The plant energy management machinery: an essential hub for stress resilience and developmental dynamics with great potential for crop improvement

Plants coordinate resource uptake, developmental pace, and morphological efficiency. This ensures that energy use is balanced across time and tissues, enabling resilience and stable growth under fluctuating environmental conditions. The plant energy management machinery encompasses the interconnected signalling and metabolic networks that coordinate energy acquisition, storage, mobilization, and utilization to support growth, development, and environmental adaptation. In contrast to animals, where dedicated organs such as fat bodies in Drosophila and the liver in mammals, play crucial roles in energy metabolism and sensing (Chatterjee and Perrimon, 2021), plants exhibit a more integrative concept of nutrient and energy regulation. Here, the term ‘nutrients’ extends beyond simple energy carriers to include a broad spectrum of organic and inorganic compounds, such as sugars, amino acids, nitrate, phosphate, and lipids, that function both as metabolic substrates and as signalling molecules, influencing gene expression, enzyme activity, developmental transitions, and growth. Energy management in plants can be defined as the combined signalling network that regulates the flow of energy from photosynthetic and stored reserves (including starch, lipids, and nitrogen compounds) to diverse energy-consuming processes, which are modulated according to developmental stage and environmental context (Fig. 1). Two central regulators orchestrating this balance are the kinases TOR (Target of Rapamycin) and SnRK1 (SNF1-related kinase 1) which are homologs of mammalian mTOR and AMPK (AMP-activated protein kinase). TOR complex 1 (TORC1) integrates nutrient availability, energy status, and environmental cues to promote anabolic metabolism, protein synthesis, and cell proliferation, and to suppress autophagy under favourable conditions (Busche et al., 2026; Crespo et al., 2026; Saksena et al., 2026; SharathKumar et al., 2026). Conversely, SnRK1 functions as a regulator of catabolic and stress-responsive pathways, maintaining energy balanced during nutrient limitation, darkness, or abiotic or biotic stress (Sanagi et al., 2026; SharathKumar et al., 2026). The activities of TOR and SnRK1 are antagonistically regulated to maintain cellular energy homeostasis. While under high-energy conditions, TOR is active and represses the activity and expression of SnRK1 components, energy depletion activates SnRK1, which then acts to inhibit TOR activity. Trehalose 6-phosphate (T6P) is a key signalling molecule whose concentration closely tracks cellular sucrose levels and effectively ‘senses’ the plant’s primary mobile energy source. It modulates SnRK1 activity, switching off catabolic pathways when energy is plentiful (Fichtner and Lunn, 2021; Sanagi et al., 2026). T6P thus acts as an essential metabolic checkpoint that integrates the cellular carbon status with the fundamental trade-off between growth and resilience (Fig. 1). Beyond these canonical pathways, plant energy management integrates a wide array of regulatory inputs, including hormonal cues, light signals, and circadian rhythms, which interact through complex feedback loops to fine-tune plant cellular and intracellular energy management in relation to developmental stage and changing conditions (reviewed by Earle et al., 2026; Saksena et al., 2026; SharathKumar et al., 2026) (Fig. 1). The core energy management machinery, comprising SnRKs, TORC, and the T6P pathway, and its interactions with multiple signals through complex feedback regulation to regulate growth and resilience trade-offs. At the intracellular level, the chloroplast plays a particularly crucial role in energy supply. Crespo et al. (2026) review how it interacts bidirectionally with the energy management machinery in algae and plants, balancing growth with photosynthesis via recently discovered molecular mechanisms. Mitochondria are known key players of cellular energy balance, as further highlighted by the work of Chatterjee et al. (2026) in this Issue. These authors show that overexpression of a lactate dehydrogenase increased mitochondrial respiration and ATP synthesis, reduced reactive oxygen species (ROS) accumulation, and enhanced tolerance to abiotic stresses in rice. The energy management machinery may participate in such regulation, as a recent study demonstrated that it adjusts growth and metabolism to changes in mitochondrial energy production (Canal et al., 2024). Taken together, these interconnected mechanisms ensure that energy fluxes are dynamically adjusted to internal metabolic demand and external environmental fluctuations. Collectively, the plant energy management machinery provides a highly adaptive framework for optimizing resource use, sustaining growth, and enhancing resilience in changing environments (Earle et al., 2026). Plants represent a decentralized multicellular system in which cellular and local decisions collectively define organismal performance. Each plant cell must continuously assess its internal metabolic status and integrate information about global energy and resource availability, despite the apparent absence of an overarching control centre. Communication among organs occurs primarily through metabolite and hormone fluxes, enabling coordination without anatomical specialization for systemic control (Earle et al., 2026; Lauschke et al., 2026; Önder et al., 2026). Experimental observations, such as pot size-dependent growth limitation, illustrate that the overall energy budget of the plant constrains organ development and reproductive output, systematically adjusting biomass production and final outcomes (e.g. total fruit number) to total assimilate availability (Poorter et al., 2012). The review by Saksena et al. (2026) highlights how the energy management machinery integrates signals from all key plant growth regulators to ensure developmental plasticity in fluctuating environmental conditions (Fig. 1). These include growth-promoting phytohormones such as auxin, gibberellin, brassinosteroid, and cytokinin, as well as growth-inhibiting phytohormones such as abscisic acid, ethylene, salicylic acid, and jasmonic acid, the latter two being particularly important for pathogen defence responses (Busche et al., 2026; Saksena et al., 2026). Furthermore, recent works also add nitric oxide, a gaseous molecule that signals nitrogen availability, to this list (Saksena et al., 2026). However, the spatiotemporal specificity of these interactions across different cell types and tissues, and the extent to which the energy management machinery simultaneously integrates multiple plant growth regulators, will require further investigation. Plant metabolic and developmental regulation emerges from complex network interactions rather than linear signalling cascades. Energy status is sensed both directly by signalling through metabolites such as sugars, amino acids, phosphate, and nitrate, and indirectly via its effect on the energy management system. The distinction is often not clear, as some metabolite levels, such as that of T6P, directly affect the activity of SnRK1 (Fichtner and Lunn, 2021; Zacharaki et al., 2022) or interact with the energy management machinery through complex feedback regulation. In addition, this complex signalling network is affected by environmental signals such as light and various stress-related stimuli (Belda-Palazón et al., 2022). Light regulates development, photosynthesis, resource allocation, and defence responses. SharathKumar et al. (2026) discuss recent findings showing that light signalling intersects with the core energy management machinery (Fig. 1), linking energy status with growth, immunity, and stress resilience, and pinpoint some exciting areas of research to explore, such as the role of photoreceptors in this signalling axis. Plants match sink demand with source supply through integrated signalling networks across all organs. Long-distance signalling molecules, including sugars (e.g. sucrose and T6P), amino acids, nitrate, phosphate, and phytohormones such as auxin and abscisic acid, mediate this integration. Several contributions in this Issue highlight how the shifts in energy status reverberate through source–sink dynamics, modulating carbohydrate partitioning, nutrient uptake, and growth priorities. Lauschke et al. (2026) review recent protein interaction studies indicating that phloem-loading sugar transporters integrate phytohormones, calcium, and phytochrome signalling, while Önder et al. (2026) discuss potential differences in the mechanisms that allocate sugars to terminal sinks versus axial sinks such as stems, taproots, and tubers. Choi et al. (2026) illustrate that TORC1 integrates signals from multiple mineral nutrients (N, P, K, S, Fe, and K) via specific transporters and intermediate signalling proteins. The research manuscript by Tran et al. (2026) shows that altering the expression of a potential nitrogen transporter in poplar affects nitrogen homeostasis and nitrogen-free phenolic compounds, including lignin, suggesting possible applications in forestry. Finally, Earle et al. (2026) discuss how combinations of carbon with phosphate or nitrate influence root–shoot resource allocation. Development of new organs (e.g. leaves, roots, and flowers) is a major resource cost, and the rate of their formation has to be adjusted to internal and external resource signals. However, plant development is not just regulated by classical cues, but includes signals directly reporting on nutrient availability (especially sugars and the three major macronutrients N, P, and K), particularly seen in the interface of the molecular networks controlling the transition between developmental stages, as collectively reviewed in this Issue by Sanagi et al. (2026), Choi et al. (2026), and Earle et al. (2026). For example, low carbon availability activates SnRK1 which slows down shoot apical meristem (SAM) activity and overall anabolic growth (Peixoto and Baena-González, 2022). Both carbon and nitrogen signals promote SAM activity (directly or through a second messenger), but this effect is suppressed when energy supply is scarce, demonstrating how nutrients integrate to regulate growth (Landrein et al., 2018; Olas et al., 2019; Lopes et al., 2024; Earle et al., 2026). In that regard it is important to note that nutrient signals converge on shared components of the central meristem maintenance and flowering networks, suggesting common signal perception hubs that coordinate plant developmental plasticity through SAM activity (Landrein et al., 2018; Olas et al., 2019; Wang et al., 2022; Gramma et al., 2024; Lopes et al., 2024; Musialak-Lange et al., 2025). As a key developmental transition for reproductive success, flowering is tightly controlled by light, nutrients, and drought (Sanagi et al., 2026; SharathKumar et al., 2026). In this Issue, Sanagi et al. (2026) review how the T6P pathway, SnRKs, and TOR play central roles in the regulation of flowering in response to these different inputs via flowering integrators and floral meristem identity genes. Complementing this perspective, recent work shows that the TOR complex component RAPTOR1B contributes directly to the photoperiod pathway of the flowering network, revealing an evolutionarily conserved link between TORC1 and photoperiod-dependent flowering (Urrea-Castellanos et al., 2025). In the root system, plants exhibit a ‘foraging’ response: roots grow preferentially into nutrient-rich soil patches, thereby optimizing nutrient acquisition while limiting investment in poorer zones (Earle et al., 2026). For example, signalling responses to iron and phosphorus deficiency are strongly interconnected with the energy management machinery, jointly controlling root architecture, particularly lateral roots and root hair development, as reviewed in Choi et al. (2026). At the leaf scale, plants alter leaf structural traits depending on resource availability. Plants form thinner, larger area leaves under limiting conditions versus thicker, more robust leaves when resources are plentiful, which is reflected in variations of the ‘specific leaf area’, as discussed in this Issue by Earle et al. (2026) and SharathKumar et al. (2026). Collectively, these responses enable plants to reduce investment costs while maintaining or even optimizing acquisition capacity under changing environmental conditions. Feeding a growing population under increasingly unpredictable constraints demands crops that balance productivity with resilience. Understanding how plants integrate energy resource signals to coordinate growth under stress is therefore central to the next generation of sustainable agriculture. Meeting the demands of modern agriculture is, however, increasingly difficult given the complexity of combined stresses (e.g. drought, heat, nutrient limitation, and biotic stresses). Modern high-yielding crops, optimized for rapid growth, have lost the growth–stress plasticity characteristic of wild relatives, as discussed by Busche et al. (2026). Growth–resilience trade-offs depend on how species link energy management with development: fast-growing, acquisitive species tend to rely on high morphological efficiency, whereas more conservative species favour robustness and storage strategies (de Tombeur et al., 2023). Understanding the intersection between energy management and developmental regulation will therefore inform crop improvement strategies aimed at resource use efficiency and climate resilience. From an applied perspective, the core energy management machinery offers a promising target for enhancing biotic and abiotic stress resilience, as reviewed for maize by Busche et al. (2026). Unlike morphological adaptations that require extensive developmental reprogramming, modulation of energy signalling can improve tolerance across multiple stresses without compromising overall architecture. Thus, morphological and developmental plasticity buffers environmental changes, enabling survival in variable conditions. There is therefore significant potential for translating insights from plant energy management for targeted optimization of crop development under nutrient or stress constraints. Understanding how energy management confers adaptive flexibility thus represents a major outstanding question in the pursuit of sustainable, resilient agriculture. In addition, due to its central role in the regulation of proliferation and resource allocation, the energy management machinery is fundamental for biomass production in diverse unicellular algae, which has applications in biotechnology and the production of biofuels (Takeuchi and Benning, 2019; Crespo et al., 2026). Deciphering how plants integrate energy management with developmental regulation will be essential for building next-generation resilient, resource-efficient crops. As agriculture faces increasingly complex stress combinations, understanding these interactions will be key to restore the adaptive flexibility lost during intensive breeding for yield. As well as recent developments, Box 1 highlights the key outstanding questions that must be addressed to fully harness plant energy management for basic research, crop improvement, and biotechnology. Can we expand chemical tools to dissect plant energy management? TOR inhibitors, whose specificity is now clearly demonstrated in planta (Perdoux et al., 2024), have greatly advanced understanding of the TOR pathway (Crespo et al., 2026; Saksena et al., 2026). Could inhibitors/activators be developed for other parts of the energy management machinery? This remains challenging given the size and redundancy of families such as SnRKs, but might benefit from AI-assisted design (García et al., 2025) or in vivo screens of chemical libraries (He et al., 2024). How can we visualize energy management with cellular precision? Recent in vivo SnRK1 activity reporters (Sanagi et al., 2026) have enabled dynamic analyses of energy and stress responses. Equivalent activity sensors in other components of the energy management machinery should complement these and might uncover subcellular or tissue-specific functions. Cell cycle indicators (Desvoyes et al., 2020), hormone sensors (Isoda et al., 2021), or nutrient sensors (Chen et al., 2022) will help characterize related processes. What are the plant-specific branches of the energy management network? Early work focused on homologues of animal and yeast components (Sanagi et al., 2026), but recent interactomic studies and genetic screens have uncovered plant-specific connections between TOR/SnRK1 signalling, phytohormones, nutrient status, and chloroplast activity (Choi et al., 2026; Crespo et al., 2026; Saksena et al., 2026). It will be important to continue these efforts and implement them in relevant tissues such as specific meristems, tubers, or fruits. How can we leverage these insights for agriculture or biotechnology? A recent example is the use of a plant-permeable, sunlight-activated T6P precursor, which, for example, improved yields in wheat under diverse field conditions (Griffiths et al., 2025). TOR inhibitors have also been used in both algae and crops (Busche et al., 2026; Crespo et al., 2026), paving the way for pharmacogenetic screens targeting specific energy management traits. Together with sensor technologies, tissue- or cell-specific -omics approaches (O’Leary et al., 2025), and advances in genome editing, these tools could enable the selection of species-specific stress-resilient lines. This Editorial covers the topic of a stimulating 4-day meeting on ‘Plant Energy Management: Molecular Mechanisms and Signalling’ held in Umeå (Sweden) in August 2024, which forms the basis for the reviews and research manuscripts in this Special Issue. We wish to thank all participants of the meeting and contributing authors.