Biology subjects

Gonzalez, N.

Publications and source records attributed to Gonzalez, N..

At least 19 recordsLinked to original sources

bioRxiv2026

Nitrate regulates anchor root development

Nitrogen is a critical nutrient necessary for plant growth and survival. Plasticity in root architecture helps adapt to soil nitrogen levels for optimal nitrogen uptake; the nitrate form of soil nitrogen is a major modulator of root architecture. Although details of nitrate-regulated primary and lateral root growth are known, nitrate-regulated formation of anchor roots, which arise from the collet, is not understood. In this work, we uncover a role for nitrate in the regulation of anchor root formation. We find that cytokinin inhibits anchor root formation with rising nitrate. These cytokinin effects on anchor root formation rely on regulated indole-3-butyric acid (IBA) to indole-3-acetic acid (IAA) conversion. These data point toward a mechanism by which nitrate controls a previously underappreciated aspect of nitrate-dependent root architecture driven by anchor roots.

plant biology↗

bioRxiv2026

The free amino acid-rich biostimulant, Leafamine, promotes cell division in tomato roots and alleviates heat stress effects

Several tomato (Solanum lycopersicum) varieties are sensitive to heat stress, which compromises plant growth, development, and ultimately yield. Biostimulants represent a promising approach to improve crop performance, yet their widespread adoption is hindered by the incomplete understanding of their mechanisms of action. This study aimed to elucidate the physiological and molecular effects of a protein hydrolysate-based biostimulant (Leafamine(R)), in tomato, under both optimal and heat stress conditions. Leafamine(R) increased primary root length by 15 to 20% compared to the controls, independent of the tested conditions, through promotion of cell division and potentially expansion. Transcriptomic analyses revealed the upregulation of genes involved in cell division and expansion under both optimal and heat stress conditions and the downregulation of heat stress markers under heat stress conditions. Hormone and metabolite profiling showed elevated levels of jasmonic and salicylic acid, putrescine, citrulline, and GABA, after Leafamine(R) treatment, consistent with the activation of stress tolerance pathways. Leafamine(R) pre-treated seedlings exhibited reduced growth inhibition during heat exposure, suggesting a priming effect. These findings highlight Leafamine(R) as a promising biostimulant for enhancing tomato growth in the context of climate change and the potential of biostimulants generically.

plant biology↗

bioRxiv2026

In planta haploid induction in maize and tomato through disruption of KOKOPELLI

Haploid induction is a key component of doubled haploid technology and an increasingly valuable tool for plant breeding, genome editing, and clonal seed production. While in planta haploid induction through haploid inducer lines offers significant advantages over in vitro approaches, its application remains limited in many crop species. Previously, disruption of the sperm cell-expressed KOKOPELLI (KPL) gene was shown to induce maternal haploids in Arabidopsis thaliana. Here, we report the creation of novel haploid inducer lines in two globally important crops, maize (Zea mays), a major staple food crop, and tomato (Solanum lycopersicum), a widely cultivated vegetable crop. Using targeted genome editing, we generated mutations in KPL orthologs and demonstrated that loss of KPL function confers haploid induction capacity, enabling the production of haploid seedlings in both species. These findings establish KPL as a conserved target to trigger haploid induction and expand the genetic toolbox available for haploid inducer development in crop species.

Plant Biology↗

bioRxiv2026

Context-dependent ATP7 Interactions with Parkinson's Disease-associated Genes Modulate Copper Homeostasis Phenotypes

Copper is an essential micronutrient required by enzymes that catalyze oxygen-dependent reactions, but toxic in excess. Mutations in the ATP7A and ATP7B copper transporters cause neuropsychiatric symptoms and neurodegeneration by mechanisms that remain to be elucidated. We previously reported that the ATP7A biochemical interactome is enriched in Parkinsons disease (PD) and neurodegeneration associated proteins, yet the functional outcomes of these interactions are unknown. Using Drosophila, we tested genetic interactions between ATP7 mutants that alter copper levels and a subset of these PD and neurodegeneration causative genes and found sex differences with some candidate genes enhancing ATP7 deleterious phenotypes in both sexes, while others were sex specific. Most notably, we found that Lrrk2 (Lrrk), the most commonly mutated gene in familial forms of PD, protects against ATP7 dysfunction in epidermal epithelial cells with a stronger effect in males than females. However, in dopaminergic neurons Lrrk plays a role in intracellular copper induced toxicity in females but not males, supporting context dependent interactions between ATP7A and PD-associated genes to protect against disruptions in copper homeostasis. Summary StatementWe performed a genetic interaction screen to explore the relationship between copper homeostasis and Parkinsons disease and other neurodegeneration associated genes.

genetics↗

bioRxiv2026

Distinct signaling mechanisms and proteome phenotypes are elicited by compartment-specific genetic defects of copper homeostasis

Impairments to the complex machinery regulating copper homeostasis lead to neurodevelopmental diseases, demonstrating the importance of copper for neuronal health and maintenance. The exact mechanisms by which the brain responds to copper deficiency following disruptions to the copper transporters ATP7A and CTR1 in conditions such as Menkes disease remain unclear, though failure to supply complex IV of the respiratory chain with copper is suspected to account for substantial pathology. Here, we studied mechanisms of copper deficiency using systems biology approaches to contrast isogenic CTR1- and COX17-deficient cells, which model copper deficiency at the level of the whole cell or complex IV, respectively. Multiomics approaches revealed distinct signaling mechanisms elicited by compartment-specific genetic defects of copper homeostasis, spanning multiple organelles and biological functions. Specifically, COX17 KO cells exhibited elevated AMPK activity and blunted mTOR activity relative to CTR1-null cells. Manipulating mTOR activity elicited inverse effects on survival in CTR1-deficient cells and flies as compared to their COX17-deficient counterparts. Increased mTOR activity and downstream protein synthesis is adaptive in models of copper deficiency but deleterious in COX17-deficient cells and flies. We propose that mTOR activation represents a resilience mechanism that fails following sustained copper deficiency and impairments to mitochondrial respiration. SignificanceO_LIComparative proteomics reveals distinct molecular mechanisms downstream of compartmentalized copper deficiency C_LIO_LICOX17- and CTR1-deficient cells exhibit distinct patterns of AMPK/mTOR pathway activity C_LIO_LImTOR and downstream S6K activity is protective in cellular copper deficiency but not in compartmentalized mitochondrial copper deficiency C_LI

cell biology↗

bioRxiv2025

Metabolic Trajectories During Surgical Stress in Patients Undergoing Cardiac Surgery

Stress hyperglycemia (SH) during acute illness is linked to adverse surgical outcomes, yet the accompanying metabolic perturbations are incompletely characterized. We profiled longitudinal metabolic changes in adults without diabetes undergoing cardiac surgery to identify pathways associated with perioperative SH (defined as point-of-care glucose [≥]140 mg/dL on [≥]3 readings or [≥]180 mg/dL once). Blood was collected at baseline before surgery (T0) and at 2 h (T1), 24-48 h (T2), and 72-96 h (T3) after surgical initiation. High-resolution metabolomics (LC-MS) was integrated with continuous glucose monitoring and inflammatory/cardiac biomarkers. At T0, several pathways were associated with subsequent SH, including bile acid metabolism, the carnitine shuttle, and fatty-acid oxidation, suggesting preoperative metabolic susceptibility. In longitudinal analyses, participants who developed SH showed coordinated postoperative changes with significant enrichment of pathways not evident at baseline, C21-steroid hormone biosynthesis, glycerophospholipid metabolism, and glycosphingolipid (ceramide) metabolism, consistent with lipid remodeling and inflammatory signaling during surgical stress. Individuals with SH also exhibited higher inflammatory biomarker levels (high-sensitivity C-reactive protein and soluble urokinase plasminogen activator receptor). A machine-learning model using early metabolomic features predicted SH with an area under the receiver operating characteristic curve of 0.86. These findings highlight distinct preoperative and perioperative metabolic trajectories associated with SH and implicate established dysglycemia-related pathways, as well as stress-induced pathways in perioperative metabolic dysregulation. Pathway enrichment analyses were exploratory and hypothesis-generating; validation in larger cohorts and assessment of implications for clinical outcomes are warranted.

biochemistry↗

bioRxiv2025

Dynamic changes to the plastoglobule lipidome and proteome in water-deficient maize

AbstractDrought represents one of the most severe challenges faced by agriculture and leveraging resources to promote crop resilience is critical. The plastoglobule lipid droplets of chloroplasts, present in all photosynthetic organisms, are suggested to be a major orchestrator of adaptive responses to environmental perturbations, thus representing a potentially significant, untapped target for enhancement of crop resilience. Yet, the functions of plastoglobules are unclear and their molecular composition incompletely described. Here, we provide a thorough investigation of the protein and lipid compositions of plastoglobules and thylakoids at six time-points over the course of a water-deficit and recovery treatment in B73 inbred maize. Our results establish the prominent components of the plastoglobule polar lipid surface and neutral lipid interior in an important crop species, including the presence of mono- and di-galactosyl diacylglycerol lipids enriched in saturated acyl groups, and the prevalence of various triacylglycerols and plastoquinone-9 derivatives. Quantitative proteomics identifies prominent Fibrillins and Activity of bc1 Complex Kinases at the plastoglobule as well as many proteins with known or putative roles in prenyl-lipid and redox metabolism. A remarkably high proportion of the Fibrillin 4 on the plastoglobules coincided with a preponderance of plastoquinone-9, supporting a role for Fibrillin 4 in plastoquinone accumulation at plastoglobules. Collectively, our results provide a solid foundation for the study of plastoglobules in crop plants.

plant biology↗

bioRxiv2025

Functional analysis of FW2.2-LIKE proteins in tomato: SlFWL5 regulates leaf size and morphology.

The CELL NUMBER REGULATOR/FW2.2-like (CNR/FWL) gene family comprises PLAC8 domain-containing membrane-associated proteins. The CNR/FWL gene family was named in reference to its founding member, the FW2.2 gene, which determines fruit size in tomato via a negative regulation on cell divisions. The functional characterization of PLAC8 domain-containing CNR/FWL proteins in plants is still very scarce, and only recently the molecular and cellular mode of action of FW2.2 was identified as regulating plasmodesmata-mediated cell-to-cell communication. In the present study, we provided a functional analysis of SlFWL genes in tomato, aiming at investigating any direct role in the control of organ growth. Based on a combination of molecular and cellular approaches, we selected three SlFWL proteins, namely SlFWL2, -4 and -5, which are localized at the plasma membrane. Gain- and loss-of-function transgenic plants were generated to explore their putative role as regulators of organ growth in tomato. This allowed us to shed light more specifically on the critical involvement of SlFWL5 in leaf development. We here showed that SlFWL5 is a plasmodesmata-localized protein that regulates leaf size and morphology via cell expansion, most probably through cell-to-cell communication. This original finding underscores further the importance of the CNR/FWL family members in growth regulation. Highlight: The FW2.2-LIKE protein SlFWL5 is localized at plasmodesmata and may have a role in cell-to-cell communication to regulate cell expansion during leaf development.

plant biology↗

bioRxiv2024

Modulating activity of the APC/C regulator SlSAMBA improves the sugar and antioxidant content of tomato fruits

The Anaphase-Promoting Complex/Cyclosome (APC/C) is an E3 ubiquitin ligase that plays a crucial role in ubiquitin-dependent proteolysis of key cell cycle regulators, which is completed by 26S proteasome. Previously, SAMBA, a plant-specific regulator of the APC/C, was identified in Arabidopsis as a critical factor controlling organ size through the regulation of cell proliferation. Here, by assessing its role in the crop tomato (Solanum lycopersicum), we confirm that SAMBA is a conserved APC/C regulator in plants. Two slsamba genome-edited lines were characterized showing delayed growth, reduced plant size and altered fruit morphology, which were linked to changes in cell division and expansion. Notably, untargeted metabolomics revealed altered flavonoid profiles, along with elevated Brix values in the fruits, indicating a sweeter taste. Accordingly, transcriptomics uncovered a change in temporal gene expression gradients during early fruit development, correlating with the alterations in sugar metabolism and revealing changes in cell wall biosynthesis genes. This study provides the first evidence of SAMBAs role in regulating fruit development, metabolic content, and, ultimately, quality. These important findings offer potential applications for improving the nutritional quality and overall performance of tomato.

plant biology↗

bioRxiv2024

Identification and validation of drugs for repositioning in Glioblastoma: a computational and experimental workflow

PurposeGlioblastoma (GBM) remains a formidable challenge in oncology due to its invasiveness and resistance to treatment, i.e. surgery, radiotherapy, and chemotherapy with temozolomide. This study aimed to develop and validate an integrated model to predict the sensitivity of GBM to alternative chemotherapeutics and to identify novel candidate drugs and combinations for the treatment of GBM. Patients and MethodsWe utilized the drug sensitivity response data of 272 compounds from CancerRxTissue, a validated predictive model, to identify drugs with therapeutic potential for GBM. Using the IC50, we selected potentially effective drugs among those predicted to be blood-brain barrier permeable via in silico algorithms. We ultimately selected drugs with targets overexpressed and associated with worse prognosis in GBM for experimental in vitro validation. ResultsThe workflow proposed predicted that GBM is more sensitive to Etoposide and Cisplatin, in comparison with Temozolomide, effects that were validated in vitro in a set of GBM cellular models. Using this workflow, we identified a set of 5 novel drugs to which GBM would exhibit high sensitivity and selected Daporinad, a blood-brain barrier permeant NAMPT inhibitor, for further preclinical in vitro evaluation, which aligned with the in silico prediction. ConclusionOur results suggest that this workflow could be useful to select potentially effective drugs and combinations for GBM, according to the molecular characteristics of the tumor. This comprehensive workflow, which integrates computational prowess with experimental validation, could constitute a simple tool for identifying and validating compounds with potential for drug reporpusing in GBM and other tumors.

cancer biology↗

bioRxiv2024

The Zinc Finger protein SlZFP2 is essential for tomato fruit locular tissue morphogenesis

In tomato (Solanum lycopersicum L.) fruit, the locular tissue (LT) is a unique jelly-like tissue that differentiates from the central axis of the fruit after ovule fertilization. LT is essential for seed development and dispersal by preventing early germination and initiating fruit ripening. In this work, we studied a "gel-less" mutant and identified the underlying mutation in the coding sequence of the C2H2 zinc finger transcription factor (TF) SlZFP2. Histological, cytological and molecular characterization from knockout-CRISPR/Cas9 lines for this gene revealed the strong and early impact of zfp2 mutation on cell cycle and endocycle in LT. Additionally, model-based analysis of cellular data revealed that cell cycle was the main altered process, explaining the zfp2 mutant phenotype. Further laser capture microdissection coupled with RNA-Seq analysis of young LT highlighted global expression changes between WT and zfp2 mutant and led to a preliminary list of potential direct targets of the SlZFP2 TF. This multifaceted approach not only uncovered a new role for SlZFP2 TF as an essential regulator of LT morphogenesis, but also provides a foundation for future works aimed at deciphering the intricate regulatory networks governing fruit tissue development in tomato. One sentence summaryAlteration of cell division and endoreduplication in a gel-less mutant reveals the role of the transcription factor SlZFP2 in tomato locular tissue morphogenesis

plant biology↗

bioRxiv2023

Role of RIPK1 in Diffuse Gliomas pathology

PurposeThe aim of the present work was to investigate the role of Receptor-interacting protein kinase 1 (RIPK1) both in mutated and wild type isocitrate dehydrogenase (IDH) Diffuse Gliomas (DG). Patients and MethodsWe analyzed RIPK1 mRNA expression in DG databases from The Cancer Genome Atlas (TCGA) containing clinical, genomic and transcriptomic information from 661 patients. Transcriptomic studies (mRNA expression levels, correlation heatmaps, survival plots and Gene Ontology and meta-analysis of immune gene signatures) were performed with USC Xena and R. Statistical significance was set at p-values less than 0.05. ResultsThe results showed a lower survival probability in patients belonging to the high RIPK1 expression subgroup compared to those samples with low RIPK1 expression. We also observed a higher expression of RIPK1 in wtIDH samples compared to those with mIDH. In order to further characterize the role of RIPK1 in DG, we performed a Gene Ontology and Pathway Enrichment Analysis using the Xena platforms differential expression tool. The results showed that RIPK1 is involved in inflammatory and immune responses. Hence, the expression levels of some of the genes involved in the following molecular processes crucial for cancer progression were studied: proliferation, epithelial-mesenchymal transition, immune cell infiltration and cell death pathways. Briefly, the results showed significant differences in genes related to increased cellular dedifferentiation, proinflammatory cell death pathways and tumor infiltrating immune cells gene signatures (Welchs t-test). ConclusionRIPK1 over-expression is associated with a poor prognosis in DG. This fact, together with our results suggest that RIPK1 may play a crucial role in glioma pathogenesis highlighting the need to take into account RIPK1 expression levels for decision making when choosing or designing therapeutic alternatives. CONTEXT SUMMARYO_ST_ABSKey ObjectiveC_ST_ABSEvaluate the role of the Receptor-interacting protein kinase 1 (RIPK1) in Diffuse Gliomas (DG) pathology through an exhaustive in silico patient database analysis. Knowledge generatedWe demonstrated that RIPK1 is overexpressed in more aggressive DG and correlates with clinical attributes associated with poor prognosis. In addition, our analyses showed that high RIPK1 expression correlates with key genes involved in pro inflammatory cell death pathways and an increased expression of immune gene signatures suggesting greater immunological infiltration in the tumor. RelevanceOur results from patient database analyses propose RIPK1 as a new relevant molecular prognosis marker for DG. Our findings are in concordance with different preclinical studies and provide additional information that can be useful for decision making when choosing therapeutic strategies and for the development of novel therapeutic approaches such as gene or immunotherapy. This work was presented inXIII Argentine Congress of Bioinformatics and Computational Biology (XIII CAB2C), XIII International Conference of the Iberoamerican Society of Bioinformatics (XIII SoIBio) and III Annual Meeting of the Ibero-American Artificial Intelligence Network for Big BioData (III RiaBio).

bioinformatics↗

bioRxiv2023

The FW2.2/CNR protein regulates cell-to-cell communication in tomato by modulating callose deposition at plasmodesmata

The FW2.2 gene is the founding member of the CELL NUMBER REGULATOR (CNR) gene family. More than 20 years ago, FW2.2 was the first cloned gene underlying a Quantitative Trait Locus (QTL) governing fruit size/weight in tomato. However, despite this discovery, the molecular mechanisms by which FW2.2 acts as a negative regulator of cell divisions during fruit growth remain undeciphered. In the present study, we confirm that FW2.2 is a transmembrane spanning protein, whose both N- and C-terminal ends are facing the apoplast. We unexpectedly found that FW2.2 is located at plasmodesmata (PD). FW2.2 participates in the spatiotemporal regulation of callose deposition at PD via an interaction with Callose Synthases, which suggests a regulatory role in cell-to-cell communication by modulating PD transport capacity and trafficking of signaling molecules during fruit development.

plant biology↗

bioRxiv2023

Ploidy-specific transcriptomes shed light on the heterogeneous identity and metabolism of developing pericarp cells

Endoreduplication, during which cells increase their DNA content through successive rounds of full genome replication without cell division, is the major source of endopolyploidy in higher plants. Endoreduplication plays pivotal roles in plant growth and development and is associated with the activation of specific transcriptional programs that are characteristic to each cell type, thereby defining their identity. In plants, endoreduplication is found in numerous organs and cell types and especially in agronomically valuable ones, such as the fleshy fruit (pericarp) of tomato presenting high ploidy levels. We used the tomato pericarp tissue as a model system to explore the transcriptomes associated with endoreduplication progression during fruit growth. We confirmed that expression globally scales with ploidy level and identified sets of genes differentially expressed when comparing ploidy levels at a specific developmental stage. We found that non-endoreduplicated cells are defined by cell division state and cuticle synthesis while endoreduplicated cells are mainly defined by their metabolic activity changing rapidly over time. By combining this dataset with publicly available spatiotemporal pericarp expression data, we proposed a map describing the distribution of ploidy levels within the pericarp. These transcriptome-based predictions were validated by quantifying ploidy levels within the pericarp tissue. This in situ ploidy quantification revealed the dynamic progression of endoreduplication and its cell layer specificity during early fruit development. In summary, the study sheds light on the complex relationship between endoreduplication, cell differentiation, and gene expression patterns in the tomato pericarp. Significance statementThe progression of endoreduplication is very dynamic during early fruit development and displays cell layer specific patterns. The integration of ploidy distribution maps with ploidy-specific transcriptome data revealed that gene expression in the pericarp is controlled in a ploidy-specific manner during the early stages of tomato fruit development, resulting in the spatialization of transcriptional programs.

plant biology↗

bioRxiv2022

Various tomato cultivars display contrasted morphological and molecular responses to a heat wave.

Climate change is one of the biggest threats that human society currently needs to face. Heat waves associated with global warming negatively affect plant growth and development and will increase in frequency. Tomato is one of the most produced and consumed fruit in the world but remarkable yield losses occur every year due to the sensitivity of many cultivars to heat stress. New insights into how tomato plants are responding to heat waves will contribute to the development of new cultivars with high yields under harsh temperature conditions. In this study, the analysis of microsporogenesis and pollen germination rate of eleven tomato cultivars after exposure to a simulated heat wave revealed differences between genotypes. The transcriptome of floral buds at two developmental stages of five cultivars selected based on their pollen germination tolerance or sensitivity, revealed common and specific molecular responses implemented by tomato cultivars to cope with heat waves. These data provide valuable insights into the underlying molecular adaptation of floral buds to heat stress and will contribute to the development of future climate resilient tomato varieties.

plant biology↗

bioRxiv2022

Solanum lycopersicum CLASS-II KNOX genes regulate fruit anatomy via gibberellin-dependent and independent pathways.

The pericarp is the predominant tissue determining the structural characteristics of most fruits. However, the molecular and genetic mechanisms controlling pericarp development remain only partially understood. Previous studies have identified that CLASS-II KNOX genes regulate fruit size, shape, and maturation in Arabidopsis thaliana and Solanum lycopersicum. Here we characterized the roles of the Solanum lycopersicum CLASS-II KNOX (TKN-II) genes in pericarp development via a detailed histological, anatomical, and karyotype analysis of the TKN-II knockdown (35S:amiR-TKN-II) fruits. We identify that 35S:amiR-TKN-II pericarps contain more cells around their equatorial perimeter and fewer cell layers than the control. In addition, the cell sizes but not the ploidy levels of these pericarps were dramatically reduced. Further, we demonstrate that fruit shape and pericarp layer number phenotypes of the 35S:amiR-TKN-II fruits can be overridden by the procera mutant, known to induce a constitutive response to the plant hormone gibberellin. However, neither the procera mutation nor exogenous gibberellin application can fully rescue the reduced pericarp width and cell size phenotype of 35S:amiR-TKN-II pericarps. Our findings establish that TKN-II genes regulate tomato fruit anatomy, acting via gibberellin to control fruit shape but utilizing a gibberellin-independent pathway to control the size of pericarp cells. HighlightTomato CLASS-II KNOX genes regulate fruit and pericarp anatomy via GA-dependent and independent pathways.

plant biology↗

bioRxiv2021

Association between quinolone use in food animals and gonococcal resistance to ciprofloxacin: an ecological study

BackgroundConcentrations of fluoroquinolones up to 200-fold lower than the MIC have been shown to be able to select for antimicrobial resistance in E. coli and Salmonella spp. (the minimum selection concentration - MSC). We aimed to i) establish what the ciprofloxacin MSC is for Neisseria gonorrhoeae and ii) Assess at a country level if the prevalence of gonococcal ciprofloxacin resistance is associated with the concentration of quinolones used in food animal production (an important determinant of long-term low dose ciprofloxacin exposures in humans). Methodsi). To assess if sub-inhibitory ciprofloxacin concentrations could select for de novo generated resistant mutants, susceptible WHO-P was serially passaged at 1, 1/10, 1/100 and 1/1000 of the ciprofloxacin MIC of WHO-P (0.004mg/L) on GC agar plates. ii) Spearmans correlation was used to assess the association between the prevalence of ciprofloxacin resistance in N. gonorrhoeae and the two independent variables - quinolone use for animals and quinolone consumption by humans. ResultsCiprofloxacin concentrations as low as 1/1000 of the MIC of WHO-P were able to select for ciprofloxacin resistance. The prevalence of ciprofloxacin resistance in N. gonorrhoeae was positively associated with quinolone use for food animals ({rho}=0.47; P=0.004; N=34). ConclusionFurther individual level research is required to assess if low doses of ciprofloxacin from ingested foodstuffs are able to select for ciprofloxacin resistance in N. gonorrhoeae and other species.

microbiology↗

bioRxiv2020

KIX8 and KIX9 are conserved repressors of organ size in the asterid species tomato

Plant organ size and shape are major agronomic traits that depend on cell division and expansion, which are both regulated by complex gene networks. In several eudicot species belonging to the rosid clade, organ growth is controlled by a repressor complex consisting of PEAPOD (PPD) and KINASE-INDUCIBLE DOMAIN INTERACTING (KIX) proteins. The role of these proteins in asterids, which together with the rosids constitute most of the core eudicot species, is still unknown. We used CRISPR-Cas9 genome editing to target SlKIX8 and SlKIX9 in the asterid model species tomato (Solanum lycopersicum) and analyzed loss-of-function phenotypes. We found that loss of function of SlKIX8 and SlKIX9 led to the production of enlarged, dome-shaped leaves and that these leaves exhibited increased expression of putative SlPPD target genes. Unexpectedly, kix8 kix9 mutants carried enlarged fruits with increased pericarp thickness due to cell expansion. At the molecular level, protein interaction assays indicated that SlKIX8 and SlKIX9 act as adaptors between the SlPPD and SlTOPLESS co-repressor proteins. Our results show that KIX8 and KIX9 are regulators of organ growth in asterids and can provide strategies to improve important traits in produce such as thickness of the fruit flesh. One sentence summaryTwo transcriptional repressors negatively regulate organ growth in tomato with loss-of-function lines producing enlarged fruits due to an appearance of more expanded cells in the fruit flesh.

plant biology↗