CPK28-NLP7 module integrates cold-induced Ca ²⁺ signal and transcriptional reprogramming in Arabidopsis

Abstract

Exposure to cold triggers a spike in cytosolic calcium (Ca 2+ ) that often leads to transcriptional reprogramming in plants. However, how this Ca 2+ signal is perceived and relayed to the downstream cold signaling pathway remains unknown. Here, we show that the CALCIUM-DEPENDENT PROTEIN KINASE 28 (CPK28) initiates a phosphorylation cascade to specify transcriptional reprogramming downstream of cold-induced Ca 2+ signal. Plasma membrane (PM)–localized CPK28 is activated rapidly upon cold shock within 10 seconds in a Ca 2+ -dependent manner. CPK28 then phosphorylates and promotes the nuclear translocation of NIN-LIKE PROTEIN 7 (NLP7), a transcription factor that specifies the transcriptional reprogramming of cold-responsive gene sets in response to Ca 2+ , thereby positively regulating plant response to cold stress. This study elucidates a previously unidentified mechanism by which the CPK28-NLP7 regulatory module integrates cold-evoked Ca 2+ signal and transcriptome and thus uncovers a key strategy for the rapid perception and transduction of cold signals from the PM to the nucleus.

CPK28 is a modulator of purinergic signaling in plant growth and defense

“…These previous observations provide support for our finding based on protein-protein interaction studies, which indicate direct interactions between CPK6 and CPK28 with P2K1 (Figure 3). CPKs impart various effects on plant growth, development, and responses to abiotic and biotic stresses, primarily through the phosphorylation of their target proteins (Atif et al, 2019;Ding et al, 2022;Huang et al, 2020;Monaghan et al, 2015;Wei et al, 2014;Zhao et al, 2021). While the first study characterizing CPK28 in Arabidopsis revealed its involvement in plant stem elongation and vascular development (Matschi et al, 2013), it has been shown its crucial role in immune signaling (Monaghan et al, 2014) and abiotic stress responses (Ding et al, 2022).…”

The OsNLP3/4‐OsRFL module regulates nitrogen‐promoted panicle architecture in rice

“…A novel function of OsNLP3/4 in panicle development NIN-LIKE PROTEINs are pivotal transcription factors for early N signaling, N fixation and cold stress responses and act as receptors of nitrate, as recently reported for AtNLP7 (Mu & Luo, 2019;Jiang et al, 2021;Ding et al, 2022;Liu et al, 2022). However, the regulation of NLPs in development has rarely been studied.…”

Subfamily C7 Raf-like kinases MRK1, RAF26, and RAF39 regulate immune homeostasis and stomatal opening inArabidopsis thaliana

“…RECEPTOR KINASE 4 (HERK4), WALL-ASSOCIATED KINASE 1 (WAK1), WAK2, and L-TYPE LECTIN RECEPTOR KINASE IV.1 (LECRK-IV.1) (Table S2). CPK28 is a multifunctional protein with roles in immune signaling (Monaghan et al, 2014(Monaghan et al, , 2015, vegetative-to-reproductive stage transition (Matschi et al, 2013(Matschi et al, , 2015, temperature stress responses (Hu et al, 2021;Ding et al, 2022b), and more (Jin et al, 2017;Ding et al, 2022a). The potential for CPK28 to associate with so many RKs and RLCKs at the plasma membrane may reflect this broad functionality.…”