Fig 1.
Phylogenetic tree of FAE1 and FAD2 proteins from Arabidopsis and six Brassica species of U’s triangle (B. nigra, B. oleracea, B. rapa, B. carinata, B. juncea and B. napus).
Different phylogenetic groups are represented in different colors. The accession numbers for query proteins are given as follows: AtFAE1 (AT4G34520), BolFAE1 (BolC3t20858H), BniFAE1 (BniB03g020700.2N), BraFAE1 (BraA08g016330.3.5C), BnaFAE1.1 (A08p16760.1_BnaDAR), BnaFAE1.2 (C03p85720.1_BnaDAR), BjuFAE1.1 (BjuVB03G19720), BjuFAE1.2 (BjuVA08G16890), BcaFAE1.1 (BcaB03g11828), BcaFAE1.2 (BcaC01g00899), AtFAD2 (AT3G12120.1), BolFAD2.1 (BolC5t34237H), BolFAD2.2 (BolC1t05264H), BniFAD2 (BniB01g052830.2N), BraFAD2 (BraA05g035880.3.5C), BnaFAD2.1 (C05p55690.1_BnaDAR), BnaFAD2.2 (A05p37230.1_BnaDAR), BjuFAD2.1 (BjuVB01G42140), BjuFAD2.2 (BjuVA05G37350), BcaFAD2.1 (BcaB06g25543), BcaFAD2.2 (BcaC05g29288) and BcaFAD2.3 (BcaC09g48213).
Table 1.
Pairwise sequence resemblance and divergence percentages between FAE1 and FAD2 proteins.
Fig 2.
Gene structure, domain and motif analysis of FAE1 and FAD2 proteins from six Brassica species and Arabidopsis.
(a) Gene structure of FAE1 and FAD2 genes and domain positions were drawn in Gene Structure Display Server (GSDS) by submitting the full length and coding DNA sequences of FAE1 and FAD2 genes and the BED file for the location of domains selecting proteins’ ordinates. The colored rectangles represent different gene and protein features (see legend for details). (b) Motif analysis was performed using MEME suite v5.5.5 and a total of 15 and 13 statistically significant motifs were identified among the query proteins of FAE1 and FAD2, respectively, which are represented by different colors as given in the legend. See caption of Fig 1 for the accession numbers of the proteins. Motif sequences found in FAE1 and FAD2 proteins are given in S3 Table.
Fig 3.
Cis-acting element analysis of the promoter regions of the FAE1 and FAD2 genes from six Brassica species and Arabidopsis.
Different cis-regulatory elements are represented in different colours as per legend. The cis-regulatory elements are abbreviated as follows: AuxRE, auxin-related responsive element; LRE, light-responsive element; LTRE, low-temperature related element; EERE, endosperm expression regulatory element; ARE, anaerobic induction element; MERE, meristem specific regulatory element; ZMRE, zein metabolism regulatory element; DRE, drought inducibility element; ABRE, abscisic acid-responsive element; MeJARE, methyl jasmonate-responsive element; GARE, gibberellic acid-responsive element; DSRE, defense- and stress-related element; CCRE, circadian control regulatory element; SARE, salicylic acid-responsive element; AnRE, anoxic specific inducibility element; ESNRE, Endosperm specific negative expression element; SSRE, Seed specific regulatory element.
Fig 4.
Phenotypic response of B. juncea and B. napus under control, 100 and 200 mM NaCl stress.
Fig 5.
Effect of NaCl stress on the growth attributes in B. juncea and B. napus. Panel (a-f) represent growth attributes, i.e., shoot length (a), root length (b), shoot fresh weight (c), root fresh weight (d), shoot dry weight (e) and root dry weight (f) in B. juncea and B. napus, respectively.
Gray and black colored bars represent B. juncea and B. napus, respectively. Each data point displays the mean ± SD calculated from three biological repeats (Tukey’s HSD, P < 0.05).
Fig 6.
The expression of FAE1.1 and FAD2.1 genes in different tissues of B. juncea and B. napus under NaCl stress.
(a–e) represent gene expression in flower, silique, leaf, stem and root tissue, respectively under control and NaCl stress conditions. Light yellow, yellow and orange colored bars represent 0, 100 and 200 mM NaCl concentrations, respectively. Each data point displays the mean ± SD calculated from three biological repeats (Tukey’s HSD, P < 0.05).
Fig 7.
Effect of salt stress on yield parameters of B. juncea and B. napus. Pictures of representative plants at maturity under 0, 100 and 200 mM NaCl stress.
Fig 8.
Effect of salinity on growth and yield-related traits of B. juncea and B. napus.
(a) shows plant height, (b) number of primary branches, (c) number of siliques per plant, (d) silique length, (e) number of seeds per silique, and (f) seed yield per plant. Gray and black colored bars represent B. juncea and B. napus, respectively. Data are presented as mean ± SE of biological replicates (Tukey’s HSD, P < 0.05).
Fig 9.
Effect of NaCl stress on the total oil and protein content in the seeds of B. juncea and B. napus.
Black and red lines represent oil and protein content, respectively. Each data point displays the mean ± SD calculated from three biological repeats (Tukey’s HSD, P < 0.05).
Fig 10.
NaCl-induced change in the fatty acid composition in the seeds of B. juncea and B. napus.
(a–g) represent Erucic acid, Eicosenoic acid, Oleic acid, Stearic acid, Palmitic acid, Linoleic acid and Linolenic acid content, repectively. Light gray, gray and black colored bars represent 0, 100 and 200 mM NaCl concentrations, respectively. Each data point displays the mean ± SD calculated from three biological repeats (Tukey’s HSD, P < 0.05).