Data_Sheet_2_QTL Mapping of Seed Glucosinolate Content Responsible for Environment in Brassica napus.XLSX

<p>Glucosinolates (GSLs) are a major class of secondary metabolites. The content of seed GSL is largely regulated by environments in rapeseed (Brassica napus). However, the genetic control of seed GSL content responsible for environment in B. napus has been poorly understood. In the current study, a doubled haploid (DH) population from a cross between winter and semi-winter lines of rapeseed was grown in two distinct eco-environments, Germany and China, to evaluate the eco-environment effect and dissect the quantitative trait loci (QTL) responsible for environment for seed GSL in rapeseed. The deviation value of GSL content between eco-environments (GSLE) was calculated for each line in the DH population and the QTLs for GSLE were detected. GSLE ranged from −46.90 to 36.13 μmol g⁻¹ meal in the DH population, suggesting the prominent eco-environmental effects for seed GSL in rapeseed. Four QTLs for GSLE were identified on chromosomes A04, A06, and A09 explaining 4.70∼9.93% of the phenotypic variation. Comparison of QTLs of seed GSL content between different eco-environments found three QTLs for GSL on A02 from 37.6 to 45.4 cM, A04 from 0 to 17.2 cM, and A09 from 67.0 to 98.6 cM exhibited significant difference of QTL effect between the German and Chinese eco-environments (P < 0.01), indicating the environment sensibility of these loci on seed GSL content. Moreover, flowering time (FT), an important environment adaptation trait in plant, was also investigated in this study. Comparative QTL analysis among GSLE, GSL, and FT revealed that three regions on chromosomes A02, A04, and A09 not only exhibited significant differences in QTL effect between Germany and China, but also co-located with the QTL intervals of GSLE and FT. Our results revealed that most of the GSL loci can influence GSL accumulation under different eco-environments, whereas the three QTL intervals on A02, A04, and A09 might be sensitive to the eco-environments for seed GSL content.</p

DataSheet_1_Brassica juncea BRC1-1 induced by SD negatively regulates flowering by directly interacting with BjuFT and BjuFUL promoter.docx

Flowering is crucial for sexual reproductive success in angiosperms. The core regulatory factors, such as FT, FUL, and SOC1, are responsible for promoting flowering. BRANCHED 1 (BRC1) is a TCP transcription factor gene that plays an important role in the regulation of branching and flowering in diverse plant species. However, the functions of BjuBRC1 in Brassica juncea are largely unknown. In this study, four homologs of BjuBRC1 were identified and the mechanism by which BjuBRC1 may function in the regulation of flowering time was investigated. Amino acid sequence analysis showed that BjuBRC1 contained a conserved TCP domain with two nuclear localization signals. A subcellular localization assay verified the nuclear localization of BjuBRC1. Expression analysis revealed that BjuBRC1-1 was induced by short days and was expressed abundantly in the leaf, flower, and floral bud but not in the root and stem in B. juncea. Overexpression of BjuBRC1-1 in the Arabidopsis brc1 mutant showed that BjuBRC1-1 delayed flowering time. Bimolecular fluorescent complementary and luciferase complementation assays showed that four BjuBRC1 proteins could interact with BjuFT in vivo. Notably, BjuBRC1 proteins formed heterodimers in vivo that may impact on their function of negatively regulating flowering time. Yeast one-hybrid, dual-luciferase reporter, and luciferase activity assays showed that BjuBRC1-1 could directly bind to the promoter of BjuFUL, but not BjuFT or BjuSOC1, to repress its expression. These results were supported by the reduced expression of AtFUL in transgenic Arabidopsis overexpressing BjuBRC1-1. Taken together, the results indicate that BjuBRC1 genes likely have a conserved function in the negative regulation of flowering in B. juncea.</p

Table_1_Genome-Wide Association Study Reveals Both Overlapping and Independent Genetic Loci to Control Seed Weight and Silique Length in Brassica napus.XLSX

<p>Seed weight (SW) is one of three determinants of seed yield, which positively correlates with silique length (SL) in Brassica napus (rapeseed). However, the genetic mechanism underlying the relationship between seed weight (SW) and silique length (SL) is largely unknown at present. A natural population comprising 157 inbred lines in rapeseed was genotyped by whole-genome re-sequencing and investigated for SW and SL over four years. The genome-wide association study identified 20 SNPs in significant association with SW on A01, A04, A09, C02, and C06 chromosomes and the phenotypic variation explained by a single locus ranged from 11.85% to 34.58% with an average of 25.43%. Meanwhile, 742 SNPs significantly associated with SL on A02, A03, A04, A07, A08, A09, C01, C03, C04, C06, C07, and C08 chromosomes were also detected and the phenotypic variation explained by a single locus ranged from 4.01 to 48.02% with an average of 33.33%, out of which, more than half of the loci had not been reported in the previous studies. There were 320 overlapping or linked SNPs for both SW and SL on A04, A09, and C06 chromosomes. It indicated that both overlapping and independent genetic loci controlled both SW and SL in B. napus. On the haplotype block on A09 chromosome, the allele variants of a known gene BnaA.ARF18.a controlling both SW and SL were identified in the natural population by developing derived cleaved amplified polymorphic sequence (dCAPS) markers. These findings are valuable for understanding the genetic mechanism of SW and SL and also for rapeseed molecular breeding programs.</p