TaSnRK2.4, an SNF1-type serine/threonine protein kinase of wheat (Triticum aestivum L.), confers enhanced multistress tolerance in Arabidopsis

Abstract

Osmotic stresses such as drought, salinity, and cold are major environmental factors that limit agricultural productivity worldwide. Protein phosphorylation/dephosphorylation are major signalling events induced by osmotic stress in higher plants. Sucrose non-fermenting 1-related protein kinase2 family members play essential roles in response to hyperosmotic stresses in Arabidopsis, rice, and maize. In this study, the function of TaSnRK2.4 in drought, salt, and freezing stresses in Arabidopsis was characterized. A translational fusion protein of TaSnRK2.4 with green fluorescent protein showed subcellular localization in the cell membrane, cytoplasm, and nucleus. To examine the role of TaSnRK2.4 under various environmental stresses, transgenic Arabidopsis plants overexpressing wheat TaSnRK2.4 under control of the cauliflower mosaic virus 35S promoter were generated. Overexpression of TaSnRK2.4 resulted in delayed seedling establishment, longer primary roots, and higher yield under normal growing conditions. Transgenic Arabidopsis overexpressing TaSnRK2.4 had enhanced tolerance to drought, salt, and freezing stresses, which were simultaneously supported by physiological results, including decreased rate of water loss, enhanced higher relative water content, strengthened cell membrane stability, improved photosynthesis potential, and significantly increased osmotic potential. The results show that TaSnRK2.4 is involved in the regulation of enhanced osmotic potential, growth, and development under both normal and stress conditions, and imply that TaSnRK2.4 is a multifunctional regulatory factor in Arabidopsis. Since the overexpression of TaSnRK2.4 can significantly strengthen tolerance to drought, salt, and freezing stresses and does not retard the growth of transgenic Arabidopsis plants under well-watered conditions, TaSnRK2.4 could be utilized in transgenic breeding to improve abiotic stresses in crops.

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

“…1A). To compare FaSnRK2s with AtSnRK2s and other SnRK2s reported previously (Park et al, 1993;Mustilli et al, 2002;Hrabak et al, 2003;Mao et al, 2010;Bucholc et al, 2011), we constructed a phylogenetic tree based on the full-length complementary DNA (cDNA) sequences of the selected SnRK2s using the neighbor-joining method in MEGA6 software (Fig. 1B).…”

“…The full-length SnRK2 cDNA sequences from Arabidopsis, maize (Zea mays), Triticum polonicum, potato (Solanum tuberosum), wheat (Triticum aestivum), and Nicotiana plumbaginifolia were obtained from the NCBI nucleotide database (http://www.ncbi.nlm.nih.gov/nucleotide/) as reported in previous studies (Park et al, 1993;Mustilli et al, 2002;Hrabak et al, 2003;Mao et al, 2010;Bucholc et al, 2011).…”

Cyclin dependent protein kinases and stress responses in plants

“…Additionally, overexpression of those genes favored root development, benefited water and nutrient uptake and did not retard the growth of transgenic plants, indicating their strong potential in transgenic breeding assays for the improvement of abiotic stress tolerance in crops. 23,24 The induction of mitogen-activated protein kinase (MAPK) cascades transduce stress stimuli into cellular responses. MAPK cascades are widespread in eukaryotes and the typical module generally consists of a MAPK kinase kinase (MAPKKK), a …”

Cloning and characterization of a SnRK2 gene from Jatropha curcas L.

“…OsSAPK4 overexpression significantly enhanced salt tolerance in transgenic rice (Diédhiou et al, 2008). Additionally, TaSnRK2.4 from wheat and ZmSAPK8 from corn were recently reported to enhance multi-stress and salt tolerance, respectively, in transgenic Arabidopsis (Mao et al, 2010;Ying et al, 2011).…”