Location: Cotton Fiber Bioscience Research
Title: A deletion/duplication in the Ligon-lintless-2 locus induces siRNAs that inhibits cotton fiber cell elongationAuthor
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Submitted to: Plant Physiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/22/2022 Publication Date: 8/23/2022 Citation: Naoumkina, M.A., Thyssen, G.N., Fang, D.D., Florane, C.B., Li, P. 2022. A deletion/duplication in the Ligon-lintless-2 locus induces siRNAs that inhibits cotton fiber cell elongation. Plant Physiology. 190(3):1792-1805. https://doi.org/10.1093/plphys/kiac384. DOI: https://doi.org/10.1093/plphys/kiac384 Interpretive Summary: Most cultivated cotton varieties have two types of seed fibers: short fuzz fiber strongly adhered to the seed coat, and long lint fiber used in the textile industry. Ligon lintless-2 (Li2) is a dominant cotton mutant that has normal vegetative phenotype, but produces very short lint fiber on the seeds. We discovered a large structural rearrangement at the end of chromosome D13 in the Li2 mutant, including a large deletion and an inverted duplication. The gene Gh_D13G2437 is located at junction of the inverted repeat in duplicated region. We found that small interfering RNA was produced from the gene Gh_D13G2437 in the Li2 but not in the wild type. The small interfering RNA produced from Gh_D13G2437 gene suppresses a family of proteins involved in nuclear transport that results in shorter fiber in the Li2 mutant. Technical Abstract: Most cultivated cotton varieties have two types of seed fibers: short fuzz fiber strongly adhered to the seed coat, and long lint fiber used in the textile industry. The Ligon lintless-2 (Li2) cotton mutant has a normal vegetative phenotype, but produces very short lint fiber on the seeds. The Li2 mutation is controlled by a single dominant gene. We discovered a large structural rearrangement at the end of chromosome D13 in the Li2 mutant based on whole genome sequencing and genetic mapping of segregating populations. The rearrangement contains a 177 kb deletion and a 221 kb duplication positioned as a tandem inverted repeat. The gene Gh_D13G2437 is located at junction of the inverted repeat in duplicated region. During transcription such structure spontaneously forms self-complementary hairpin RNA of Gh_D13G2437 followed by production of small interfering RNA (siRNA). The Gh_D13G2437 encodes a Ran binding protein 1 (RanBP1) that preferentially expresses during cotton fiber elongation. The abundance of siRNA produced from Gh_D13G2437 negatively correlates with the abundance of highly homologous RanBP1 family transcripts during fiber elongation, resulting in shorter fiber phenotype in the Li2. Overexpression of the Gh_D13G2437 in the Li2 mutant recovered the long lint fiber phenotype. |
