Open AccessGenetic variation of BnaA3.NIP5;1 expressing in the lateral root cap contributes to boron deficiency tolerance in Brassica napus
Author(s) -
Ming He,
Sheliang Wang,
Cheng Zhang,
Liu Liu,
Jinyao Zhang,
Shou Qiu,
Hong Wang,
Guangsheng Yang,
Shaowu Xue,
Lei Shi,
Fangsen Xu
Publication year - 2021
Publication title -
plos genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.587
H-Index - 233
eISSN - 1553-7404
pISSN - 1553-7390
DOI - 10.1371/journal.pgen.1009661
Subject(s) - biology , brassica , rapeseed , gene , allele , genetics , cultivar , genetic variation , quantitative trait locus , botany
Boron (B) is essential for vascular plants. Rapeseed ( Brassica napus ) is the second leading crop source for vegetable oil worldwide, but its production is critically dependent on B supplies. BnaA3 . NIP5;1 was identified as a B-efficient candidate gene in B . napus in our previous QTL fine mapping. However, the molecular mechanism through which this gene improves low-B tolerance remains elusive. Here, we report genetic variation in BnaA3 . NIP5; 1 gene, which encodes a boric acid channel, is a key determinant of low-B tolerance in B . napus . Transgenic lines with increased BnaA3 . NIP5;1 expression exhibited improved low-B tolerance in both the seedling and maturity stages. BnaA3.NIP5;1 is preferentially polar-localized in the distal plasma membrane of lateral root cap (LRC) cells and transports B into the root tips to promote root growth under B-deficiency conditions. Further analysis revealed that a CTTTC tandem repeat in the 5’UTR of BnaA3 . NIP5;1 altered the expression level of the gene, which is tightly associated with plant growth and seed yield. Field tests with natural populations and near-isogenic lines (NILs) confirmed that the varieties carried BnaA3 . NIP5;1 Q allele significantly improved seed yield. Taken together, our results provide novel insights into the low-B tolerance of B . napus , and the elite allele of BnaA3 . NIP5;1 could serve as a direct target for breeding low-B-tolerant cultivars.