Nondestructive estimation of fatty acid composition in seeds of Brassica napus L. by near-infrared spectroscopy

The feasibility of near-infrared (NIR) spectroscopy for the nondestructive determination of fatty acid composition in rapeseed was examined. NIR spectra were measured on extracted oil, intact rapeseed kernels, and an intact signle rapeseed with an InfraAlyzer 500 in a syrup cup or a single-grain cup. NIR spectra were scanned from 1100 to 2500 nm at 2-nm intervals. As the percentage of linoleic acid increased, the spectral values in the region 1696–1724 nm, where linoleic acid has its absorption band, became always stronger downward in second-derivative NIR spectra. As the percentage of erucic acid increased the spectral value at 1728 nm, where erucic acid has its absorption band, became always a little bit stronger downward in the second-derivative NIR spectra. On the basis of their NIR spectral patterns, linoleic acid and erucic acid could be successfully determined in both intact seed kernels and in a single seed of rape without damaging them.     

Solubilization of Acyl-CoA elongases from developing rapeseed (Brassica napus L.)

Acyl-CoA elongases are important in producing high-erucic acid rapeseed. The effects of Triton X-100,N-octyl-β-D-glucopyranoside and deoxycholate on the C18:1-CoA and C20:1-CoA elongase(s) have been studied by using a 15,000 ×g pellet from developing rapeseed. The synthesis of very long chain monounsaturated fatty acids (VLCMFA) and, in particular, that of erucic acid were stimulated by Triton X-100, whatever the substrate used. In the presence ofN-octyl-β-D-glucopyranoside, the elongase activity was practically unchanged, whereas deoxycholate strongly inhibited VLCMFA synthesis. Triton X-100 was chosen for the solubilization, at an optimal Triton X-100/protein (w/w) ratio of 2.5. Acyl-CoAs were the major products synthesized by the solubilized acyl-CoA elongase(s). The analysis of the reaction intermediates showed that the entire elongation complex has been solubilized and was still functional.     

Breeding to Increase the Concentration of 2-phenylethyl Glucosinolate in the Roots of Brassica napus

Root concentrations of 2-phenylethyl glucosinolate in canola, Brassica napus, influence the susceptibility of the crop to the root lesion nematode (Pratylenchus neglectus), as well as the nematicidal effect of root tissues as they degrade in the soil. Plants containing high 2-phenylethyl glucosinolate should therefore reduce soil populations of P. neglectus. A selection program was developed to increase the proportion of total glucosinolates contributed by 2-phenylethyl glucosinolate in the roots of B. napus cv. Dunkeld. Variation within this accession was observed to be stable across the S₁ and S₂ generations. The segregation observed for 2-phenylethyl glucosinolate percentage suggested that the trait was encoded at a single locus, with the "high" phenotype being dominant. Plants with the high 2-phenylethyl glucosinolate phenotype (>45% of total glucosinolates) were shown to be significantly more resistant to P. neglectus than otherwise identical "low" phenotypes (<45% of total).     

Cultivar identification inBrassica napus L. by reversed-phase high-performance liquid chromatography of ethanol extracts

A method has been developed to identify cultivars of oilseed rape (Brassica napus L.), an outcrossing species, by reversed-phase high-performance liquid chromatography (HPLC) based on the separation of ethanol-extractable seed components. Defatted flour was extracted into 70% ethanol in water, and chromatography was carried out in a reversed-phase C18 column. Optimum results were achieved with water solvent and a gradient to 50% acetonitrile, and peak detection at 210 nm and 240 nm. Trifluoroacetic acid (0.1%) was added to dissociate proteins. Extraction and chromatographic conditions were reproducible, and significant differences were found in the chromatograms of the 29 cultivars studied. The chromatographic differences between these cultivars were stable over a range of growing environments. It was possible to allocate unknown cultivars to their correct classes with the HPLC method together with discriminate analysis. This test has potential as a method of characterization for cultivar registration. This paper was presented in part at the 83rd AOCS Annual Meeting, Toronto, Ontario, Canada, May 1992.     

Ectopic Expression of BraYAB1-702, a Member of YABBY Gene Family in Chinese Cabbage,Causes Leaf Curling,Inhibition of Development of Shoot Apical Meristem and Flowering Stage Delaying in Arabidopsis thaliana

YABBY gene family plays an important role in the polarity development of lateral organs. We isolated the BraYAB1-702 gene, a member of the YABBY gene family, from young leaves of Chinese cabbage line 06J45. The full-length gene has a 937 bp CDNA sequence and contains an open reading frame (ORF) of 702 bp. The subcellular localization analysis showed that the expression product of the gene was localized in the nucleus. Ectopic expression of BraYAB1-702 in Arabidopsis thaliana caused leaf curling from the adaxial epidermises to abaxial epidermises; the partial abaxialization of the adaxial epidermises of leaves; leaf trichomes and stomata numbers being significantly increased; the plants being severely stunted; the flowering stage being remarkably delayed and inhibiting the development of shoot apical meristem (SAM) with the down-regulation of the expression of SHOOT MERISTEMLESS (STM), Brevipedicellus (BP) and KNAT2 which were related to the development of shoot apical meristem. These results from the present research help to reveal the molecular mechanism of BraYAB1-702 gene in the establishment of adaxial–abaxial polarity of the lateral organs in Chinese cabbage.     

Glutathione Transferases Superfamily: Cold-Inducible Expression of Distinct GST Genes in Brassica oleracea

Plants, as sessile organisms, can suffer serious growth and developmental consequences under cold stress conditions. Glutathione transferases (GSTs, EC 2.5.1.18) are ubiquitous and multifunctional conjugating proteins, which play a major role in stress responses by preventing oxidative damage by reactive oxygen species (ROS). Currently, understanding of their function(s) during different biochemical and signaling pathways under cold stress condition remain unclear. In this study, using combined computational strategy, we identified 65 Brassica oleracea glutathione transferases (BoGST) and characterized them based on evolutionary analysis into 11 classes. Inter-species and intra-species duplication was evident between BoGSTs and Arabidopsis GSTs. Based on localization analyses, we propose possible pathways in which GST genes are involved during cold stress. Further, expression analysis of the predicted putative functions for GST genes were investigated in two cold contrasting genotypes (cold tolerance and susceptible) under cold condition, most of these genes were highly expressed at 6 h and 1 h in the cold tolerant (CT) and cold susceptible (CS) lines, respectively. Overall, BoGSTU19, BoGSTU24, BoGSTF10 are candidate genes highly expressed in B. oleracea. Further investigation of GST superfamily in B. oleracea will aid in understanding complex mechanism underlying cold tolerance in plants.     

Influence of Green,Red and Blue Light Emitting Diodes on Multiprotein Complex Proteins and Photosynthetic Activity under Different Light Intensities in Lettuce Leaves (Lactuca sativa L.)

The objective of this study was to investigate the response of light emitting diodes (LEDs) at different light intensities (70 and 80 for green LEDs, 88 and 238 for red LEDs and 80 and 238 μmol m⁻² s⁻¹ for blue LEDs) at three wavelengths in lettuce leaves. Lettuce leaves were exposed to (522 nm), red (639 nm) and blue (470 nm) LEDs of different light intensities. Thylakoid multiprotein complex proteins and photosynthetic metabolism were then investigated. Biomass and photosynthetic parameters increased with an increasing light intensity under blue LED illumination and decreased when illuminated with red and green LEDs with decreased light intensity. The expression of multiprotein complex proteins including PSII-core dimer and PSII-core monomer using blue LEDs illumination was higher at higher light intensity (238 μmol m⁻² s⁻¹) and was lowered with decreased light intensity (70–80 μmol m⁻² s⁻¹). The responses of chloroplast sub-compartment proteins, including those active in stomatal opening and closing, and leaf physiological responses at different light intensities, indicated induced growth enhancement upon illumination with blue LEDs. High intensity blue LEDs promote plant growth by controlling the integrity of chloroplast proteins that optimize photosynthetic performance in the natural environment.     

Analysis of genetic effects and heritabilities for linoleic and α‐linolenic acid content of Brassica napus L. across Chinese environments

A genetic model for quantitative traits of seed in diploid plant was applied to analyze the main genetic effects and genotype × environment (GE) interaction effects for linoleic and α‐linolenic acid content of rapeseed (Brassica napus L.) by using two year experimental data with 8 parents and their F₁ and F₂. Results indicated that the performance of linoleic (C18:2) and α‐linolenic acid content (C18:3) of rapeseed were simultaneously controlled by diploid embryo nuclear genes, cytoplasmic genes and diploid maternal plant nuclear genes, and the GE interaction effects for these two seed quality traits were more important than the genetic main effects. The total narrow‐sense heritability was 69.5% and 41.8% for C18:2 and C18:3, respectively, and the GE interaction heritabilities were found to be larger than the general heritabilities for both quality traits. It was suggested by the predicted genetic effects that Huashuang 3 was better than other parents for improving offspring of C18:2 and Youcai 601, Zhongyou 821, Eyouchangjia and Zhong R‐888 for decreasing C18:3.     

Polymorphisms in Myostatin Gene and Associations with Growth Traits in the Common Carp (Cyprinus carpio L.)

Myostatin (MSTN) is a member of the transforming growth factor-β superfamily that negatively regulates skeletal muscle development and growth. In the present study, partial genomic fragments of MSTN were screened for single nucleotide polymorphisms (SNPs) in selected common carp individuals from wild populations, and two SNPs in intron 2 (c.371 + 749A > G, c.371 + 781T > C) and two synonymous SNPs in exon 3 (c.42A > G, c.72C > T) were identified. Genotyping by direct sequencing of polymerase chain reaction (PCR) products for these four SNPs were performed in 162 individuals from a commercial hatchery population. Association analysis showed that two SNPs in exon 3 were significantly associated with body weight (BW) and condition factor (K), and haplotype analyses revealed that haplotype H7H8 showed better growth performance. Our results demonstrated that some of the SNPs in MSTN may have positive effects on growth traits and suggested that MSTN could be a candidate gene for growth and marker-assisted selection in common carp.     

The effect of freezing on the analysis of chlorophyll content of canola seed (Brassica napus L.)

High levels of chlorophyll in harvested canola seed result in loss of revenue to producers and problems for processors. Studies on chlorophyll degradation often require plant material to be stored for some time prior to measuring the chlorophyll content. Storage of unripe canola seed in a freezer for up to one month prior to measuring the chlorophyll content did not alter the chlorophyll level in the seed. Seeds were frozen while still in the pods as well as after removal with no change in chlorophyll content over time.     

Structure-activity relationships of cyclopentane analogs of jasmonic acid for induced responses of canola seedlings,Brassica napus L

Jasmonic acid (JA) has potent activity in enhancing cotyledon toughness and stimulating the biosynthesis of 3-indolymethyl glucosinolate in seedlings of canola,Brassica napus L. Structure-activity relationships among cyclopentane analogs of JA revealed that maximum activity in both systems was achieved when an acetyl side chain (or a methylated acetyl side chain) occurred at the C-1 ring position, ann-pentenyl side chain at the C-2 ring position, and a keto group at the C-3 ring position. Although coronatine and coronafacic acid both possess a cyclopentane ring with a keto group at the C-3 position, only coronatine was active inB. napus seedlings. Coronatine, a chlorosis-inducing toxin essential to the infectivity of pathovars ofPseudomonas syringae, acted as a complete molecular mimic of JA and had the same stimulatory effect on specific indole glucosinolates inBrassica species, thereby casting doubt on the hypothesis that indole glucosinolates serve in bacterial pathogen defense. Similarities and differences for structural requirements for activity among several diverse physiological systems affected by jasmonates likely reflect species-, tissue-, and developmental-specific differences.