biologia plantarum

Biologia plantarum 55:689, 2011 | DOI: 10.1007/s10535-011-0169-5

Construction and functional analysis of pathogen-inducible synthetic promoters in Brassica napus

F. Shokouhifar^1,2, M. R. Zamani^1,*, M. Motallebi¹, A. Mousavi¹, M. A. Malboobi¹

¹ National Institute of Genetic Engineering and Biotechnology, Tehran, Iran

² Ferdowsi University of Mashhad, Mashhad, Iran

In this study, we selected two known pathogen-inducible cis-acting elements, F and E17, to construct synthetic pathogen-inducible promoters for analysis in transformed canola (Brassica napus L.). The synthetic promoter approach was used, which involved the insertion of dimers and combining two cis-acting elements (E17 and F) upstream of the minimal CaMV 35S promoter. Canola plants were transformed by three constructs, pGEE, pGFF, pGFFEE containing synthetic promoters (SP), SP-EE, SP-FF and SP-FFEE, respectively. Analyses of histochemical and fluorometric GUS expression indicated that synthetic promoters responded to fungal elicitors and phytohormone treatments. The SP-FF promoter showed high responses against methyl jasmonate and Sclerotinia sclerotiorum, while SP-EE demonstrated inducibility only in response to salicylic acid and Rhizoctonia solani. The SP-EE promoter similar to SP-FFEE, did not respond to S. sclerotiorum and methyl jasmonate. However, SP-FFEE was highly induced by R. solani elicitors and showed that the level of GUS expression was greater than that by either of E17 or F elements alone. These three synthetic promoters did not activate the expression of the reporter gene in response to cold, heat, UV and wounding.

Keywords: canola; cis-acting element; elicitor; fungal infection; reporter gene

Received: March 8, 2010; Accepted: June 29, 2010; Published: December 1, 2011  Show citation