Creation of CENH3 haploid inducer lines and transcriptome study of CENH3 stability in Cichorium intybus

General introduction

To extract more inulin per root from the chicory plant, in this project we want to develop a production method for F1 hybrid chicory. F1 hybrids in agricultural crops are the result of a cross between two homozygous lines, usually inbreeding. In previous research we have demonstrated that F1 industrial chicory hybrids have the potential to produce 20% more inulin in the roots than traditional cultivars. This is relevant as inulin, a chain of fructose molecules, is used as a prebiotic dietary fiber in dairy and bakery products, among others. Inulin extracted from plants is known in the food world as a prebiotic dietary fiber or as a fat replacer. In the broader bioeconomy, inulin is also emerging as an interesting raw material in cosmetics. Specifically, the researchers in this project are focusing on making haploids (as an intermediate step before producing homozygous parental lines), after crossing with haploid inducer lines containing a modified CENH3, KNL2, DMP or MTL protein. Second, they are gathering knowledge about the genetic background of Cytoplasmic Male Sterility (stability) in chicory.

Research approach

The project has now ended. The researchers used both natural variation screening and CRISPR to find or modify knockdown and knockout versions in CENH3, KNL2, DMP and MTL genes in Cichorium intybus. For CRISPR, they used guide RNAs that target one or more of these genes. Thus, a collection of slightly different variants (mutants) was built. In addition, a cytogenetics toolbox was also developed in Cichorium intybus to investigate chromosome elimination in potential haploid inducers. Differential gene expression between CMS and wild-type chicory was also investigated.

Relevance/Valorisation

The project has succeeded in identifying a number of possible haploid inducers, which have yet to be tested. If haploids can be induced via these plants, this would be a major step forward in the production of genetically completely uniform seed lots with predictable inulin content, especially when combined with a controlled pollination system based on CMS.