Isolation of Brassica napus MYC2 gene and analysis of its expression in response to water deficit stress

Document Type : Original article


1 Department of Crop Production and Plant Breeding, College of Agriculture, Shiraz University, Shiraz, Iran

2 Department of Crop Production and Plant Breeding, College of Agriculture, Shiraz University


Manipulation of stress related transcription factors to improve plant stress tolerance is a major goal of current biotechnology researches. MYC2 gene encodes a key stress-related transcription factor involved in Jasmonate (JA) and abscisic acid (ABA) signaling pathways in Arabidopsis. Brassica napus, as a globally important oilseed crop, is a close relative of Arabidopsis.  In the present study, a 960bp cDNA fragment of B. napus MYC2 (BnMYC2) was isolated, cloned and sequenced. The deduced amino acid sequence of the BnMYC2 cDNA fragment showed high homology with Arabidopsis thaliana MYC2 and the putative Brassica oleracea MYC2, implying the conserved functions among these orthologous genes. The expression analysis by a semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) revealed that BnMYC2 is a drought inducible gene. A different expression profile of BnMYC2 was observed between drought tolerant and sensitive B. napus cultivars. The drought tolerant cultivar showed a higher accumulation of BnMYC2 transcript in response to water deficit stress during the studied time course. This result indicates that BnMYC2 may contribute to drought tolerance in B. napus.


1. Shinozaki K, Yamaguchi-Shinozaki K. Gene networks involved in drought stress response and tolerance. J Exp Bot 2007;58:221-227.
2. Umezawa T, Fujita M, Fujita Y, Yamaguchi-Shinozaki K, Shinozaki K.  Engineering drought tolerance in plants: discovering and tailoring genes to unlock the future. Curr Opin Biotech 2006;17:113-122
3. Nakashima K, Yamaguchi-Shinozaki K. Regulons involved in osmotic stress-responsive and cold stress-responsive gene expression in plants Physiol Plantarum 2006;126:62-71.
4. Seki M, Umezawa T, Urano K, Shinozaki K. Regulatory metabolic networks in drought stress responses. Curr Opin Plant Biol 2007;10:296-302.
5. Bartels D, Sunkar R. Drought and salt tolerance in plants. Crit Rev Plant Sci 2005;24:23-58.
6. Abe H, Yamaguchi-Shinozaki K, Urao T, Iwasaki T, Hosokawa D, Shinozaki K. Role of Arabidopsis MYC and MYB homologs in drought and abscisic acid-regulated gene expression. Plant Cell 1997;9:1859-1868.
7. Abe H, Urao T, Ito T, Seki M, Shinozaki K, Yamaguchi-Shinozaki K. Arabidopsis AtMYC2  (bHLH) and AtMYB2 (MYB) function as transcriptional activators in abscisic acid signaling. Plant Cell 2003;15:63-78.
8. Boter M, Ruíz-Rivero O, Abdeen A,  Prat S. Conserved MYC transcription factors play a key role in jasmonate signaling both in tomato and Arabidopsis.Genes Dev 2004;18: 1577-1591.
9. Dombrecht B, Xue GP, Sprague SJ, Kirkegaard JA, Ross JJ, Reid JB, Fitt GP, Sewelam N, Schenk PM, Manners JM, Kazan K. MYC2 differentially modulates diverse jasmonate-dependent functions in Arabidopsis. Plant Cell 2007;19:2225-2245.
10. Lorenzo O, Chico JM, Sanchez-Serrano JJ, Solano R. JASMONATE-INSENSITIVE 1 encodes a MYC transcription factor essential to discriminate between different Jasmonate regulated defense responses in Arabidopsis. Plant Cell 2004;16:1938-1950.
11. Verhage A, Vlaardingerbroek I, Raaijmakers C, Dam NM, Van Dicke M, Van Wees SCM, Pieterse CMJ. Rewiring of the jasmonate signaling pathway in Arabidopsis during insect herbivory. Front Plant Sci 2011;2:1-12.
12. Yadav V, Mallappa  C, Gangappa SN, Bhatia S,  Chattopadhyay S. A basic helix-loop-helix transcription factor in Arabidopsis, MYC2, acts as a repressor of blue light mediated photomorphogenic growth. Plant Cell 2005;17:1953-1966.
13. Gangappa SN, Prasad VBR, Chattopadhyay S. Functional interconnection of MYC2 and SPA1 in the photomorphogenic seedling development of Arabidopsis. Plant Physiol 2010;154:1210-1219.
14. Shin J, Heidrich K, Sanchez-Villarreal A, Parker JE, Davis SJ. Time for coffee represses MYC2 protein accumulation to provide time-of-day regulation of jasmonate signaling. Plant Cell 2012;24:2470-2482.
15. Kazan K, Manners JM. MYC2: the master in action. Mol Plant 2012;6:686-703.
16. Todd AT, Liu E, Polvi SL, Pammett RT, Page JE. A functional genomics screen identifies diverse transcription factors that regulate alkaloid biosynthesis in Nicotiana benthamiana. Plant J 2010;62:589-600.
17. Engelberth J, Contreras CF, Viswanathan S. Transcriptional analysis of distant signaling induced by insect elicitors and mechanical wounding in Zea mays. PLoS One 2012;7:e34855
18. Zhao ML, Wang JN, Shan W, Fan JG, Kuang JF, Wu KQ, Li  XP, Chen WX, He  FY, Chen JY, Lu WJ. Induction of jasmonate signaling regulators MaMYC2s and their physical Interactions with MaICE 1 in methyl jasmonate-induced chilling tolerance in banana fruit. Plant Cell Environ 2013;36:30-51.
19. Seo JS, Joo J, Kim MJ, Kim YK, Nahm BH, Song SI, Cheong JJ, Lee JS, Kim JK, Choi YD. OsbHLH148, a basic helix-loop-helix protein, interacts with OsJAZ proteins in a jasmonate signaling pathway leading to drought tolerance in rice. Plant J 2011;65: 907-921.
20. Miyamoto K, Shimizu T, Mochizuki S, Nishizawa Y, Minami E, Nojiri H, Yamane H, Okada K. Stress-induced expression of the transcription factor ReRJ1 is tightly regulated in response to jasmonic acid accumulation in rice. Protoplasma 2013;250: 241-249.
21. Aliakbari, M. Isolation and characterization of MYC2 transcription factor gene in a drought tolerant rapeseed cultivar. MSc Thesis 2010; Shiraz University.