- Calcium-ROS-NO signalling integration in plant immunity: mechanistic interactions and feedback regulation. [Review]Planta. 2026 Sep 30; 264(5).P
- This review establishes Ca2+, ROS and NO signalling as an integrated feedback network that links pathogen perception, calcium decoding, local and systemic defence, and maintenance of immune homeostasis across tissues. Calcium (Ca2+) signalling is a central component of plant immune responses and provides a mechanistic link between pathogen perception and downstream defence activation. Immune stim…
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- Tree grafting: an introspection with reference to breeding, production and productivity in Hevea brasiliensis. [Review]
- CONCLUSIONS: Grafting has transformed the propagation and productivity of perennial tree crops, but genetically variable rootstocks and functional stock-scion interactions can limit the uniform expression of elite scion potential. Evidence from Hevea brasiliensis highlights the need for compatible and uniform rootstocks, self-rooted planting material, and emerging graft assisted biotechnological approaches to improve plantation uniformity and productivity. Due to high heterozygosity and difficulty in fixing desirable traits, grafting has long been the preferred method of propagation in many perennial crops. Hevea brasiliensis, a perennial tree and the primary source of natural rubber (NR), is widely propagated through grafting. As an outbreeding, highly heterozygous species, grafting preserves traits of hybrids developed through prolonged selection. Combined with genetic improvement, grafting has substantially increased rubber productivity worldwide, from ~300 kg ha[-1] to ~3000 kg ha[-1]. However, actual plantation yields remain below potential due to significant tree-to-tree variation in latex production, even among genetically uniform clones. In addition to environmental factors, stock-scion interactions are recognized as important determinants of intra-clonal variation, although their underlying molecular mechanisms remain poorly understood. Research integrating anatomical, physiological, and genetic approaches generating genome, metabolome, and proteome data has identified several key contributors to this phenomenon. This review discusses the current knowledge on factors influencing stock-scion interactions in rubber and provides a general framework to address hetero-grafting related variability issues in perennial crops propagated by grafting. The issues discussed are of use to breeders and geneticists to optimize growth and yield in such crops via more precise and sustainable exploitation of their elite genotypes.
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- Cross talk between plant photoreceptor signaling and chloroplast signaling: implications for physiological regulation. [Review]
- CONCLUSIONS: This review focuses on the bidirectional integrated network formed by light signaling and photosynthesis, providing insights for research aimed at optimizing plant energy balance, resource allocation, and stress resilience to facilitate crop improvement. Photoreceptor-mediated light signaling constitutes the core pathway through which plants perceive light quality, intensity, and duration to precisely modulate growth and development. Crucially, this signaling network extensively interacts with and engages in cross talk with the photosynthetic system, forming a sophisticated regulatory circuit. This integration allows plants to balance energy harvest (photosynthesis) with energy consumption (growth and development), thereby optimizing resource allocation and stress resilience under fluctuating environmental conditions. This review systematically examines the key components and molecular mechanisms that define photoreceptor signaling over the past two decades, including phytochromes, cryptochromes, and downstream factors such as COP1, PIFs, and HY5. A central focus of this review is the bidirectional interaction mechanism between photoreceptor signaling and chloroplast function. In this context, bidirectional regulation refers to two interconnected processes: (i) anterograde control, in which nuclear photoreceptor signaling regulates chloroplast biogenesis, photosynthetic gene expression, and chloroplast positioning; (ii) retrograde signaling, whereby chloroplast functional status generates metabolic and redox-derived signals that feed back to the nucleus to reshape light signaling outputs. Importantly, emerging evidence suggests that these pathways do not operate independently but instead converge at shared transcriptional and signaling nodes, forming an integrated regulatory network that coordinates energy capture with growth and stress responses. Finally, the review summarizes major advances and open questions in light signaling theory, discusses innovative applications in intelligent, spectral-tunable lighting systems for controlled-environment agriculture, and offers future perspectives on applying light resource research to sustainable crop improvement.
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- TML functions in Arabidopsis pollen tube penetration into the stigma and style. [Journal Article]
- CONCLUSIONS: Decreased TML expression compromises pollen tube growth in the stigma and style, indicating that TML is critical for the penetration of pollen tubes into the stigma and style during pollination. In flowering plants, the penetration of the pollen tube into the maternal stigma tissue is a crucial step for successful pollination. Endocytosis is a vital process for pollen tube growth in vitro and in vivo. TML is one subunit of the TPLATE/TSET complex, the core complex for clathrin-dependent endocytosis. TML is localized in the lateral region of growing pollen tubes, but its function is unknown in pollen tube. In this study, we found that decreased TML expression compromises pollen tube growth in the stigma and style, despite comparable growth in vitro to the wild type. Our results indicate that TML plays a role in the penetration of pollen tubes into the stigma and style during pollination.
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- Medicinal-plant immunity and specialized metabolism in plant-pathogen interactions: mechanisms and applications. [Review]
- Medicinal-plant immunity and specialized metabolism are mechanistically linked, but rigorous receptor validation, causal multi-omics, and field trials are needed for reliable translational applications. Medicinal plants combine classical immune signaling with lineage-specific specialized metabolism. This review focuses on the immune systems of medicinal plants and on how pathogen perception resha…
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- MicroRNA172 regulates growth under low nitrogen conditions in Arabidopsis thaliana. [Journal Article]
- CONCLUSIONS: miR172 and its target genes TOE1 and TOE2 regulate low nitrogen (LN) dependent root elongation growth in Arabidopsis thaliana. Overexpression of miR172 suppresses LN mediated PR elongation. Reduced responses of miR172 overexpression lines and toe1-2;toe2-1 mutants to LN are associated with impaired nitrate assimilation, suggesting a role of the miR172-TOE1/TOE2 module in regulating plant growth under LN conditions. MicroRNAs (miRNAs), a class of small non-coding regulatory RNAs, play important roles in various aspects of plant growth and stress responses, including nutrient deficiency. The availability of nitrogen (N), an essential mineral for plant growth, affects the expression of several miRNAs. However, the function of miRNAs in modulating root responses under low nitrogen (LN) condition remains elusive. Here we report that LN differentially regulates miR172 expression levels, which modulate plant response. Overexpression of miR172 (miR172OE) reduced the plant response to LN-mediated PR elongation, whereas miR172-target mimic (MIM172) lines exhibited enhanced LN-dependent PR elongation in Arabidopsis thaliana (Arabidopsis). Cellular analysis at the root tip revealed that miR172OE plants exhibited a reduced response to LN-mediated root cell elongation and meristem zone (MZ) inhibition, whereas MIM172 plants maintained LN-responsive regulation of these cellular parameters comparable to wild-type. Consistent with these findings, LN-mediated suppression of chlorophyll levels was compromised in miR172OE plants. Analysis of miR172 target genes suggests that among the known targets [SCHLAFMUTZE (SMZ), SCHNARCHZAPFEN (SNZ), APETALA2 (AP2), TARGET OF EAT1 (TOE1), TOE2, and TOE3], TOE1 and TOE2 are involved in LN-dependent elongation of PR through modulation of cellular activities at the root tip. The toe1-2;toe2-1 double mutants showed reduced response to PR elongation and compromised cell elongation under LN condition. Further, chlorate sensitivity assay data suggest that reduced response of miR172OE lines and toe1-2;toe2-1 double mutants under LN condition is associated with a reduced nitrate assimilation pathway. Together, our findings suggest the role of miR172 and its targets TOE1 and TOE2 in regulating nitrogen-responsive growth and the nitrate assimilation pathway.
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- Involvement of cytokinin response factor 6 in the integration of abiotic stress responses with metabolism and growth in Arabidopsis thaliana. [Review]
- CONCLUSIONS: This review highlights the importance of the CYTOKININ RESPONSE FACTOR 6 transcription factor as a plant regulatory nexus integrating responses to multiple abiotic stresses with metabolism, growth and development. Cytokinin Response Factors constitute a subfamily of plant transcription factors that have been identified as cytokinin-responsive APETALA2/ethylene-responsive element binding proteins and further characterised as components of cytokinin signalling. Besides being involved in the canonical cytokinin signalling pathway, they are part of complex networks of interactive regulation. Their mode of action, their interactions and their functions however remain to be fully understood. Among cytokinin response factors that are currently identified and characterised in Arabidopsis thaliana, CYTOKININ RESPONSE FACTOR 6 has been extensively studied as it is related to numerous developmental, nutritional, hormonal, abiotic stress and biotic stress processes. CYTOKININ RESPONSE FACTOR 6 was thus recently shown to be part of a SNF1-related kinase1/Jumonji C domain-containing JMJ15 regulatory axis involved in energy, oxidative stress and growth co-regulation. This review focusses on involvement of CYTOKININ RESPONSE FACTOR 6 in the integration of abiotic stress responses with metabolism, growth and development, and on the underlying mechanisms of this integration. The characterisation of CYTOKININ RESPONSE FACTOR 6 as a stress-growth nexus will be highlighted in terms of regulatory processes and mechanisms. The essential roles of this stress-growth nexus will be discussed in the context of multiple stresses and global changes with potential implications for plant biodiversity dynamics and agricultural sustainability.
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- Exogenous regulators that alleviate waterlogging stress in plants: mechanisms, integration, and translational strategies. [Review]
- CONCLUSIONS: Exogenous regulators mitigate waterlogging stress via a three-tier framework; integrated strategies boost field waterlogging resilience effectively. Waterlogging, an increasingly critical constraint on crop productivity with climate change amplifying extreme precipitation, limits rhizospheric O2 diffusion to induce hypoxia. This rapidly impairs mitochondrial respiration, forces a shift to low-efficiency glycolysis and fermentation, and accumulates potentially toxic by-products. Upon postanoxic stress, plants face an oxidative burst that compromises membrane integrity, suppresses photosynthesis, and destabilizes yield. Despite inherent adaptive programs (e.g., aerenchyma formation, adventitious rooting), most crops remain vulnerable to prolonged/recurrent waterlogging, necessitating practical interventions complementing genetic improvement. Here, we synthesize evidence that exogenous inputs-including phytohormones, osmoprotectants, antioxidants, gaseous signaling molecules, mineral nutrients, and beneficial microorganisms-mitigate injury by coordinating early signaling, metabolic maintenance, and rhizosphere stabilization. We integrate these effects into a three-tier framework: (i) resetting hypoxia perception/response thresholds, (ii) sustaining energy/redox homeostasis via balanced mitochondrial function and fermentation, and (iii) converting short-term tolerance to sustained recovery through morphological remodeling and rhizosphere improvement. Finally, we outline a translational strategy coupling exogenous regulation with functional microbiomes, targeted genetic improvement, and agronomic management to enhance field robustness and reduce environment-driven "effect drift". Highlights Exogenous regulators improve plant-waterlogging tolerance via a three-layer regulatory framework. A combined application of exogenous substances, microbiome, genetics, and agronomy enhances field waterlogging resistance. Hypoxia response, energy metabolism, and ROS homeostasis are core regulatory targets for stress alleviation.
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- Receptor-like kinase-mediated cell wall integrity signaling in plant environmental stress responses. [Review]
- CONCLUSIONS: Receptor-like kinases (RLKs) serve as central signaling hubs that integrate extracellular signals with intracellular responses to maintain cell wall integrity and cellular homeostasis. Their structural and functional diversity enables precise perception of developmental, immune, and environmental cues. Recent advances in structural biology, phosphoproteomics, and genome engineering have substantially deepened our understanding of RLK function and regulation. Harnessing this knowledge offers promising opportunities to engineer crops with enhanced resilience to biotic and abiotic stresses, contributing to sustainable agriculture under a changing climate. Plants are continually exposed to mechanical, osmotic, and biotic stresses that threaten cell wall integrity and cellular homeostasis. Receptor-like kinases (RLKs) represent one of the largest families of plasma membrane receptors and function as key sensors that connect extracellular cues with intracellular signaling networks. Positioned at the cell wall-plasma membrane interface, RLKs perceive diverse signals, including microbe-associated molecular patterns (MAMPs), damage-associated molecular patterns (DAMPs), endogenous peptides, and changes in cell wall architecture. Major RLK subfamilies, including leucine-rich repeat RLKs (LRR-RLKs), lysin motif RLKs (LysM-RLKs), Catharanthus roseus RLK1-like kinases (CrRLKs), and wall-associated kinases (WAKs), have evolved specialized ligand-recognition mechanisms that enable signaling specificity and functional diversity. Following activation, RLKs assemble dynamic receptor complexes that initiate phosphorylation cascades involving mitogen-activated protein kinases, calcium-dependent signaling pathways, reactive oxygen species (ROS) production, and hormonal regulators. These interconnected networks integrate developmental processes with immune and abiotic stress responses, allowing plants to coordinate growth, defense, and environmental stress adaptation. Recent advances in structural biology, phosphoproteomics, and genome engineering have expanded understanding of RLK-mediated signaling and revealed opportunities for crop improvement. Here, the review synthesizes current knowledge of RLK structural diversity, signal transduction mechanisms, and network integration, highlighting their central role in cell wall integrity surveillance, stress adaptation, and emerging strategies for engineering climate-resilient crops.
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- Molecular and metabolic drivers of oil quality and bioenergy potential in Jatropha curcas. [Journal Article]
- CONCLUSIONS: Combining biochemical, molecular, and multivariate analyses identified candidate signatures and L10P41 as a promising bioenergy ideotype, supporting targeted selection for oil quality and bioenergy performance in Jatropha curcas. Jatropha curcas L. is a promising bioenergy crop, but its genetic improvement requires a deeper understanding of the molecular and metabolic factors underlying variation in oil quality, fatty acid (FA) composition, and phorbol ester (PE) accumulation. We characterized FA composition during seed development and evaluated mature-seed oil content, PE concentration, higher heating value (HHV), and the expression of KASIII, MFP2, and JcBAHD-AT in 12 contrasting elite breeding genotypes. Stage-specific principal component analysis (PCA), complemented by hierarchical cluster analysis (HCA), revealed developmentally dynamic variation in FA composition and genotype relationships. Comparison with biochemical and expression data indicated associations among lipid composition, candidate-gene expression, PE concentration, and energy performance. The L10P41 genotype combined an oleic acid-enriched profile, relatively high oil content, elevated HHV, and distinct KASIII and MFP2 expression patterns, emerging as a promising bioenergy ideotype. Variation in HHV among genotypes, including relatively high values in some genotypes with comparatively low oil content, indicated that energy performance cannot be inferred from total oil content alone and may also be associated with differences in oil composition. The putative BAHD acyltransferase gene JcBAHD-AT exhibited genotype- and stage-specific expression patterns consistent with a potential role in specialized diterpenoid metabolism; however, its relationship with PE accumulation remains associative and requires functional validation. Genotypes combining high oil content with comparatively low PE concentrations further indicated that these traits can coexist and are not necessarily tightly coupled. Overall, integrating molecular, biochemical, and multivariate analyses revealed candidate signatures associated with oil quality and bioenergy potential, advancing the identification of promising genotypes for targeted selection and precision breeding in J. curcas.
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- Kinase crosstalk coordinates stress adaptation and metabolic homeostasis in plants. [Review]
- CONCLUSIONS: Crosstalk among MAPKs, CDPKs, SnRKs, and TOR establishes a dynamic regulatory framework that balances energy homeostasis, defense, and development under stress conditions. Continued advances in systems biology and functional genomics will further clarify these complex interactions and accelerate the development of crops with enhanced stress resilience, growth stability, and resource-use efficiency. Plants rely on complex kinase signaling networks to sense, integrate, and respond to rapidly fluctuating environmental stresses. Central to these networks are mitogen-activated protein kinases (MAPKs), calcium-dependent protein kinases (CDPKs), sucrose non-fermenting-1-related kinases (SnRKs), and the Target of Rapamycin (TOR) complex, which collectively coordinate stress perception, metabolic regulation, and growth adaptation. Although the individual functions of these pathways have been extensively characterized, a unified mechanistic framework describing their interconnected roles across diverse stress conditions remains incomplete. Here, we synthesize recent advances in plant stress signaling to propose an integrated model of kinase crosstalk that highlights key nodes of convergence, reciprocal regulation, and metabolic-hormonal integration. We emphasize the antagonistic interplay between SnRK1 and TOR as a central regulatory hub controlling energy balance and stress adaptation, while MAPK and CDPK cascades intersect with SnRK1-mediated autophagy and TOR-dependent anabolic growth pathways. In addition, hormonal signaling networks involving abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA) provide further layers of regulatory coordination that improve cellular responses to environmental stress. Collectively, these interconnected kinase networks orchestrate survival strategies, metabolic homeostasis, and resilience under adverse conditions. By integrating these signaling modules into a systems-level framework, this review provides mechanistic insights and emerging perspectives for engineering crops with enhanced stress tolerance, growth stability, and energy-use efficiency.
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- Analysis of the synergistic effect between CiFTIP1 and CiFT in flowering regulation of citrus. [Journal Article]
- CONCLUSIONS: Overexpression of CiFTIP1 enhances the long-distance transport of the florigen protein CiFT, leading to early flowering in tomato, with a synergistic effect when co-expressed with CiFT, and provides a potential strategy for regulating flowering time in fruit trees. FTIP1 is a key regulator involved in the long-distance transport of the florigen protein FT. To investigate the role of citrus CiFTIP1 in regulating the transport of CiFT, transgenic tomato plants were employed as experimental materials in this study. Phenotypic analysis revealed that overexpression of CiFTIP1 promoted early flowering in tomato and upregulated the expression of key flowering genes SlLFY and SlAP1, and downregulated SlTFL. By crossing CiFT and CiFTIP1 overexpression lines, the double-overexpression hybrids exhibited a marked synergistic early-flowering effect, flowering earlier than single-overexpression plants. Grafting experiments further confirmed that double-overexpression plants used as rootstocks possessed a stronger capability to induce early flowering in wild-type scions. Notably, higher CiFT fluorescence signal and protein abundance were detected in wild-type scions grafted onto double-overexpression rootstocks, confirming that CiFTIP1 acts as a molecular chaperone to effectively enhance the transport efficiency of CiFT protein. This study clarified the molecular mechanism by which CiFTIP1 synergistically regulated flowering via enhancing the mobility of CiFT protein between rootstocks and scions. It also provided innovative strategies for flowering time regulation, hybrid breeding efficiency improvement, and production cycle management of fruit trees.
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- Effects of latitude and extreme temperatures on the expression of cleistogamous flowers and pollen viability in soybean (Glycine max) under field conditions. [Journal Article]
- CONCLUSIONS: Developing soybean flowers exposed to higher maximum temperatures during the week preceding full anthesis show a strong association with cleistogamy, but without a latitudinal gradient. Higher mean maximum temperature also had a moderate but significant negative effect on pollen viability. Soybean displays a range of reproductive strategies, including the production of both closed, self-pollinated cleistogamous flowers and open, self- and cross-pollinated chasmogamous flowers, as well as variation in the pollen viability among flowers. The incidence of cleistogamy and pollen viability could be related to stressful environmental conditions. This research examines under field conditions the relationship between latitude and the mean-maximum temperatures (data from National Meteorological Service) to which buds are exposed 1 week before sampling, with cleistogamy and pollen viability. The number of cleistogamous flowers (n = 50 flowers per site) and pollen viability (n = 5 flowers of each type per site, staining pollen with lactophenol to estimate the percentage of non-viable pollen) were measured across a broad latitudinal range (21 sites) and considering mean-maximum temperatures during the week before sampling flowers in full anthesis. The regression models were applied to interpret the response variables disentangling the effects of both factors. The proportion of cleistogamous flowers was high across sites (63.1 to 98%). The model with mean-maximum temperature as fixed factor showed a significant association with the occurrence of cleistogamy and with pollen viability. This trend suggests that higher temperatures (i.e., high mean daily temperatures) one week before anthesis are associated with changes in reproductive soybean traits throughout the latitudinal gradient. Given the observed increase in the frequency and intensity of maximum temperatures during the flowering season associated with climate change, our research implies an impact on the pollination and fertilization of soybean with possible implications for crop production.
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- DELLA proteins enhance cadmium tolerance by coordinating redox protection and cadmium partitioning in Arabidopsis. [Journal Article]
- Cadmium (Cd) toxicity requires plants to coordinate growth restraint with cellular protection, but the upstream regulatory mechanism remains unclear. Here, we identify the gibberellin (GA)-DELLA module as a positive regulator of Cd tolerance in Arabidopsis thaliana. Cd exposure reduced endogenous GA levels, shifted GA metabolic gene expression toward a low-GA state, and increased DELLA protein ab…
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- Floral dynamics in the protandrous flowers of Bauhinia variegata (Fabaceae): phase-specific morphology, scent, and nectar production. [Journal Article]
- CONCLUSIONS: Protandry in Bauhinia variegata is expressed through coordinated changes in floral morphology, scent composition, secretory activity, and nectar presentation, whereas petal reflectance remains stable; molecular docking further indicates that key phase-associated volatiles are structurally compatible with a bee odourant-binding protein, supporting mechanistic plausibility of olfactory detectability without demonstrating behavioral attraction. Bauhinia variegata exhibits protandrous flowers in which floral morphology, scent production, and nectar presentation change through anthesis. Here, we examined anthesis, stigma receptivity, petal reflectance, volatile organic compound (VOC) composition across floral organs and phases, secretory structures, nectar dynamics, and the structural compatibility of selected phase-discriminant VOCs with a honeybee odourant-binding protein. Flowers exhibited prolonged anthesis, opening at night and remaining functional for 2-3 days. Pollen release predominated during the 1st day (staminate phase), whereas maximal stigma receptivity occurred on the 2nd day (pistillate phase), accompanied by elongation and curvature of the style. Petal reflectance remained stable across phases. Floral scent was spatially heterogeneous among organs and temporally dynamic across anthesis, with terpene-rich bouquets dominated by α-pinene and β-pinene and with phase- or organ-informative compounds including nonanal, limonene, trans-caryophyllene, and 6-methyl-5-hepten-2-one. Cavitated secretory trichomes and sepals showed evidence of terpene-associated secretion. Nectar volume and total sugar content peaked during the pistillate phase, coinciding with strongest stigma receptivity. Molecular docking with AmelOBP14 showed that key phase-associated VOCs are structurally compatible with a bee odourant-binding protein, providing complementary mechanistic support for their potential olfactory detectability. Together, these results show that protandry in B. variegata is expressed through coordinated changes in morphology, scent, secretory activity, and nectar presentation, indicating a complex signalling strategy; however behavioural responses of floral visitors remain to be tested.
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