Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 7 (11), 1646-1659
eCollection

Expression Profiles of BrMYB Transcription Factors Related to Glucosinolate Biosynthesis and Stress Response in Eight Subspecies of Brassica rapa

Affiliations

Expression Profiles of BrMYB Transcription Factors Related to Glucosinolate Biosynthesis and Stress Response in Eight Subspecies of Brassica rapa

Mi-Suk Seo et al. FEBS Open Bio.

Abstract

Brassica rapa is a polyploid species with phenotypically diverse cultivated subspecies. Glucosinolates (GSLs) are secondary metabolites that contribute to anticarcinogenic activity and plant defense in Brassicaceae. Previously, complete coding sequences of 13 BrMYB transcription factors (TFs) related to GSL biosynthesis were identified in the B. rapa genome. In the present study, we investigated GSL content and expression levels of these BrMYB TFs in 38 accessions belonging to eight subspecies of B. rapa. Twelve identified GSLs were detected and were classified into three chemical groups based on patterns of GSL content and expression profiles of the BrMYB TFs. GSL content and BrMYB TF expression levels differed among genotypes, including B. rapa subspecies pekinensis, chinensis and rapa. BrMYB28.3, BrMYB51.1 and BrMYB122.2 positively regulated GSL content in 38 accessions. Furthermore, expression levels of BrMYB28s and BrMYB34.3 increased under most abiotic and biotic stress treatments. The three BrMYB51 paralogs also showed drastically increased expression levels after infection with Pectobacterium carotovorum. The results of the present study improve our understanding of the functional diversity of these 13 BrMYB TFs during the evolution of polyploid B. rapa.

Keywords: BrMYB transcription factors; Brassica rapa subspecies; DNA‐binding domain; desulfo; expression profiling; glucosinolate; stress defense mechanism.

Figures

Figure 1
Figure 1
ClustalW aa sequence alignment of the R2R3‐MYB domain in GSL biosynthetic TFs of 13 Brassica rapa accessions. The shading of the alignment represents different degrees of conservation among sequences. The R2 and R3 binding domains are boxed in white and black, respectively.
Figure 2
Figure 2
Phenotypes of eight subspecies of Brassica rapa used in the present study. Subspecies of each accession were extracted from the passport data of RDA Genebank. Genotypes for subspecies follow the nomenclature of Zhao et al. 45. Genotypes for subspecies were confirmed by a field test in 2011.
Figure 3
Figure 3
Identification of individual GSL composition in the three subspecies of Brassica rapa. (A) Content of aliphatic, indolic and aromatic GSLs comprising total GSL content for three subspecies. (B) Ratio of aliphatic, indolic and aromatic GSLs in total GSL content of three subspecies. (C) Ratio of individual GSL in aliphatic GSLs of three subspecies. (D) Ratio of individual GSL in indolic GSLs of three subspecies. GRA, glucoraphanin.
Figure 4
Figure 4
Relative expression analysis of BrMYB TFs related to GSL biosynthesis in 38 accessions of Brassica rapa. The Bractin gene was used as the quantitative control. Values indicated the average of three biological replicates. The relative expression was calculated as the fold increase relative to ssp. narinosa IT215413 with the lowest total GSL content.
Figure 5
Figure 5
Expression analysis of nine BrMYB TFs related to GSL biosynthesis at different developmental stages in Brassica rapa. BLCS0D, seeds, mature; BLCS2D, seedling (2 days old); BLCS1W, whole plant, 1 week old vegetative stage (7 days old); BLCS2W, whole plant, 2 weeks old vegetative stage (14 days old); BLCC0D, whole plant, 3 weeks old vegetative stage (21 days old); BLCC1D, whole plant, 1 day after light‐chilled at 4 °C (22 days old); BLCC1W, whole plant, 1 week after light‐chilled at 4 °C (28 days old); BLCC4W, whole plant, 4 weeks after light‐chilled at 4 °C (56 days old); BLCC7W, whole plant, 7 weeks after light‐chilled at 4 °C (70 days old); BLCA1D, whole plant, 1 day after greenhouse growth (71 days old); BLCA2D, whole plant, 2 days after green house growth (72 days old); BLCA1W, whole plant, 1 week after green house growth (77 days old; BLCA2W, whole plant, 2 weeks after greenhouse growth (84 days old); BLCA3W, whole plant, 3 weeks after greenhouse growth (91 days old). LCS, vegetative stage; LCC, chilling treatment (vernalization); LCA, growth stage after chilling treatment (reproductive stage).
Figure 6
Figure 6
Microarray expression analysis at different abiotic stresses of nine BrMYB TFs related to GSL biosynthesis of Brassica rapa. Control, 3‐week‐old whole plant; cold, 4 °C cold treatment; drought, air‐dry; salt, 250 mm NaCl; ABA, 100 μm abscisic acid.
Figure 7
Figure 7
Microarray analysis of effects of two biotic stresses on the expression of nine BrMYB TFs related to GSL biosynthesis in Brassica rapa. (A) Expression changes after infection with Plasmodiophora brassicae (BCR_CTR28, non‐infected 28‐day‐old roots; BCR_INR28, 28‐day‐old roots infected by P. brassicae; BCR_CTR38, non‐infected 38‐day‐old roots; BCR_INR38, infected 38‐day‐old roots; BCR_CTR55, non‐infected 55‐day‐old roots; BCR_INR55, infected 55‐day‐old roots). (B) Expression changes after infection of Pectobacterium carotovorum (BPC00, non‐infected reference, leaf, one‐third upper part from the top; BPC6–48, 6–48 h post infection, non‐necrotic).

Similar articles

See all similar articles

Cited by 3 PubMed Central articles

References

    1. Hayes JD, Kelleher MO and Eggleston IM (2008) The cancer chemopreventive actions of phytochemicals derived from GSLs. Eur J Nutr 47, 73–88. - PubMed
    1. Mun JH, Kwon SJ, Seol YJ, Kim J, Jin M, Kim JS, Lim MH, Lee SI, Hong JK, Park TH et al (2010) Sequence and structure of Brassica rapa chromosome A3. Genome Biol 11, R94. - PMC - PubMed
    1. Wang X, Wang H, Wang J, Sun R, Wu J, Liu S, Bai Y, Mun JH, Bancroft I, Cheng F et al (2011) The genome of the mesopolyploid crop species Brassica rapa . Nat Genet 43, 1035–1157. - PubMed
    1. Mun JH, Yu HJ, Shin JY, Oh MJ, Hwang HJ and Chung H (2012) Auxin response factor gene family in Brassica rapa: genomic organization, divergence, expression, and evolution. Mol Genet Genomics 287, 765–784. - PMC - PubMed
    1. Zang YX, Kim HU, Kim JA, Lim MH, Jin M, Lee SC, Kwon SJ, Lee SI, Hong JK, Park TH et al (2009) Genome‐wide identification of glucosinolate synthesis genes in Brassica rapa . FEBS J 276, 3559–3574. - PubMed

LinkOut - more resources

Feedback