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WRKY TFs represent a large family of transcriptional regulators that play a key role in plant response to biotic and abiotic stresses. Safflower, Carthamus tinctorius, is cultivated for vegetable oil extracted from seeds. It is grown in semi-arid regions and is resistant to abiotic stresses such as drought, temperature and salinity. However, stress resilience in safflower is poorly understood. In the present study, by analyzing available EST data set, we identified 21 putative CtWRKYs in safflower. The CtWRKYs were classified into three groups based on the phylogeny of their WRKY domains. Majority of identified CtWRKYs categorized into group III. Also, abiotic stress response of five CtWRKYs was studied in safflower plants subjected to drought, temperature, cold, salt and dehydration stresses by qRT-PCR. All the CtWRKYs were responsive to multiple abiotic stresses, suggesting they positively or negatively affect plant resistance to various abiotic stresses. Our results will be useful for further functional characterization of CtWRKYs and stress tolerance in safflower.
Rinerson CI, Rabara RC, Tripathi P, Shen QJ, Rushton PJ. The evolution of WRKY transcription factors. BMC Plant Biology. 2015;15:66.
Sari D, Nedim M, Cengiz Toker. Assessment of resistance gene analog, peroxidase and WRKY gene polymorphisms in the genus Lens miller. Turkish Journal of Botany. 2016;40:121–29.
Eulgem T, Rushton PJ, Robatzek S, Somssich IE. The WRKY superfamily of plant transcription factors. Trends in Plant Science. 2000;5(5):199-206.
Ulker B, Somssich IE.WRKY transcription factors: From DNA binding towards biological function. Current Opinion in Plant Biology. 2004;7(5):491-498.
Bakshi M, Oelmuller R.WRKY transcription factors: Jack of many trades in plants. Plant Signal Behavior. 2014;9(2):e27700.
Rushton PJ, Somssich IE, Ringler P, Shen QXJ. WRKY transcription factors. Trends in Plant Science. 2010;15(5):247-258.
Li S, Fu Q, Huang W, Yu D. Functional analysis of an Arabidopsis transcription factor WRKY25 in heat stress. Plant Cell Reports. 2009;28(4):683-693.
Jiang YQ, Deyholos MK. Functional characterization of Arabidopsis NaCl-inducible WRKY25 and WRKY33 transcription factors in abiotic stresses. Plant Molecular Biology. 2009;69(1-2):91-105.
Li S, Fu Q, Chen L, Huang W, Yu D. Arabidopsis thaliana WRKY25, WRKY26 and WRKY33 coordinate induction of plant thermo-tolerance. Planta. 2011;233(6): 1237-1252.
Liu L, Zhang Z, Dong J, Wang, T. Overexpression of MtWRKY76 increases both salt and drought tolerance in Medicago truncatula. Environmental and Experimental Botany. 2016;123:50–58.
Raineri J, Wang S, Peleg Z, Blumwald E, Chan RL. The rice transcription factor OsWRKY47 is a positive regulator of the response to water deficit stress. Plant Molecular Biology. 2015;88(4-5):401– 13.
Ding ZJ, Yan JY, Xu XY, Yu DQ, Li GX, Zhang SQ, Zheng SJ. Transcription factor WRKY46 regulates osmotic stress responses and stomatal movement independently in Arabidopsis. The Plant Journal. 2014;79(1):13-27.
Jaffar MA, Song A, Faheem M, Chen S, Jiang J, Liu C, Fan Q, Chen F. Involvement of CmWRKY10 in drought tolerance of Chrysanthemum through the ABA-signaling pathway. International Journal of Molecular Sciences. 2016;17(5):693.
Narusaka M, Shirasu K, Noutoshi Y, Kubo Y, Shiraishi T, Iwabuchi M, Narusaka Y. RRS1 and RPS4 provide a dual resistance-gene system against fungal and bacterial pathogens. The Plant Journal. 2009;60(2): 218-226.
Johnson CS, Kolevski B, Smith DR. Transparent testa glabra2, a trichome and seed coat development gene of Arabidopsis, encodes a WRKY Transcription factor. The Plant Cell. 2002;14(6):1359-1375.
Luo M, Dennis ES, Berger F, Peacock WJ, Chaudhury A. MINISEED3 (MINI3), a WRKY family gene and HAIKU2 (IKU2), a leucine-rich repeat (LRR) kinase gene, are regulators of seed size in Arabidopsis. Proceeding of National Academic of Sciences (USA). 2005;102(48):17531-17536.
Dajue L, Mundel H. Safflower (Carthamus tinctorius L.) promoting the conservation and use of underutilized and neglected crops. International Plant Genetic Resources Institute, Rome, Institute of Plant Genetics and Crop Plant Research, Gatersleben; 1996.
Kar G, Kumar A, Martha M. Water use efficiency and crop co-efficients of dry season oilseed crops. Agriculture water Management. 2007;87(1):73–82.
Hussain MI, Lyra DA, Farooq M, Nikoloudakis N, Khalid N. Salt and drought stresses in safflower: A review. Agronomy for Sustainable Development. 2016;36(1): 1–31.
Rudd Stephen. Expressed sequence tags: Alternative or complement to whole genome sequences? Trends in Plant Science. 2003;8(7):321-329.
Singh B, Kukreja S, Goutam U. Milestones achieved in response to drought stress through reverse genetic approaches. F1000 Research. 2018;7:1311.
Fin RD, Coggill P, Eberhardt RY, Eddy SR, Mistry J, Mitchell AL, Potter SC, Salazar GA. The Pfam protein family’s database: towards a more sustainable future. Nucleic Acids Research. 2016;44(D1):D279–D285.
Kumar S, Stecher G, Li M, Knyaz C, Tamura K. MEGA X: Molecular evolutionary genetics analysis across computing platforms. Molecular Biology and Environment. 2018;35(6):1547- 1549.
Sonnhammer ELL, Ostlund G. In Paranoid 8: Orthology analysis between 273 proteomes, mostly eukaryotic. Nucleic Acids Research. 2014;43:D234-D239.
Thippeswamy M, Sivakumar M, Sudhakarbabu O, Chandraobul Reddy P, Veeranagamallaiah G, Pandurangaiah M, Ramya M, Nareshkumar A, Kirankumar T, Chinta Sudhakar. Generation and analysis of drought stressed subtracted expressed sequence tags from safflower (Carthamus tinctorius L.). Plant Growth Regulation. 2013;69(1):29–41.
Chen F, Hu Y, Vannozzi A, Wu K, Cai H, Mullis M, Qin Y, Zhang L. The WRKY transcription factor family in model plants and crops. Critical Reviews in Plant Sciences. 2018;36(5-6):311-335.
Goel R, Pandey A, Trivedi PK, Asif MH. Genome-wide analysis of the Musa WRKY gene family: Evolution and differential expression during development and stress. Frontier in Plant Science. 2016;7:299.
Berri S, Abbruscato P,Faivre-Rampant O, Brasileiro AC, Fumasoni I, Satoh K, Kikuchi S, Oiffaneli P. Characterization of WRKY Co-Regulatory Networks in Rice and Arabidopsis. BMC Plant Biology. 2009; 9:120:1–22.
Basu S, Roychoudhury A. Expression profiling of abiotic stress-inducible genes in response to multiple stresses in rice (Oryza sativa L.) varieties with contrasting level of stress tolerance. BioMed Research International. 2014;706890:1-12.
Wei W, Zhang Y, Han L, Guan Z, Chai T. A novel WRKY transcriptional factor from Thlaspi caerulescens negatively regulates the osmotic stress tolerance of transgenic tobacco. Plant Cell Reports. 2008;27(4):795–803.
Baldoni E, Paolo B, Franca L, Monica M, Annamaria G. Comparative leaf and root transcriptomic analysis of two rice japonica cultivars reveals major differences in the root early response to osmotic stress. Rice. 2016;9(1):25.
Jiang Y, Liang G, Yu D. Activated expression of WRKY57 confers drought tolerance in Arabidopsis. Molecular Plant. 2012;5(6):1375-1388.
Chen J, Nolan TM, Ye H, Zhang M, Tong H, Xin P, Chu J, Chu C, Li Z, Yin Y. Arabidopsis WRKY46, WRKY54 and WRKY70 transcription factors are involved in brassinosteroid-regulated plant growth and drought response. The Plant Cell. 2017;29(6):1425-1439.
Hossain MA, Henriquez-Valencia C, Gomez-Paez M, Medina J, Orellana A, Vicente-Carbajosa J, Zouhar J. Identification of novel components of the unfolded Protein response in Arabidopsis. Frontier in Plant Science. 2016;7:650.
Ashwini N, Sajeevan RS, Udaykumar M, Nataraja KN. Identification and characterization of OSWRKY71 variant in indica genotypes. Rice Science. 2016; 23(6):297-305.