Project name: Global differential gene expression between Medicago truncatula wild type R108 and Mting2-1 mutant.

Description: Medicago truncatula (Medicago) flowering is promoted by winter cold (vernalization) followed by long day photoperiods (VLD). By analysing a Tnt1 insertion mutant and 17 CRISPR-Cas9 gene-edited lines with delayed flowering, we identified INHIBITOR OF GROWTH (ING) 2 (MtING2) encoding a plant homeodomain (PHD) zinc finger and predicted H3K4me2/3 epigenome reader in Medicago. There are two ING genes in most plants, but their physiological role has not been described. Mting2 mutants had many developmental abnormalities including delayed flowering particularly in VLD, compact architecture, abnormal leaves with extra leaflets but no trichomes and smaller seeds and seed barrels. RNA-Seq experiments indicated that >7000 genes are mis-expressed in the Mting2 mutant consistent with its strong mutant phenotypes. Mting2 did not show reduced accumulation of the strong floral promoter FLOWERING LOCUS T-LIKE gene, MtFTa1, but did have increased expression of MtTFL1c, consistent with the delayed flowering of the mutant. ChIP-Seq analysis identified >5000 novel H3K4me3 locations in the genome of Mting2-1 mutant compared to wild type, which overlapped with some differentially expressed genes. Overall, our study has uncovered an important physiological role of a plant ING gene in development, flowering and gene expression, which likely involves an epigenetic mechanism.Overall design: Germinated seeds from wild type R108 and Mting2-1 mutant plants were grown under vernalised long day conditions in sterile culture. Trifoliate leaves or shoot apices were harvested from 13–15-day-old plants at 4 h after dawn (ZT4). Three biological replicates per tissue type for each genotype were harvested. Total RNA was extracted and sent for RNA-sequencing. Three biological replicates of leaves and shoots from wild type R108 and Mting2-1 mutant made up a total of 12 RNA-Seq libraries.

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: ModelOrganism

Last updated: 2021-11-22