed and accuracy with which the plant cell can mobilize its defenses often determine if the plant will resist the attack (Hammond-Kosack and Parker, 2003;Pastor et al, 2014).…”

Evaluación De La Respuesta Fisiológica Frente a Distintos Niveles De Estrés Hídrico en Portainjerto S De Aguacate Susceptibles a Rosellinia Necatrix

“…Si bien, pueden existir diferencias dependiendo de la naturaleza del estímulo, muchos de los mecanismos de defensa de la planta son comunes frente a ambos tipos de estímulos. Los mecanismos de `priming´ se basan en que las plantas pueden acumular productos de genes de defensa de forma transitoria o permanente adquiriendo así un estado de pre-defensa o una resistencia inducida que les permite responder más rápido y de forma más eficaz cuando se ven sometidas de nuevo a estrés (Conrath et al 2006, Pastor et al 2014. Trabajos previos han puesto de manifiesto que muchas de las respuestas observadas frente al ataque de patógenos son comunes a muchos de los mecanismos de respuesta frente al estrés hídrico (Fleishmann et al 2005;Martínez-Ferri et al 2016).…”