RESUMO
Plasticity in root system architecture (RSA) allows plants to adapt to changing nutritional status in the soil. Phosphorus availability is a major determinant of crop yield, and RSA remodeling is critical to increasing the efficiency of phosphorus acquisition. Although substantial progress has been made in understanding the signaling mechanism driving phosphate starvation responses in plants, whether and how epigenetic regulatory mechanisms contribute is poorly understood. Here, we report that the Switch defective/sucrose non-fermentable (SWI/SNF) ATPase BRAHMA (BRM) is involved in the local response to phosphate (Pi) starvation. The loss of BRM function induces iron (Fe) accumulation through increased LOW PHOSPHATE ROOT1 (LPR1) and LPR2 expression, reducing primary root length under Pi deficiency. We also demonstrate that BRM recruits the histone deacetylase (HDA) complex HDA6-HDC1 to facilitate histone H3 deacetylation at LPR loci, thereby negatively regulating local Pi deficiency responses. BRM is degraded under Pi deficiency conditions through the 26 S proteasome pathway, leading to increased histone H3 acetylation at the LPR loci. Collectively, our data suggest that the chromatin remodeler BRM, in concert with HDA6, negatively regulates Fe-dependent local Pi starvation responses by transcriptionally repressing the RSA-related genes LPR1 and LPR2 in Arabidopsis thaliana.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Histonas/metabolismo , Cromatina/metabolismo , Fosfatos/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fósforo/metabolismo , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/metabolismo , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismoRESUMO
BACKGROUND: We evaluated the long-term cost-effectiveness of antihypertensive traditional Chinese medicines (TCMs) and to compare the cost-effectiveness of a combined treatment consisting of compound Apocynum tablets and Nifedipine sustained-release tablets with the cost-effectiveness of treatment with Nifedipine sustained-release tablets alone. METHODS: A Markov model was used to simulate the potential incremental cost-effectiveness per quality-adjusted life year (QALY) to be gained from compound Apocynum tablets and Nifedipine sustained-release tablets compared with Nifedipine sustained-release tablets alone. Model parameter estimates were informed by previously published studies. The direct medical costs of outpatients with hypertension were estimated from the health care provider's perspective. A 5% annual discount rate was applied to both costs and QALYs. RESULTS: TCMs combined with Nifedipine sustained-release tablets group generated a total 20-year cost of 11,517.94 RMB (US $1739.87), whereas Nifedipine sustained-release tablets alone group resulted in a 20-year cost of 7253.71 RMB (US $1095.73). TCMs combined with Nifedipine sustained-release tablets group resulted in a generation of 12.69 QALYs, whereas Nifedipine sustained-release tablets alone group resulted in 12.50. The incremental cost-utility ratio was 22,443.32 RMB (US $3390.23) per QALY. Considering the threshold of 1 GDP per capita in China in 2018 (US $9764.95), the combination of compound Apocynum tablets and Nifedipine sustained-release tablets was a cost-effective strategy. One-way and probabilistic sensitivity analysis showed unchanged results over an acceptable range. CONCLUSIONS: Combining Traditional Chinese Medicines with chemical medicines is more cost-effective strategy in the treatment of hypertension.