Project description:Deciphering the various chemical modifications of both DNA and the histone compound of chromatin not only leads to a better understanding of the genome-wide organization of epigenetic landmarks and their impact on gene expression but may also provide some insights into the evolutionary processes. Although both histone modifications and DNA methylation have been widely investigated in various plant genomes, here we present the first study for the genus Lupinus. Lupins, which are members of grain legumes (pulses), are beneficial for food security, nutrition, health and the environment. In order gain a better understanding of the epigenetic organization of genomes in lupins we applied the immunostaining of methylated histone H3 and DNA methylation as well as whole-genome bisulfite sequencing. We revealed variations in the patterns of chromatin modifications at the chromosomal level among three crop lupins, i.e. L. angustifolius (2n=40), L. albus (2n=50) and L. luteus (2n=52), and the legume model plant Medicago truncatula (2n=16). Different chromosomal patterns were found depending on the specific modification, e.g. H3K4me2 was localised in the terminal parts of L. angustifolius and M. truncatula chromosomes, which is in agreement with the results that have been obtained for other species. Interestingly, in L. albus and L. luteus this modification was limited to one arm in the case of all of the chromosomes in the complement. Additionally, H3K9me2 was detected in all of the analysed species except L. luteus. DNA methylation sequencing (CG, CHG and CHH contexts) of aforementioned crop but also wild lupins such as L. cosentinii (2n=32), L. digitatus (2n=36), L. micranthus (2n=52) and L. pilosus (2n=42) supported the range of interspecific diversity. The examples of epigenetic modifications illustrate the diversity of lupin genomes and could be helpful for elucidating further epigenetic changes in the evolution of the lupin genome.
Project description:Phosphorus (P) and iron (Fe) deficiency are major limiting factors for plant productivity worldwide. White lupin (Lupinus albus L.) has become a model plant for understanding plant adaptations to P and Fe deficiency, because of its ability to form cluster roots, bottle-brush-like root structures that play an important role in the uptake of P and Fe from soil. However, little is known about the signaling pathways involved in sensing and responding to P and Fe deficiency. Sucrose, sent in increased concentrations from the shoot to the root, has been identified as a long- distance signal of P and Fe deficiencies. To unravel responses to sucrose as a signal, we performed Oxford Nanopore cDNA sequencing of white lupin roots treated with sucrose for 10 min, 15 min, and 20 min, compared to untreated controls. We identified a set of 17 genes, including two bHLH transcription factors, that were upregulated at all three time points of sucrose treatment. GO (gene ontology) analysis revealed enrichment of auxin- and gibberellin-responses as early as 10 min after sucrose addition, and the emerging of ethanol-responses at 20 min of sucrose treatment, indicating a sequential involvement of these hormones in plant responses to sucrose.
Project description:An RNA-Seq Transcriptome Analysis of Orthophosphate-Deficient White Lupin Reveals Novel Insights into Phosphorus Acclimation in Plants