Sucrose non-fermenting 1-related protein kinase 2 (SnRK2): a family of protein kinases involved in hyperosmotic stress signaling

Abstract

Our understanding of plant adaptation to abiotic stresses, which include drought, salinity, non-optimal temperatures and poor soil nutrition, is limited, although significant strides have been made in identifying some of the gene players and signaling partners. Several protein kinases get activated in plants in response to osmotic stress and the stress hormone abscisic acid (ABA). Among these is a superfamily of sucrose non-fermenting protein kinase genes (SnRK2). This review focuses on the developments related to the activity, substrates, interacting proteins and gene regulation of SnRK2 gene family members. Reversible phosphorylation as a crucial regulatory mechanism turns out to be a rule rather than an exception in plant responses to abiotic stress. Nine out of thirteen bZIP transcription factors (ABI5/ABF/AREB family) share the recognition motif, R-Q-X-S/T, suggesting that likely SnRK2 kinases have a major role in regulating gene expression during hyperosmotic stress.

SUCROSE NONFERMENTING1-RELATED PROTEIN KINASE2.6, an Ortholog of OPEN STOMATA1, Is a Negative Regulator of Strawberry Fruit Development and Ripening

“…The SnRK2 family has been suggested to have evolved specifically for hyperosmotic stress signaling (Boudsocq et al, 2004;Umezawa et al, 2004;Kobayashi et al, 2005;Fujii et al, 2007;Shukla and Mattoo, 2008;Fujita et al, 2009). For example, Kobayashi et al (2005) identified 10 SnRK2 protein kinases encoded in rice (Oryza sativa), and all of these SnRK2s were specifically activated by osmotic stress at both the transcriptional and the posttranscriptional levels.…”

“…SUCROSE NONFERMENTING1-RELATED PROTEIN KINASES2 (SnRK2s) are a family of plant-specific protein kinases implicated in stress and abscisic acid (ABA) signaling (Yoshida et al, 2002;Boudsocq et al, 2004;Kobayashi et al, 2005;Umezawa et al, 2004;Fujii et al, 2007;Shukla and Mattoo, 2008;Fujita et al, 2009;Hirayama et al, 2010;Kulik et al, Figure 1. Phylogenetic analysis of SnRK2.6 proteins.…”

“…fleshy fruit arose as a mechanism to facilitate seed dispersal and promote the survival of the plant in everchanging environments (Coombe, 1976), the regulation of fruit ripening by external cues is of great importance in the plant's adaptation to environmental stresses (Shulaev et al, 2008). Given that OST1 is a critical mediator of ABA signaling, and that SnRK2s are tightly associated with plant stress signaling (Yoshida et al, 2002;Boudsocq et al, 2004;Umezawa et al, 2004;Kobayashi et al, 2005;Fujii et al, 2007;Shukla and Mattoo, 2008;Fujita et al, 2009;Hirayama et al, 2010;Kulik et al, 2011;Hrabak et al, 2013), we sought to identify the ortholog of OST1 in strawberry and to evaluate whether this protein contributes to the regulation of strawberry fruit development and ripening, and particularly whether it modulates fruit ripening in response to temperature.…”

MicroRNAs and targets in senescent litchi fruit during ambient storage and post-cold storage shelf life

“…It has been reported that cellular energy status plays a vital role in regulating litchi fruit senescence and browning [ 5 ]. As an energy regulator, snf1-related kinase 1 (SnRK1) has been reported to be involved in the global regulation of carbon and nitrogen metabolism, further affecting the cellular energy level [ 6 , 7 ]. Moreover, pathogen infection usually induces fruit senescence and browning.…”

Identification of major QTLs associated with agronomical traits and candidate gene mining in soybean

“…In addition, SnRK2 and SnRK3 are directly related to abscisic acid signal transduction [48]. Glyma.01G019400, Glyma.08G207900 and Glyma.08G273500 were annotated as indole-3-acetic acid-inducible genes; indole-3acetic acid is a ubiquitous endogenous auxin in plants.…”