MOS1 functions closely with TCP transcription factors to modulate immunity and cell cycle in Arabidopsis

Abstract

These authors contributed equally to this work. SUMMARYEmerging evidence indicates a close connection between cell-cycle progression and the plant immune responses. In Arabidopsis, MODIFIER OF snc1-1 (MOS1) modulates a number of processes including endoreduplication and plant disease resistance, but the molecular mechanism underlying this modulation was not fully understood. Here, we provide biochemical and genetic evidence that TEOSINTE BRANCHED 1, CYCLOIDEA, PCF1 (TCP) transcription factors TCP15 and its homologues are mediators of MOS1 function in the immune response and are likely to be also involved in cell-cycle control. MOS1 and TCP proteins have a direct physical interaction. They both bind to the promoter of the immune receptor gene SUPRESSOR OF npr1-1, CONSTITUTIVE 1 (SNC1) and modulate its expression and consequently immune responses. MOS1 and TCP15 both affect the expression of cell-cycle genes D-type CYCLIN 3;1 (CYCD3;1), which may mediate the MOS1 function in cell-cycle modulation. In addition, CYCD3;1 overexpression upregulates immune responses, and SNC1 expression. This study investigated and revealed a role for MOS1 in transcriptional regulation through TCP15 and its homologues. This finding suggests the coordination of cell-cycle progression and plant immune responses at multiple levels.

TCP transcription factors interact with ZED1‐related kinases as components of the temperature‐regulated immunity

“…To verify this, we also generated the p35S::TCP15‐SRDX transgenic plants by fusing TCP15 with a modified EAR motif repression domain SRDX, which dominantly suppresses the activities of endogenous TCPs that function redundantly with TCP15 (Li et al, ). Similar to previous findings (Zhang et al, ), the transgenic p35S::TCP15‐SRDX plants exhibited an apparently retarded growth with autoimmune phenotype (Figure S3). These findings demonstrate that TCPs play an inhibitory role in governing plant immunity possibly by associating with ZRKs.…”

“…The fractionated nuclear and cytosolic proteins from transgenic pTCP15::TCP15-GFP and pTCP15::TCP15-GFP;zed1-D plants transferred from 18 into 25°C for indicated times were immunoblotted, and the Histone H3 (H3) and β-ACTIN (ACT) were used as the nuclear and cytosolic internal controls, respectively the p35S::TCP15-SRDX transgenic plants by fusing TCP15 with a modified EAR motif repression domain SRDX, which dominantly suppresses the activities of endogenous TCPs that function redundantly with TCP15 . Similar to previous findings (Zhang et al, 2018), the transgenic p35S::TCP15-SRDX plants exhibited an apparently retarded growth with autoimmune phenotype ( Figure S3). These findings demonstrate that TCPs play an inhibitory role in governing plant immunity possibly by associating with ZRKs.…”

“…Therefore, it is likely that the regulations of SNC1 by TCPs and/or ZRKs are complicated or at multiple layers in the absence and/or presence of pathogen, which possibly depends on the varied abundances of TCPs, ZRKs, and their interacting partners under different conditions. Indeed, a recent work also reported that TCP15 could interact with MOS1 (MODIFIER OF SNC1) to promote the expression of SNC1 in a MOS1‐dependent manner under normal growth condition, though an elevated PR1 expression was still observed in their TCP15‐SRDX plants (Zhang et al, ). Nevertheless, our findings that TCPs and ZRKs are responsive to ambient temperature and the autoimmune phenotype of snc1‐2 could be inhibited by overexpressed TCP15 or ZED1 strongly suggest that the nuclear TCP‐ZRK‐modulated immunity might represent a possible guarding mechanism in response to the ambient temperature and/or other abiotic stimuli.…”

Quantitative Proteomic Analysis of Alligator Weed Leaves Reveals That Cationic Peroxidase 1 Plays Vital Roles in the Potassium Deficiency Stress Response

“…TCP15 from Arabidopsis acts as a repressor of anthocyanin accumulation under high light intensity by modulating the expression of transcription factors involved in the induction of anthocyanin biosynthesis genes [39]. Subsequent research suggests that TCP15 modulates auxin and cytokinin levels, the immune response, and the cell cycle in Arabidopsis [40,41]. In our study, one TCP15 was down-regulated, which may affect the expression of many target genes involved in cell cycle progression and the hormone levels in alligator weed leaf; therefore, TCP15 and its target genes should be the research focus of LK stress in the future.…”

HOS15 and HDA9 negatively regulate immunity through histone deacetylation of intracellular immune receptor NLR genes in Arabidopsis

“…The mechanisms for transcriptional control of NLR genes include alternative splicing, alternative polyadenylation, small RNA induced post-transcriptional regulation, and transcription factors controlled gene regulation (Lai & Eulgem 2018;Zhang et al, 2018). Recent evidences indicate that chromatin modifications and remodeling also are important for the expression of NLR genes including SNC1 Palma et al, 2010;Xia et al, 2013;Zou et al, 2014;Zou et al, 2017;Zhang et al, 2018). A number of positive regulators of SNC1 expression at the chromatin level have been reported.…”