Low phosphate represses histone deacetylase complex1 to regulate root system architecture remodeling in Arabidopsis

Abstract

The mechanisms involved in the regulation of gene expression in response to phosphate (Pi) deficiency have been extensively studied, but their chromatin-level regulation remains poorly understood.We examined the role of histone acetylation in response to Pi deficiency by using the histone deacetylase complex1 (hdc1) mutant. Genes involved in root system architecture (RSA) remodeling were analyzed by quantitative real-time polymerase chain reaction (qPCR) and chromatin immunoprecipitation qPCR.We demonstrate that histone H3 acetylation increased under Pi deficiency, and the hdc1 mutant was hypersensitive to Pi deficiency, with primary root growth inhibition and increases in root hair number. Concomitantly, Pi deficiency repressed HDC1 protein abundances. Under Pi deficiency, hdc1 accumulated higher concentrations of Fe 3+ in the root tips and had higher expression of genes involved in RSA remodeling, such as ALUMINUM-ACTIVATED MALATE TRANSPORTER1 (ALMT1), LOW PHOSPHATE ROOT1 (LPR1), and LPR2 compared with wild-type plants. Furthermore, Pi deficiency enriched the histone H3 acetylation of ALMT1 and LPR1. Finally, genetic evidence showed that LPR1/2 was epistatic to HDC1 in regulating RSA remodeling.Our results suggest a chromatin-level control of Pi starvation responses in which HDC1-mediated histone H3 deacetylation represses the transcriptional activation of genes involved in RSA remodeling in Arabidopsis.

SIZ1 negatively regulates aluminum resistance by mediating the STOP1–ALMT1 pathway in Arabidopsis

“…Chromatin immunoprecipitation assay was conducted as described previously (Xu et al, 2020). Briefly, approximately 1.5 g root tissues were cross‐linked with 1% formaldehyde, and then the nuclei were isolated and lysed.…”

“…Root elongation of seedlings treated with and without Al was measured using a ruler and the relative root elongation was calculated to assess Al resistance. Low Pi treatment was conducted as previously described (Xu et al, 2020). Briefly, seeds were sowed on the low Pi medium supplemented with 10 μmol/L Pi (−Pi) and the high Pi medium containing 625 μmol/L Pi (+Pi).…”

Prospects of Genetics and Breeding for Low Phosphate Tolerance: an Integrated Approach from Soil to Cell

“…Furthermore, it was demonstrated that up to 40% of rice genes undergo chromatin state changes in response to low Pi availability and that genes that are differentially expressed in response to Pi limitation are overrepresented in this set of genes with low-Pi activated chromatin dynamics (Foroozani et al 2020). Another chromatin modi cation, histone deacetylation, was recently shown to repress the transcriptional activation of genes related to the modi cation of root architecture in response to low Pi in Arabidopsis (Xu et al 2020). Altogether, recent evidence highlights the importance of epigenetic regulation on plant adaptation to low Pi availability and its value as the foundation for the development of innovative genome manipulation tools that might enable breeders to produce low-Pi tolerant crops (Figure 5).…”

Epigenetic regulation: another layer in plant nutrition

“…19,37 Concomitantly, under P sufficient conditions the HISTONE DEACETYLASE COMPLEX 1 (HDC1) protein directly acts as a repressor of genes involved in P starvationrelated remodeling of the root system architecture. 18 When the root system encounters P starvation, HDC1 protein levels are reduced by probable proteasome-mediated degradation, leading to the up-regulation of genes involved in root system architecture remodeling. Altogether, these discoveries show the importance of dynamic histone active and repressive marks enrichment to respond to P starvation.…”