diff --git a/README.md b/README.md index 8bdcef09534ff863e884793b7dfe479f01d59954..03a392827a909ea8d72dc311752ab70d26697633 100644 --- a/README.md +++ b/README.md @@ -21,5 +21,27 @@ This project was mainly conducted at the [Institute of Plant Biochemistry at HHU - https://orcid.org/0000-0002-9134-6511 - Benjamin Stich - https://orcid.org/0000-0001-6791-8068 +- Steven Kelly + - https://orcid.org/0000-0003-1250-7055 - Andreas P.M.Weber - https://orcid.org/0000-0003-0970-4672 + + +## Abstract +C3-C4 intermediate photosynthesis has evolved at least five times convergently in the Brassicaceae, despite +this family lacking _bona fide_ C4 species. The establishment of this carbon concentrating mechanism is known +to require a complex suite of ultrastructural modifications as well as changes in spatial expression patterns, +which are both thought to be underpinned by a reconfiguration of existing gene-regulatory networks. However, +to date, the mechanisms which underpin the reconfiguration of these gene networks are largely unknown. +In this study, we used a pan-genomic association approach to identify genomic features that could confer +differential gene expression toward the C3-C4 intermediate state by analysing eight C3 species and seven +C3-C4 species from five independent origins in the Brassicaceae. We found a strong correlation between +transposable element (TE) insertions in cis-regulatory regions and the C3-C4 intermediacy. Specifically, our +study revealed 113 gene models in which presence of a TE within a gene correlates with C3-C4 intermediate +photosynthesis. In this set, genes involved in the photorespiratory glycine shuttle are enriched, including the +glycine decarboxylase P-protein whose expression domain undergoes a spatial shift during the transition to +C3-C4 photosynthesis. When further interrogating this gene, we discovered independent TE insertions in its +upstream region which we conclude to be responsible for causing the spatial shift in _GLDP1_ gene expression. +Our findings hint at a pivotal role of TEs in the evolution of C3-C4 intermediacy, especially in mediating +differential spatial gene expression. +