Participatory breeding for Securing Organic Cotton and Genetic Diversity

Participatory breeding for Securing Organic Cotton and Genetic Diversit

Rescuing Non-Gm Organic Cotton Seed Through Participatory Breeding Approach

Introduction of Bt-cotton and its fast adoption in India posed a major threat to availability of non-GM cotton seed for organic production. With the continuous growth of the organic market it is important to maintain non-GM germplasm, to enlarge the offer of organic cultivars with a better performance that meet the demand of the market, and to rebuild the seed sovereignty of organic smallholder cotton farmers. This study aims to examine relative yield performance and fibre length of commercially cultivated American Gossypium hirsutum (HV) and Desi cotton G. arboreum (AV) varieties in comparison with the advance (F6-F8) HV and AV lines developed under Seeding the Green Future (SGF) program at different sites. Analysis revealed wide range in seed cotton yield across different locations in both, heavy and light soils resulting from the unpredictable weather conditions, an extended period of drought during sowing followed by flash flooding during the 2018-19 cotton-growing season. However, both advance (F6-F8) HV and AV lines gave promising results and were at par with the performance of commercial HV and AV cultivars. Analysis of data on fibre quality revealed encouraging results with mean fibre length of >28 mm observed in Bandapari and Akola, especially with advance (F6-F8) AV lines, which is minimum industrial standard. While desi cotton G. arboretum has inherent ability to adapt under adverse climatic condition and is well known for tolerance to sucking pests and drought if coupled with such important quality parameter can help in securing the availability of non-GM seed. This is of special importance as desi cotton does not cross-pollinate with Bt-cotton and shows clearly distinguished leaf morphology. In the current scenario, where the integrity of Indian organic cotton under the spotlight due to GM contamination, there is a need to reorient research efforts to ensure that the existing wealth of genetic diversity of traditional Desi cotton can be capitalized in organic production and industrial processing

Recognition of single-stranded nucleic acids by small-molecule splicing modulators

Risdiplam is the first approved small-molecule splicing modulator for the treatment of spinal muscular atrophy (SMA). Previous studies demonstrated that risdiplam analogues have two separate binding sites in exon 7 of the SMN2 pre-mRNA: (i) the 5′-splice site and (ii) an upstream purine (GA)-rich binding site. Importantly, the sequence of this GA-rich binding site significantly enhanced the potency of risdiplam analogues. In this report, we unambiguously determined that a known risdiplam analogue, SMN-C2, binds to single-stranded GA-rich RNA in a sequence-specific manner. The minimum required binding sequence for SMN-C2 was identified as GAAGGAAGG. We performed all-atom simulations using a robust Gaussian accelerated molecular dynamics (GaMD) method, which captured spontaneous binding of a risdiplam analogue to the target nucleic acids. We uncovered, for the first time, a ligand-binding pocket formed by two sequential GAAG loop-like structures. The simulation findings were highly consistent with experimental data obtained from saturation transfer difference (STD) NMR and structure-affinity-relationship studies of the risdiplam analogues. Together, these studies illuminate us to understand the molecular basis of single-stranded purine-rich RNA recognition by small-molecule splicing modulators with an unprecedented binding mode