Salinity threatens productivity of economically important crops such as tomato (Solanum lycopersicum L.). WRKY transcription factors appear, from a growing body of knowledge, as important regulators of abiotic stresses tolerance. Tomato SlWRKY3 is a nuclear protein binding to the consensus CGTTGACC/T W box. SlWRKY3 is preferentially expressed in aged organs, and is rapidly induced by NaCl, KCl, and drought. In addition, SlWRKY3 responds to salicylic acid, and 35S::SlWRKY3 tomatoes showed under salt treatment reduced contents of salicylic acid. In tomato, overexpression of SlWRKY3 impacted multiple aspects of salinity tolerance. Indeed, salinized (125 mM NaCl, 20 days) 35S::SlWRKY3 tomato plants displayed reduced oxidative stress and proline contents compared to WT. Physiological parameters related to plant growth (shoot and root biomass) and photosynthesis (stomatal conductance and chlorophyll a content) were retained in transgenic plants, together with lower Na+ contents in leaves, and higher accumulation of K+ and Ca2+. Microarray analysis confirmed that many stress-related genes were already up-regulated in transgenic tomatoes under optimal conditions of growth, including genes coding for antioxidant enzymes, ion and water transporters, or plant defense proteins. Together, these results indicate that SlWRKY3 is an important regulator of salinity tolerance in tomato.

Departamento de Genética Molecular de Plantas Centro Nacional de Biotecnología Consejo Superior de Investigaciones Científicas Campus Universidad AutónomaMadrid Spain

Département Sciences du Vivant Centre Wallon de Recherches AgronomiquesGembloux Belgium

Groupe de Recherche en Physiologie Végétale Earth and Life Institute Agronomy Université Catholique de LouvainLouvain la Neuve Belgium

Institut des Sciences de la Vie Université Catholique de LouvainLouvain la Neuve Belgium

Institute of Experimental Botany Academy of Sciences of the Czech RepublicPrague Czechia

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Agarwal P., Dabi M., Sapara K. K., Joshi P. S., Agarwal P. K. (2016). Ectopic expression of JcWRKY transcription factor confers salinity tolerance via salicylic acid signaling. Front. Plant Sci. 7:1541 10.3389/fpls.2016.01541 PubMed DOI PMC

Albacete A., Ghanem M. E., Martínez-Andújar C., Acosta M., Sánchez-Bravo J., Martínez V., et al. (2008). Hormonal changes in relation to biomass partitioning and shoot growth impairment in salinized tomato (Solanum lycopersicum L.) plants. J. Exp. Bot. 59 4119–4131. 10.1093/jxb/488331813ern251 PubMed DOI PMC

Banerjee A., Roychoudhury A. (2015). WRKY proteins: signaling and regulation of expression during abiotic stress responses. Sci. World J. 2015:807560 10.1155/2015/807560 PubMed DOI PMC

Bates L. S., Waldren R. P., Teare I. D. (1973). Rapid determination of free proline for water stress studies. Plant Soil 39 205–207. 10.1007/BF00018060 DOI

Berri S., Abbruscato P., Faivre-Rampant O., Brasileiro A. C., Fumasoni I., Satoh K., et al. (2009). Characterization of WRKY co-regulatory networks in rice and Arabidopsis. BMC Plant Biol. 9:120 10.1186/1471-2229-9-120 PubMed DOI PMC

Chang W., Liu X., Zhu J., Fan W., Zhang Z. (2016). An aquaporin gene from halophyte Sesuvium portulacastrum, SpAQP1, increases salt tolerance in transgenic tobacco. Plant Cell Rep. 35 385–395. 10.1007/s00299-015-1891-9 PubMed DOI

Chen C., Chen Z. (2000). Isolation and characterization of two pathogen- and salicylic acid-induced genes encoding WRKY DNA-binding proteins from tobacco. Plant Mol. Biol. 42 387–396. 10.1023/A:1006399311615 PubMed DOI

Chen L., Song Y., Li S., Zhang L., Zou C., Yu D. (2012). The role of WRKY transcription factors in plant abiotic stresses. Biochim. Biophys. Acta 1819 120–128. 10.1016/j.bbagrm.2011.09.002 PubMed DOI

Chu X., Wang C., Chen X., Lu W., Li H., Wang X., et al. (2015). The cotton WRKY gene GhWRKY41 positively regulates salt and drought stress tolerance in transgenic Nicotiana benthamiana. PLoS ONE 10:e0143022 10.1371/journal.pone.0143022 PubMed DOI PMC

Ciolkowski I., Wanke D., Birkenbihl R. P., Somssich I. (2008). Studies on DNA-binding selectivity of WRKY transcription factors lend structural clues into WRKY-domain function. Plant Mol. Biol. 68 81–92. 10.1007/s11103-008-9353-1 PubMed DOI PMC

Clough S. J., Bent A. F. (1998). Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana. Plant J. 16 735–743. 10.1046/j.1365-313x.1998.00343.x PubMed DOI

Cuartero J., Bolarín M. C., Asíns M. J., Moreno V. (2006). Increasing salt tolerance in the tomato. J. Exp. Bot. 57 1045–1058. 10.1093/jxb/erj102 PubMed DOI

Ding Z. J., Yan J. Y., Xu X. Y., Yu D. Q., Li G. X., Zhang S. Q., et al. (2014). Transcription factor WRKY46 regulates osmotic stress responses and stomatal movement independently in Arabidopsis. Plant J. 79 13–27. 10.1111/tpj.12538 PubMed DOI

Ellul P., Garcia-Sogo B., Pineda B., Ríos G., Roig L. A., Moreno V. (2003). The ploidy level of transgenic plants in Agrobacterium-mediated transformation of tomato cotyledons (Lycopersicon esculentum Mill.) is genotype and procedure dependent. Theor. Appl. Genet. 106 231–238. 10.1007/s00122-002-0928-y PubMed DOI

Fan X., Guo Q., Xu P., Gong Y., Shu H., Yang Y., et al. (2015). Transcriptome-wide identification of salt-responsive members of the WRKY gene family in Gossypium aridum. PLoS ONE 10:e0126148 10.1371/journal.pone.0126148 PubMed DOI PMC

Godoy M., Franco-Zorrilla J. M., Pérez-Pérez J., Oliveros J. C., Lorenzo O., Solano R. (2011). Improved protein-binding microarrays for the identification of DNA-binding specificities of transcription factors. Plant J. 66 700–711. 10.1111/j.1365-313X.2011.04519.x PubMed DOI

Gong X., Zhang J., Hu J., Wang W., Wu H., Zhang Q., et al. (2015). FcWRKY70, a WRKY protein of Fortunella crassifolia, functions in drought tolerance and modulates putrescine synthesis by regulating arginine decarboxylase gene. Plant Cell Environ. 88 2248–2262. 10.1111/pce.12539 PubMed DOI

Gostincar C., Turk M., Plemenitas A., Gunde-Cimerman N. (2009). The expressions of Delta 9-, Delta 12-desaturases and an elongase by the extremely halotolerant black yeast Hortaea werneckii are salt dependent. FEMS Yeast Res. 9 247–256. 10.1111/j.1567-1364.2009.00481.x PubMed DOI

Guo D., Zhang J., Wang X., Han X., Wei B., Wang J., et al. (2015). The WRKY transcription factor WRKY71/EXB1 controls shoot branching by transcriptionally regulating RAX genes in Arabidopsis. Plant Cell 27 3112–3127. 10.1105/tpc.15.00829 PubMed DOI PMC

Hichri I., Heppel S. C., Pillet J., Léon C., Czemmel S., Delrot S., et al. (2010). The basic helix-loop-helix transcription factor MYC1 is involved in the regulation of the flavonoid biosynthesis pathway in grapevine. Mol. Plant 3 509–523. 10.1093/mp/ssp118 PubMed DOI

Hichri I., Muhovski Y., Clippe A., Žižková E., Dobrev P. I., Motyka V., et al. (2016). SlDREB2, a tomato dehydration-responsive element-binding 2 transcription factor, mediates salt stress tolerance in tomato and Arabidopsis. Plant Cell Environ. 39 62–79. 10.1111/pce.12591 PubMed DOI

Hichri I., Muhovski Y., Žižkova E., Dobrev P. I., Franco-Zorilla J. M., Solano R., et al. (2014). The Solanum lycopersicum Zinc Finger2 cysteine-2/histidine-2 repressor-like transcription factor regulates development and tolerance to salinity in tomato and Arabidopsis. Plant Physiol. 164 1967–1990. 10.1104/pp.113.225920 PubMed DOI PMC

Hu Y., Chen L., Wang H., Zhang L., Wang F., Yu D. (2013). Arabidopsis transcription factor WRKY8 functions antagonistically with its interacting partner VQ9 to modulate salinity stress tolerance. Plant J. 74 730–745. 10.1111/tpj.12159 PubMed DOI

Huang S., Gao Y., Liu J., Peng X., Niu X., Fei Z., et al. (2012). Genome-wide analysis of WRKY transcription factors in Solanum lycopersicum. Mol. Genet. Genomics 287 495–513. 10.1007/s00438-012-0696-6 PubMed DOI

Jiang Y., Deyholos M. K. (2006). Comprehensive transcriptional profiling of NaCl-stressed Arabidopsis roots reveals novel classes of responsive genes. BMC Plant Biol. 6:25 10.1186/1471-2229-6-25 PubMed DOI PMC

Jiang Y., Deyholos M. K. (2009). Functional characterization of Arabidopsis NaCl-inducible WRKY25 and WRKY33 transcription factors in abiotic stresses. Plant Mol. Biol. 69 91–105. 10.1007/s11103-008-9408-3 PubMed DOI

Karimi M., Inzé D., Depicker A. (2002). GATEWAY vectors for Agrobacterium-mediated plant transformation. Trends Plant Sci. 7 193–195. 10.1016/S1360-1385(02)02251-3 PubMed DOI

Kim K. C., Lai Z., Fan B., Chen Z. (2008). Arabidopsis WRKY38 and WRKY62 transcription factors interact with histone deacetylase 19 in basal defense. Plant Cell 20 2357–2371. 10.1105/tpc.107.055566 PubMed DOI PMC

Li H., Xu Y., Xiao Y., Zhu Z., Xie X., Zhao H., et al. (2010). Expression and functional analysis of two genes encoding transcription factors, VpWRKY1 and VpWRKY2, isolated from Chinese wild Vitis pseudoreticulata. Planta 232 1325–1337. 10.1007/s00425-010-1258-y PubMed DOI

Li J. B., Luan Y. S., Jin H. (2012). The tomato SlWRKY gene plays an important role in the regulation of defense responses in tobacco. Biochem. Biophys. Res. Commun. 427 671–676. 10.1016/j.bbrc.2012.09.120 PubMed DOI

Li J. B., Luan Y. S., Liu Z. (2015). Overexpression of SpWRKY1 promotes resistance to Phytophthora nicotianae and tolerance to salt and drought stress in transgenic tobacco. Physiol. Plant. 155 248–266. 10.1111/ppl.12315 PubMed DOI

Liu Q. L., Zhong M., Li S., Pan Y. Z., Jiang B. B., Jia Y., et al. (2013). Overexpression of a chrysanthemum transcription factor gene, DgWRKY3, in tobacco enhances tolerance to salt stress. Plant Physiol. Biochem. 69 27–33. 10.1016/j.plaphy.2013.04.016 PubMed DOI

Lu Y., Chi X., Li Z., Yang Q., Li F., Liu S., et al. (2010). Isolation and characterization of a stress-dependent plastidial delta12 fatty acid desaturase from the Antarctic microalga Chlorella vulgaris NJ-7. Lipids 45 179–187. 10.1007/s11745-009-3381-8 PubMed DOI

Lutts S., Almansouri M., Kinet J. M. (2004). Salinity and water stress have contrasting effects on the relationship between growth and cell viability during and after stress exposure in durum wheat callus. Plant Sci. 167 9–18. 10.1016/j.plantsci.2004.02.014 DOI

Lutts S., Kinet J. M., Bouharmont J. (1996). NaCl-induced senescenvce in leaves of rice (Oryza sativa L.) cultivars differing in salinity resistance. Ann. Bot. 78 389–398. 10.1006/anbo.1996.0134 DOI

Navarro J. M., Martínez V., Carvajal M. (2000). Ammonium, bicarbonate and calcium effects on tomato plants grown under saline conditions. Plant Sci. 157 89–96. 10.1016/S0168-9452(00)00272-7 PubMed DOI

Nie L., Feng J., Fan P., Chen X., Guo J., Lv S., et al. (2015). Comparative proteomics of root plasma membrane proteins reveals the involvement of calcium signalling in NaCl-facilitated nitrate uptake in Salicornia europaea. J. Exp. Bot. 66 4497–4510. 10.1093/jxb/erv216 PubMed DOI PMC

Niu C. F., Wei W., Zhou Q. Y., Tian A. G., Hao Y. J., Zhang W. K., et al. (2012). Wheat WRKY genes TaWRKY2 and TaWRKY19 regulate abiotic stress tolerance in transgenic Arabidopsis plants. Plant Cell Environ. 35 1156–1170. 10.1111/j.1365-3040.2012.02480.x PubMed DOI

Núñez-Ramírez R., Sánchez-Barrena M. J., Villalta I., Vega J. F., Pardo J. M., Quintero F. J., et al. (2012). Structural insights on the plant salt-overly-sensitive 1 (SOS1) Na(+)/H(+) antiporter. J. Mol. Biol. 424 283–294. 10.1016/j.jmb.2012.09.015 PubMed DOI

Orellana S., Yañez M., Espinoza A., Verdugo I., González E., Ruiz-Lara S., et al. (2010). The transcription factor SlAREB1 confers drought, salt stress tolerance and regulates biotic and abiotic stress-related genes in tomato. Plant Cell Environ. 33 2191–2208. 10.1111/j.1365-3040.2010.02220.x PubMed DOI

Ouyang B., Yang T., Li H., Zhang L., Zhang Y., Zhang J., et al. (2007). Identification of early salt stress response genes in tomato root by suppression subtractive hybridization and microarray analysis. J. Exp. Bot. 58 507–520. 10.1093/jxb/erl258 PubMed DOI

Pandey G. K., Kanwar P., Singh A., Steinhorst L., Pandey A., Yadav A. K., et al. (2015). Calcineurin B-like protein-interacting protein kinase CIPK21 regulates osmotic and salt stress responses in Arabidopsis. Plant Physiol. 169 780–792. 10.1104/pp.15.00623 PubMed DOI PMC

Parida A. K., Das A. B. (2005). Salt tolerance and salinity effects on plants: a review. Ecotoxicol. Environ. Saf. 60 324–349. 10.1016/j.ecoenv.2004.06.010 PubMed DOI

Pérez-Alfocea F., Balibrea M. E., Santa Cruz A., Estañ M. T. (1996). Agronomical and physiological characterization of salinity tolerance in a commercial tomato hybrid. Plant Soil 180 251–257. 10.1007/BF00015308 DOI

Phukan U. J., Jeena G. S., Shukla R. K. (2016). WRKY transcription factors: molecular regulation and stress responses in plants. Front Plant Sci. 7:760 10.3389/fpls.2016.00760 PubMed DOI PMC

Qin Y., Tian Y., Liu X. (2015). A wheat salinity-induced WRKY transcription factor TaWRKY93 confers multiple abiotic stress tolerance in Arabidopsis thaliana. Biochem. Biophys. Res. Commun. 464 428–433. 10.1016/j.bbrc.2015.06.128 PubMed DOI

Redmann R. E., Haraldson J., Gusta L. V. (1986). Leakage of UV-absorbing substances as a measure of salt injury in leaf tissue of woody species. Physiol. Plant. 67 87–91. 10.1111/j.1399-3054.1986.tb01267.x DOI

Rinerson C. I., Rabara R. C., Tripathi P., Shen Q. J., Rushton P. J. (2015a). The evolution of WRKY transcription factors. BMC Plant Biol. 15:66 10.1186/s12870-015-0456-y PubMed DOI PMC

Rinerson C. I., Scully E. D., Palmer N. A., Donze-Reiner T., Rabara R. C., Tripathi P., et al. (2015b). The WRKY transcription factor family and senescence in switchgrass. BMC Genomics 16:912 10.1186/s12864-015-2057-4 PubMed DOI PMC

Rushton P. J., Somssich I. E., Ringler P., Shen Q. J. (2010). WRKY transcription factors. Trends Plant Sci. 15 247–258. 10.1016/j.tplants.2010.02.006 PubMed DOI

Schluttenhofer C., Yuan L. (2015). Regulation of specialized metabolism by WRKY transcription factors. Plant Physiol. 167 295–306. 10.1104/pp.114.251769 PubMed DOI PMC

Shen Y., Shen L., Shen Z., Jing W., Ge H., Zhao J., et al. (2015). The potassium transporter OsHAK21 functions in the maintenance of ion homeostasis and tolerance to salt stress in rice. Plant Cell Environ. 38 2766–2779. 10.1111/pce.12586 PubMed DOI

Shi W., Hao L., Li J., Liu D., Guo X., Li H. (2014). The Gossypium hirsutum WRKY gene GhWRKY39-1 promotes pathogen infection defense responses and mediates salt stress tolerance in transgenic Nicotiana benthamiana. Plant Cell Rep. 33 483–498. 10.1007/s00299-013-1548-5 PubMed DOI

Song H., Wang P., Hou L., Zhao S., Zhao C., Xia H., et al. (2016). Global analysis of WRKY genes and their response to dehydration and salt stress in soybean. Front. Plant Sci. 7:9 10.3389/fpls.2016.00009 PubMed DOI PMC

Subramanian C., Woo J., Cai X., Xu X., Servick S., Johnson C. H., et al. (2006). A suite of tools and application notes for in vivo protein interaction assays using bioluminescence resonance energy transfer (BRET). Plant J. 48 138–152. 10.1111/j.1365-313X.2006.02851.x PubMed DOI

Tamura K., Stecher G., Peterson D., Filipski A., Kumar S. (2013). MEGA6: molecular evolutionary genetics analysis version 6.0. Mol. Biol. Evol. 30 2725–2729. 10.1093/molbev/mst197 PubMed DOI PMC

Ülker B., Somssich I. E. (2004). WRKY transcription factors: from DNA binding towards biological function. Curr. Opin. Plant Biol. 7 491–498. 10.1016/j.pbi.2004.07.012 PubMed DOI

Vandesompele J., De Preter K., Pattyn F., Poppe B., Van Roy N., De Paepe A., et al. (2002). Accurate normalization of real-time quantitative RT–PCR data by geometric averaging of multiple internal control genes. Genome Biol. 3:Research0034. PubMed PMC

Volkmar K. M., Hu Y., Steppuhn H. (1998). Physiological responses of plants to salinity: a review. Can. J. Plant Sci. 78 19–27. 10.4141/P97-020 DOI

Wang C., Deng P., Chen L., Wang X., Ma H., Hu W., et al. (2013). A wheat WRKY transcription factor TaWRKY10 confers tolerance to multiple abiotic stresses in transgenic tobacco. PLoS ONE 8:e65120 10.1371/journal.pone.0065120 PubMed DOI PMC

Wang F., Chen H. W., Li Q. T., Wei W., Li W., Zhang W. K., et al. (2015). GmWRKY27 interacts with GmMYB174 to reduce expression of GmNAC29 for stress tolerance in soybean plants. Plant J. 83 224–236. 10.1111/tpj.12879 PubMed DOI

Wang H. S., Yu C., Tang X. F., Zhu Z. J., Ma N. N., Meng Q. W. (2014). A tomato endoplasmic reticulum (ER)-type omega-3 fatty acid desaturase (LeFAD3) functions in early seedling tolerance to salinity stress. Plant Cell Rep. 33 131–142. 10.1007/s00299-013-1517-z PubMed DOI

Wang L., Li Q., Lei Q., Feng C., Gao Y., Zheng X., et al. (2015). MzPIP2;1: an aquaporin involved in radial water movement in both water uptake and transportation, altered the drought and salt tolerance of transgenic Arabidopsis. PLoS ONE 10:e0142446 10.1371/journal.pone.0142446 PubMed DOI PMC

Wang X., Zeng J., Li Y., Rong X., Sun J., Sun T., et al. (2015). Expression of TaWRKY44, a wheat WRKY gene, in transgenic tobacco confers multiple abiotic stress tolerances. Front. Plant Sci. 6:615 10.3389/fpls.2015.00615 PubMed DOI PMC

Xiong W., Xu X., Zhang L., Wu P., Chen Y., Li M., et al. (2013). Genome-wide analysis of the WRKY gene family in physic nut (Jatropha curcas L.). Gene 524 124–132. 10.1016/j.gene.2013.04.047 PubMed DOI

Yamasaki K., Kigawa T., Watanabe S., Inoue M., Yamasaki T., Seki M., et al. (2012). Structural basis for sequence-specific DNA recognition by an Arabidopsis WRKY transcription factor. J. Biol. Chem. 287 7683–7691. 10.1074/jbc.M111.279844 PubMed DOI PMC

Yang L., Zhao X., Yang F., Fan D., Jiang Y., Luo K. (2016). PtrWRKY19, a novel WRKY transcription factor, contributes to the regulation of pith secondary wall formation in Populus trichocarpa. Sci. Rep. 6:18643 10.1038/srep18643 PubMed DOI PMC

Yang Q., Chen Z. Z., Zhou X. F., Yin H. B., Li X., Xin X. F., et al. (2009). Overexpression of SOS (Salt Overly Sensitive) genes increases salt tolerance in transgenic Arabidopsis. Mol. Plant 2 22–31. 10.1093/mp/ssn058 PubMed DOI PMC

Yu S., Ligang C., Liping Z., Diqiu Y. (2010). Overexpression of OsWRKY72 gene interferes in the abscisic acid signal and auxin transport pathway of Arabidopsis. J. Biosci. 35 459–471. 10.1007/s12038-010-0051-1 PubMed DOI

Zhang C. Q., Xu Y., Lu Y., Yu H. X., Gu M. H., Liu Q. Q. (2011). The WRKY transcription factor OsWRKY78 regulates stem elongation and seed development in rice. Planta 234 541–554. 10.1007/s00425-011-1423-y PubMed DOI

Zhang L., Gu L., Ringler P., Smith S., Rushton P. J., Shen Q. J. (2015). Three WRKY transcription factors additively repress abscisic acid and gibberellin signaling in aleurone cells. Plant Sci. 236 214–222. 10.1016/j.plantsci.2015.04.014 PubMed DOI

Zheng L., Liu G., Meng X., Liu Y., Ji X., Li Y., et al. (2013). A WRKY gene from Tamarix hispida, ThWRKY4, mediates abiotic stress responses by modulating reactive oxygen species and expression of stress-responsive genes. Plant Mol. Biol. 82 303–320. 10.1007/s11103-013-0063-y PubMed DOI

Zhou L., Wang N. N., Gong S. Y., Lu R., Li Y., Li X. B. (2015). Overexpression of a cotton (Gossypium hirsutum) WRKY gene, GhWRKY34, in Arabidopsis enhances salt-tolerance of the transgenic plants. Plant Physiol. Biochem. 96 311–320. 10.1016/j.plaphy.2015.08.016 PubMed DOI

Zhou Q.-Y., Tian A.-G., Zou H. F., Xie Z. M., Lei G., Huang J., et al. (2008). Soybean WRKY-type transcription factor genes, GmWRKY13, GmWRKY21, and GmWRKY54, confer differential tolerance to abiotic stresses in transgenic Arabidopsis plants. Plant Biotechnol. J. 6 486–503. 10.1111/j.1467-7652.2008.00336.x PubMed DOI

Zhu G. Y., Kinet J. M., Lutts S. (2001). Characterization of rice (Oryza sativa L.) F3 populations selected for salt resistance. I. Physiological behavior during vegetative growth. Euphytica 121 251–263. 10.1023/A:1012016431577 DOI

Zhu M., Chen G., Zhang J., Zhang Y., Xie Q., Zhao Z., et al. (2014). The abiotic stress-responsive NAC-type transcription factor SlNAC4 regulates salt and drought tolerance and stress-related genes in tomato (Solanum lycopersicum). Plant Cell Rep. 33 1851–1863. 10.1007/s00299-014-1662-z PubMed DOI

Pepper immunity against Ralstonia solanacearum is positively regulated by CaWRKY3 through modulation of different WRKY transcription factors