Sesame (Sesamum indicum L.)

The wild allotetraploid sesame genome provides novel insights into evolution and lignan biosynthesis

INTRODUCTION

The wild tetraploid sesame (Sesamum schinzianum), an ancestral relative of diploid cultivated sesame, grows in the tropical desert of the African Plateau. As a valuable seed resource, wild sesame has several advantageous traits, such as strong environmental adaptability and an extremely high content of sesamolin in its seeds. High-quality genome assembly is essential for a detailed understanding of genome structure, genome evolution and crop improvement.

OBJECTIVES

Here, we generated two high-quality chromosome-scale genomes from S. schinzianum and a cultivated diploid elite sesame (Sesamum indicum L.) to investigate the potential genetic basis underlying these traits of wild sesame.

METHODS

The long-read data from PacBio Sequel II platform and high-throughput chromosome conformation capture (Hi-C) data were used to construct high-quality sesame genome. Then dissecting the molecular mechanisms of sesame evolution and lignan biosynthesis through comparative genomics and transcriptomics.

RESULTS

We found evidence of divergent evolution that involved differences in the number, sequence and expression level of homologous genes between the two sets of subgenomes from allotetraploids in S. schinzianum, all of which might be driven by subfunctionalization after polyploidization. Furthermore, it was found that a great number of genes involved in the stress response have undergone positive selection and resulted from gene family expansion in the wild sesame genome compared with the cultivated sesame genome, which, overall, is associated with adaptative evolution to the environment. We hypothesized that the sole functional member CYP92B14 (SscC22g35272) could be associated with high content of sesamolin in wild sesame seeds.

CONCLUSION

This study provides high-quality wild allotetraploid sesame and cultivated sesame genomes, reveals evolutionary features of the allotetraploid genome and provides novel insights into lignan synthesis pathways. Meanwhile, the wild sesame genome will be an important resource to conduct comparative genomic and evolutionary studies and plant improvement programmes.

Oilseed Cakes in the Food Industry; A Review on Applications, Challenges, and Future Perspectives

:

By-products from the food sector now have a wide range of applications. Low-cost raw materials, followed by low-cost goods, are regarded as one of the sectors’ top goals. Because of its economic relevance, reduced price, and nutrients such as protein, fiber, carbs, and antioxidants, oilseed cakes (OCs) have found a desirable place in livestock and poultry feed. Furthermore, because the cake has the same desirable nutrients, its usage in the food business is unavoidable. However, its use in this sector is not simply for nutritious purposes and has it has different impacts on flavor, texture, color, and antioxidant qualities. Therefore, as a result of its desirable qualities, the cake can be more useful in extensive applications in the food business, as well as in the manufacture of supplements and novel foods. The current review looks at the reapplications of byproducts obtained from oilseeds (soybean, sunflower, sesame, canola, palm kernel, peanut, mustard, and almond) in the food sector in the future. Furthermore, allergenicity, toxicity, antinutritional compounds, and techniques of extracting cakes from oilseeds have been discussed.

Formulation and Characterization of Chia (Salvia hispanica) Seed Spread with Incorporation of Sesame (Sesamum indicum) Seed, Watermelon (Citrullus lanatus) Seed, and Pumpkin (Cucurbita pepo) Seed

The work aims at the production and formulation of plant-based nutritionally enriched butter-like spread products using chia seed, sesame seed, watermelon seed, and pumpkin seed in different ratios, with incorporation of olive oil. The formulated spread butters COB (chia + olive oil), CSOB (chia + sesame + olive oil), CWOB (chia + watermelon + olive oil), and CPOB (chia + pumpkin + olive oil) are of superior quality due to its antioxidant and nutrient content. The antioxidant property of all the formulated spread butter is characterized by total phenolic content (TPC), DPPH free radical scavenging activity, and FRAP assay and the results indicated that CSOB has the highest TPC value of 68.73 ± 0.01 µg GAE/ml and CWOB has the highest DPPH and FRAP activity of 52.30 ± 0.01% and 51.01 ± 0.01 µg of AAE/ml, respectively. The physicochemical properties of all the formulated butter was also analyzed via acid value, peroxide value, and totox value and the results were satisfactory with CPOB having the lowest Totox value of 2.25 ± 0.01. Functional properties of the spread butter are also investigated and the results were satisfactory. All the formulated butters are medicinally and nutritionally beneficial, and it can be used as an alternative to the conventional one.

Complete genome sequence of the sesame pathogen Ralstonia solanacearum strain SEPPX 05

Ralstonia solanacearum is a soil-borne phytopathogen associated with bacterial wilt disease of sesame. R. solanacearum is the predominant agent causing damping-off from tropical to temperate regions. Because bacterial wilt has decreased the sesame industry yield, we sequenced the SEPPX05 genome using PacBio and Illumina HiSeq 2500 systems and revealed that R. solanacearum strain SEPPX05 carries a bipartite genome consisting of a 3,930,849 bp chromosome and a 2,066,085 bp megaplasmid with 66.84% G+C content that harbors 5,427 coding sequences. Based on the whole genome, phylogenetic analysis showed that strain SEPPX05 is grouped with two phylotype I strains (EP1 and GMI1000). Pan-genomic analysis shows that R. solanacearum is a complex species with high biological diversity and was able to colonize various environments during evolution. Despite deletions, insertions, and inversions, most genes of strain SEPPX05 have relatively high levels of synteny compared with strain GMI1000. We identified 104 genes involved in virulence-related factors in the SEPPX05 genome and eight absent genes encoding T3Es of GMI1000. Comparing SEPPX05 with other species, we found highly conserved secretion systems central to modulating interactions of host bacteria. These data may provide important clues for understanding underlying pathogenic mechanisms of R. solanacearum and help in the control of sesame bacterial wilt.