Pattern recognition receptors confer plant salt tolerance via WRKY18/WRKY40 transcription factors

Abstract

172/175 words)Pattern recognition receptors (PRRs) bind microbe-and damage-associated molecular patterns (MAMPs/DAMPs, respectively) to enhance host immunity in animals and plants. Here, we report that PRRs also confer salt tolerance in the model plant Arabidopsis thaliana following recognition of cognate ligands, such as bacterial flagellin and EF-Tu and the endogenous Pep peptides. Pattern-triggered salt tolerance (PTST) requires the PRR-associated kinases BAK1 and BIK1, and the NADPH oxidase RBOHD. Transcriptome profiling reveals an inventory of PTST target genes, which increase or acquire salt responsiveness following an exposure to immunogenic patterns.In their regulatory DNA sequences, specific binding sites for a subset of WRKY transcription factors are over-represented. Accordingly, PTST requires WRKY40 and WRKY18, which activate salt tolerance-related genes but attenuate pathogen defenserelated genes, including the EDS1 immunity activator. PRR signaling leads to sustained WRKY40/WRKY18 accumulation under salt stress and utilizes both WRKYs for salt tolerance. The PRR-WRKY40/WRKY18 module also confers salt tolerance after challenge with non-pathogenic bacteria. Our findings give molecular insight into signaling plasticity underlying biotic-abiotic stress cross-tolerance in plants conferred by PRRs.

Pseudomonas simiae WCS417: star track of a model beneficial rhizobacterium

“…The spectrum of effectiveness of the biological control activity seems to be relatively unspecific, as besides the soil-borne fungal diseases mentioned above, WCS417 was demonstrated to control other soil-borne diseases, such as bacterial wilt, caused by Ralstonia solanacearum (Ran et al 2005) and the nematode Xiphinema index (Canchignia et al 2017). In a recent study, colonization of the roots of peppermint (Mentha piperita) by WCS417 improved the antioxidant status of plants grown under drought stress leading to enhanced drought tolerance (Chiappero et al 2019), and in the model plant Arabidopsis (Arabidopsis thaliana) it improved salt tolerance (Loo et al 2020). Hence, WCS417 emerged as a versatile biocontrol agent with capacities that enable it to suppress various soilborne pathogens in a wide range of plant species, and to improve tolerance against abiotic stresses.…”

Comparative Transcriptome and Metabolome Analysis of Resistant and Susceptible Piper Species Upon Infection by the Oomycete Phytophthora Capsici

“…This is one of the most diverse families of transcriptional regulators in plants, and its members are essential components of signaling webs that control a variety of plant activities (Rushton et al, 2010 ); they comprise key plant stress response genes and are involved in multiple immune regulation processes, including both ETI and PTI. WRKY TFs have been reported to promote secondary metabolite synthesis, enhance plant salt tolerance, participate in response to fungus infection (Loo et al, 2020 ), and contribute to bacterial resistance. For example, overexpression of OsWRKYL3 in rice can increase resistance to bacterial blight and rice blast, and it contributes to the disease resistance response mediated by the major resistance factor Xa3/Xa26 (Qiu et al, 2007 ).…”

Arabidopsis root responses to salinity depend on pectin modification and cell wall sensing

“…To investigate whether the lack of FER or HERK1/THE1-4 had an effect on salt-induced gene expression levels, we selected three salt-induced marker genes [17], [40]- [42] and checked their expression in response to salt application.…”

“…We chose ProPEP3, WRKY40 and RRTF1 because they are strongly induced within 1 h from salt application and because they have been described responsive to a wide number of salt dependent modifications, like cell wall changes, ABAdependent signaling and reactive oxygen species (ROS) [17], [40]- [42] (Table S2). We treated wt, fer-4 and herk1the1-4 seedlings for 1 h and found that the expression level of salt responsive genes was higher in response to salt in the mutant lines when compared to the wt controls ( Figure 1D).…”

“…To investigate whether the lack of FER or HERK1/THE1-4 had an effect on salt-induced gene expression levels, we selected three salt-induced marker genes (Engelsdorf et al, 2018;Loo et al, 2020;Nakaminami et al, 2018;Soliman and Meyer, 2019) and checked their expression in response to salt application. We chose ProPEP3, WRKY40 and RRTF1 because they are strongly induced within 1 h from salt application and because they have been described responsive to a wide number of salt dependent modifications, like cell wall changes, ABA-dependent signaling and reactive oxygen species (ROS) (Engelsdorf et al, 2018;Loo et al, 2020;Nakaminami et al, 2018;Soliman and Meyer, 2019) (Table S2).…”