A naturally occurring variation in the BrMAM-3 gene is associated with aliphatic glucosinolate accumulation in Brassica rapa leaves

Jifang Zhang; Hui Wang; Zhiyuan Liu; Jianli Liang; Jian Wu; Feng Cheng; Shiyong Mei; Xiaowu Wang

doi:10.1038/s41438-018-0074-6

A naturally occurring variation in the BrMAM-3 gene is associated with aliphatic glucosinolate accumulation in Brassica rapa leaves

Hortic Res. 2018 Dec 1:5:69. doi: 10.1038/s41438-018-0074-6. eCollection 2018.

Authors

Jifang Zhang^#^{1

2}, Hui Wang^#^{1

3}, Zhiyuan Liu¹, Jianli Liang¹, Jian Wu¹, Feng Cheng¹, Shiyong Mei², Xiaowu Wang¹

Affiliations

¹ 1Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, 100081 Beijing, China.
² 2Institute of Southern Economic Crops, Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, 410205 Changsha, China.
³ 3College of Horticulture, Qingdao Agricultural University, 266109 Qingdao, China.

^# Contributed equally.

Abstract

Glucosinolate profiles significantly vary among Brassica rapa genotypes. However, the molecular basis of these variations is largely unknown. In this study, we investigated a major quantitative trait locus (QTL) controlling aliphatic glucosinolate accumulation in B. rapa leaves. The QTL, which encompasses three tandem MAM genes and two MYB genes, was detected in two BC₂DH populations. Among the five-candidate genes, only the expression level of BrMAM-3 (Bra013007) was significantly correlated with the accumulation of aliphatic glucosinolates in B. rapa leaves. We identified a naturally occurring insertion within exon 1 of BrMAM-3, which is predicted to be a loss-of-function mutation, as confirmed by qRT-PCR. We determined that the loss of function was associated with the low glucosinolate content in B. rapa accessions. Furthermore, overexpressing the BrMAM-3 gene resulted in an increase in total aliphatic glucosinolates in Arabidopsis transgenic lines. Our study provides insights into the molecular mechanism underlying the accumulation of aliphatic glucosinolates in B. rapa leaves, thereby facilitating in the manipulation of total aliphatic glucosinolate content in Brassica crops.