| Agriculture plays a significant role in worldwide economy and plants oil are very valuable agricultural commodity.The manipulation of seed oil composition so as to deliver enhanced fatty acid compositions,which are appropriate for feed or fuel,has always been a main objective of genetic engineering.Genetic engineering approaches particularly to develop high quality Brassica napus(rapeseed)along increased oil content has emerged as state-of-the-art oil quality modalities,offering promising alternatives to existing conventional breeding methods.Although,significant advancements have been witnessed in manipulation of rapeseed oil but it is still very challenging to serve as first line modalities for enhancing nutritional quality of rapeseed due to existing certain limitations.Such as 1)benightedness of lipid regulation 2)complicated process of fatty acid biosynthesis 3)complexity of B.napus due to redundancy of A and C genome,that makes a quite problematic to target a specific gene and furnish high quality molecular marker using genome wide association study(GWAS).Such as,in numerous cases,a gene contain multiple homologues copies distributed in different loci of B.napus genomic DNA,and among these homologous loci there might be a divergence of roles in contributions to their corresponding phenotypes.Fatty acid composition of rapeseed is majorly determine its oil nutritional quality and quantity,which actually composed of numerous fatty acid types with different chain length of carbons and desaturation level.From last few years,oil with high proportion of α-linolenic acid(ω-3 fatty acid)is widely concerned for nutritional purpose.In our first work,we performed(GWAS)that combine high throughput genome resequencing and phenotyping that can hasten the dissection of genetic architecture and identification of genes related to ω-fatty acid,a rapeseed nutritional oil quality trait using identified single nucleotide polymorphism(SNP)for correlation analysis.Approximately,114 SNPs were detected in BnFATA and BnFAD3 associated with ω-3 oil quality trait.Further,association of these detected loci were evaluated to investigate their proportions in contribution of ω-3 oil synthesis.These outcomes will definitely boost our understanding of fatty acid metabolism in B.napus.Moreover,this finding may facilitate the marker based breeding efforts to improve fatty acid composition and quality of B.napus.B.napus have attracted many researchers’ attention due to its several characteristics related to oleic acid,as it comprising of high oleic acid concentration and consequently have high oxidation stability as compared to polyunsaturated fatty acid(PUFA),and prolonged shelf life.Secondly,for determination of high proportion of oleic acid content,GWAS was conducted to detect the oleic acid composition in 324 genetically diverse rapeseed accessions and selected the loci of BnFAD2 and BnFAE1 that contributed to high proportion of oleic acid content.The chosen loci were further expressed in Saccharomyces cerevisiae to assessed their function and validate the promising candidate gene loci based on SNP marker.Furthermore,the identified SNP marker was further used to select the rapeseed cultivar of high oleic acid content by locus specific PCR confirmation.This study provide an insight into genetic architecture of nutritional oil quality,which would be beneficial for genetic improvement and selection of B.napus cultivars with high nutritional quality.Abiotic stresses such as high temperature,cold,drought and high salinity can really alter the physiological processes and restrain the photosynthesis activity of plants.In consequence of theses adverse environmental stresses,the production rate and quality of rapeseed oil is reduced.Therefore,it becomes a huge challenge to enhance crop production in this fluctuating climate conditions and meet the demands of ever-increasing population.Finally,we investigated the role of small heat shock protein(sHSPs),ubiquitous proteins induce in plants to protect them from extreme environmental stress and help to adjust in adverse climate conditions.However,despite of being recent literature cited on that the role of different sHPSs in numerous plant species,the study of sHPSs in rapeseed against stresses is extremely narrow.For this perseverance,we developed B.napus through transformation of isolated sHSP17.6 from Nicotiana tabacum(NtHSP17.6)and characterized its function in rapeseed under various abiotic stresses.Phylogenetic analysis and subcellular localization prediction revealed that NtHSP17.6 is a cytosolic class I protein.Upon heat stress,B.napus plants overexpressing NtHSP17.6 showed high expression along less loss of water content,and high proline,soluble sugar and chlorophyll content.Likewise,the same tolerance can be detected under drought and salt stress by observing normal root growth and high biomass of transgenic rapeseed than wild type,suggested the key role of NtHSP17.6 upon abiotic stresses.These overexpression analyses suggest that NtHSP17.6 in B.napus confers high resistance against heat,drought and slightly towards salt stress.These findings will be helpful to develop economical stress tolerant crops and avert yield lossIn nutshell,in this work,we exclusively focus on the utilization of GWAS and overexpression of exogenous genes to tackle the existing challenges of rapeseed complex genome and lipid regulation by developing allele specific marker for selection of high quality traits using novel-targeted genes.Additionally,we have developed high quality agronomic trait of B.napus overexpressing exogenous gene against stresses.We have firm believe that the present work will open up promising avenues and surely draw attention of the wider scientific community particularly,plant genetic engineer and breeders to devote sincere efforts for enhancing nutritional quality and yield of rapeseed as well as foster the design of advanced strategies to develop transgenic rapeseed to prevent yield loss.Moreover,these findings will definitely beneficial for Agriculture engineering as well to improve crop production,which is the prime impetus of this sector.Conclusively,this study will be proven advantageous and fruitful in a broader perspective of the advancement of existing knowledge and will truly shift this approach from bench to bedside. |
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