The IBI1 Receptor of β-Aminobutyric Acid Interacts with VOZ Transcription Factors to Regulate Abscisic Acid Signaling and Callose-Associated Defense

Abstract

External and internal signals can prime the plant immune system for a faster and/or stronger response to pathogen attack. β-aminobutyric acid (BABA) is an endogenous stress metabolite that induces broad-spectrum disease resistance in plants. BABA perception in Arabidopsis is mediated by the aspartyl tRNA synthetase IBI1, which activates priming of multiple immune responses, including callose-associated cell wall defenses that are under control by abscisic acid (ABA). However, the immediate signaling components after BABA perception by IBI1, as well as the regulatory role of ABA therein, remain unknown. Here, we have studied the early signaling events controlling IBI1-dependent BABA-induced resistance (BABA-IR), using untargeted transcriptome and protein interaction analyses. Transcriptome analysis revealed that IBI1-dependent expression of BABA-IR against the biotrophic oomycete Hyaloperonospora arabidopsidis is associated with suppression of ABA-inducible abiotic stress genes. Protein interaction studies identified the VOZ1 and VOZ2 transcription factors (TFs) as IBI1-interacting partners, which are transcriptionally induced by ABA but suppress pathogen-induced expression of ABA-dependent genes. Furthermore, we show that VOZ TFs require nuclear localization for their contribution to BABA-IR by mediating augmented expression of callose-associated defense. Collectively, our study indicates that the IBI1-VOZ signaling module channels pathogen-induced ABA signaling toward cell wall defense while simultaneously suppressing abiotic stress-responsive genes.

A single amino acid transporter controls the uptake of priming-inducing beta-amino acids and the associated trade-off between induced resistance and plant growth

“…2A-B). Since RBH-IR against Hpa in Arabidopsis is associated with augmented effectiveness of callose-rich papillae (Buswell et al, 2018), we quantified the effectiveness callose-mediated cell wall defence at 3 dpi, as detailed previously (Schwarzenbacher et al, 2020). All original iri lines consistently lacked RBH-IR and concomitantly failed to augment callose-mediated defence upon RBH treatment (Fig.…”

The DC1 domain protein BINUCLEATE POLLEN is required for pollen development in Arabidopsis thaliana

“…VOZ1 and VOZ2 are transcription factors that belong to the NAC transcription factor family, and were reported as involved in the control of flowering time (Celesnik et al, 2013; Yasui and Kohchi, 2014), either through the binding of PhyB (Yasui et al, 2012), Flowering Locus C (Mimida et al, 2011) or Constans (Koguchi et al, 2017; Kumar et al, 2018). VOZ proteins were also related to biotic and abiotic stress responses (Nakai et al, 2013; Song et al, 2018; Schwarzenbacher et al, 2020; Wang et al, 2021). VOZ1 and VOZ2 were proved to be functionally redundant, as single mutants for each gene showed normal phenotypes, but voz1voz2 double mutants displayed phenotypic defects (Yasui et al, 2012; Celesnik et al, 2013; Nakai et al, 2013; Kumar et al, 2018).…”

β-Aminobutyric Acid Induced Resistance against Alternaria Fruit Rot in Apple Fruits

“…Previous studies showed that BABA induces a variety of defense mechanisms, including production of phenolics, ROS, PR proteins, callose, lignin and more, depending on the host–pathogen system [ 21 , 25 , 34 , 35 , 36 , 37 ]. In a recent study, Schwarzenbacher et al [ 38 ] showed that BABA interacts with VOZ transcription factors to regulate abscisic acid signaling and callose-associated defense against downy mildew in Arabidopsis. The reactions of apple tissue to BABA warrants a special study.…”