RESUMO
Nutrient availability profoundly influences plant root system architecture, which critically determines crop productivity. While Arabidopsis has provided important insights into the genetic responses to nutrient deficiency, translating this knowledge to crops, particularly wheat, remains a subject of inquiry. Here, examining a diverse wheat population under varying nitrogen (N), phosphorus (P), potassium (K), and iron (Fe) levels, we uncover a spectrum of root responses, spanning from growth inhibition to stimulation, highlighting genotype-specific strategies. Furthermore, we reveal a nuanced interplay between macronutrient deficiency (N, P, and K) and Fe availability, emphasizing the central role of Fe in modulating root architecture. Through genome-wide association mapping, we identify 11 quantitative trait loci underlying root traits under varying nutrient availabilities, including homologous genes previously validated in Arabidopsis, supporting our findings. In addition, utilizing transcriptomics, ROS imaging, and antioxidant treatment, we uncover that wheat root growth inhibition by nutrient deficiency is attributed to ROS accumulation, akin to the role of ROS in governing Arabidopsis root responses to nutrient deficiency. Therefore, our study reveals the conservation of molecular and physiological mechanisms between Arabidopsis and wheat to adjust root growth to nutrient availability, paving the way for targeted crop improvement strategies aimed at increasing nutrient use efficiency.
RESUMO
Plant roots release phytochemicals into the soil environment to influence nutrient availability and uptake. Arabidopsis thaliana roots release phenylpropanoid coumarins in response to iron (Fe) deficiency, likely to enhance Fe uptake and improve plant health. This response requires sufficient phosphorus (P) in the root environment. Nonetheless, the regulatory interplay influencing coumarin production under varying availabilities of Fe and P is not known. Through genome-wide association studies, we have pinpointed the influence of the ABC transporter G family member, PDR9, on coumarin accumulation and trafficking (homeostasis) under combined Fe and P deficiency. We show that genetic variation in the promoter of PDR9 regulates its expression in a manner associated with coumarin production. Furthermore, we find that MYB63 transcription factor controls dedicated coumarin production by regulating both COUMARIN SYNTHASE (COSY) and FERULOYL-CoA 6'-HYDROXYLASE 1 (F6'H1) expression while orchestrating secretion through PDR9 genes under Fe and P combined deficiency. This integrated approach illuminates the intricate connections between nutrient signaling pathways in coumarin response mechanisms.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cumarínicos/metabolismo , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Homeostase , Raízes de Plantas/genética , Raízes de Plantas/metabolismoRESUMO
Efficiently regulating growth to adapt to varying resource availability is crucial for organisms, including plants. In particular, the acquisition of essential nutrients is vital for plant development, as a shortage of just one nutrient can significantly decrease crop yield. However, plants constantly experience fluctuations in the presence of multiple essential mineral nutrients, leading to combined nutrient stress conditions. Unfortunately, our understanding of how plants perceive and respond to these multiple stresses remains limited. Unlocking this mystery could provide valuable insights and help enhance plant nutrition strategies. This review focuses specifically on the regulation of phosphorous homeostasis in plants, with a primary emphasis on recent studies that have shed light on the intricate interactions between phosphorous and other essential elements, such as nitrogen, iron, and zinc, as well as non-essential elements like aluminum and sodium. By summarizing and consolidating these findings, this review aims to contribute to a better understanding of how plants respond to and cope with combined nutrient stress.
Assuntos
Minerais , Plantas , Ferro , Fósforo , NutrientesRESUMO
Nutrient sensing and signaling are essential for adjusting growth and development to available resources. Deprivation of the essential mineral phosphorus (P) inhibits root growth.1 The molecular processes that sense P limitation to trigger early root growth inhibition are not known yet. Target of rapamycin (TOR) kinase is a central regulatory hub in eukaryotes to adapt growth to internal and external nutritional cues.2,3 How nutritional signals are transduced to TOR to control plant growth remains unclear. Here, we identify Arabidopsis-root-specific kinase 1 (ARSK1), which attenuates initial root growth inhibition in response to P limitation. We demonstrate that ARSK1 phosphorylates and stabilizes the regulatory-associated protein of TOR 1B (RAPTOR1B), a component of the TOR complex 1, to adjust root growth to P availability. These findings uncover signaling components acting upstream of TOR to balance growth to P availability.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fosfatos/metabolismo , Transdução de Sinais/fisiologia , Sirolimo/farmacologia , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismoRESUMO
Owing to the impending global scarcity of high-quality sources of phosphate (Pi) fertilizers, lowering its use in crop production requires improved insights into factors stimulating Pi uptake from the soil as well as the efficacious use by plants. Following decades of extensive research on plants' adaptation to Pi deficiency with mitigated success in the field, a better understanding of how plants exposed to zinc (Zn) deficiency accumulate much more Pi provides a novel strategy in comparison to when plants are grown in Zn-rich soils. In this context, we review current knowledge and molecular events involved in the Pi and Zn signaling crosstalk in plants that will bear great significance for agronomical and rudimentary research applications.
RESUMO
Elevated atmospheric CO2 enhances photosynthetic rate,1 thereby increasing biomass production in plants. Nevertheless, high CO2 reduces the accumulation of essential nutrients2 such as phosphorus (P),3 which are required for photosynthetic processes and plant growth. How plants ensure enhanced growth despite meager P status remains enigmatic. In this study, we utilize genome-wide association analysis in Arabidopsis thaliana to identify a P transporter, PHT4;3, which mediates the reduction of P in chloroplasts at high CO2. Decreasing chloroplastic P fine-tunes the accumulation of a sugar-P metabolite, phytic acid, to support plant growth. Furthermore, we demonstrate that this adaptive mechanism is conserved in rice. Our results establish a mechanistic framework for sustainable food production against the backdrop of soaring CO2 levels across the world.
Assuntos
Arabidopsis , Fósforo , Fósforo/metabolismo , Dióxido de Carbono/metabolismo , Ácido Fítico/metabolismo , Estudo de Associação Genômica Ampla , Cloroplastos , Arabidopsis/metabolismo , Plantas/metabolismo , Homeostase , Açúcares/metabolismoRESUMO
Iron deficiency hampers photosynthesis and is associated with chlorosis. We recently showed that iron deficiency-induced chlorosis depends on phosphorus availability. How plants integrate these cues to control chlorophyll accumulation is unknown. Here, we show that iron limitation downregulates photosynthesis genes in a phosphorus-dependent manner. Using transcriptomics and genome-wide association analysis, we identify two genes, PHT4;4 encoding a chloroplastic ascorbate transporter and bZIP58, encoding a nuclear transcription factor, which prevent the downregulation of photosynthesis genes leading to the stay-green phenotype under iron-phosphorus deficiency. Joint limitation of these nutrients induces ascorbate accumulation by activating expression of an ascorbate biosynthesis gene, VTC4, which requires bZIP58. Furthermore, we demonstrate that chloroplastic ascorbate transport prevents the downregulation of photosynthesis genes under iron-phosphorus combined deficiency through modulation of ROS homeostasis. Our study uncovers a ROS-mediated chloroplastic retrograde signaling pathway to adapt photosynthesis to nutrient availability.
Assuntos
Ferro/metabolismo , Fósforo/metabolismo , Fotossíntese/genética , Fotossíntese/fisiologia , Plantas/metabolismo , Transdução de Sinais , Arabidopsis , Clorofila/metabolismo , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Homeostase , Deficiências de Ferro , Cinética , Nutrientes , Plantas/genética , TranscriptomaRESUMO
Photomorphogenesis, light-mediated development, is an essential feature of all terrestrial plants. While chloroplast development and brassinosteroid (BR) signaling are known players in photomorphogenesis, proteins that regulate both pathways have yet to be identified. Here we report that DE-ETIOLATION IN THE DARK AND YELLOWING IN THE LIGHT (DAY), a membrane protein containing DnaJ-like domain, plays a dual-role in photomorphogenesis by stabilizing the BR receptor, BRI1, as well as a key enzyme in chlorophyll biosynthesis, POR. DAY localizes to both the endomembrane and chloroplasts via its first transmembrane domain and chloroplast transit peptide, respectively, and interacts with BRI1 and POR in their respective subcellular compartments. Using genetic analysis, we show that DAY acts independently on BR signaling and chlorophyll biogenesis. Collectively, this work uncovers DAY as a factor that simultaneously regulates BR signaling and chloroplast development, revealing a key regulator of photomorphogenesis that acts across cell compartments.
Assuntos
Proteínas de Arabidopsis/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Membrana/metabolismo , Morfogênese/fisiologia , Proteínas Quinases/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Brassinosteroides/metabolismo , Clorofila/biossíntese , Cloroplastos/metabolismo , Estiolamento/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Técnicas de Silenciamento de Genes , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP40/isolamento & purificação , Luz , Proteínas de Membrana/genética , Proteínas de Membrana/isolamento & purificação , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Morfogênese/efeitos da radiação , Mutação , Plantas Geneticamente Modificadas , Proteínas Quinases/genética , RNA-Seq , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Plântula/crescimento & desenvolvimento , Transdução de Sinais/fisiologiaRESUMO
Phosphorus (P) is an essential macronutrient for all living organisms. Importantly, plants require a large amount of P to grow, and P deficiency causes huge losses in plant production. Although this issue can be mitigated by the appropriate use of phosphate (Pi) rock-derived P fertilizers, phosphate rock is a finite natural resource. Moreover, the increased demand for food as a result of our growing global population is another factor contributing to a prospective P crisis. While creating crops that are resilient to Pi deficiency presents great scientific challenge, the current progress in our understanding of how plants regulate Pi homeostasis offers some opportunities for further study. In this review, we present the published research supporting these opportunities, which are based on the molecular mechanisms that plants have evolved to respond to P deficiency. First, we focus on recent advances in P sensing and signaling pathways in the regulation of root system architecture. Next, we describe the mechanisms that regulate Pi transport and accumulation, in a Pi- (or other nutrient) dependent manner. Integrating these data will help to design an innovative strategy for improving Pi nutrition in plants. In addition, this will help with Pi scarcity, one of the challenges facing agriculture in the twenty first century.