Inter-plant signals can be transmitted via plant volatiles or exudates as well as through biological connections such as parasitic plants and common mycorrhizal networks (CMN), formed by mycorrhizal fungi. The molecular...Inter-plant signals can be transmitted via plant volatiles or exudates as well as through biological connections such as parasitic plants and common mycorrhizal networks (CMN), formed by mycorrhizal fungi. The molecular mechanisms underlying mycorrhiza-mediated inter-plant signals and their functional significance in plant defence against pathogens represent an emerging area of research, expanding our understanding of inter-plant communication beyond well-studied intra-plant systemic signals and responses such as systemic acquired resistance and induced systemic resistance. By examining mechanistic bases and evolutionary perspectives from both phyto- and mycocentric viewpoints, we aim to clarify how CMN may contribute to inter-plant information exchange and resulting plant community-level defence against pests and pathogens. Ongoing investigations into cross-kingdom crosstalk offer novel insights into candidate molecular mechanisms, such as small RNA trafficking, potentially involved in CMN-mediated inter-plant signalling. We further highlight the significance of conceptualizing crops as interconnected plant systems, a framework that will be critical in shaping future research directions. Finally, we address the challenges and future perspectives for the development of microbiological plant growth supplements and utilizing CMN to mediate inter-plant danger signals for sustainable agroecosystem designs.
Protein homeostasis relies on chaperones such as HSP70 and HSP90, which assist in the folding, activation, and turnover of client proteins. Their activity is modulated by co-chaperones, many of which contain tetratricope...Protein homeostasis relies on chaperones such as HSP70 and HSP90, which assist in the folding, activation, and turnover of client proteins. Their activity is modulated by co-chaperones, many of which contain tetratricopeptide repeat (TPR) domains. A subset of these, known as carboxylate clamp TPR (CC-TPR) domains, possess distinctive structural features that mediate interactions with the chaperones' C-terminal EEVD motifs. This review focuses on plant TPR-containing co-chaperones, particularly those with CC-TPR domains, because they provide the structural basis for selective HSP70 and HSP90 recognition -a central but understudied aspect of plant proteostasis. We summarize advances in understanding the structure and diversity of plant TPR co-chaperones, and discuss three representative examples: AtRPAP3, a component of the R2T complex; HOP, a co-chaperone integrating hormonal and stress responses; and SGT1, a TPR protein that interacts with HSP90 through a TPR-independent mechanism and is crucial for immunity and development. Comparative evidence reveals both conservation and plant-specific diversification of TPR co-chaperone function, reflecting their adaptation to environmental and developmental cues. We conclude that plant TPR proteins constitute a versatile regulatory layer that coordinates chaperone activity across multiple cellular processes. Understanding their mechanisms will be essential to map the chaperone networks that underpin plant resilience and growth.
The Fusarium metabolite culmorin (CUL) frequently co-occurs with the mycotoxin deoxynivalenol (DON) on cereals. While DON is recognized as a major Fusarium virulence factor on plants, the function of CUL is still unclear...The Fusarium metabolite culmorin (CUL) frequently co-occurs with the mycotoxin deoxynivalenol (DON) on cereals. While DON is recognized as a major Fusarium virulence factor on plants, the function of CUL is still unclear. Herein, we show that CUL-deficient F. graminearum mutants created by CLM1 deletion are less aggressive on wheat than the wild-type, accompanied by increased DON-3-glucoside/DON ratios in infected wheat ears. In root elongation assays with wheat and Brachypodium distachyon, CUL had no effect alone but significantly increased the toxicity of DON. Analysis of DON/CUL-treated roots further indicated that both wheat and B. distachyon are able to glucosylate CUL and that its presence impedes DON-glucosylation in both species. We identified two B. distachyon UDP-glucosyltransferases (UGT) able to glucosylate CUL and further investigated the effect of CUL on the kinetics of validated DON-glucosylating plant UGTs (BdUGT5g03300, HvUGT13248, OsUGT79). This suggested that CUL inhibits DON-glucosylation either by serving as competitive substrate with DON or by unproductive binding. Especially BdUGT5g03300 was strongly inhibited by CUL and even its glucosides. Our results indicate that CUL contributes to Fusarium virulence by weakening plant-defences related to UGT-catalysed DON-detoxification. As even CUL-glucosides are potentially inhibitory to UGTs, this implies a complex synergy of CUL with DON.
Mitochondria are central to plant metabolism, yet the diversity of mechanisms plants use to cope with mitochondrial stress and its implications in cellular signaling are not fully understood. In this study, we analyzed A...Mitochondria are central to plant metabolism, yet the diversity of mechanisms plants use to cope with mitochondrial stress and its implications in cellular signaling are not fully understood. In this study, we analyzed Arabidopsis noxy (nonresponding to oxylipins) mutants affected in 9-HOT (9(S)-hydroxy-10,12,15-octadecatrienoic acid) signaling, mitochondrial function and ethylene (ET) signaling to dissect plant responses to a range of mitochondrial stresses, including inhibitors of all electron transport chain complexes and mitochondrial translation. All noxy mutants showed resistance to antimycin A (AA), implicating Complex III and 9-HOT signaling in mitochondrial stress adaptation. Notably, noxy22/eto1-14, an ET overproducer mutant, displayed resistance to all tested inhibitors independently of the canonical mitochondrial retrograde pathway mediated by ANAC017. We found similar results in eto1-5 and eto1-13 alleles, thus sustaining a role for ET in mitochondrial protection. Histochemical and RNA-seq analysis revealed that AA induced ANAC017-regulated genes early and independently of ET signaling whereas EIN2 contributed in later induction of AA-associated immune responses. EIN2 was required for full activation of AA-induced resistance against the biotrophic pathogen Hyaloperonospora arabidopsidis, but not against the necrotroph Plectosphaerella cucumerina. Collectively, our findings point to a complex network that coordinates distinct but overlapping responses to mitochondrial dysfunction and integrates them into broader stress pathways.
Precise regulation of reproductive growth is vital for plant reproductive success and resource management. Here, we characterize Growth Regulating Factor 9 (NnGRF9), an atypical 14-3-3 family protein in lotus (Nelumbo nu...Precise regulation of reproductive growth is vital for plant reproductive success and resource management. Here, we characterize Growth Regulating Factor 9 (NnGRF9), an atypical 14-3-3 family protein in lotus (Nelumbo nucifera), and demonstrate its positive role in shade-induced flower bud abortion. Overexpression of NnGRF9 increases, while silencing reduces, bud abortion, with evidence suggesting that NnGRF9 promotes autophagy during this process. We further identified a reciprocal regulatory loop between NnGRF9 and the energy sensor kinase NnSnRK1, in which NnGRF9 promotes NnSnRK1 expression and activity, whereas NnSnRK1 interacts with NnGRF9 and may regulate its stability. Functional hierarchy analysis places NnGRF9 upstream of NnSnRK1 in regulating both bud abortion and autophagy. NnSnRK1 directly interacts with NnATG6, but not with NnATG1, and manipulation of NnATG6 expression demonstrates that it functions downstream in the regulation of both autophagy and bud abortion. Population genetic analysis reveals that NnGRF9 has been subject to positive selection during lotus evolution, with its allelic variation correlating with differences in flowering abundance among cultivars. In summary, this study elucidates an NnGRF9-NnSnRK1-NnATG6 regulatory pathway that connects shade stress to reproductive fate, and provides population genetic evidence for its role in lotus adaptation and domestication.
The functions of approximately one-third of the proteins in the model plant Arabidopsis thaliana remain unknown. It is likely that some of the genes encoding these proteins are essential, and thus indispensable for the s...The functions of approximately one-third of the proteins in the model plant Arabidopsis thaliana remain unknown. It is likely that some of the genes encoding these proteins are essential, and thus indispensable for the survival of the plant; furthermore, these genes would be included in the minimum viable set required for plant life. Evolutionarily conserved single copy genes in flowering plants are enriched in essential housekeeping functions. Building on this observation, we designed a reverse genetic screen that focuses on evolutionarily conserved single copy Arabidopsis genes of unknown function with predominant expression in meristematic cells. This approach identified a previously uncharacterized essential Arabidopsis gene, named as EARLY ABORTION 1 (EBO1). Mutation of the EBO1 locus disrupts gametophyte and/or early embryo development, resulting in defective ovule or seed development. A functional fluorescent EBO1 fusion protein was found to localize to the nucleus, and co-immunoprecipitation experiments detected an interaction between EBO1 and Nucleolar Protein 58 (NOP58) and proteins involved in RNA metabolism, chromatin modification, and transcription. The presented results open a new line of investigation into an evolutionarily conserved mechanism involved in the development of both male and female gametophytes as well as seeds.
Flowering marks a pivotal transition in a plant's life cycle, signalling the shift from vegetative growth to reproductive development. Over the years, extensive research has uncovered key genes and regulatory networks go...Flowering marks a pivotal transition in a plant's life cycle, signalling the shift from vegetative growth to reproductive development. Over the years, extensive research has uncovered key genes and regulatory networks governing this process. Central to this regulation is the Florigen Activation Complex (FAC), along with its interacting partners and upstream and downstream components, which have been well-characterized across numerous plant species. More recently, attention has turned to a lesser-known gene, FLOWERING PROMOTING FACTOR 1 (FPF1). Initially identified in Arabidopsis thaliana, FPF1 is a plant-specific gene lacking known functional domains, yet it plays a conserved and critical role in floral induction across diverse species. Despite its discovery in 1997, the molecular mechanism of FPF1 remained elusive until recent studies began to unravel the function of FPF and its homologs. One such study revealed that FPF1-Like Protein 1 (FLP1) in Arabidopsis is expressed in phloem companion cells sites of FLOWERING LOCUS T (FT) production. Like AtFT, AtFLP1 acts as a mobile florigenic signal, though it operates independently of the canonical AtFT pathway. AtFLP1 promotes flowering by activating the floral homeotic gene SEP3, suggesting an alternative regulatory route also influenced by photoperiod. Interestingly, studies in Brachypodium distachyon have highlighted a contrasting role for FLP-like genes, where they negatively regulate flowering by interfering with the FAC, underscoring species-specific diversity in its function. While initial studies have been majorly focused on their role in flowering, in recent years FPF1 family genes have also been implicated in other developmental processes, including stem and root elongation and shade avoidance responses. In this review, we explore these emerging insights into FPF1-like proteins, examining their multifaceted roles in flowering regulation and broader developmental functions, with a special emphasis on the most recent and impactful studies.
The co-evolutionary arms race between crops and their parasites requires continuous identification of new resistance mechanisms. Broomrape (Orobanche cumana), a root parasitic plant, poses a severe threat to sunflower (H...The co-evolutionary arms race between crops and their parasites requires continuous identification of new resistance mechanisms. Broomrape (Orobanche cumana), a root parasitic plant, poses a severe threat to sunflower (Helianthus annuus) production, yet the genetic architecture underlying host resistance remains poorly understood. To address this, we established a high-throughput phenotyping platform to quantify root infestation across a diverse sunflower association mapping (SAM) population. Combining this phenotypic resource with a dual genome-wide association study (GWAS) strategy based on both single nucleotide polymorphisms (SNPs) and k-mers, we highlight the genetic basis of broomrape resistance at unprecedented resolution. Our analyses revealed quantitative trait loci (QTLs) and identified novel candidate genes, including putative leucine-rich repeat receptor kinases potentially involved in parasite recognition and defense activation. Importantly, the k-mer approach circumvented reference genome bias and uncovered key genomic introgressions from wild Helianthus relatives that contribute substantially to resistance. These findings demonstrate the utility of integrating high-resolution phenotyping with advanced association mapping to dissect complex host-parasite interactions. Moreover, they emphasize the enduring value of wild germplasm as a reservoir of adaptive variation, providing crop breeders with crucial tools to counter the rapid evolutionary dynamics of parasitic plants.
Present in various subcellular compartments, cysteine is the major source of reduced sulfur and thus represents a key metabolite for various biosynthetic pathways as well as for redox homeostasis as a component of glutat...Present in various subcellular compartments, cysteine is the major source of reduced sulfur and thus represents a key metabolite for various biosynthetic pathways as well as for redox homeostasis as a component of glutathione. As photosynthetic organisms assimilate inorganic sulfate and reduce it into sulfide before its incorporation into cysteine, there are strong relationships between cysteine homeostasis and all pathways involved in its synthesis and utilization. Over the last decade, cysteine degradation leading to hydrogen sulfide release has been linked to different physiological responses to both abiotic and biotic stresses. In this review, we summarize current knowledge about cysteine homeostasis, cysteine signaling in immunity and cysteine-dependent sulfur trafficking. We also illustrate the importance of cysteine signaling through the synthesis of hydrogen sulfide by describing the diversity of cysteine desulfhydrases in photosynthetic organisms and by discussing their roles in plant physiology.
Although orchid pollination is often highly specialized, fully mycoheterotrophic orchids are generally thought to favor autonomous self-pollination because of carbon limitation, shaded habitats, and patchy population str...Although orchid pollination is often highly specialized, fully mycoheterotrophic orchids are generally thought to favor autonomous self-pollination because of carbon limitation, shaded habitats, and patchy population structure. Here, we investigated six nectarless, fully mycoheterotrophic Gastrodia species in Japan using long-term pollinator observations and hand-pollination experiments, together with phylogenomic analyses of all six species, floral scent analyses of three species, and larval rearing experiments in four species. All six species were self-compatible but incapable of autonomous selfing and relied on drosophilid flies for pollination. Pollinator assemblage dissimilarity was significantly correlated with interspecific genetic differentiation, indicating phylogenetically structured pollinator use. Fruit-feeding drosophilids pollinated all species, whereas mycophagous drosophilids contributed substantially to pollination only in G. foetida and G. nipponica. In these two species, larvae frequently developed in decaying floral tissues, consistent with brood-site mutualism. In G. confusa and G. pubilabiata, larval survival was sporadic and humidity dependent, indicating an intermediate condition between brood-site deception and mutualism. Floral scents of three representative species were dominated by fermentation-related volatiles, but blend composition differed among species. Together, these findings reveal a deception-mutualism continuum within Gastrodia and suggest that evolutionary history, together with floral scent variation, helps shape pollinator interactions in these orchids.
Vitamin B1 is a vital cofactor in cellular metabolism, but must be obtained through the diet in humans. Polished (white) rice, a dietary staple for much of the global population, contains very low levels of vitamin B1, w...Vitamin B1 is a vital cofactor in cellular metabolism, but must be obtained through the diet in humans. Polished (white) rice, a dietary staple for much of the global population, contains very low levels of vitamin B1, which contributes to widespread thiamin deficiency in regions that rely heavily on rice. To address this issue, we engineered rice to express the Saccharomyces cerevisiae thiamin transporter gene THI7 under the control of the endosperm-specific GLUTELIN1 (GT1) promoter. We found that endosperm-specific expression of yeast THI7 significantly increased thiamin levels by up to 24% in unpolished and 26% in polished seeds in transgenic rice lines with moderate to high THI7 expression. This increase was specific to free thiamin, with no change in thiamin monophosphate or thiamin diphosphate, consistent with the known transporter activity of THI7. Importantly, the transgenic plants displayed normal phenotypes under field conditions. Our findings demonstrate that endosperm-targeted expression of a heterologous thiamin transporter is an effective strategy for enhancing vitamin B1 content in rice grains, offering a new approach for biofortification that complements metabolic engineering of biosynthetic pathways.
Plant cuticular waxes form a critical hydrophobic barrier covering aerial organs, serving as the first line of defense against abiotic and biotic stresses and playing a vital role in reproductive development. However, re...Plant cuticular waxes form a critical hydrophobic barrier covering aerial organs, serving as the first line of defense against abiotic and biotic stresses and playing a vital role in reproductive development. However, regulatory networks that orchestrate cuticular wax deposition in response to environmental cues and developmental programs, particularly in cereal crops, remain elusive. This review integrates current knowledge by identifying genes implicated in wax formation in Arabidopsis and major graminaceous crops. We detail the molecular mechanisms of wax biosynthesis and export, and place a major focus on the intricate transcriptional regulatory modules that integrate signals from drought, salinity, and pathogens, as well as developmental signals critical for anther cuticle formation and male fertility. Conserved and species-specific adaptations in these networks are highlighted, emphasizing how natural variation in these pathways underpins adaptive traits. We also discuss evolutionary perspectives and critically identify key knowledge gaps, such as the unresolved trade-offs between abiotic and biotic stress resistance and the mechanistic basis of anther cuticle development under heat stress, providing insights into leveraging cuticular traits for climate-resilient crop design.
Hypoxia is integral to the plant life cycle, occurring during both development and environmental stresses like flooding. The class I phytoglobins (PGB1s) have emerged as important regulators of plant hypoxia responses in...Hypoxia is integral to the plant life cycle, occurring during both development and environmental stresses like flooding. The class I phytoglobins (PGB1s) have emerged as important regulators of plant hypoxia responses in both these contexts due to their multifaceted roles in nitric oxide (NO) and ROS homeostasis, and alternative energy generation. Physiological PGB1 expression overlaps with developmental hypoxic niches, facilitating hypoxic energy generation through the PGB1-NO cycle. Sustained induction of PGB1 by various signals during the progression of a flooding event reflects its important but potentially distinct roles in flooding stress acclimation. These include short-term PGB1-mediated NO scavenging to stabilize ERF-VII TFs, and in the long-term hypoxic energy generation, oxidative stress mitigation, and maintenance of auxin transport. Here we provide an overview of the current understanding of how PGB1 biochemistry, localization, and regulatory architecture are connected and of relevance for hypoxia acclimation. We highlight key unanswered questions in our understanding of PGB1 biology that will be essential for clarifying its contribution to hypoxia acclimation and plant environmental resilience.
Alternative splicing (AS) has emerged as a regulatory layer in plant adaptation to the environment. In particular, biotic stresses trigger a drastic remodeling of the plant AS landscape, with minimal overlap with changes...Alternative splicing (AS) has emerged as a regulatory layer in plant adaptation to the environment. In particular, biotic stresses trigger a drastic remodeling of the plant AS landscape, with minimal overlap with changes at the gene expression level, suggesting an additional, albeit poorly understood, mechanism of regulation. Recent studies have revealed that effectors from unrelated pathogens target core spliceosome components as well as accessory splicing factors. While this targeting is beginning to shed light on the relevance of the modulation of the plant AS landscape for pathogen invasion, it has also led to the identification of novel splicing factors, allowing the discovery of unexplored characteristics of the plant splicing machinery. Here, we review this emerging field, which delineates an additional battleground in the evolutionary arms race between plants and pathogens and has the potential to advance our biochemical and mechanistic understanding of the plant spliceosomal complex.
This article comments on: Gómez-Felipe A, de Folter S, Kierzkowski D. 2026. Auxin and cytokinin regulate growth dynamics underlying carpel initiation in Arabidopsis. Journal of Experimental Botany 77, 1743–1755. https://...This article comments on: Gómez-Felipe A, de Folter S, Kierzkowski D. 2026. Auxin and cytokinin regulate growth dynamics underlying carpel initiation in Arabidopsis. Journal of Experimental Botany 77, 1743–1755. https://doi.org/10.1093/jxb/eraf535
White lupin (Lupinus albus L.) develops bottlebrush-like root structures called cluster roots (CRs) under phosphorus deficiency to mobilize sparingly soluble phosphates in soil. The development of CRs is a highly coordin...White lupin (Lupinus albus L.) develops bottlebrush-like root structures called cluster roots (CRs) under phosphorus deficiency to mobilize sparingly soluble phosphates in soil. The development of CRs is a highly coordinated process mediated largely by the expression of thousands of genes, in which transcription factors (TFs) play critical roles. However, key TFs governing CR development and their associated regulatory networks remain poorly understood. Here, we constructed a stage-ordered TF-gene regulatory network using published transcriptomic datasets from distinct CR developmental stages. We then established an analytical workflow to decipher this network and identified novel transcriptional modules controlling CR development. Through experimental validation, we demonstrated that the 'LaTCP14-like-LaBZR1-like' regulatory module is essential for CR formation, with a parallel crucial role in general lateral root development. Overall, our systematic analysis provides insights into the stage-ordered transcriptional programs underpinning CR development in white lupin and the mechanisms of root specialization in response to nutrient deprivation in plants.
Suitable plant architecture is key to maximizing crop yield. Stem growth habit is a crucial characteristic of soybean plant architecture. Here, we investigated the combined effect of the Dt2 gene (producing semi-determin...Suitable plant architecture is key to maximizing crop yield. Stem growth habit is a crucial characteristic of soybean plant architecture. Here, we investigated the combined effect of the Dt2 gene (producing semi-determinate growth habit) and a loss-of-function e1-nl allele of the floral repressor E1. Comparisons among near-isogenic lines with different maturity genotypes indicated that the loss or repression of E1 function enhanced the effect of Dt2 on main stem node numbers. Dt2 expression in stem tips was upregulated in early growing stages under long-day conditions (LD) by the Dt2 and e1-nl alleles in an additive manner. Additionally, an Arabidopsis APETALA1 ortholog was highly upregulated in a Dt2/e1-nl line. The electrophoretic mobility shift assay revealed that the E1 DNA-binding domain bound to several genomic sites harboring key polymorphisms differentiating Dt2 from dt2 alleles. One of these sites had different transcription activities between Dt2 and dt2 alleles, and these activities were repressed by E1. Together, our data suggest that the Dt2 allele confers semi-determinacy by being preferentially induced when released from the repression by E1. The allelic combination of Dt2 and e1-nl confers a distinct semi-determinate phenotype, which would facilitate the use of the Dt2 allele, particularly under LD at high latitudes.