Distinct osmo-sensing protein kinase pathways are involved in signalling moderate and severe hyper-osmotic stress (original) (raw)
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FEBS Letters, 2002
Five Ca(2+)-independent protein kinases were rapidly activated by hypoosmotic stress, moderate or high hyperosmolarity induced by several osmolytes, sucrose, mannitol or NaCl. Three of these kinases, transiently activated by hypoosmolarity, recognised by anti-phosphorylated mitogen-activated protein (MAP) kinase antibodies, sensitive to a MAP kinase inhibitor and inactivated by the action of a tyrosine phosphatase, corresponded to MAP kinases. Using specific antibodies, two of the MAP kinases were identified as AtMPK6 and AtMPK3. The two other protein kinases, durably activated by high hyperosmolarity, did not belong to the MAP kinase family. Activation of AtMPK6 and AtMPK3 by hypoosmolarity depended on upstream protein kinases sensitive to staurosporine and on calcium influx. In contrast, these two transduction steps were not involved in the activation of the two protein kinases activated by high hyperosmolarity.
Journal of Experimental Botany, 2014
Dual-specificity mitogen-activated protein kinases kinases (MAPKKs) are the immediate upstream activators of MAPKs. They simultaneously phosphorylate the TXY motif within the activation loop of MAPKs, allowing them to interact with and regulate multiple substrates. Often, the activation of MAPKs triggers their nuclear translocation. However, the spatiotemporal dynamics and the physiological consequences of the activation of MAPKs, particularly in plants, are still poorly understood. Here, we studied the activation and localization of the Medicago sativa stress-induced MAPKK (SIMKK)-SIMK module after salt stress. In the inactive state, SIMKK and SIMK co-localized in the cytoplasm and in the nucleus. Upon salt stress, however, a substantial part of the nuclear pool of both SIMKK and SIMK relocated to cytoplasmic compartments. The course of nucleocytoplasmic shuttling of SIMK correlated temporally with the dual phosphorylation of the pTEpY motif. SIMKK function was further studied in Arabidopsis plants overexpressing SIMKK-yellow fluorescent protein (YFP) fusions. SIMKK-YFP plants showed enhanced activation of Arabidopsis MPK3 and MPK6 kinases upon salt treatment and exhibited high sensitivity against salt stress at the seedling stage, although they were salt insensitive during seed germination. Proteomic analysis of SIMKK-YFP overexpressors indicated the differential regulation of proteins directly or indirectly involved in salt stress responses. These proteins included catalase, peroxiredoxin, glutathione S-transferase, nucleoside diphosphate kinase 1, endoplasmic reticulum luminal-binding protein 2, and finally plasma membrane aquaporins. In conclusion, Arabidopsis seedlings overexpressing SIMKK-YFP exhibited higher salt sensitivity consistent with their proteome composition and with the presumptive MPK3/MPK6 hijacking of the salt response pathway.
Journal of Experimental Botany, 2014
Dual-specificity mitogen-activated protein kinases kinases (MAPKKs) are the immediate upstream activators of MAPKs. They simultaneously phosphorylate the TXY motif within the activation loop of MAPKs, allowing them to interact with and regulate multiple substrates. Often, the activation of MAPKs triggers their nuclear translocation. However, the spatiotemporal dynamics and the physiological consequences of the activation of MAPKs, particularly in plants, are still poorly understood. Here, we studied the activation and localization of the Medicago sativa stress-induced MAPKK (SIMKK)-SIMK module after salt stress. In the inactive state, SIMKK and SIMK co-localized in the cytoplasm and in the nucleus. Upon salt stress, however, a substantial part of the nuclear pool of both SIMKK and SIMK relocated to cytoplasmic compartments. The course of nucleocytoplasmic shuttling of SIMK correlated temporally with the dual phosphorylation of the pTEpY motif. SIMKK function was further studied in Arabidopsis plants overexpressing SIMKK-yellow fluorescent protein (YFP) fusions. SIMKK-YFP plants showed enhanced activation of Arabidopsis MPK3 and MPK6 kinases upon salt treatment and exhibited high sensitivity against salt stress at the seedling stage, although they were salt insensitive during seed germination. Proteomic analysis of SIMKK-YFP overexpressors indicated the differential regulation of proteins directly or indirectly involved in salt stress responses. These proteins included catalase, peroxiredoxin, glutathione S-transferase, nucleoside diphosphate kinase 1, endoplasmic reticulum luminal-binding protein 2, and finally plasma membrane aquaporins. In conclusion, Arabidopsis seedlings overexpressing SIMKK-YFP exhibited higher salt sensitivity consistent with their proteome composition and with the presumptive MPK3/MPK6 hijacking of the salt response pathway.
Journal of Plant Physiology, 2011
The WNK (With No Lysine K) serine-threonine kinases have been shown to be osmosensitive regulators and are critical for cell volume homeostasis in humans. We previously identified a soybean root-specific WNK homolog, GmWNK1, which is important for normal late root development by fine-tuning regulation of ABA levels. However, the functions of WNKs in plant osmotic stress response remains uncertain. In this study, we generated transgenic Arabidopsis plants with constitutive expression of GmWNK1. We found that these transgenic plants had increased endogenous ABA levels and altered expression of ABAresponsive genes, and exhibited a significantly enhanced tolerance to NaCl and osmotic stresses during seed germination and seedling development. These findings suggest that, in addition to regulating root development, GmWNK1 also regulates ABA-responsive gene expression and/or interacts with other stress related signals, thereby modulating osmotic stress responses. Thus, these results suggest that WNKs are members of an evolutionarily conserved kinase family that modulates cellular response to osmotic stresses in both animal and plants.
CBL-interacting protein kinase, CIPK21, regulates osmotic and salt stress responses in Arabidopsis
Plant Physiology, 2015
The role of calcium-mediated signaling has been extensively studied in plant responses to abiotic stress signals. Calcineurin Blike proteins (CBLs) and CBL-interacting protein kinases (CIPKs) constitute a complex signaling network acting in diverse plant stress responses. Osmotic stress imposed by soil salinity and drought is a major abiotic stress that impedes plant growth and development and involves calcium-signaling processes. In this study, we report the functional analysis of CIPK21, an Arabidopsis (Arabidopsis thaliana) CBL-interacting protein kinase, ubiquitously expressed in plant tissues and up-regulated under multiple abiotic stress conditions. The growth of a loss-of-function mutant of CIPK21, cipk21, was hypersensitive to high salt and osmotic stress conditions. The calcium sensors CBL2 and CBL3 were found to physically interact with CIPK21 and target this kinase to the tonoplast. Moreover, preferential localization of CIPK21 to the tonoplast was detected under salt stress condition when coexpressed with CBL2 or CBL3. These findings suggest that CIPK21 mediates responses to salt stress condition in Arabidopsis, at least in part, by regulating ion and water homeostasis across the vacuolar membranes. Drought and salinity cause osmotic stress in plants and severely affect crop productivity throughout the world. Plants respond to osmotic stress by changing a number of cellular processes (
The Journal of biological chemistry, 2004
Several calcium-independent protein kinases were activated by hyperosmotic and saline stresses in Arabidopsis cell suspension. Similar activation profiles were also observed in seedlings exposed to hyperosmotic stress. One of them was identified to AtMPK6 but the others remained to be identified. They were assumed to belong to the SNF1 (sucrose nonfermenting 1)-related protein kinase 2 (SnRK2) family, which constitutes a plant-specific kinase group. The 10 Arabidopsis SnRK2 were expressed both in cells and seedlings, making the whole SnRK2 family a suitable candidate. Using a family-specific antibody raised against the 10 SnRK2, we demonstrated that these non-MAPK protein kinases activated by hyperosmolarity in cell suspension were SnRK2 proteins. Then, the molecular identification of the involved SnRK2 was investigated by transient expression assays. Nine of the 10 SnRK2 were activated by hyperosmolarity induced by mannitol, as well as NaCl, indicating an important role of the SnRK...
The Arabidopsis Kinase-Associated Protein Phosphatase Regulates Adaptation to Na+ Stress
PLANT PHYSIOLOGY, 2007
The kinase-associated protein phosphatase (KAPP) is a regulator of the receptor-like kinase (RLK) signaling pathway. Loss-of-function mutations rag1-1 (root attenuated growth1-1) and rag1-2, in the locus encoding KAPP cause NaCl hypersensitivity in Arabidopsis thaliana. The NaCl hypersensitive phenotype exhibited by rag1 seedlings includes reduced shoot and primary root growth, root tip swelling and increased lateral root formation. The phenotype exhibited by rag1-1 seedlings is associated with a specific response to Na + toxicity. The sensitivity to Na + is Ca 2+ -independent and is not due to altered intracellular K + /Na + . Analysis of the genetic interaction between rag1-1 and salt overly sensitive1 (sos1)-14 revealed that KAPP is not a component of the SOS signal transduction pathway, the only Na + homeostasis signaling pathway identified so far in plants. All together, these results implicate KAPP as a functional component of the RLK signaling pathway, which also mediates adaptation to Na + stress. RLK pathway components, known to be modulated by NaCl at mRNA level, are constitutively down-regulated in rag1-1 mutant plants. The effect of NaCl on their expression is not altered by the rag1-1 mutation. 4 LITERATURE CITED Baskin TI, Wilson JE (1997) Inhibitors of protein kinases and phosphatases alter root morphology and disorganize cortical microtubules. Plant Physiol 113: 493-502 Bechtold N, Ellis J, Pelletier G (1993) In-Planta Agrobacterium-Mediated Gene-Transfer by Infiltration of Adult Arabidopsis-Thaliana Plants. Comptes Rendus Acad. Sci. Ser. III-Sci. Vie-Life Sci 316:1194-1199 Becker D (1990) Binary vectors which allow the exchange of plant selectable markers and reporter genes. Nucleic Acids Res 18:203 Becraft PW (2002) Receptor kinase signaling in plant development. Annu Rev Cell De. Jones JD, Kamiya Y (1999) The tomato DWARF enzyme catalyses C-6 oxidation in brassinosteroid biosynthesis. Proc Natl Acad Sci USA 96:1761-1766 Braun DM, Stone JM, Walker JC (1997) Interaction of the maize and Arabidopsis kinase interaction domains with a subset of receptor-like protein kinases: implications for transmembrane signaling in plants. Plant J 12:83-95 Buer CS, Masle J, Wasteneys GO (2000) Growth conditions modulate root-wave phenotypes in Arabidopsis. Plant Cell Physiol 41:1164-1170 20 Chinnusamy V, Schumaker K, Zhu JK (2004) Molecular genetic perspectives on crosstalk and specificity in abiotic stress signalling in plants. J Exp Bot 55: 225-236 Chory J (1997) Light modulation of vegetative development. Plant Cell 9: 1225-1234 Chory J, Li J (1997) Gibberellins, brassinosteroids and light-regulated development. Plant Cell Environ 20: 801-806 Clark SE (2001) Cell signalling at the shoot meristem. Nature Rev Mol Cell Bio 2: 276-284 Clouse SD (2002) Brassinosteroid signaling: Novel downstream components emerge. Curr Biol 12: R485-R487 Cock JM, Vanoosthuyse V, Gaude T (2002) Receptor kinase signalling in plants and animals: distinct molecular systems with mechanistic similarities. Curr Opin Cell Biol 14: 230-236 Dievart A, Clark SE (2004) LRR-containing receptors regulating plant development and defense. Development 131: 251-261 Downie JA, Walker SA (1999) Plant responses to nodulation factors. Curr Opin Plant Biol 2: 483-489 Endre G, Kereszt A, Kevei Z, Mihacea S, Kalo P, Kiss GB (2002) A receptor kinase gene regulating symbiotic nodule development. Nature 417: 962-966 Epstein E (1998) How calcium enhances plant salt tolerance. Science 280: 1906-1907 21 Gomez-Gomez L, Bauer Z, Boller T (2001) Both the extracellular leucine-rich repeat domain and the kinase activity of FLS2 are required for flagellin binding and signaling in Arabidopsis. Plant Cell 13: 1155-1163 Halfter U, Ishitani M, Zhu JK (2000) The Arabidopsis SOS2 protein kinase physically interacts with and is activated by the calcium-binding protein SOS3. Proc Natl Acad Sci USA 97: 3735-3740 Hasegawa PM, Bressan RA, Zhu JK, Bohnert HJ (2000) Plant cellular and molecular responses to high salinity. Annu Rev Plant Physiol Plant Molec Biol 51: 463-499 He JX, Zhang JG, Yan DQ, Zhang JS, Chen SY (2004). A salt-responsive receptor-like kinase gene regulated by ethylene signaling pathway encodes a plasma membrane serine/threonine kinase. Theor Appl Genet 109: 377-383 Herve C, Dabos P, Galaud JP, Rouge P, Lescure B (1996) Characterization of an Arabidopsis thaliana gene that defines a new class of putative plant receptor kinases with an extracellular lectin-like domain.
Osmotic signaling in plants: multiple pathways mediated by emerging kinase families
Plant physiology, 2005
. Regulation of gene expression in response to drought, salt, and cold: involvement of ABA-dependent and ABA-independent pathways. Cis-acting elements are shown in boxes and transcription factors are in ovals. Pathways I, II, and V are ABA dependent and based on ABRE or MYBR/MYCR cis-acting elements. Pathways III, IV, VI, and VII are ABA independent and based on DRE/CRT or still unidentified cis-acting sequences. Both types of pathways are implemented in drought, salt, and cold signaling. Some transcription factors like ABFs and DREB2s are stress activated to induce gene expression, whereas others, like CBFs, require biosynthesis first.
Plant Physiology, 2000
Reversible protein phosphorylation/dephosphorylation plays important roles in signaling the plant adaptive responses to salinity/drought stresses. Two protein kinases with molecular masses of 48 and 40 kD are activated in tobacco cells exposed to NaCl. The 48-kD protein kinase was identified as SIPK (salicylic acid-induced protein kinase), a member of the tobacco MAPK (mitogen-activated protein kinase) family that is activated by various other stress stimuli. The activation of the 40-kD protein kinase is rapid and dose-dependent. Other osmolytes such as Pro and sorbitol activate these two kinases with similar kinetics. The activation of 40-kD protein kinase is specific for hyperosmotic stress, as hypotonic stress does not activate it. Therefore, this 40-kD kinase was named HOSAK (high osmotic stress-activated kinase). HOSAK is a Ca2+-independent kinase and uses myelin basic protein (MBP) and histone equally well as substrates. The kinase inhibitor K252a rapidly activates HOSAK in to...
International Journal of Genomics, 2021
Abiotic stress is the major threat confronted by modern-day agriculture. Salinity is one of the major abiotic stresses that influence geographical distribution, survival, and productivity of various crops across the globe. Plants perceive salt stress cues and communicate specific signals, which lead to the initiation of defence response against it. Stress signalling involves the transporters, which are critical for water transport and ion homeostasis. Various cytoplasmic components like calcium and kinases are critical for any type of signalling within the cell which elicits molecular responses. Stress signalling instils regulatory proteins and transcription factors (TFs), which induce stress-responsive genes. In this review, we discuss the role of ion transporters, protein kinases, and TFs in plants to overcome the salt stress. Understanding stress responses by components collectively will enhance our ability in understanding the underlying mechanism, which could be utilized for cr...