Arabidopsis HEAT SHOCK FACTOR BINDING PROTEIN is required to limit meiotic crossovers and HEI10 transcription

Abstract

The number of meiotic crossovers is tightly controlled and most depend on pro‐crossover ZMM proteins, such as the E3 ligase HEI10. Despite the importance of HEI10 dosage for crossover formation, how HEI10 transcription is controlled remains unexplored. In a forward genetic screen using a fluorescent crossover reporter in Arabidopsis thaliana, we identify heat shock factor binding protein (HSBP) as a repressor of HEI10 transcription and crossover numbers. Using genome‐wide crossover mapping and cytogenetics, we show that hsbp mutations or meiotic HSBP knockdowns increase ZMM‐dependent crossovers toward the telomeres, mirroring the effects of HEI10 overexpression. Through RNA sequencing, DNA methylome, and chromatin immunoprecipitation analysis, we reveal that HSBP is required to repress HEI10 transcription by binding with heat shock factors (HSFs) at the HEI10 promoter and maintaining DNA methylation over the HEI10 5′ untranslated region. Our findings provide insights into how the temperature response regulator HSBP restricts meiotic HEI10 transcription and crossover number by attenuating HSF activity.

The effect of DNA polymorphisms and natural variation on crossover hotspot activity in Arabidopsis hybrids

“…This method is based on extremely short interval lines (ESILs), which carry fluorescent reporters expressed in seeds, separated by no more than 50 kb. The fluorescently tagged intervals provide both precise CO frequency measurements 11,50,[52][53][54][55][56] and an easy assay for recombinants based on seed fluorescence. We used a recently developed large-scale collection of fluorescent reporter lines in Arabidopsis 57 to construct five ESILs by crossing the selected single-color reporter lines in the Col-0 background (Supplementary Fig.…”

Why do plants need the ZMM crossover pathway? A snapshot of meiotic recombination from the perspective of interhomolog polymorphism

“…This coarsening model has been recently supported by experimental data showing that SC is critical for funneling chromosomal HEI10 distribution (Durand et al 2022) The dose-dependent effects of HEI10 on crossover number suggests the existence of factors that affect HEI10 expression and activity. A heat shock factor binding protein HSBP that regulates crossover number via controlling HEI10 transcription has already been identified (Kim et al 2022), and an additional protein functionally linked to HEI10, HEIP1, that participates in crossover regulation has been recently described in rice (Li et al 2018). Moreover, other regulatory circuits, such as that including HCR1, which encodes a protein phosphatase, were shown to have anti-recombination roles in the regulation of the ZMM pathway (Nageswaran et al 2021).…”

Genome-Wide Analysis of the HSF Gene Family Reveals Its Role in Astragalus mongholicus under Different Light Conditions

“…Several studies have demonstrated that HSFs play important roles in plant responses to high-temperature stress. Overexpression of ATHSFA1 and SlHSFA1 significantly increased heat tolerance in Arabidopsis thaliana and Solanum lycopersicum [8]. The class A HSF gene TaHsfA2d, which is similar to Oryza sativa OsHsfA2d, was isolated from wheat, and plants overexpressing TaHsfA2d in A. thaliana showed higher tolerance to high temperatures [9].…”