Biology subjects

Reuscher, S.

Publications and source records attributed to Reuscher, S..

4 recordsLinked to original sources

bioRxiv2025

Structural variation at lhcb6 underlies genetic variation in photosystem II maximum quantum efficiency in maize

Targeted utilization of native genetic diversity can expand the genetic basis of traits that exhibit limited genetic variation in elite breeding material and can enhance our understanding of the genotype-phenotype relationships associated with complex traits in crops. In a genome-wide association study in a European maize landrace we identified quantitative trait loci (QTL) that affected the maximum quantum efficiency of photosystem II (Fv/Fm) in field experiments. In a forward genetic approach, we focused on a QTL on chromosome 10, explaining a large proportion of the genetic variance for Fv/Fm in growth stages V4 (35%) and V6 (47%), for genetic dissection and candidate gene discovery. Integrating molecular and physiological information we show that allelic variation at the gene encoding LIGHT HARVESTING CHLOROPHYLL A/B BINDING PROTEIN6 (LHCB6), a component of the photosystem II (PSII) light-harvesting complex (LHCII) antenna, underlies the variation in Fv/Fm. We demonstrate that the allelic variation results from a hAT transposon insertion at lhcb6 and is associated with differential accumulation of the LHCII antenna components LHCB6 and LHCB3, leading to differences in non-photochemical quenching (NPQ) and plant biomass accumulation. Based on proteomic analyses we propose candidate genes that compensate the unfavorable effects caused by impaired LHCII antenna assembly. Our work provides novel insights into the function of lhcb6 in the context of LHCII antenna assembly and demonstrates the value of natural variation in landraces for the understanding and genetic improvement of complex photosynthetic processes.

genetics↗

bioRxiv2025

Genetic architecture and functional consequences of lateral root length in maize (Zea mays L.)

Understanding the genetic basis of root architecture and its relevance for crop productivity can contribute to the sustainable intensification of agriculture. Leveraging the phenotypic and allelic diversity of an Austrian maize landrace, we dissected the genetic basis of lateral root (LR) length across developmental stages. LR length, a relevant trait for breeding resource-efficient varieties, showed high heritability in our experiments. We discovered eight quantitative trait loci (QTL) for LR length at the reproductive stage R2, overlapping with four QTL at stage R6 but not with QTL detected at vegetative stage V6, suggesting that the genetic regulation of LR length might differ in vegetative and reproductive stages. We fine-mapped qlr1, the most significant QTL for LR length, to a region of 2.3 Mb containing 46 annotated genes. Based on whole-genome sequence and comparative genomics analyses we suggest a candidate gene underlying qlr1. Additionally, we examined the impact of nitrogen, phosphorus, and irrigation treatments on root and shoot development, finding that LR length positively correlates with biomass accumulation under optimal nutrient supply but not under nitrogen stress. Our work provides insights into the genetic regulation of LR length in maize and its relevance for the adaptation to specific growing environments. HighlightMultiple QTL affect lateral root length in maize at different developmental stages. The correlation between lateral root length and biomass accumulation varies under diverse field conditions.

genetics↗

bioRxiv2024

Embracing native diversity to enhance maximum quantum efficiency of photosystem II in maize (Zea mays L.)

Sustainability of maize cultivation would benefit tremendously from early sowing but is hampered by low temperatures during early development in temperate climate. We show that allelic variation of subunit M of NADH-dehydrogenase-like (NDH) complex (ndhm1), discovered in a European maize landrace affects several quantitative traits relevant during early development in cold climates through NDH-mediated cyclic electron transport (CET) around photosystem I, a process crucial for photosynthesis. Starting from a genome-wide association study (GWAS) for maximum potential quantum yield of photosystem II in dark-adapted leaves (Fv/Fm) we capitalized on large phenotypic effects of a hAT transposon insertion in ndhm1 on quantitative traits early plant height (EPH), Fv/Fm, chlorophyll content and cold tolerance caused by reduced protein levels of NDHM and associated NDH components. Analysis of the native allelic series of ndhm1 revealed a rare allele of ndhm1 which is associated with small albeit significant effects on maximum potential quantum yield of photosystem II in dark- and light adapted leaves (Fv/Fm, {Phi}PSII) and early plant height compared to common alleles. Our work showcases the extraction of novel, favorable alleles from locally adapted landraces, offering an efficient strategy for broadening the genetic variation of elite germplasm by breeding or genome editing.

plant biology↗

bioRxiv2022

Npl3 functions in mRNP assembly by recruitment of mRNP components to the transcription site and their transfer onto the mRNA

RNA-binding proteins (RBPs) control every RNA metabolic process by multiple protein-RNA and protein-protein interactions. Their roles have largely been analyzed by crude mutations, which abrogate multiple functions at once and likely impact the structural integrity of the large messenger ribonucleoprotein particle (mRNP) assemblies, these proteins often function in. Using UV-induced RNA-protein crosslinking and subsequent mass spectrometric analysis, we first identified more than 100 in vivo RNA crosslinks in 16 nuclear mRNP components in S. cerevisiae. For functional analysis, we chose Npl3, for which we determined crosslinks in its two RNA recognition motifs (RRM) and in the flexible linker region connecting the two. Using NMR and structural analyses, we show that both RRM domains and the linker uniquely contribute to RNA recognition. Interestingly, mutations in these regions cause different phenotypes, indicating distinct functions of the different RNA-binding domains of Npl3. Notably, the npl3-Linker mutation strongly impairs recruitment of several mRNP components to chromatin and incorporation of further mRNP components into nuclear mRNPs, establishing a function of Npl3 in nuclear mRNP assembly. Taken together, we determined the specific function of the RNA-binding activity of the nuclear mRNP component Npl3, an approach that can be applied to many RBPs in any RNA metabolic process.

biochemistry↗