Type-A response regulators negatively mediate heat stress response by altering redox homeostasis in Arabidopsis

Abstract

Besides the long-standing role of cytokinins (CKs) as growth regulators, their current positioning at the interface of development and stress responses is coming into recognition. The current evidence suggests the notion that CKs are involved in heat stress response (HSR), however, the role of CK signaling components is still elusive. In this study, we have identified a role of the CK signaling components type-A Arabidopsis response regulators (ARRs) in HSR in Arabidopsis. The mutants of multiple type-A ARR genes exhibit improved basal and acquired thermotolerance and, altered response to oxidative stress in our physiological analyses. Through proteomics profiling, we show that the type-A arr mutants experience a ‘stress-primed’ state enabling them to respond more efficiently upon exposure to real stress stimuli. A substantial number of proteins that are involved in the heat-acclimatization process such as the proteins related to cellular redox status and heat shock, are already altered in the type-A arr mutants without a prior exposure to stress conditions. The metabolomics analyses further reveal that the mutants accumulate higher amounts of α-and γ-tocopherols, which are important antioxidants for protection against oxidative damage. Collectively, our results suggest that the type-A ARRs play an important role in heat stress response by affecting the redox homeostasis in Arabidopsis.

Responses to abiotic and biotic stresses - from the cellular level to fruit development - contributions of the Czech Centre for Experimental Plant Biology

“…These results position CK as a modulator of sulphur uptake, assimilation and remobilisation in plant defence and as a putative regulator of ROS homeostasis (Pavlů et al 2022). The role in the regulation of ROS metabolism was confirmed in experiments using mutants with negative components of the CK signalling pathway (type-A ARRs), which exhibited enhanced heat stress tolerance associated with the accumulation of enzymes of ROS metabolism, including glutathione peroxidase, glutathione S-transferases, and superoxide dismutase (Jindal et al 2022).…”

Genome‐wide identification and expression analysis of SlRR genes in response to abiotic stress in tomato

“…2014; Jindal et al . 2022; Rehman et al . 2022), we propose a complete model of RR response to stress, depicting a transcriptional response network (Fig.…”

“…It has been assumed that RRs affect stress and hormone signal regulation. Based on prior studies and our analysis (Kurepa et al 2014;Jindal et al 2022;Rehman et al 2022), we propose a complete model of RR response to stress, depicting a transcriptional response network (Fig. 7).…”

Lack of Purple Acid PhosphataseSlPAP26bcompromises the phosphorus starvation response in tomato independent of SlPHR1 and SlPHL1

“…N2 and all the samples were lyophilized and subsequently used for proteome analysis by LC/MS. Total protein extracts were prepared as previously described (Jindal et al, 2022) and portions of samples corresponding to 5 µg of peptide were analyzed by nanoflow reverse-phase liquid chromatography-mass spectrometry using a 15 cm C18 Zorbax column (Agilent), a Dionex Ultimate 3000 RSLC nano-UPLC system, and the Orbitrap Fusion Lumos Tribrid Mass Spectrometer equipped with a FAIMS Pro Interface. All samples were analyzed using alternating FAIMS compensation voltages of −40, −50, and −75 V. The measured spectra were recalibrated, filtered (precursor mass-350-5000 Da; S/N threshold-1.5), and searched against the ITAG4.1 (retrieved from the Sol Genomics Network, https://solgenomics.net/ftp//genomes/Solanum_lycopersicum/annotation/ITAG4.1_release/) and common contaminants databases using Proteome Discoverer 2.5 (Thermo, algorithms SEQUEST and MS Amanda (Dorfer et al, 2014) .…”