Biomedical subjects

Jochen Kumlehn

Publications and source records attributed to Jochen Kumlehn.

3 recordsLinked to original sources

PubMed2026

Cloning, Transformation, and Reporter Gene Analysis of the SalT Promoter in Barley (Hordeum vulgare).

Constitutive gene expression can lead to pleiotropic effects. Therefore, spatial or temporal restriction of expression via specific promoters provides a more targeted approach. This study aimed to clone the SalT promoter and analyze its activity in transgenic barley using GFP and GUS reporter genes. The T-DNA constructs carrying the SalT promoter were introduced into barley cv. Golden Promise, and transgenic plants were confirmed through PCR, hygromycin selection, and Southern hybridization. Both constructs, SalT-GFP and SalT-GUS, were transformed in barley cv. Golden Promise. Here, we characterized the expression pattern of the SalT promoter in barley and utilized it to drive the expression of reporter genes GFP and GUS. The SalT promoter was isolated from rice genomic DNA, cloned into the pNos-AB-M vector, and confirmed through PCR and restriction analysis. Subsequently, GFP and GUS genes were cloned under the SalT promoter in the same vector. The constructs were then subcloned into the p6U vector for plant expression. Agrobacterium-mediated genetic transformation of barley cultivar "Golden Promise" was conducted, resulting in successful integration of the transgenes. Callus induction, regeneration, and root formation efficiency were assessed, demonstrating the potential of the SalT promoter to drive gene expression during various stages of plant development. Molecular analyses, including PCR and Southern hybridization, confirmed the presence and integration of transgenes in the barley genome. Furthermore, GFP fluorescence and GUS staining analyses revealed strong expression of the respective genes under control of the SalT promoter in different plant tissues. This study provides insights into the application of the SalT promoter for genetic manipulation and functional characterization in barley, offering opportunities for crop improvement and biotechnological applications.

Hordeum↗

PubMed2025

A haplotype-resolved pangenome of the barley wild relative Hordeum bulbosum.

Wild plants can contribute valuable genes to their domesticated relatives1. Fertility barriers and a lack of genomic resources have hindered the effective use of crop-wild introgressions. Decades of research into barley's closest wild relative, Hordeum bulbosum, a grass native to the Mediterranean basin and Western Asia, have yet to manifest themselves in the release of a cultivar bearing alien genes2. Here we construct a pangenome of bulbous barley comprising 10 phased genome sequence assemblies amounting to 32 distinct haplotypes. Autotetraploid cytotypes, among which the donors of resistance-conferring introgressions are found, arose at least twice, and are connected among each other and to diploid forms through gene flow. The differential amplification of transposable elements after barley and H. bulbosum diverged from each other is responsible for genome size differences between them. We illustrate the translational value of our resource by mapping non-host resistance to a viral pathogen to a structurally diverse multigene cluster that has been implicated in diverse immune responses in wheat and barley.

Hordeum↗

PubMed2025

Barley resistance and susceptibility to fungal cell entry involve the interplay of ROP signaling with phosphatidylinositol-monophosphates.

Rho-of-plant small GTPases (ROPs) are regulators of plant polar growth and of plant-pathogen interactions. The barley ROP, RACB, is involved in susceptibility toward infection by the barley powdery mildew fungus Blumeria hordei (Bh) but little is known about the cellular pathways that connect RACB signaling to disease susceptibility. Here we identify novel RACB interaction partners of plant or fungal origin by untargeted co-immunoprecipitation of constitutively active (CA) RACB tagged by green fluorescent protein from Bh-infected barley epidermal layers and subsequent analysis by liquid chromatography-coupled mass spectrometry. Three of the immunoprecipitated proteins, a plant phosphoinositide phosphatase, a plant phosphoinositide phospholipase, and a putative Bh-effector protein, are involved in the barley-Bh-pathosystem and support disease resistance or susceptibility, respectively. RACB and its plant interactors bind to overlapping anionic phospholipid species in vitro, and in the case of RACB, this lipid interaction is mediated by its carboxy-terminal polybasic region (PBR). Fluorescent markers for anionic phospholipids show altered subcellular distribution in barley cells during Bh attack and under expression of a RACB-binding fungal effector. Phosphatidylinositol 4-phosphate, phosphatidylinositol 3,5-bisphosphate, and phosphatidylserine show a distinct enrichment at the haustorial neck region, suggesting a connection to subcellular targeting of RACB at this site. The interplay of ROPs with anionic phospholipids and phospholipid-metabolizing enzymes may thus enable the subcellular enrichment of components pivotal for success or failure of fungal penetration.

Hordeum↗