Melatonin is a naturally occurring compound in plants. Here, we tested the effect of exogenous melatonin on rapeseed（Brassica napus L.） grown under salt stress. Application of 30 μmol L^-1 melatonin alleviated salt...Melatonin is a naturally occurring compound in plants. Here, we tested the effect of exogenous melatonin on rapeseed（Brassica napus L.） grown under salt stress. Application of 30 μmol L^-1 melatonin alleviated salt-induced growth inhibition, and the shoot fresh weight, the shoot dry weight, the root fresh weight, and the root dry weight of seedlings treated with exogenous melatonin increased by 128.2, 142.9, 122.2, and 124.2%, respectively, compared to those under salt stress. In addition, several physiological parameters were evaluated. The activities of antioxidant enzymes including peroxidase（POD）, catalase（CAT） and ascorbate peroxidase（APX） were enhanced by 16.5, 19.3, and 14.2% compared to their activities in plants without exogenous melatonin application under salt stress, while the H2O2 content was decreased by 11.2% by exogenous melatonin. Furthermore, melatonin treatment promoted solute accumulation by increasing the contents of proline（26.8%）, soluble sugars（15.1%） and proteins（58.8%）. The results also suggested that higher concentrations（〉50 μmol L^-1） of melatonin could attenuate or even prevent the beneficial effects on seedling development. In conclusion, application of a low concentration of exogenous melatonin to rapeseed plants under salt stress can improve the H2O2-scavenging capacity by enhancing the activities of antioxidant enzymes such as POD, CAT and APX, and can also alleviate osmotic stress by promoting the accumulation of osmoregulatory substances such as soluble proteins, proline, and water soluble glucan. Ultimately, exogenous melatonin facilitates root development and improves the biomass of rapeseed seedlings grown under salt stress, thereby effectively alleviating the damage of salt stress in rapeseed seedlings.展开更多
14 yellow-seeded rapeseed lines (Brassia napus L.) from different genetic sources were used to analyze diversity of testa pigments content, oil and protein content, and RAPD markers. The results showed that the anthoc...14 yellow-seeded rapeseed lines (Brassia napus L.) from different genetic sources were used to analyze diversity of testa pigments content, oil and protein content, and RAPD markers. The results showed that the anthocyanin and melanin were the most important pigments in testa and their content were responsible for the variation in seed color ranging from orange to black yellow, 14 yellow-seeded lines could be classified into 3 groups: high anthocyanin content group with anthocyanin content over 2. 54 mg g-1 DW, the seed color was light yellow or orange; low pigments content group with low content of anthocyanin and melanin, the testa was transparent and the seed color was light yellow, greenish yellow or twany; high melanin content group with melanin content over 178. 4U(A290nm) , the testa was black, the seed color was black yellow. Oil content changed from 36.2% to 45. 5%, protein content from 21.1% to 27.7% , and the correlation analysis revealed that the oil content is highly significantly negatively correlated with the protein content. The cluster analysis showed that the extensive genetic variation existed among 14 yellow-seeded lines by using unweighted paired group method with arithmetic average (UPGMA) based on RAPD markers which were amplified with decamer primers, the genetic similarity among them ranged from 0. 25 to 0.909, and 14 yellow-seeded lines could put into 2 clusters corresponding to genome difference.展开更多
Seed weight is a component of seed yield in rapeseed(Brassica napus L.).Although quantitative trait loci(QTL)for seed weight have been reported in rapeseed,only a few causal quantitative trait genes(QTGs)have been ide...Seed weight is a component of seed yield in rapeseed(Brassica napus L.).Although quantitative trait loci(QTL)for seed weight have been reported in rapeseed,only a few causal quantitative trait genes(QTGs)have been identified,resulting in a limitation in understanding of seed weight regulation.We constructed a gene coexpression network at the early seed developmental stage using transcripts of 20,408 genes in QTL intervals and 1017 rapeseed homologs of known genes from other species.Among the 10 modules in this gene coexpression network,modules 1 and 2 were core modules and contained genes involved in source–flow–sink processes such as synthesis and transportation of fatty acid and protein,and photosynthesis.A hub gene SERINE CARBOXYPEPTIDASE-LIKE 19(SCPL19)was identified by candidate gene association analysis in rapeseed and functionally investigated using Arabidopsis T-DNA mutant and overexpression lines.Our study demonstrates the power of gene coexpression analysis to prioritize candidate genes from large candidate QTG sets and enhances the understanding of molecular mechanism for seed weight at the early developmental stage in rapeseed.展开更多
As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to h...As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to heat stress during B.napus seed filling is helpful in the genetic improvement of heat-tolerant rapeseed.The effects of heat stress on seed oil accumulation and chlorophyll fluorescence characteristics of 29 B.napus germplasms with different oil content and environmental sensitivity,including 6 rapeseed varieties which exhibited environmentsensitive/insensitive and with high,medium or low oil content,were tested by whole plant heat stress or the in vitro silique culture system.Both assay exhibited similar trend on oil content of the rapeseed germplasms.The heat effect on the chlorophyll fluorescence kinetic parameters F_(v)/F_(m),ETR and Y(Ⅱ)were also consistent.Heat stress significantly decreased oil content,although there was abundant genetic variation on heat tolerance among the genotypes.Correlation analysis showed that the decrease rate of F_(v)/F_(m) of silique heat-stressed B.napus developing seed was positive correlative to the decrease rate of mature seed oil content of the whole plant heat-stressed rapeseed(R=0.9214,P-value<0.01).Overall,the results indicated that heat stress inhibited oil accumulation and photosynthesis in B.napus developing seed.The decrease rate of chlorophyll fluorescence parameter F_(v)/F_(m) of heat-stressed developing seed could be used as the index of heat tolerant rapeseed identification.Further,two heat insensitive rapeseed varieties with high oil content were identified.展开更多
To better understand waterlogging effect on leaf senescence in winter rapseed (Brassica napus L.) during flowering stage, experiments were designed to explore foliar K application influences on adverse effects of wate...To better understand waterlogging effect on leaf senescence in winter rapseed (Brassica napus L.) during flowering stage, experiments were designed to explore foliar K application influences on adverse effects of waterlogging stress. Winter rapeseed was sprayed with K after waterlogging at initial flowering stage. Results indicated that waterlogging significantly decreased leaf net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr). It also declined maximum quantum yield of PS II (Fv/Fm), quantum yield of electron transport (ΦPS II) and photochemical quenching (qP), but increased leaf non-photochemical quenching (NPQ) and minimal fluorescence (Fo). Interestingly, exogenous application of K significantly alleviated waterlogging-induced photosynthesis inhibition. Foliar K application increased RuBisCO activation, chlorophyll and soluble protein contents, while significantly decreased MDA content under waterlogging stress. Moreover, K supplementation improved accumulation of K+, Ca2+, Mg2+, N, Zn2+, Mn2+, Fe2+ in leaves. In general, foliar K application is effective inalleviating deleterious effects of waterlogging stress and delays leaf senescence of winter rapeseed.展开更多
Nutrient deficiency stresses often occur simultaneously in soil. Thus, it＇s necessary to investigate the mechanisms underlying plant responses to multiple stresses through identification of some key stress-responsive...Nutrient deficiency stresses often occur simultaneously in soil. Thus, it＇s necessary to investigate the mechanisms underlying plant responses to multiple stresses through identification of some key stress-responsive genes. Quantitative real-time PCR （qRT-PCR） is essential for detecting the expression of the interested genes, of which the selection of suitable reference genes is a crucial step before qRT-PCR. To date, reliable reference genes to normalize qRT-PCR data under different nutrient deficiencies have not been reported in plants. In this study, expression of ten candidate reference genes was detected in leaves and roots of rapeseed （Brassica napus L.） after implementing different nutrient deficiencies for 14 days. These candidate genes, included two traditionally used reference genes and eight genes selected from an RNA- Seq dataset. Two software packages （GeNorm, NormFinder） were employed to evaluate candidate gene stability. Results showed that VHA-E1 was the highest-ranked gene in leaves of nutrient-deficient rapeseed, while VHA-G1 and UBC21 were most stable in nutrient-deficient roots. When rapeseed leaves and roots were combined, UBC21, HTB1, VHA-G1 and A CT7 were most stable among all samples. To evaluate the stabilities of the highest-ranked genes, the relative expression of two target genes, BnTrxl;1 and BnPhtl;3 Were further determined. The results showed that the relative expression of BnTrxl;1 depended on reference gene selection, suggesting that it＇s necessary to evaluate the stability of reference gene prior to qRT-PCR. This study provides suitable reference genes for gene expression analysis of rapeseed responses to different nutrient deficiencies, which is essential for elucidation of mechanisms underlying rapeseed responses to multiple nutrient deficiency stresses展开更多
As a big rapeseed(Brassica napus L.) producing and consuming country, China provides more and more rapeseed oil year by year. With the development of demand for rapeseed and import of edible oil, rapeseed breeding and...As a big rapeseed(Brassica napus L.) producing and consuming country, China provides more and more rapeseed oil year by year. With the development of demand for rapeseed and import of edible oil, rapeseed breeding and production is facing a great challenge. New situation has proposed higher requirements to yield, oil quality and safety, etc. In the review, some aspects about rapeseed breeding in China were reported, including breeding of high-oil content rapeseed, breeding of extremely early-maturing rapeseed, development of mechanization and development of chemical emasculation. Some prospects and expectations were also proposed.展开更多
Rapeseed(Brassica napus L.) is the world?s second produced oilseed and accounts for nearly 12% of world major vegetable oil production.For the last 10 years,the production,planting area,and yield of rapeseed have been...Rapeseed(Brassica napus L.) is the world?s second produced oilseed and accounts for nearly 12% of world major vegetable oil production.For the last 10 years,the production,planting area,and yield of rapeseed have been stable,with improvement of seed quality and especially seed oil content.This paper presented the worldwide rapeseed research by using the bibliometric analysis of papers published during the period 2011–2021.In total,7617 articles and reviews were included in this analysis.Our results showed that the global publication on rapeseed increased substantially in the past 11 years,and the number of publications of China grew significantly in particular.China was the largest contributor to rapeseed research with higher H-index value and number of citations compared to the other countries.China also had the largest number of leading universities and institutions,of which Huazhong Agricultural University was the most productive.The scientific mapping including co-authorship network of countries/regions and authors,and co-occurrence network of author keywords were analyzed using VOSviewer software.The most common rapeseed research topics included oil,rapeseed meal,yield,biodiesel,fatty acids,salt stress,and proteins,while the current research focused on topics such as:abiotic stress,evolution,expression analysis,phylogenetic analysis,heterosis,polyploidy,and transcriptomics.This paper depicts the knowledge structure of current global rapeseed research that may help direct the future studies for relevant researchers.展开更多
Yellow-seeded rapeseed (Brassica napus L.) is a new kind of breeding resources with yellow color, increased oil and protein content and less unwanted crude fiber content due to the thinner and transparent testa compar...Yellow-seeded rapeseed (Brassica napus L.) is a new kind of breeding resources with yellow color, increased oil and protein content and less unwanted crude fiber content due to the thinner and transparent testa compared with traditional black or brown-seeded rapeseed. To analyze the longevity of the yellow-seeded rapeseed during storage, the physiological differences between the yellow and black-seeded near-isogenic lines were studied by artificial ageing method. The testa rate, anthocyanin content and melanin content of yellow-seeded rapeseeds decreased by 20.1, 25.2, and 80.4% respectively than black-seeded rapeseed. During artificial ageing, the yellow-seeded rapeseed showed significantly different effect of ageing compared with the black-seeded, as demonstrated by faster deterioration with lower germination percentage, seed vigour index, reducing sugar and soluble protein contents than the black-seeded, as well as a drastic increase in electrical conductivity, malnodialdehyde (MDA) content and a rapid decrease in activities of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). The results suggested that the transparent testa of the yellow-seeded rapeseed lost some abilities to protect the embryo against adverse environmental conditions and thus led to a poor storability.展开更多
Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known a...Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known about the genetic mechanisms of GSL accumulation in rapeseed flowering stalks. In this study, the variation and genetic architecture of GSL metabolites in flowering stalk tissues were investigated for the first time among a panel of 107 accessions. All GSL compounds exhibited continuous and wide variations in the present population. Progoitrin,glucobrassicanapin and gluconapin were the most abundant GSL compounds. Five quantitative trait loci(QTL) significantly associated with three GSL compounds were identified by genome-wide association study. GRA_C04 was under selected during modern breeding, in which the ratio of lower GSL haplotype(HAP2) in the accessions bred before 1990(52.56%) was significantly lower than that after 1990(78.95%). Four candidate genes, BnaA01. SOT16, BnaA06. SOT17, Bna A06. MYB51a, and Bna A06. MYB51b, were identified in the GTL_A01 and 4OH_A06 regions.These findings provide new insights into GSL biosynthesis in flowering stalk tissues and facilitate quality improvement in rapeseed flowering stalks.展开更多
China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cu...China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cultivar Zhongshuang 11 （Brassica napus L.） was employed in two rounds of field experiments from 2009 to 2011. Seeds were sown with machine, three combine harvesting times namely combine harvesting A, B, and C （CHA, CHB, and CHC） were designed and manual harvesting （MH） as control was performed at maturity. The harvesting treatments were determined according to color of pod and seed in the field. Seed yield loss and quality in different treatments were evaluated. Results showed that both seed yields and harvesting losses in 2009-2010 were higher than that in 2010-2011, whereas seed oil contents in 2010-2011 were higher than that in 2009-2010. The highest yield appeared in CHB, which was significantly higher than that in MH. Furthermore, harvesting loss in CHB were 50% that in MH. Seed oil content and chlorophyll exhibited no obvious difference between CHB and MH. Economic profit analysis demonstrated that mechanical sowing/combine harvesting （MS/CH） showed an input/output ratio of 1：1.6, and it was 1：1.2 in mechanical sowing/manual harvesting （MS/MH）. Labor-cost accounted for more than 70% of the total cost in MS/MH, which led to low profitability to a great extent. Our results suggested that CHB was the optimum harvesting time for winter oilseed rape along the Yangtze River.展开更多
RNA sequencing of the sensitive GH01 variety of Brassica napus L. seedling roots under 12 h of waterlogging was compared with previously published data of the ZS9 tolerant variety to unravel genetic mechanisms of wate...RNA sequencing of the sensitive GH01 variety of Brassica napus L. seedling roots under 12 h of waterlogging was compared with previously published data of the ZS9 tolerant variety to unravel genetic mechanisms of waterlogging tolerance beyond natural variation. A total of 2 977 genes with similar expression patterns and 17 genes with opposite expression patterns were identiifed in the transcription proifles of ZS9 and GH01. An additional 1 438 genes in ZS9 and 1 861 genes in GH01 showed strain speciifc regulation. Analysis of the overlapped genes between ZS9 and GH01 revealed that waterlogging tolerance is determined by ability to regulate genes with similar expression patterns. Moreover, differences in both gene expression proifles and abscisic acid (ABA) contents between the two varieties suggest that ABA may play some role in waterlogging tolerance. This study identiifes a subset of candidate genes for further functional analysis.展开更多
Seeds might deteriorate,and lose the ability to germinate when stored under high temperature and high humidity.Brassica napus is one of the most important oil crops in China.However,B.napus seeds were generally stored...Seeds might deteriorate,and lose the ability to germinate when stored under high temperature and high humidity.Brassica napus is one of the most important oil crops in China.However,B.napus seeds were generally stored through summer season with high ambient temperature,which lead to seed viability loss.In order to understand the mechanism of seed response to heat stress and improve seed heat tolerance,B.napus seeds were treated with high temperature(40℃)and ultra-high temperature(60℃)for 4 h.The germination of heatstressed seeds were obviously slower,the germination index and vigor index decreased with temperature increase from 40 to 60℃,and the 40℃ pretreatment could improve the seed tolerance to 60℃ heat stress.Transcriptomics results showed that 442 differentially expressed genes(DEGs)were identified in seeds after heat stress.Gene ontology and KEGG pathway enrichment analysis revealed that some of the genes were involved in posttranslational modification,protein turnover,chaperones and carbohydrate transport,metabolic pathways and secondary metabolites biosynthesis pathway.Among these DEGs,sHSP and transcription factors genes were involved in heat stress tolerance.Thirty-two overlapping genes under different high temperature stress(40℃ and 60℃)were enriched in biological processes of response to oxidative stress and abiotic stimulus.The expression trends of 12 genes randomly selected from the RNA-seq data were almost consistent with the results of qRT-PCR.Our results revealed several potential candidate genes and pathways related to heat responsive by high temperature,which is beneficial for further improving the heat tolerance in B.napus seeds.展开更多
To better understand the effect of high temperature on seed viability, artificial aging treatments were implemented on 472 accessions of rapeseed (Brassica napus L.) by constant high temperature at 70℃for 8h. Results...To better understand the effect of high temperature on seed viability, artificial aging treatments were implemented on 472 accessions of rapeseed (Brassica napus L.) by constant high temperature at 70℃for 8h. Results showed a remarkable impact of constant heat on seed germination. After heat treatment, considerable variation was found in seed germinability, some genotypes even lost the ability to germinate. The effect of accelerated aging was highly significant. Germination parameters varied among ecotypes. Seed viability varied with different origin, and was significantly and positively correlated with seed yield per plant and dry weight of aboveground parts per plant among 14 agronomic traits. Germination traits were positively correlated with oil contents.展开更多
基金supported by the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences (CAAS)the Hubei Agricultural Science and Technology Innovation Center, Chinathe Canola Key Industrial Innovation Team of Xiaogan, China
文摘Melatonin is a naturally occurring compound in plants. Here, we tested the effect of exogenous melatonin on rapeseed（Brassica napus L.） grown under salt stress. Application of 30 μmol L^-1 melatonin alleviated salt-induced growth inhibition, and the shoot fresh weight, the shoot dry weight, the root fresh weight, and the root dry weight of seedlings treated with exogenous melatonin increased by 128.2, 142.9, 122.2, and 124.2%, respectively, compared to those under salt stress. In addition, several physiological parameters were evaluated. The activities of antioxidant enzymes including peroxidase（POD）, catalase（CAT） and ascorbate peroxidase（APX） were enhanced by 16.5, 19.3, and 14.2% compared to their activities in plants without exogenous melatonin application under salt stress, while the H2O2 content was decreased by 11.2% by exogenous melatonin. Furthermore, melatonin treatment promoted solute accumulation by increasing the contents of proline（26.8%）, soluble sugars（15.1%） and proteins（58.8%）. The results also suggested that higher concentrations（〉50 μmol L^-1） of melatonin could attenuate or even prevent the beneficial effects on seedling development. In conclusion, application of a low concentration of exogenous melatonin to rapeseed plants under salt stress can improve the H2O2-scavenging capacity by enhancing the activities of antioxidant enzymes such as POD, CAT and APX, and can also alleviate osmotic stress by promoting the accumulation of osmoregulatory substances such as soluble proteins, proline, and water soluble glucan. Ultimately, exogenous melatonin facilitates root development and improves the biomass of rapeseed seedlings grown under salt stress, thereby effectively alleviating the damage of salt stress in rapeseed seedlings.
文摘14 yellow-seeded rapeseed lines (Brassia napus L.) from different genetic sources were used to analyze diversity of testa pigments content, oil and protein content, and RAPD markers. The results showed that the anthocyanin and melanin were the most important pigments in testa and their content were responsible for the variation in seed color ranging from orange to black yellow, 14 yellow-seeded lines could be classified into 3 groups: high anthocyanin content group with anthocyanin content over 2. 54 mg g-1 DW, the seed color was light yellow or orange; low pigments content group with low content of anthocyanin and melanin, the testa was transparent and the seed color was light yellow, greenish yellow or twany; high melanin content group with melanin content over 178. 4U(A290nm) , the testa was black, the seed color was black yellow. Oil content changed from 36.2% to 45. 5%, protein content from 21.1% to 27.7% , and the correlation analysis revealed that the oil content is highly significantly negatively correlated with the protein content. The cluster analysis showed that the extensive genetic variation existed among 14 yellow-seeded lines by using unweighted paired group method with arithmetic average (UPGMA) based on RAPD markers which were amplified with decamer primers, the genetic similarity among them ranged from 0. 25 to 0.909, and 14 yellow-seeded lines could put into 2 clusters corresponding to genome difference.
基金provided by the National Natural Science Foundation of China(32201776)the Natural Science Foundation of Chongqing(cstc2019jcyj-bsh X0055,cstc2019jcyj-zdxm X0012)。
文摘Seed weight is a component of seed yield in rapeseed(Brassica napus L.).Although quantitative trait loci(QTL)for seed weight have been reported in rapeseed,only a few causal quantitative trait genes(QTGs)have been identified,resulting in a limitation in understanding of seed weight regulation.We constructed a gene coexpression network at the early seed developmental stage using transcripts of 20,408 genes in QTL intervals and 1017 rapeseed homologs of known genes from other species.Among the 10 modules in this gene coexpression network,modules 1 and 2 were core modules and contained genes involved in source–flow–sink processes such as synthesis and transportation of fatty acid and protein,and photosynthesis.A hub gene SERINE CARBOXYPEPTIDASE-LIKE 19(SCPL19)was identified by candidate gene association analysis in rapeseed and functionally investigated using Arabidopsis T-DNA mutant and overexpression lines.Our study demonstrates the power of gene coexpression analysis to prioritize candidate genes from large candidate QTG sets and enhances the understanding of molecular mechanism for seed weight at the early developmental stage in rapeseed.
基金funded by the Natural Science Foundation of Zhejiang Province(LY20C130006)the National Natural Science Foundation of China(32172018)the State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products(2010DS700124-ZZ1805).
文摘As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to heat stress during B.napus seed filling is helpful in the genetic improvement of heat-tolerant rapeseed.The effects of heat stress on seed oil accumulation and chlorophyll fluorescence characteristics of 29 B.napus germplasms with different oil content and environmental sensitivity,including 6 rapeseed varieties which exhibited environmentsensitive/insensitive and with high,medium or low oil content,were tested by whole plant heat stress or the in vitro silique culture system.Both assay exhibited similar trend on oil content of the rapeseed germplasms.The heat effect on the chlorophyll fluorescence kinetic parameters F_(v)/F_(m),ETR and Y(Ⅱ)were also consistent.Heat stress significantly decreased oil content,although there was abundant genetic variation on heat tolerance among the genotypes.Correlation analysis showed that the decrease rate of F_(v)/F_(m) of silique heat-stressed B.napus developing seed was positive correlative to the decrease rate of mature seed oil content of the whole plant heat-stressed rapeseed(R=0.9214,P-value<0.01).Overall,the results indicated that heat stress inhibited oil accumulation and photosynthesis in B.napus developing seed.The decrease rate of chlorophyll fluorescence parameter F_(v)/F_(m) of heat-stressed developing seed could be used as the index of heat tolerant rapeseed identification.Further,two heat insensitive rapeseed varieties with high oil content were identified.
文摘To better understand waterlogging effect on leaf senescence in winter rapseed (Brassica napus L.) during flowering stage, experiments were designed to explore foliar K application influences on adverse effects of waterlogging stress. Winter rapeseed was sprayed with K after waterlogging at initial flowering stage. Results indicated that waterlogging significantly decreased leaf net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr). It also declined maximum quantum yield of PS II (Fv/Fm), quantum yield of electron transport (ΦPS II) and photochemical quenching (qP), but increased leaf non-photochemical quenching (NPQ) and minimal fluorescence (Fo). Interestingly, exogenous application of K significantly alleviated waterlogging-induced photosynthesis inhibition. Foliar K application increased RuBisCO activation, chlorophyll and soluble protein contents, while significantly decreased MDA content under waterlogging stress. Moreover, K supplementation improved accumulation of K+, Ca2+, Mg2+, N, Zn2+, Mn2+, Fe2+ in leaves. In general, foliar K application is effective inalleviating deleterious effects of waterlogging stress and delays leaf senescence of winter rapeseed.
基金supported by the grants from the Agricultural Science and Technology Innovation Program,Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2013OCRI)the Excellent Young Scientist Fund of Chinese Academy of Agricultural Sciences(1610172015004)an open project funded by State Key Laboratory for the Conservation and Utilization of Subtropical Agro-bioresources,China(SKLCUSA-b201403)
文摘Nutrient deficiency stresses often occur simultaneously in soil. Thus, it＇s necessary to investigate the mechanisms underlying plant responses to multiple stresses through identification of some key stress-responsive genes. Quantitative real-time PCR （qRT-PCR） is essential for detecting the expression of the interested genes, of which the selection of suitable reference genes is a crucial step before qRT-PCR. To date, reliable reference genes to normalize qRT-PCR data under different nutrient deficiencies have not been reported in plants. In this study, expression of ten candidate reference genes was detected in leaves and roots of rapeseed （Brassica napus L.） after implementing different nutrient deficiencies for 14 days. These candidate genes, included two traditionally used reference genes and eight genes selected from an RNA- Seq dataset. Two software packages （GeNorm, NormFinder） were employed to evaluate candidate gene stability. Results showed that VHA-E1 was the highest-ranked gene in leaves of nutrient-deficient rapeseed, while VHA-G1 and UBC21 were most stable in nutrient-deficient roots. When rapeseed leaves and roots were combined, UBC21, HTB1, VHA-G1 and A CT7 were most stable among all samples. To evaluate the stabilities of the highest-ranked genes, the relative expression of two target genes, BnTrxl;1 and BnPhtl;3 Were further determined. The results showed that the relative expression of BnTrxl;1 depended on reference gene selection, suggesting that it＇s necessary to evaluate the stability of reference gene prior to qRT-PCR. This study provides suitable reference genes for gene expression analysis of rapeseed responses to different nutrient deficiencies, which is essential for elucidation of mechanisms underlying rapeseed responses to multiple nutrient deficiency stresses
基金Supported by Earmarked Fund for Modern Agro-industry Technology Research System of China(CARS-13)National Key Research and Development Plan(JFYS2016ZY03002156)+6 种基金Ministry of Agriculture Experimental Observation of the Upper Reaches of the Yangtze River Oil Crop Science Station(09203020)Sichuan Crop Breeding CommunityInnovation Ability Promotion Project of Sichuan Provincial Finance(2016zypz-013)Sichuan Province Innovation Team FundingNatural Science Foundation of China(NSFC31360262)Science and Technology Achievements Transformation Project of Sichuan Province(2017CC0052)SAAS Modern Agricultural Technology Special Fund(2015JSCX-012)
文摘As a big rapeseed(Brassica napus L.) producing and consuming country, China provides more and more rapeseed oil year by year. With the development of demand for rapeseed and import of edible oil, rapeseed breeding and production is facing a great challenge. New situation has proposed higher requirements to yield, oil quality and safety, etc. In the review, some aspects about rapeseed breeding in China were reported, including breeding of high-oil content rapeseed, breeding of extremely early-maturing rapeseed, development of mechanization and development of chemical emasculation. Some prospects and expectations were also proposed.
文摘Rapeseed(Brassica napus L.) is the world?s second produced oilseed and accounts for nearly 12% of world major vegetable oil production.For the last 10 years,the production,planting area,and yield of rapeseed have been stable,with improvement of seed quality and especially seed oil content.This paper presented the worldwide rapeseed research by using the bibliometric analysis of papers published during the period 2011–2021.In total,7617 articles and reviews were included in this analysis.Our results showed that the global publication on rapeseed increased substantially in the past 11 years,and the number of publications of China grew significantly in particular.China was the largest contributor to rapeseed research with higher H-index value and number of citations compared to the other countries.China also had the largest number of leading universities and institutions,of which Huazhong Agricultural University was the most productive.The scientific mapping including co-authorship network of countries/regions and authors,and co-occurrence network of author keywords were analyzed using VOSviewer software.The most common rapeseed research topics included oil,rapeseed meal,yield,biodiesel,fatty acids,salt stress,and proteins,while the current research focused on topics such as:abiotic stress,evolution,expression analysis,phylogenetic analysis,heterosis,polyploidy,and transcriptomics.This paper depicts the knowledge structure of current global rapeseed research that may help direct the future studies for relevant researchers.
基金The authors thank 863 Project of the Ministry of Sci-ence and Technology of P.R.China(AA2003207150)948 Project of the Ministry of Agricutureof P.R.China(2003-Q04)for financial support.
文摘Yellow-seeded rapeseed (Brassica napus L.) is a new kind of breeding resources with yellow color, increased oil and protein content and less unwanted crude fiber content due to the thinner and transparent testa compared with traditional black or brown-seeded rapeseed. To analyze the longevity of the yellow-seeded rapeseed during storage, the physiological differences between the yellow and black-seeded near-isogenic lines were studied by artificial ageing method. The testa rate, anthocyanin content and melanin content of yellow-seeded rapeseeds decreased by 20.1, 25.2, and 80.4% respectively than black-seeded rapeseed. During artificial ageing, the yellow-seeded rapeseed showed significantly different effect of ageing compared with the black-seeded, as demonstrated by faster deterioration with lower germination percentage, seed vigour index, reducing sugar and soluble protein contents than the black-seeded, as well as a drastic increase in electrical conductivity, malnodialdehyde (MDA) content and a rapid decrease in activities of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). The results suggested that the transparent testa of the yellow-seeded rapeseed lost some abilities to protect the embryo against adverse environmental conditions and thus led to a poor storability.
基金supported by the Key Research and Development project of Hubei Province (Grant Nos. 2020BBB083, 2021BBA097 and 2021BBA102)the National Key Research and Development Program of China (Grant No. 2016YFD0100202)。
文摘Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known about the genetic mechanisms of GSL accumulation in rapeseed flowering stalks. In this study, the variation and genetic architecture of GSL metabolites in flowering stalk tissues were investigated for the first time among a panel of 107 accessions. All GSL compounds exhibited continuous and wide variations in the present population. Progoitrin,glucobrassicanapin and gluconapin were the most abundant GSL compounds. Five quantitative trait loci(QTL) significantly associated with three GSL compounds were identified by genome-wide association study. GRA_C04 was under selected during modern breeding, in which the ratio of lower GSL haplotype(HAP2) in the accessions bred before 1990(52.56%) was significantly lower than that after 1990(78.95%). Four candidate genes, BnaA01. SOT16, BnaA06. SOT17, Bna A06. MYB51a, and Bna A06. MYB51b, were identified in the GTL_A01 and 4OH_A06 regions.These findings provide new insights into GSL biosynthesis in flowering stalk tissues and facilitate quality improvement in rapeseed flowering stalks.
基金supported by the Special Funding for Modern Agricultural Technical System of China (Rapeseed)the National Natural Science Foundation of China (31071372)
文摘China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cultivar Zhongshuang 11 （Brassica napus L.） was employed in two rounds of field experiments from 2009 to 2011. Seeds were sown with machine, three combine harvesting times namely combine harvesting A, B, and C （CHA, CHB, and CHC） were designed and manual harvesting （MH） as control was performed at maturity. The harvesting treatments were determined according to color of pod and seed in the field. Seed yield loss and quality in different treatments were evaluated. Results showed that both seed yields and harvesting losses in 2009-2010 were higher than that in 2010-2011, whereas seed oil contents in 2010-2011 were higher than that in 2009-2010. The highest yield appeared in CHB, which was significantly higher than that in MH. Furthermore, harvesting loss in CHB were 50% that in MH. Seed oil content and chlorophyll exhibited no obvious difference between CHB and MH. Economic profit analysis demonstrated that mechanical sowing/combine harvesting （MS/CH） showed an input/output ratio of 1：1.6, and it was 1：1.2 in mechanical sowing/manual harvesting （MS/MH）. Labor-cost accounted for more than 70% of the total cost in MS/MH, which led to low profitability to a great extent. Our results suggested that CHB was the optimum harvesting time for winter oilseed rape along the Yangtze River.
文摘RNA sequencing of the sensitive GH01 variety of Brassica napus L. seedling roots under 12 h of waterlogging was compared with previously published data of the ZS9 tolerant variety to unravel genetic mechanisms of waterlogging tolerance beyond natural variation. A total of 2 977 genes with similar expression patterns and 17 genes with opposite expression patterns were identiifed in the transcription proifles of ZS9 and GH01. An additional 1 438 genes in ZS9 and 1 861 genes in GH01 showed strain speciifc regulation. Analysis of the overlapped genes between ZS9 and GH01 revealed that waterlogging tolerance is determined by ability to regulate genes with similar expression patterns. Moreover, differences in both gene expression proifles and abscisic acid (ABA) contents between the two varieties suggest that ABA may play some role in waterlogging tolerance. This study identiifes a subset of candidate genes for further functional analysis.
基金This work was supported by the Natural Science Foundation of China(31601341)The National Key Program Research and Development of China(2016YFD0100202).
文摘Seeds might deteriorate,and lose the ability to germinate when stored under high temperature and high humidity.Brassica napus is one of the most important oil crops in China.However,B.napus seeds were generally stored through summer season with high ambient temperature,which lead to seed viability loss.In order to understand the mechanism of seed response to heat stress and improve seed heat tolerance,B.napus seeds were treated with high temperature(40℃)and ultra-high temperature(60℃)for 4 h.The germination of heatstressed seeds were obviously slower,the germination index and vigor index decreased with temperature increase from 40 to 60℃,and the 40℃ pretreatment could improve the seed tolerance to 60℃ heat stress.Transcriptomics results showed that 442 differentially expressed genes(DEGs)were identified in seeds after heat stress.Gene ontology and KEGG pathway enrichment analysis revealed that some of the genes were involved in posttranslational modification,protein turnover,chaperones and carbohydrate transport,metabolic pathways and secondary metabolites biosynthesis pathway.Among these DEGs,sHSP and transcription factors genes were involved in heat stress tolerance.Thirty-two overlapping genes under different high temperature stress(40℃ and 60℃)were enriched in biological processes of response to oxidative stress and abiotic stimulus.The expression trends of 12 genes randomly selected from the RNA-seq data were almost consistent with the results of qRT-PCR.Our results revealed several potential candidate genes and pathways related to heat responsive by high temperature,which is beneficial for further improving the heat tolerance in B.napus seeds.
基金supported by the Nature Science Foundation of China (31601341)
文摘To better understand the effect of high temperature on seed viability, artificial aging treatments were implemented on 472 accessions of rapeseed (Brassica napus L.) by constant high temperature at 70℃for 8h. Results showed a remarkable impact of constant heat on seed germination. After heat treatment, considerable variation was found in seed germinability, some genotypes even lost the ability to germinate. The effect of accelerated aging was highly significant. Germination parameters varied among ecotypes. Seed viability varied with different origin, and was significantly and positively correlated with seed yield per plant and dry weight of aboveground parts per plant among 14 agronomic traits. Germination traits were positively correlated with oil contents.
