CBF4/DREB1D represses XERICO to attenuate ABA, osmotic and drought stress responses in Arabidopsis

Abstract

SUMMARY Water stress can severely impact plant growth, productivity and yield. Consequently, plants have evolved various strategies through which they can respond and adapt to their environment. XERICO (XER) is a stress‐responsive RING E3 ubiquitin ligase that modulates abscisic acid (ABA) levels and promotes drought tolerance when overexpressed. To better understand the biological role of XER in stress responses, we characterized a xer‐1 hypomorphic mutant and a CRISPR/Cas9‐induced xer‐2 null mutant in Arabidopsis. Both xer mutant alleles exhibited increased drought sensitivity, supporting the results from overexpression studies. Furthermore, we discovered that both xer mutants have greater stomatal indices and that XER is expressed in epidermal cells, indicating that XER functions in the epidermis to repress stomatal development. To explore XER spatiotemporal and stress‐dependent regulation, we conducted a yeast one‐hybrid screen and found that CBF4/DREB1D associates with the XER 5′ untranslated region (5′‐UTR). We generated three cbf4 null mutants with CRISPR/Cas9 and showed that CBF4 negatively regulates ABA responses, promotes stomatal development and reduces drought tolerance, in contrast to the roles shown for XER. CBF4 is induced by ABA and osmotic stress, and localizes to the nucleus where it downregulates XER expression via the DRE element in its 5′‐UTR. Lastly, genetic interaction studies confirmed that xer is epistatic to cbf4 in stomatal development and in ABA, osmotic and drought stress responses. We propose that the repression of XER by CBF4 functions to attenuate ABA signaling and stress responses to maintain a balance between plant growth and survival under adverse environmental conditions.

Identification and Characterization of the AREB/ABF Gene Family in Three Orchid Species and Functional Analysis of DcaABI5 in Arabidopsis

“…Individual AREB/ABF s were also found targeted by specific TFs. For instance, DcaABI5 was predicted to be specifically targeted by 39 TFs among five AREB/ABF s from D. catenatum , and more detailed analysis showed that DcaABI5 was probably regulated by dehydration-responsive element-binding protein 1C (DREB1C, AT4G25470) and DERB1D (AT5G51990), two proteins involved in cold acclimation and drought tolerance [ 50 , 51 , 52 ]. Overall, the predicted TF regulatory network of the orchid AREB/ABF s implied their potential roles in growth development, stress response, and network associations.…”

The chromatin remodeller MdRAD5B enhances drought tolerance by coupling MdLHP1‐mediated H3K27me3 in apple

“…On the other hand, the expression of 246 DEGs with decreased DARs was repressed in MdRAD5B RNAi transgenic plants under dehydration conditions as compared with GL‐3 plants (Figure 4e ). Among these 466 DEGs, homologues of MdRCI2A , MdNF‐YB3 , MdXERICO , MdGBF3 , and MdABF2‐Like are positive regulators of drought tolerance (Kim et al ., 2004 ; Medina et al ., 2005 ; Ramegowda et al ., 2017 ; Sato et al ., 2019 ; Vonapartis et al ., 2022 ). The homologue of MdTSPO increases drought tolerance by enhancing ABA sensitivity (Guillaumot et al ., 2009 ), while the homologue of MdGIM2 decreases drought tolerance by negatively regulating ABA sensitivity (Liu et al ., 2019 ).…”

Comparative transcriptome analysis reveals the function of SlPRE2 in multiple phytohormones biosynthesis, signal transduction and stomatal development in tomato

“…ABA plays a crucial role in plant response to abiotic stresses such as drought and salinity Vonapartis, et al 2022). Under environmental stress conditions, the ABA biosynthesis is enhanced and the elevated ABA content induces seed dormancy, inhibits plant growth, minimizes water loss from transpiration, and induces stress-related gene expression (Bharath, et al 2021; Nakashima and Yamaguchi-Shinozaki 2013).…”