Immunity priming uncouples the growth-defense tradeoff in tomato

Abstract

AbstractLacking an adaptive immune system, plants have developed an array of mechanisms to protect themselves against pathogen invasion. The deployment of defense mechanisms is imperative for plant survival, however, defense activation can come at the expense of plant growth, leading to the “growth-defense trade-off” phenomenon. Following pathogen exposure, plants can develop resistance to further attack. This is known as induced resistance, or priming. Here, we investigated the growth-defense trade-off, examining how defense priming affects tomato development and growth. We found that defense priming can promote, rather than inhibit, plant development. Using defense pathway mutants, we found that defense priming and growth tradeoffs can be uncoupled, with growth and defense being positively correlated. We found that cytokinin response is activated during induced resistance, and is required for the observed growth and disease resistance resulting from resistance activation. Taken together, our results suggest that growth promotion and induced resistance can be co-dependent, and that defense priming can, within a certain developmental window, not necessitate a trade-off on growth, but rather, encourage and drive developmental processes and promote plant yield.Summary statementGrowth-defense tradeoffs in plants result in loss of yield. Here, we demonstrate that immunity priming in different pathways uncouples this tradeoff and allows for disease resistant plants with robust growth.