Biology subjects

Karsai, I.

Publications and source records attributed to Karsai, I..

4 recordsLinked to original sources

bioRxiv2026

Catcher in the rye: museomics reveals the identity of cereal remains recovered from a late nineteenth century antique furniture

Historical crop remains preserved in everyday objects are an underused archive of agrobiodiversity change, yet their degraded DNA resists conventional analysis. We recovered cereal grains and straws used as upholstery padding in a Central European settee dated to about 1870 to 1900. We identified and characterized the specimen by genome skimming. Damage-aware sequencing confirmed authentic historical DNA of modest, late nineteenth-century age. The assembled plastome placed the specimen securely within rye, and a genome-wide SNP panel of rye landraces resolved it inside cultivated Secale cereale subsp. cereale, closest to a Hungarian bred rye and a Slovak upland landrace and remote from wild or eastern lineages. Screening 192 stress-associated loci recovered the structural machinery of resistance, abiotic stress and aluminum tolerance pathways, while heading-date genotyping showed the Weining earliness allele at Hd2R already present. Divergence across 36 domestication sweep regions concentrated at a few improvement loci. Integrating these genomic signals with genebank passport data and an 1891 newspaper record, we interpret the specimen as a tall Central European rye at the threshold between landrace and improved variety. Historical crop material, read this way, preserves both genomes and the traces of human agricultural practice.

genomics↗

bioRxiv2025

Vernalization regulatory network identifies potential novel functions for ZCCT genes within HvVRN2

O_LIFlowering is a key yield determinant, controlled by environmental and genetic factors. Vernalization requirement, a prolonged cold period to promote flowering, is determined in barley (Hordeum vulgare L.) by the allele in HvVRN1 and the presence of locus HvVRN2, which consists of two ZCCT genes: HvVRN2a and HvVRN2b. While the effect of HvVRN2 presence is well-known, its outcome on the transcriptome and other genes outside the flowering/vernalization pathway remains unknown. C_LIO_LINear-isogenic lines with presence/absence of HvVRN2, were subjected to different lengths of vernalization treatments, identifying the expression dynamics of both HvVRN2 genes and wider transcriptional responses controlled by VRN2. C_LIO_LIOur work revealed previously unknown differences in expression levels of the two HvVRN2 genes, in responses to its main repressor, HvVRN1, and an effect on tillering. Besides, we shed new light on the repressing mechanism of VRN2 on flowering, using protein modelling. A regulatory network analysis pointed at new candidate genes for flowering regulation related to the vernalization pathway, and suggested additional biological roles for HvVRN2b. C_LIO_LIThis study re-establishes HvVRN2 as a central gene for understanding barley responses to environmental cues, beyond its previously accepted simple role, and expands the catalogue of genes related to the vernalization pathway, which may be targeted in barley breeding. C_LI

plant biology↗

bioRxiv2021

Light spectra trigger divergent gene expression in barley cultivars

Light spectra influence barley development, causing a diverse range of responses among cultivars that are poorly understood. Here, we exposed three barley genotypes with different light sensitivities to two light sources: fluorescent bulbs, over-representing green and red wavebands, and metal halide lamps, with a more balanced spectrum. We used RNA sequencing to identify the main genes and pathways involved in the different responses, and RT-qPCR to validate the expression values. Different grades of sensitivity to light spectra were associated with transcriptional reprogramming, plastid signals, and photosynthesis. The genotypes were especially divergent in the expression of genes regulated by transcription factors from MADS-box, WRKY, and NAC families, and in specific photoreceptors such as phytochromes and cryptochromes. Variations in light spectra also affected the expression of circadian clock, flowering time, and frost tolerance genes, among others, resembling plant responses to temperature. The relation between PPD-H1, HvVRN1, and HvFT1 expression might explain genotypic differences. Light-sensitive genotypes experienced a partial reversion of the vernalization process and senescence-related stress under the less favorable light quality conditions. The observed light-quality sensitivities reveal a complex mechanism of adaptation to regions with specific light quality features and/or possible regulation of light spectra in plant development during early spring. HighlightDevelopment genes were affected by light quality in the barley varieties tested. Different grades of sensitivity were related to the expression of transcription factors, senescence, light signaling and cold-regulated genes.

plant biology↗

bioRxiv2018

Long-day increase of HvVRN2 expression marks the deadline to fulfill the vernalization requirement in winter barley

Vernalization and photoperiod cues are integrated in winter barley plants to flower in the right conditions. We hypothesize that there is a timeframe to satisfy the vernalization needs in order to flower in the optimum moment. Growth and expression of different flowering promoters (HvVRN1, HvCO2, Ppd-H1, HvFT1, HvFT3) and repressors (HvVRN2, HvCO9 and HvOS2) were evaluated in two winter barley varieties under: (1) natural increasing photoperiod, without vernalization, and (2) under short day conditions in three insufficient vernalization treatments. Here, we provide evidence of the existence of a day-length threshold, around 12 h 30 min in our latitudes (Zaragoza, Spain, 41{degrees}43N), marked by the rise of HvVRN2 expression, which defines the moment in which cold requirement must be satisfied to acquire competency to flower. Before that, expression of HvCO2 was induced and might be promoting HvFT1 in both inductive and non-inductive conditions. HvFT3, to be effectively expressed, must receive induction of cold or plant development, through downregulation of HvVRN2 and HvOS2. We emphasize the contribution of HvOS2, together with HvVRN2, in the delay of flowering in vernalization-responsive cultivars. Understanding this complex mechanism of flowering might be useful for breeders to define varieties, particularly in a climate change scenario.

plant biology↗