Genetic analysis of agronomic and quality traits in mustard (Brassica juncea)

Effect of Storage Temperature on Storage Life and Sensory Attributes of Packaged Mustard Microgreens

Short shelf life limits the commercial value of mustard microgreens. The present study was conducted to evaluate the effects of different storage temperatures on postharvest quality and sensory attributes of mustard microgreens to identify the optimum storage temperature. Mustard microgreens were stored at 5, 10, 15, 20, and 25 °C in 150 µm polyethylene bags. Samples were drawn at 0, 1, 2, 4, 7, 10, and 14 days and tested for changes in total chlorophyll content, tissue electrolyte leakage, weight loss, antioxidant activity, and sensory attributes. Storage temperature significantly (p < 0.05) affected the product quality, shelf life, and sensory quality. When stored at 5 °C, mustard microgreens showed no significant changes in antioxidant activity or tissue electrolyte leakage and minimal change in other parameters and maintained good overall sensory quality for 14 days. Samples stored at 10 and 15 °C retained good overall sensory quality for 4 and 2 days, respectively. When stored at 20 and 25 °C, microgreens deteriorated beyond consumption within one day. A storage temperature of 5 °C in 150 µm polythene bags can preserve high postharvest quality and sensory attributes for 14 days.

Removing the major allergen Bra j I from brown mustard (Brassica juncea) by CRISPR/Cas9

Food allergies are a major health issue worldwide. Modern breeding techniques such as genome editing via CRISPR/Cas9 have the potential to mitigate this by targeting allergens in plants. This study addressed the major allergen Bra j I, a seed storage protein of the 2S albumin class, in the allotetraploid brown mustard (Brassica juncea). Cotyledon explants of an Indian gene bank accession (CR2664) and the German variety Terratop were transformed using Agrobacterium tumefaciens harboring binary vectors with multiple single guide RNAs to induce either large deletions or frameshift mutations in both Bra j I homoeologs. A total of 49 T₀ lines were obtained with up to 3.8% transformation efficiency. Four lines had large deletions of 566 up to 790 bp in the Bra j IB allele. Among 18 Terratop T₀  lines, nine carried indels in the targeted regions. From 16 analyzed CR2664 T₀  lines, 14 held indels and three had all four Bra j I alleles mutated. The majority of the CRISPR/Cas9-induced mutations were heritable to T₁ progenies. In some edited lines, seed formation and viability were reduced and seeds showed a precocious development of the embryo leading to a rupture of the testa already in the siliques. Immunoblotting using newly developed Bra j I-specific antibodies revealed the amount of Bra j I protein to be reduced or absent in seed extracts of selected lines. Removing an allergenic determinant from mustard is an important first step towards the development of safer food crops.

Sustainable Use of Bioactive Compounds from Solanum Tuberosum and Brassicaceae Wastes and by-Products for Crop Protection-A Review

Defatted seed meals of oleaginous Brassicaceae, such as Eruca sativa, and potato peel are excellent plant matrices to recover potentially useful biomolecules from industrial processes in a circular strategy perspective aiming at crop protection. These biomolecules, mainly glycoalkaloids and phenols for potato and glucosinolates for Brassicaceae, have been proven to be effective against microbes, fungi, nematodes, insects, and even parasitic plants. Their role in plant protection is overviewed, together with the molecular basis of their synthesis in plant, and the description of their mechanisms of action. Possible genetic and biotechnological strategies are presented to increase their content in plants. Genetic mapping and identification of closely linked molecular markers are useful to identify the loci/genes responsible for their accumulation and transfer them to elite cultivars in breeding programs. Biotechnological approaches can be used to modify their allelic sequence and enhance the accumulation of the bioactive compounds. How the global challenges, such as reducing agri-food waste and increasing sustainability and food safety, could be addressed through bioprotector applications are discussed here.

Genome wide association analyses to understand genetic basis of flowering and plant height under three levels of nitrogen application in Brassica juncea (L.) Czern & Coss

Timely transition to flowering, maturity and plant height are important for agronomic adaptation and productivity of Indian mustard (B. juncea), which is a major edible oilseed crop of low input ecologies in Indian subcontinent. Breeding manipulation for these traits is difficult because of the involvement of multiple interacting genetic and environmental factors. Here, we report a genetic analysis of these traits using a population comprising 92 diverse genotypes of mustard. These genotypes were evaluated under deficient (N75), normal (N100) or excess (N125) conditions of nitrogen (N) application. Lower N availability induced early flowering and maturity in most genotypes, while high N conditions delayed both. A genotyping-by-sequencing approach helped to identify 406,888 SNP markers and undertake genome wide association studies (GWAS). 282 significant marker-trait associations (MTA's) were identified. We detected strong interactions between GWAS loci and nitrogen levels. Though some trait associated SNPs were detected repeatedly across fertility gradients, majority were identified under deficient or normal levels of N applications. Annotation of the genomic region (s) within ± 50 kb of the peak SNPs facilitated prediction of 30 candidate genes belonging to light perception, circadian, floral meristem identity, flowering regulation, gibberellic acid pathways and plant development. These included over one copy each of AGL24, AP1, FVE, FRI, GID1A and GNC. FLC and CO were predicted on chromosomes A02 and B08 respectively. CDF1, CO, FLC, AGL24, GNC and FAF2 appeared to influence the variation for plant height. Our findings may help in improving phenotypic plasticity of mustard across fertility gradients through marker-assisted breeding strategies.

Fatty acid composition and oil content during coriander fruit development

Coriander contains petroselinic acid, an isomer fatty acid of oleic acid. Coriander seed oil has been proposed as novel food ingredient in the European Union. Field experiments were performed at Auch (France) during two seasons (2010 and 2011). From flowering to maturity, fruits were harvested weekly and oil content and fatty acid (FA) compositions were determined. Fruits presented 2% more oil in 2010 than in 2011. Petroselinic acid (PA) contents was higher in 2011 than in 2010. Oil accumulation began earlier after flowering (2 DAF) in 2011. A first step in accumulation was identified between two and 21 DAF characterized by high SFA and PUFA, which decreased 21 DAF. Subsequently, PA increased to its highest concentration (30-55 DAF) and SFA and PUFA reached their lowest. These results suggest that higher concentrations of PA can be achieved by collecting fruits before full maturity.

Deciphering allelic variations for seed glucosinolate traits in oilseed mustard (Brassica juncea) using two bi-parental mapping populations

QTL mapping by two DH mapping populations deciphered allelic variations for five different seed glucosinolate traits in B. juncea. Allelic variations for five different seed glucosinolate (GS) traits, namely % propyl, % butyl, % pentyl, aliphatics and total GS content were studied through QTL analysis using two doubled haploid (DH) mapping populations. While the high GS parents in two populations differed in their profiles of seed aliphatic GS, the low GS parents were similar. Phenotypic data of seed GS traits from three environments of the two populations were subjected to QTL analysis. The first population (referred to as DE population) detected a total of 60 QTL from three environments which upon intra-population meta-QTL analysis were merged to 17 S-QTL (Stable QTL) and 15 E-QTL (Environment QTL). The second population (referred to as VH population) detected 58 QTL from the three environments that were merged to 15S-QTL and 16E-QTL. In both the populations, majority of S-QTL were detected as major QTL. Inter-population meta-analysis identified three C-QTL (consensus QTL) formed by merging major QTL from the two populations. Candidate genes of GS pathway were co-localized to the QTL regions either through genetic mapping or through in silico comparative analysis. Parental allelic variants of QTL or of the co-mapped candidate gene(s) were determined on the basis of the significantly different R (2) values of the component QTL from the two populations which were merged to form C-QTL. The results of the study are significant for marker-assisted transfer of the low GS trait and also for developing lines with lower GS than are present in Brassica juncea.

Genetic Variability in Glucosinolates in Seed ofBrassica juncea: Interest in Mustard Condiment

Brassica junceais mostly used for oil production which implies selection of genotypes with low glucosinolates level and high oil content. In contrast, condiment production needs varieties with high level in some glucosinolates including sinigrin. The genetic variability was studied mostly by molecular tools. The objectives were almost the decrease of glucosinolates level in order to use the oilcake for animal feed. The aim of this work is to study the genetic variability for different glucosinolates and their relationships with agronomical traits within a large collection ofBrassica junceagenotypes for condiment uses. A collection of 190 genotypes from different origins was studied in Dijon (France). Oil content and total glucosinolates, and sinigrin and gluconapin levels were measured. Flowering and maturation durations, seed yield, and yield components were also measured. Large variability was observed between genotypes for the measured traits within the studied collection. Total glucosinolates varied twofold between extreme genotypes. Values of sinigrin content varied from 0 to more than 134 µmol·g−1. Correlations between glucosinolates traits and both phenological and agronomical characters are presented and discussed for their potential for industrial condiment uses.

Glucosinolate metabolism, functionality and breeding for the improvement of Brassicaceae vegetables

Unique secondary metabolites, glucosinolates (S-glucopyranosyl thiohydroximates), are naturally occurring S-linked glucosides found mainly in Brassicaceae plants. They are enzymatically hydrolyzed to produce sulfate ions, D-glucose, and characteristic degradation products such as isothiocyanates. The functions of glucosinolates in the plants remain unclear, but isothiocyanates possessing a pungent or irritating taste and odor might be associated with plant defense from microbes. Isothiocyanates have been studied extensively in experimental in vitro and in vivo carcinogenesis models for their cancer chemopreventive properties. The beneficial isothiocyanates, glucosinolates that are functional for supporting human health, have received attention from many scientists studying plant breeding, plant physiology, plant genetics, and food functionality. This review presents a summary of recent topics related with glucosinolates in the Brassica family, along with a summary of the chemicals, metabolism, and genes of glucosinolates in Brassicaceae. The bioavailabilities of isothiocyanates from certain functional glucosinolates and the importance of breeding will be described with emphasis on glucosinolates.

Natural mutations in two homoeologous TT8 genes control yellow seed coat trait in allotetraploid Brassica juncea (AABB)

Identification of the candidate gene responsible for the seed coat colour variation in Brassica juncea was undertaken following an earlier study where two independent loci (BjSc1 and BjSc2) were mapped to two linkage groups, LG A9 and B3 (Padmaja et al. in Theor Appl Genet 111:8-14, 2005). The genome search from BRAD data for the presence of flavonoid genes in B. rapa identified three candidate genes namely, DFR, TT1 and TT8 in the LG A9. Quantitative real-time PCR revealed absence of transcript for the late biosynthetic genes (LBGs) and showed significant reduction of transcript in the TT8 from the developing seeds of yellow-seeded line. While mapping of two DFR genes, the BjuA.DFR and BjuB.DFR did not show perfect co-segregation with the seed coat colour loci, that of the two TT8 genes, BjuA.TT8 and BjuB.TT8 showed perfect co-segregation with the seed coat colour phenotype. The BjuA.TT8 allele from the yellow-seeded line revealed the presence of an insertion of 1,279 bp in the exon 7 and did not produce any transcript as revealed by reverse transcriptase PCR. The BjuB.TT8 allele from the yellow-seeded line revealed the presence of an SNP (C→T) in the exon 7 resulting in a stop codon predicting a truncated protein lacking the C-terminal 8 amino acid residues and produced significantly low level of transcript than its wild-type counterpart. Hence, it is hypothesized that the mutations in both the TT8 genes are required for inhibiting the transcription of LBGs in the yellow-seeded mutant of B. juncea.

Targeted silencing of BjMYB28 transcription factor gene directs development of low glucosinolate lines in oilseed Brassica juncea

Brassica juncea (Indian mustard), a globally important oilseed crop, contains relatively high amount of seed glucosinolates ranging from 80 to 120 μmol/g dry weight (DW). One of the major breeding objectives in oilseed Brassicas is to improve the seed-meal quality through the development of low-seed-glucosinolate lines (<30 μmol/g DW), as high amounts of certain seed glucosinolates are known to be anti-nutritional and reduce the meal palatability. Here, we report the development of transgenic B. juncea lines having seed glucosinolates as low as 11.26 μmol/g DW, through RNAi-based targeted suppression of BjMYB28, a R2R3-MYB transcription factor family gene involved in aliphatic glucosinolate biosynthesis. Targeted silencing of BjMYB28 homologs provided significant reduction in the anti-nutritional aliphatic glucosinolates fractions, without altering the desirable nonaliphatic glucosinolate pool, both in leaves and seeds of transgenic plants. Molecular characterization of single-copy, low glucosinolate homozygous lines confirmed significant down-regulation of BjMYB28 homologs vis-à-vis enhanced accumulation of BjMYB28-specific siRNA pool. Consequently, these low glucosinolate lines also showed significant suppression of genes involved in aliphatic glucosinolate biosynthesis. The low glucosinolate trait was stable in subsequent generations of the transgenic lines with no visible off-target effects on plant growth and development. Various seed quality parameters including fatty acid composition, oil content, protein content and seed weight of the low glucosinolate lines also remained unaltered, when tested under containment conditions in the field. Our results indicate that targeted silencing of a key glucosinolate transcriptional regulator MYB28 has huge potential for reducing the glucosinolates content and improving the seed-meal quality of oilseed Brassica crops.

Identification of candidate genes of QTLs for seed weight in Brassica napus through comparative mapping among Arabidopsis and Brassica species

Background

Map-based cloning of quantitative trait loci (QTLs) in polyploidy crop species remains a challenge due to the complexity of their genome structures. QTLs for seed weight in B. napus have been identified, but information on candidate genes for identified QTLs of this important trait is still rare.

Results

In this study, a whole genome genetic linkage map for B. napus was constructed using simple sequence repeat (SSR) markers that covered a genetic distance of 2,126.4 cM with an average distance of 5.36 cM between markers. A procedure was developed to establish colinearity of SSR loci on B. napus with its two progenitor diploid species B. rapa and B. oleracea through extensive bioinformatics analysis. With the aid of B. rapa and B. oleracea genome sequences, the 421 homologous colinear loci deduced from the SSR loci of B. napus were shown to correspond to 398 homologous loci in Arabidopsis thaliana. Through comparative mapping of Arabidopsis and the three Brassica species, 227 homologous genes for seed size/weight were mapped on the B. napus genetic map, establishing the genetic bases for the important agronomic trait in this amphidiploid species. Furthermore, 12 candidate genes underlying 8 QTLs for seed weight were identified, and a gene-specific marker for BnAP2 was developed through molecular cloning using the seed weight/size gene distribution map in B. napus.

Conclusions

Our study showed that it is feasible to identify candidate genes of QTLs using a SSR-based B. napus genetic map through comparative mapping among Arabidopsis and B. napus and its two progenitor species B. rapa and B. oleracea. Identification of candidate genes for seed weight in amphidiploid B. napus will accelerate the process of isolating the mapped QTLs for this important trait, and this approach may be useful for QTL identification of other traits of agronomic significance.

Fine mapping of the yellow seed locus in Brassica juncea L

The yellow mustard plant in Northern Shaanxi is a precious germplasm, and the yellow seed trait is controlled by a single recessive gene. In this report, amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) techniques were used to identify markers linked to the brown seed locus in an F(2) population consisting of 1258 plants. After screening 256 AFLP primer combinations and 456 pairs of SSR primers, we found 14 AFLP and 2 SSR markers that were closely linked to the brown seed locus. Among these markers, the SSR marker CB1022 showed codominant inheritance. By integrating markers previously found to be linked to the brown seed locus into the genetic map of the F(2) population, 23 markers were linked to the brown seed locus. The two closest markers, EA02MC08 and P03MC08, were located on either side of the brown seed locus at a distance of 0.3 and 0.5 cM, respectively. To use the markers for the breeding of yellow-seeded mustard plants, two AFLP markers (EA06MC11 and EA08MC13) were converted into sequence-characterized amplified region (SCAR) markers, SC1 and SC2, with the latter as the codominant marker. The two SSR markers were subsequently mapped to the A9/N9 linkage group of Brassica napus L. by comparing common SSR markers with the published genetic map of B. napus. A BLAST analysis indicated that the sequences of seven markers showed good colinearity with those of Arabidopsis chromosome 3 and that the homolog of the brown seed locus might exist between At3g14120 and At3g29615 on this same chromosome. To develop closer markers, we could make use of the sequence information of this region to design primers for future studies. Regardless, the close markers obtained in the present study will lay a solid foundation for cloning the yellow seed gene using a map-based cloning strategy.

Prediction of drought-resistant genes in Arabidopsis thaliana using SVM-RFE

BACKGROUND

Identifying genes with essential roles in resisting environmental stress rates high in agronomic importance. Although massive DNA microarray gene expression data have been generated for plants, current computational approaches underutilize these data for studying genotype-trait relationships. Some advanced gene identification methods have been explored for human diseases, but typically these methods have not been converted into publicly available software tools and cannot be applied to plants for identifying genes with agronomic traits.

METHODOLOGY

In this study, we used 22 sets of Arabidopsis thaliana gene expression data from GEO to predict the key genes involved in water tolerance. We applied an SVM-RFE (Support Vector Machine-Recursive Feature Elimination) feature selection method for the prediction. To address small sample sizes, we developed a modified approach for SVM-RFE by using bootstrapping and leave-one-out cross-validation. We also expanded our study to predict genes involved in water susceptibility.

CONCLUSIONS

We analyzed the top 10 genes predicted to be involved in water tolerance. Seven of them are connected to known biological processes in drought resistance. We also analyzed the top 100 genes in terms of their biological functions. Our study shows that the SVM-RFE method is a highly promising method in analyzing plant microarray data for studying genotype-phenotype relationships. The software is freely available with source code at http://ccst.jlu.edu.cn/JCSB/RFET/.

Mapping of quantitative trait loci and development of allele-specific markers for seed weight in Brassica napus

Seed weight is an important component of grain yield in oilseed rape (Brassica napus L.), but the genetic basis for the important quantitative trait is still not clear. In order to identify the genes for seed weight in oilseed rape, QTL mapping for thousand seed weight (TSW) was conducted with a doubled haploid (DH) population and an F(2) population. A complete linkage map of the DH population was constructed using 297 simple sequence repeat (SSR) markers. Among nine TSW QTLs detected, two major QTLs, TSWA7a and TSWA7b, were stably identified across years and collectively explained 27.6-37.9% of the trait variation in the DH population. No significant epistatic interactions for TSW detected in the DH population indicate that the seed weight variation may be primarily attributed to additive effects. The stability and significance of TSWA7a and TSWA7b were further validated in the F(2) population with different genetic backgrounds. By cloning BnMINI3a and BnTTG2a, two B. napus homologous genes to Arabidopsis thaliana, allele-specific markers were developed for TSWA5b and TSWA5c, two TSW QTLs on A5, respectively. The importance of the major and minor QTLs identified was further demonstrated by analysis of the allelic effects on TSW in the DH population.

Fine mapping of loci involved with glucosinolate biosynthesis in oilseed mustard (Brassica juncea) using genomic information from allied species

Fine mapping of six seed glucosinolate QTL (J2Gsl1, J3Gsl2, J9Gsl3, J16Gsl4, J17Gsl5 and J3Gsl6) (Ramchiary et al. in Theor Appl Genet 116:77-85, 2007a) was undertaken by the candidate gene approach. Based on the DNA sequences from Arabidopsis and Brassica oleracea for the different genes involved in the aliphatic glucosinolate biosynthesis, candidate genes were amplified and sequenced from high to low glucosinolate Brassica juncea lines Varuna and Heera, respectively. Of the 20 paralogues identified, 17 paralogues belonging to six gene families were mapped to 12 of the 18 linkage groups of B. juncea genome. Co-mapping of candidate genes with glucosinolate QTL revealed that the candidate gene BjuA.GSL-ELONG.a mapped to the QTL interval of J2Gsl1, BjuA.GSL-ELONG.c, BjuA.GSL-ELONG.d and BjuA.Myb28.a mapped to the QTL interval of J3Gsl2, BjuA.GSL-ALK.a mapped to the QTL interval of J3Gsl6 and BjuB.Myb28.a mapped to the QTL interval of J17Gsl5. The QTL J9Gsl3 and J16Gsl4 did not correspond to any of the mapped candidate genes. The functionality and contribution of different candidate genes/QTL was assessed by allelic variation study using phenotypic data of 785 BC(4)DH lines. It was observed that BjuA.Myb28.a and J9Gsl3 contributed significantly to the base level glucosinolate production while J16Gsl4, probably GSL-PRO, BjuA.GSL-ELONG.a and BjuA.GSL-ELONG.c contributed to the C3, C4 and C5 elongation pathways, respectively. Three A genome QTL: J2Gsl1harbouring BjuA.GSL-ELONG.a, J3Gsl2 harbouring both BjuA.GSL-ELONG.c and BjuA.Myb28.a and J9Gsl3, possibly the 'Bronowski genes', were identified as most important loci for breeding low glucosinolate B. juncea. We observed two-step genetic control of seed glucosinolate in B. juncea mainly effected by these three A genome QTL. This study, therefore, provides clues to the genetic mechanism of 'Bronowski genes' controlling the glucosinolate trait and also provides efficient markers for marker-assisted introgression of low glucosinolate trait in B. juncea.

QTL analysis reveals context-dependent loci for seed glucosinolate trait in the oilseed Brassica juncea: importance of recurrent selection backcross scheme for the identification of 'true' QTL

Seed glucosinolate content in Brassica juncea is a complex quantitative trait. A recurrent selection backcross (RSB) method with a doubled haploid (DH) generation interspersing backcross generations was used for the introgression of low glucosinolate alleles from an east European gene pool B. juncea line, Heera into an Indian gene pool variety, Varuna. Phenotypic comparisons among the DH populations derived from early to advanced backcrosses revealed a shift in the mean values for various glucosinolates with the advancement of backcrossing, indicating a change in the selective values of the alleles with change in the genetic background due to the existence of epistasis and context dependencies. QTL mapping for various seed glucosinolates from early (F(1)DH) and advanced generation (BC(4)DH) populations confirmed the presence of epistasis and context dependency. The common QTL detected in both F(1)DH and BC(4)DH changed their R (2) values from the former to the later generation. Some of the QTL detected in the F(1)DH became irrelevant in the BC(4)DH population. Further, new QTL were detected in the BC(4)DH population for various glucosinolates. A validation study on a population of low glucosinolate DH lines derived from all the backcross generations of the RSB breeding programme revealed that the QTL detected in BC(4)DH were the 'true' QTL. Using glucosinolate as an example, the study provides strong evidence for the importance of the RSB method for the identification of the 'true' QTL which would be significant for marker assisted introgression of a complex quantitative trait whose expression is influenced by epistatic interactions.

Colocalization of a partially dominant gene for yellow seed colour with a major QTL influencing acid detergent fibre (ADF) content in different crosses of oilseed rape (Brassica napus)

Quantitative trait loci (QTLs) contributing to yellow seed colour and acid detergent fibre (ADF) were localized and compared in 3 mapping populations developed from 2 crosses (designated 'YE1' and 'YE2') between 2 distinct sources of true-breeding yellow-seeded oilseed rape (Brassica napus) and 2 different black-seeded genotypes. A clear correlation was observed between seed colour and ADF content in both crosses. In all 3 populations, a major QTL, with a large effect on both seed colour and ADF in multiple environments, was detected at the same position on chromosome N18. In YE1, a second minor QTL, with a small effect on seed colour but not on ADF content, was localized on chromosome N1. In YE2, no QTL was observed on N1; however, 2 minor seed-colour loci were localized to N15 and N5. A second major QTL for ADF was localized in YE1 on N13; in YE2, no other QTLs for ADF were detected. Combined QTL and segregation data for seed colour and ADF content in the different populations suggest that a partially dominant B. napus gene for seed colour on N18 contributes to a reduction in fibre content in different yellow-seeded B. napus genotypes. The other QTLs that were identified appear to represent different genes in the 2 yellow-seeded rapeseed sources, which, in each case, affect only fibre content or seed colour, respectively. Potential candidate genes and implications for marker-assisted breeding of oilseed rape with reduced seed dietary fibre content are discussed.

A conserved role of SHORT VEGETATIVE PHASE (SVP) in controlling flowering time of Brassica plants

The control of flowering time in Brassica plants is an important approach for improving productivity, as vegetative tissues are not produced after the floral transition in Brassica plants. In order to determine the feasibility of modulating flowering time in Chinese cabbage plants, genes homologous to Arabidopsis SHORT VEGETATIVE PHASE (AtSVP) were isolated from spring-type and fall-type cultivars of Chinese cabbage plants, and their functions were determined. Their deduced amino acid sequences were 91-93% identical with that of AtSVP. The expression of BcSVP was ubiquitously detected, and was unaffected by vernalization. Constitutive BcSVP expression induced late flowering with additional floral defects. This delayed flowering was attributed to the repression of FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1). BcSVP expression under the control of the AtSVP promoter also resulted in the complementation of the svp mutation in Arabidopsis. These results indicate that BcSVP is a functional equivalent of AtSVP and also suggest that BcSVP may prove useful for the genetic manipulation of flowering time in Brassica plants.