Biology subjects

Krasensky-Wrzaczek, J.

Publications and source records attributed to Krasensky-Wrzaczek, J..

4 recordsLinked to original sources

bioRxiv2025

CYSTEINE-RICH RLK2 regulates development via callose synthase-dependent symplastic transport in Arabidopsis

CYSTEINE-RICH RECEPTOR-LIKE PROTEIN KINASEs (CRKs) play an important role in plant development and stress responses. One of the best described members of the Arabidopsis CRK family is CRK2, which was proposed as a crucial regulator of intercellular transport facilitated by plasmodesmata (PD). As intercellular channels allowing symplastic communication, PD-mediated transport is predominantly regulated by callose synthase (CALS)-mediated callose deposition. This process can impact not just the distribution of molecules between adjacent cells, but also the symplastic loading of vascular tissue, thereby influencing plant stress responses and developmental processes. Here we described the overlapping expression pattern of genes encoding phylogenetically closely related CALS1 and CALS3. Both CALSs were phosphorylated in vitro by CRK2, and the genetic interaction between genes encoding CRK2 and CALS1 or CALS3 revealed their impact on callose deposition, rosette growth, primary root length, and development, represented as a decreased number of true leaves. Importantly, we observed significant accumulation of starch in crk2 mutant plants, especially in developmentally older leaves, which was reverted by the independent introduction of cals1.5 and cals3.1 into the crk2 mutant background. The observed starch accumulation was accompanied by photosynthesis inhibition. We propose that the growth and developmental alterations of crk2 are caused by decreased phloem loading, which resulted in starch accumulation in source organs, and subsequent sink tissue starvation. Our results propose CRK2 as negative regulator of CALS1 and CALS3 regulating source to sink transport, which impacts plant growth and development.

plant biology↗

bioRxiv2025

CRK2 modulates flowering in Arabidopsis together with GLYCINE-RICH RNA BINDING PROTEIN 7 (GRP7)

Timely flowering is critical for the reproductive success of plants. Plants adjust flowering time through integration of multiple internal and environmental cues. A complex signalling system lies behind this integration, including multiple proteins like the GLYCINE-RICH RNA-BINDING PROTEIN 7 (GRP7), linked to the modulation of stress and flowering in Arabidopsis. Available data show the interaction between GRP7 and the receptor-like kinase CYSTEINE-RICH RECEPTOR-LIKE KINASE 2 (CRK2). Like GRP7, CRK2 plays multifaceted roles in the coordination of stress responses and development, but its role in development remains unclear. Phenotypic analyses of the crk2 and grp7-1 single mutants as well as the crk2/grp7-1 double mutant supported the interaction between CRK2 and GRP7. Moreover, exogenous gibberellic acid did not recover the rosette phenotype of crk2 mutants but as in sensitive plants, inhibited GA-biosynthesis transcripts. The pseudo insensitivity of crk2 mutant was recovered in the crk2/grp7-1 line pointing to a common role of CRK2 and GRP7 in the modulation of gibberellin signalling. Together, CRK2 and GRP7 integrate hormonal and spatial signals required for floral transition. These insights highlight a previously unrecognized layer of regulation in GA signalling and open new avenues to understand how membrane-localized kinases and RNA-binding proteins intersect to control developmental timing.

plant biology↗

bioRxiv2020

Arabidopsis Poly(ADP-ribose)-binding protein RCD1 interacts with Photoregulatory Protein Kinases in nuclear bodies

Continuous reprogramming of gene expression in response to environmental signals is required for plant survival in changing environment. One mechanism responsible for this is signaling through hub proteins that integrate external stimuli and transcriptional responses. RADICAL-INDUCED CELL DEATH1 (RCD1) functions as a nuclear hub protein, that interacts with a variety of transcription factors through its C-terminal RST domain and acts as a co-regulator of numerous stress responses in plants. Here, a previously unknown function for RCD1 as a novel plant poly(ADP-ribose) (PAR) reader protein is described. RCD1 localizes to specific locations inside the nucleus, in a PAR-dependent manner; its N-terminal WWE domain o binds PAR and together with the PARP-like domain determines its localization to nuclear bodies (NBs), which is prevented by inhibition of PAR synthesis. RCD1 also interacts with Photoregulatory Protein Kinases (PPKs) that co-localize with RCD1 in the NBs. The PPKs, that have been associated with circadian clock, abscisic acid, and light signaling pathways, phosphorylate RCD1 at multiple sites in the intrinsically disordered region between the WWE and PARP-like domains. This affects its stability and functions in the nucleus and1 provides a mechanism where the turnover of a PAR-binding transcriptional co-regulator is controlled by nuclear protein kinases.

plant biology↗

bioRxiv2018

RCD1 Coordinates Chloroplastic and Mitochondrial Electron Transfer through Interaction with ANAC Transcription Factors

Signaling from chloroplasts and mitochondria, both dependent on reactive oxygen species (ROS), merge at the nuclear protein RADICAL-INDUCED CELL DEATH1 (RCD1). ROS produced in the chloroplasts affect the abundance, thiol redox state and oligomerization of RCD1. RCD1 directly interacts in vivo with ANAC013 and ANAC017 transcription factors, which are the mediators of the ROS-related mitochondrial complex III retrograde signa and suppresses activity of ANAC013 and ANAC017. Inactivation of RCD1 leads to increased expression of ANAC013 and ANAC017-regulated genes belonging to the mitochondrial dysfunction stimulon (MDS), including genes for mitochondrial alternative oxidases (AOXs). Accumulating AOXs and other MDS gene products alter electron transfer pathways in the chloroplasts, leading to diminished production of chloroplastic ROS and increased protection of photosynthetic apparatus from ROS damage. RCD1-dependent regulation affects chloroplastic and mitochondrial retrograde signaling including chloroplast signaling by 3-phosphoadenosine 5-phosphate (PAP). Sensitivity of RCD1 to organellar ROS provides feedback control of nuclear gene expression.

plant biology↗