The THO/TREX Complex Active in Alternative Splicing Mediates Plant Responses to Salicylic Acid and Jasmonic Acid

Abstract

Salicylic acid (SA) and jasmonic acid (JA) are essential plant immune hormones, which could induce plant resistance to multiple pathogens. However, whether common components are employed by both SA and JA to induce defense is largely unknown. In this study, we found that the enhanced disease susceptibility 8 (EDS8) mutant was compromised in plant defenses to hemibiotrophic pathogen Pseudomonas syringae pv. maculicola ES4326 and necrotrophic pathogen Botrytis cinerea, and was deficient in plant responses to both SA and JA. The EDS8 was identified to be THO1, which encodes a subunit of the THO/TREX complex, by using mapping-by-sequencing. To check whether the EDS8 itself or the THO/TREX complex mediates SA and JA signaling, the mutant of another subunit of the THO/TREX complex, THO3, was tested. THO3 mutation reduced both SA and JA induced defenses, indicating that the THO/TREX complex is critical for plant responses to these two hormones. We further proved that the THO/TREX interacting protein SERRATE, a factor regulating alternative splicing (AS), was involved in plant responses to SA and JA. Thus, the AS events in the eds8 mutant after SA or JA treatment were determined, and we found that the SA and JA induced different alternative splicing events were majorly modulated by EDS8. In summary, our study proves that the THO/TREX complex active in AS is involved in both SA and JA induced plant defenses.

Salicylic and Jasmonic Acid Synergism during Black Knot Disease Progression in Plums

“…However, the contradiction between JA and SA is not conserved in plants [ 49 ]. So far, several studies have shown the synergetic or neutral relationship between SA and JA pathways in several plant species [ 50 , 51 , 52 , 53 , 54 , 55 ]. However, unfortunately, the synergistic action of these two hormones has not received enough attention from the scientific community.…”

Decoding the molecular mechanism underlying salicylic acid (SA)‐mediated plant immunity: an integrated overview from its biosynthesis to the mode of action

“…In contrast to the above‐mentioned antagonistic interaction between SA and JA/ET in Arabidopsis and other dicots, the comprehensive defence relations between these two phytohormones are not always negative in monocots, such as rice (Sun et al 2021). For instance, JA facilitates the rice resistance to biotrophic pathogen Xanthomonas oryzae pv.…”

Lack of antagonism between salicylic acid and jasmonate signalling pathways in poplar

“…Several other studies have also suggested synergistic or neutral interactions between the SA and JA signalling pathways (Rost as et al, 2013;Lemari e et al, 2015;Betsuyaku et al, 2018;J. Chen et al, 2021;Sun et al, 2021). In poplar, NPR1 has reduced importance in SA signalling compared with in Arabidopsis (Xue et al, 2013), but the interaction between SA and JA signalling pathways in trees and other woody plant defences is not yet well understood.…”

“…In Arabidopsis , pathogen‐induced SA and SA receptors NPR3 and NPR4 can activate the JA signalling pathway required for the effector‐triggered immunity‐mediated hypersensitive response (Liu et al ., 2016). Several other studies have also suggested synergistic or neutral interactions between the SA and JA signalling pathways (Rostás et al ., 2013; Lemarié et al ., 2015; Betsuyaku et al ., 2018; J. Chen et al ., 2021; Sun et al ., 2021). In poplar, NPR1 has reduced importance in SA signalling compared with in Arabidopsis (Xue et al ., 2013), but the interaction between SA and JA signalling pathways in trees and other woody plant defences is not yet well understood.…”