Responsiveness and Adaptation to Salt Stress of the REDOX-RESPONSIVE TRANSCRIPTION FACTOR 1 (RRTF1) Gene are Controlled by its Promoter

Abstract

The REDOX RESPONSIVE TRANSCRIPTION FACTOR 1 (RRTF1) gene encodes a member of the ERF/AP2 transcription factor family involved in redox homeostasis. The RRTF1 gene shows tissue-specific responsiveness to various abiotic stress treatments including a response to salt stress in roots. An interesting feature of this response is an adaptation phase that follows its activation, when promoter levels revert to a base line level, even if salt stress is maintained. It is unclear if adaption is controlled by a switch in promoter activity or by changes in transcript levels. Here we show that the RRTF1 promoter is sufficient for the control of both activation and adaptation to salt stress. As constitutive expression of RRTF1 turned out to be detrimental to the plant, we propose that promoter-regulated adaptation evolved as a protection mechanism to balance the beneficial effects of short-term gene activation and the detrimental effects of long-term gene expression.

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

“…The copyright holder for this this version posted December 20, 2020. ; https://doi.org/10.1101/2020.12.18.423458 doi: bioRxiv preprint fer-4 and herk1the1-4 might also be responsible for their amplified susceptibility to salt. Recently it was reported that ectopic over expression of RRTF1 is detrimental to plant salt tolerance [42]. This is consistent with our observations, where the higher RRTF1 expression pattern described in both salt-treated fer-4 or herk1the1-4 is linked to the higher plant salt susceptibility (Figure 1D/S1D).…”

“…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).…”

Comparative genomic analysis of the PAL genes in five Rosaceae species and functional identification of Chinese white pear

“…Promoters regulate gene expression mainly at the transcriptional level and are coordinated by a variety of cis -acting elements and trans-acting factors (Soliman & Meyer, 2019). We discovered a great deal of hormone responsive cis -acting components in the upper reaches regulatory sequences of PbPAL s family members (Fig.…”

Genome-wide analysis of phenylalanine ammonia-lyase (PAL) gene family in five Rosaceae plants and expression analysis and functional identification of Chinese white pear

“…We also found that some families contain specific conservative motifs, which means that these specific conservative motifs may be necessary for the specific functions of the subgroup, such as motifs 20 to ClusterⅠfamily. Promoters regulate gene expression mainly at the transcriptional level and are coordinated by a variety of cis-acting elements and trans-acting factors (Soliman et al, 2019). We discovered a great deal of hormone responsive cis-acting components in the upper reaches regulatory sequences of PbPAL genes family members (Table S4).…”