Fine mapping of the BnaC04.BIL1 gene controlling plant height in Brassica napus L

Abstract

Background Plant height is an important architecture trait which is a fundamental yield-determining trait in crops. Variety with dwarf or semi-dwarf phenotype is a major objective in the breeding because dwarfing architecture can help to increase harvest index, increase planting density, enhance lodging resistance, and thus be suitable for mechanization harvest. Although some germplasm or genes associated with dwarfing plant type have been carried out. The molecular mechanisms underlying dwarfism in oilseed rape (Brassica napus L.) are poorly understood, restricting the progress of breeding dwarf varieties in this species. Here, we report a new dwarf mutant Bndwarf2 from our B. napus germplasm. We studied its inheritance and mapped the dwarf locus BnDWARF2. Results The inheritance analysis showed that the dwarfism phenotype was controlled by one semi-dominant gene, which was mapped in an interval of 787.88 kb on the C04 chromosome of B. napus by Illumina Brassica 60 K Bead Chip Array. To fine-map BnDWARF2, 318 simple sequence repeat (SSR) primers were designed to uniformly cover the mapping interval. Among them, 15 polymorphic primers that narrowed down the BnDWARF2 locus to 34.62 kb were detected using a F2:3 family population with 889 individuals. Protein sequence analysis showed that only BnaC04.BIL1 (BnaC04g41660D) had two amino acid residues substitutions (Thr187Ser and Gln399His) between ZS11 and Bndwarf2, which encoding a GLYCOGEN SYNTHASE KINASE 3 (GSK3-like). The quantitative real-time PCR (qRT-PCR) analysis showed that the BnaC04.BIL1 gene expressed in all tissues of oilseed rape. Subcellular localization experiment showed that BnaC04.BIL1 was localized in the nucleus in tobacco leaf cells. Genetic transformation experiments confirmed that the BnaC04.BIL1 is responsible for the plant dwarf phenotype in the Bndwarf2 mutants. Overexpression of BnaC04.BIL1 reduced plant height, but also resulted in compact plant architecture. Conclusions A dominant dwarfing gene, BnaC04.BIL1, encodes an GSK3-like that negatively regulates plant height, was mapped and isolated. Our identification of a distinct gene locus may help to improve lodging resistance in oilseed rape.

Genetic mapping of some key plant architecture traits in Brassica juncea using a cross between two distinct lines – vegetable type Tumida and oleiferous Varuna

“…The use of dwarfing genes has been shown to improve the resistance to plant lodging in B. napus (Muangprom et al 2006; Liu et al 2010; Yang et al 2021). Therefore, the introgression of the S-Plht-A06-1 locus from Tumida could further improve the lodging resistance of the Indian gene pool lines via reduction of Plht .…”

Genome-wide association study reveals a GLYCOGEN SYNTHASE KINASE 3 gene regulating plant height in Brassica napus

“…org/index.jsp). In B. napus, BnaC04.BIL1, which has been isolated from the dwarf mutant Bndwarf2 (Yang et al, 2021), encodes BIN2-LIKE 1, and is also a member of GSK3s.…”

“…AtBIN2 plays a role in the crosstalk between auxin and brassinosteroid signaling pathways ( ). In B. napus , BnaC04.BIL1 , which has been isolated from the dwarf mutant Bndwarf2 ( Yang et al., 2021 ), encodes BIN2-LIKE 1, and is also a member of GSK3s .…”

“…Mutation of BnaA3.IAA7 , which encodes an auxin-inducible protein, disrupted the conserved degradation motif GWPPV and reduced the affinity between BnaA3.IAA7 and the transport inhibitor in an auxin dose-dependent manner, thus inhibiting BnaA3.IAA7 degradation and auxin signaling in B. napus dwarf mutant sca ( Li et al., 2019a ). The dwarf locus BnDWARF2 was mapped to a 34.62 kb interval, in which BnaC04g41660D encoding a GLYCOGEN SYNTHASE KINASE 3 (GSK3-like) in the brassinosteroid signaling, was the causal gene controlling plant height in oilseed rape ( Yang et al., 2021 ). In addition, other genes unrelated to plant hormones may also be involved in the regulation of plant height in B. napus ; for example, the Octicosapeptide/Phox/Bem1p family protein encoding gene BnaC09g20450D contains a single nucleotide polymorphism (SNP) that co-segregates with the dwarf phenotype in df59 mutant ( Wang et al., 2020a ).…”

Transcriptome and Small RNA Sequencing Reveal the Mechanisms Regulating Harvest Index in Brassica napus

“…Combined with transcriptomic sequencing (RNA-seq) of materials with high and low HI, candidate genes involved in photosynthesis, inflorescence, and silique development were identified ( Lu et al, 2016 ). In addition, in B. napus , it was also found that the BnaA02.TB1 ( BnaA02g14010D ) that regulates lateral branch development and the BnaA02.GW2 ( BnaA02g18890D ) that regulates grain weight may be related to HI ( Chao et al, 2019 ); BnaDwf.C9 ( BnaC09g20450D ) and BnaC04.BIL1 ( BnaC04g41660D ) can affect HI by regulating plant height ( Wang X. D. et al, 2020 ; Yang et al, 2021 ). These previous studies are of great worth for helping us to elucidate the genetic mechanism of HI in B. napus .…”