The Sesame Genome Working Group (SGWG) has been formed to sequence and assemble the sesame (Sesamum indicum L.) genome. The status of this project and our planned analyses are described.

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Genome sequencing of the important oilseed crop Sesamum indicum L

Sesame (Sesamum indicum L.) is one of the oldest oilseed crops widely grown in Africa and Asia for its high-quality nutritional seeds. It is well adapted to harsh environments and constitutes an alternative cash crop for smallholders in developing countries. Despite its economic and nutritional importance, sesame is considered as an orphan crop because it has received very little attention from science. As a consequence, it lags behind the other major oil crops as far as genetic improvement is concerned. In recent years, the scenario has considerably changed with the decoding of the sesame nuclear genome leading to the development of various genomic resources including molecular markers, comprehensive genetic maps, high-quality transcriptome assemblies, web-based functional databases and diverse daft genome sequences. The availability of these tools in association with the discovery of candidate genes and QTLs for key agronomic traits including high oil content and quality, waterlogging and drought tolerance, disease resistance, cytoplasmic male sterility, high yield, pave the way to the development of some new strategies for sesame genetic improvement. As a result, sesame has graduated from an “orphan crop” to a “genomic resource-rich crop”. With the limited research teams working on sesame worldwide, more synergic efforts are needed to integrate these resources in sesame breeding for productivity upsurge, ensuring food security and improved livelihood in developing countries. This review retraces the evolution of sesame research by highlighting the recent advances in the “Omics” area and also critically discusses the future prospects for a further genetic improvement and a better expansion of this crop.

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The Emerging Oilseed Crop Sesamum indicum Enters the "Omics" Era.

Camelina sativa is a promising under-exploited oilseed crop with potential to become a biofuel feedstock. The ability to transform C. sativa would allow for the rapid introduction of novel traits into this emerging crop. We report the development of an Agrobacterium-based floral dip transformation method, requiring no vacuum-infiltration step, with transformation efficiencies up to 0.8%. C. sativa cultivars Ames 26665, “Calena” A3U7761, Ames 1043, and “Celine” were tested using Agrobacterium tumefaciens strains GV3101, EHA105, and At503. Use of all strains and cultivars resulted in transformed plants; however, GV3101 was the only Agrobacterium strain and Ames 1043 the only C. sativa cultivar to yield transformed plants under all conditions tested. Progeny analysis revealed that in approximately 78% of the transformed plants, the transgene segregated as a single locus. Furthermore, a high-throughput, filter paper-based PCR method was developed to screen marker-free transformed plants. Together, these methods will allow for easier introduction of new genes into this promising oilseed crop.

Transformation of the oilseed crop Camelina sativa by Agrobacterium-mediated floral dip and simple large-scale screening of transformants

This study investigated the plant growth promotion and stress mitigation effects of Penicillium species RDA01, NICS01, and DFC01 on sesame (Sesamum indicum L.) plants. The fungal isolates NICS01 and DFC01 significantly enhanced shoot length, root length, and fresh and dry seedling weight, due to the secretion of various concentrations of amino acids (Asp, Thr, Ser, Asn, Glu, Gly, Ala, Val, Met, Ile, Leu, Tyr, Phe, Lys, His, Try, and Arg). Penicillium sp. NICS01 increased the amount of chlorophylls, proteins, amino acids, and lignans in the sesame plants more so than in controls. Sesame plant growth was stunted by high soil salinity, and application of the three fungal isolates increased plant survival. The RDA01 and NICS01 strains significantly increased shoot length and fresh and dry seedling weights under salt stress conditions. In addition, an in vitro study of the Penicillium spp. revealed their antagonistic activity toward the pathogenic fungi Fusarium spp. Fusarium spp. reduce shoot length; co-inocu...

https://www.tandfonline.com/doi/pdf/10.1080/17429145.2014.930524

Characterization of plant growth-promoting traits of Penicillium species against the effects of high soil salinity and root disease

Major lignans of sesame sesamin and sesamolin are benzodioxol--substituted furofurans. Sesamol, sesaminol, its epimers, and episesamin are transformation products found in processed products. Synthetic routes to all lignans are known but only sesamol is synthesized industrially. Biosynthesis of furofuran lignans begins with the dimerization of coniferyl alcohol, followed by the formation of dioxoles, oxidation, and glycosylation. Most genes of the lignan pathway in sesame have been identified but the inheritance of lignan content is poorly understood. Health-promoting properties make lignans attractive components of functional food. Lignans enhance the efficiency of insecticides and possess antifeedant activity, but their biological function in plants remains hypothetical. In this work, extensive literature including historical texts is reviewed, controversial issues are critically examined, and errors perpetuated in literature are corrected. The following aspects are covered: chemical properties and transformations of lignans; analysis, purification, and total synthesis; occurrence in Seseamum indicum and related plants; biosynthesis and genetics; biological activities; health-promoting properties; and biological functions. Finally, the improvement of lignan content in sesame seeds by breeding and biotechnology and the potential of hairy roots for manufacturing lignans in vitro are outlined.

Lignans of Sesame (Sesamum indicum L.): A Comprehensive Review.

Sesame (Sesamum indicum L.) is an important oilseed crop grown in India, China, Korea, Russia, Turkey, Mexico, South America, and several countries of Africa. Sesame seeds are rich in oil, proteins, unsaturated fatty acids, vitamins, minerals, and folic acid. Nearly 70% of the world's sesame is processed into oil and meal, while the remainder is channeled to food and confectionery industries. Production of sesame is limited by several fungal diseases, water logging, salinity, and shattering of seed capsules during harvest. Introgression of useful genes from wild species into cultigens by conventional breeding has not been successful due to postfertilization barriers. The only alternative for the improvement of S. indicum is to transfer genes from other sources through genetic transformation techniques. Here, we describe a simple, fast, and reproducible method for the Agrobacterium-mediated genetic transformation of S. indicum which may be employed for the transfer of desirable traits into this economically important oilseed crop.

Sesame (Sesamum indicum L.).

Sesame (Sesamum indicum) is an important oil seed crop that has not yet been transformed genetically. We report herein for the first time successful recovery of fertile transgenic plants of sesame from cotyledon explants inoculated with Agrobacterium tumefaciens carrying a binary vector pCAMBIA2301 that contains a neomycin phosphotransferase gene (nptII) and a β-glucuronidase (GUS) gene (uidA) interrupted with an intron. Green shoots recovered from A. tumefaciens-infected explants on selection medium [Murashige and Skoog (MS) basal medium containing 25.0 μM benzyladenine (BA), 25.0 mg l−1 kanamycin and 400.0 mg l−1 cefotaxime] were rooted on MS basal medium containing 2.0 μM indole-3-butyric acid and 5.0 mg l−1 kanamycin. The rooted shoots were established in soil and grown to maturity to collect seeds. The presence, integration and expression of transgenes in putative T0 plants were confirmed by polymerase chain reaction (PCR), Southern blot hybridization and GUS histochemical assay, respectively. GUS activity was detected in vegetative and reproductive parts of T0 and T1 plants. Presence of thiol compounds in coculture medium and kanamycin selection at shoot regeneration and at rooting stages were found to be critical for transformation. The transgenes were inherited in Mendelian fashion in T1 progeny as detected by PCR. RT-PCR analysis of T1 plants confirmed the presence of transcripts of uidA gene. The transformation frequency was 1.01%, and 22–24 weeks were required from seed to seed generation time. This protocol can be used to transfer new traits in sesame for quantitative and qualitative improvement.

Agrobacterium tumefaciens-mediated genetic transformation of sesame (Sesamum indicum L.)

A non-tissue culture approach for the generation of transgenic Indian mustard (Brassica juncea) plants using Agrobacterium tumefaciens was developed. Inflorescences with floral buds were vacuum infiltrated with a suspension of A. tumefaciens strain EHA105 carrying a binary vector with an intron-containing β-glucuronidase (GUS) gene (uidA) as a scorable marker and a neomycin phosphotransferase gene (nptII) as a selectable marker. The seeds of agro-infiltrated plants (T0) were germinated on a medium containing 130 mg l−1 kanamycin, and the seedlings that remained green were considered T1 transgenic plants. Histochemical GUS assays, PCR, Southern analysis, and RT-PCR confirmed that both transgenes were integrated into the genome of T1 plants and were stably transmitted and expressed for over three generations. The transformants were obtained within 3–4 mo at a transformation frequency of 0.8%. This method may facilitate functional genomics and improvement of Brassica with novel desirable traits and with less time and expense.

Manju Yadav

Papers

Sesame (Sesamum indicum L.).

Agrobacterium tumefaciens-mediated genetic transformation of sesame (Sesamum indicum L.)

A non-tissue culture approach for developing transgenic Brassica juncea L. plants with Agrobacterium tumefaciens