Overexpression of a Calcium-Dependent Protein Kinase Confers Salt and Drought Tolerance in Rice by Preventing Membrane Lipid Peroxidation    

Abstract

The OsCPK4 gene is a member of the complex gene family of calcium-dependent protein kinases in rice (Oryza sativa). Here, we report that OsCPK4 expression is induced by high salinity, drought, and the phytohormone abscisic acid. Moreover, a plasma membrane localization of OsCPK4 was observed by transient expression assays of green fluorescent protein-tagged OsCPK4 in onion (Allium cepa) epidermal cells. Overexpression of OsCPK4 in rice plants significantly enhances tolerance to salt and drought stress. Knockdown rice plants, however, are severely impaired in growth and development. Compared with control plants, OsCPK4 overexpressor plants exhibit stronger water-holding capability and reduced levels of membrane lipid peroxidation and electrolyte leakage under drought or salt stress conditions. Also, salt-treated OsCPK4 seedlings accumulate less Na in their roots. We carried out microarray analysis of transgenic rice overexpressing OsCPK4 and found that overexpression of OsCPK4 has a low impact on the rice transcriptome. Moreover, no genes were found to be commonly regulated by OsCPK4 in roots and leaves of rice plants. A significant number of genes involved in lipid metabolism and protection against oxidative stress appear to be up-regulated by OsCPK4 in roots of overexpressor plants. Meanwhile, OsCPK4 overexpression has no effect on the expression of well-characterized abiotic stress-associated transcriptional regulatory networks (i.e. ORYZA SATIVA DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN1 and ORYZA SATIVA No Apical Meristem, Arabidopsis Transcription Activation Factor1-2, Cup-Shaped Cotyledon6 genes) and LATE EMBRYOGENESIS ABUNDANT genes in their roots. Taken together, our data show that OsCPK4 functions as a positive regulator of the salt and drought stress responses in rice via the protection of cellular membranes from stress-induced oxidative damage.

Effect of salinity stress on plants and its tolerance strategies: a review

“…The MAPKs may further regulate plant cell shapes by interacting with or regulating cortical microtubules, as was shown for MPK4 Beck et al 2011), MPK6 (Müller et al 2010), and MPK12/MPK18 (Walia et al 2009). Recently, Campo et al (2014) reported that overexpression of OsCPK4 enhanced salt tolerance in rice by preventing lipid peroxidation in membranes.…”

Leaf cDNA-AFLP analysis reveals novel mechanisms for boron-induced alleviation of aluminum-toxicity in Citrus grandis seedlings

“…Ca 2 þ signals are decoded into phosphorylation signals by the action of several plant-specific proteins such as Ca-dependent protein kinases (CPKs) and Ca/calmodulin-dependent protein kinases (Harper et al, 2004). Transgenic rice plants overexpressing rice CPK4 exhibited enhanced tolerance to salt and drought stress via protecting cellular membranes from stress-induced oxidative damage (Campo et al, 2014). The higher expression level of CPK 1-like (TDF #133-5) in 2.5 μM Bþ1.2 mM Al-treated leaves (Table 1) might provide an adaptive response to Al-toxicity by mitigating Al-induced oxidative-stress.…”

Genome-wide analysis and expression profiling of calcium-dependent protein kinases in potato (Solanum tuberosum)

“…Thus, tomato LeCDPK2 regulates ethylene biosynthesis in response to wound signalling (Kamiyoshihara et al 2010); Arabidopsis AtCPK1/2/4/5/11 phosphorylate and thereby activate NADPH oxidase to promote reactive oxygen species (ROS) production in response to abiotic and biotic stimuli (Gao et al 2013); rice OsCPK4 participates in rice tolerance to salt and drought stress by protecting cellular membranes from lipid peroxidation (Campo et al 2014), grapevine gene VaCPK29 confers tolerance to heat and osmotic stresses (Dubrovina et al 2017), whereas ZmCPK11 is involved in touch-and wound-induced pathways in maize (Szczegielniak et al 2012). CDPKs are widely involved in various types of disease resistance (Boudsocq et al 2010;Boudsocq and Sheen 2013;Romeis and Herde 2014;Wang et al 2015).…”