Assessment of FAE1 polymorphisms in three Brassica species using EcoTILLING and their association with differences in seed erucic acid contents

Nian Wang,Xiaoming Wu,Jinling Meng,Lei Shi,Huicai Ning,Yan Long,Fang Tian

doi:10.1186/1471-2229-10-137

Nian Wang, Xiaoming Wu + Show 5 more

Open Access

https://doi.org/10.1186/1471-2229-10-137

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Abstract

BackgroundFAE1 (fatty acid elongase1) is the key gene in the control of erucic acid synthesis in seeds of Brassica species. Due to oil with low erucic acid (LEA) content is essential for human health and not enough LEA resource could be available, thus new LEA genetic resources are being sought for Brassica breeding. EcoTILLING, a powerful genotyping method, can readily be used to identify polymorphisms in Brassica.ResultsSeven B. rapa, nine B. oleracea and 101 B. napus accessions were collected for identification of FAE1 polymorphisms. Three polymorphisms were detected in the two FAE1 paralogues of B. napus using EcoTILLING and were found to be strongly associated with differences in the erucic acid contents of seeds. In genomic FAE1 sequences obtained from seven B. rapa accessions, one SNP in the coding region was deduced to cause loss of gene function. Molecular evolution analysis of FAE1 homologues showed that the relationship between the Brassica A and C genomes is closer than that between the A/C genomes and Arabidopsis genome. Alignment of the coding sequences of these FAE1 homologues indicated that 18 SNPs differed between the A and C genomes and could be used as genome-specific markers in Brassica.ConclusionThis study showed the applicability of EcoTILLING for detecting gene polymorphisms in Brassica. The association between B. napus FAE1 polymorphisms and the erucic acid contents of seeds may provide useful guidance for LEA breeding. The discovery of the LEA resource in B. rapa can be exploited in Brasscia cultivation.

Highlights

FAE1 is the key gene in the control of erucic acid synthesis in seeds of Brassica species
In 2002 and 2004, one SNP was found in FAE1 between a high and a low erucic acid content B. napus cultivar [13,14], and this was reported by Nath et al [15]
In the molecular evolutionary analysis of the FAE1 sequences of the three Brassica species and Arabidopsis, we found 18 SNPs that differed between the A and C genomes

Summary

Introduction

FAE1 (fatty acid elongase1) is the key gene in the control of erucic acid synthesis in seeds of Brassica species. FAE1 (fatty acid elongase1) is the key gene in controlling erucic acid synthesis in Brassica seeds. It was originally cloned in Arabidopsis by directed transposon tagging with the maize element Activator (Ac); no intron was found in this gene [7]. A four-base nucleotide deletion within the FAE1 coding region in an LEA compared to an HEA cultivar was reported Expression these HEA and LEA FAE1 genes in yeast indicated that the SNP or indel causes the differences in erucic acid content [13,14,16]. The B. rapa (A) and B. oleracea (C) genomes have paralogous FAE1 s [17]

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