The Role of Anaphase-Promoting Complex/Cyclosome (APC/C) in Plant Reproduction

Studies on the regulation of E3 ubiquitin ligase APC3 and its interacting proteins on the tetraspore formation and release in Gracilariopsis lemaneiformis (Rhodophyta)

E3 ubiquitin ligases play significant roles in development of high plants and animals. We recently found that E3 ubiquitin ligase APC3, the subunit of the anaphase promoting complex/cyclosome, was involved in tetraspore formation and release in Gracilariopsis lemaneiformis, an economically important red alga. GlAPC3 showed opposite expression pattern in low-fertility cultivar 981 and high-fertility strain WLP during the process of tetraspore formation and release, up-regulated in 981 and down-regulated in WLP. Five proteins related to chromosome segregation, SMC3, NUF2, APC2, APC8 and APC10, were detected to interact with APC3, which were all located in the nucleus. NUF2 and CDC20 were the substrates of APC3, combined with Lysine-11, Lysine-48 and Lysine-63 of ubiquitin chains containing two or four ubiquitin. The key amino acids for ubiquitination of APC3 covered 474th Aspartate, 502nd tyrosine and 506th leucine, any mutation of which resulted in a loss of ubiquitination. During the process of tetraspore formation and release, SMC3 was significantly up-regulated only in 981, low number of tetraspore release. NUF2 and APC2 were significantly down-regulated only in WLP, with high frequency and large amount of tetraspores release. The data provided that APC3, SMC3 and NUF2 might be the key gene affecting the fertility of Gp. lemaneiformis. The study helps to explore the regulation mechanism of APC3 with SMC3 and NUF2 by the process of chromatids segregation in regulating tetraspore formation and release of Gp. lemaneiformis.

RNAi-mediated down-regulation of the endogenous GhAIP10.1 and GhAIP10.2 genes in transgenic cotton (Gossypium hirsutum) enhances the earliness and yield of flower buds

Armadillo BTB Arabidopsis protein 1 (AtABAP1) plays a central role in the cell cycle. ABAP1-interacting protein 10 (AtAIP10, a Snf1 kinase interactor-like protein) is a protein that interacts with AtABAP1. Down-regulation of the AtAIP10 gene in A. thaliana resulted in an altered cell cycle and increased photosynthesis, chlorophyll content, metabolites, plant growth, root system, seed yield, and drought tolerance. Herein, aimed to test whether the down-regulation of GhAIP10 genes can stimulate the cotton plants in a manner similar to those observed in A. thaliana. Cotton transgenic events containing transgenes carrying RNA interfering (RNAi) or artificial miRNA (amiRNA) strategies were successfully generated to down-regulate the endogenous GhAIP10.1 and GhAIP10.2 genes. From these 15 transgenic events, five RNAi-based transgenic lines and five amiRNA-based transgenic events were selected for further analyses. The down-regulation of the GhAIP10.1 and GhAIP10.2 genes was confirmed by real-time RT-PCR. Phenotypic and physiological analyses revealed that these transgenic lines exhibited earlier production and opening of flower buds, increased vegetative growth over time and root biomass, no reduction in susceptibility to root-knot nematodes, and improved drought tolerance indicated by a higher photosynthetic rate and better intrinsic water-use efficiency. Based on the high identity of amino acid sequences, motifs, domains, subcellular localization, tertiary structure, down-regulation of GhABAP1 (partner of GhAIP10), up-regulation of GhCdt1 (a marker of the ABAP1 network), up-regulation of GhCyclinB1 (a marker of the cell cycle), up-regulation of GhAP3 (involved in vegetative to reproductive transition), and the up-regulation of CAB3, NDA1, DJC22, and DNAJ11 genes (involved in plant resilience) suggested that GhAIP10.1 and GhAIP10.2 proteins may act in cotton similarly to the AtAIP10 protein in A. thaliana. Furthermore, GhAIP10.1 and GhAIP10.2 genes are suggested as biotechnological targets for cotton genetic engineering based on genome editing.

The Multifunctional Anaphase Promoting Complex 7 (APC7) Gene Is Associated With Increased Plant Growth and Improved Resistance to DNA and RNA Viruses

The anaphase promoting complex 7 (AtAPC7) is an APC/C subunit expressed in different organs of Arabidopsis thaliana and conserved among eukaryotes. A variant of the complete APC7 protein, containing its C-terminal region (named APC-CT), shows a high homology with a tobacco viral replication inhibitor (IVR-like) protein that reduces plant susceptibility to RNA viruses. Here, the role of the AtAPC7 gene was investigated by characterizing Arabidopsis plants overexpressing the full-length AtAPC7 (APC7OE) and the C-terminal portion (APC7-CTOE), by phenotypical, physiological and molecular approaches. APC7OE plants showed improved growth of vegetative organs, earlier flowering and increased photosynthetic efficiency, CO2 assimilation and productivity, compared with Col-0 control plants. Conversely, APC7-CTOE plants showed reduced susceptibility to both RNA and DNA viruses, along with an improvement in plant growth, although not surpassing APC7OE plants. Altogether, the data provide evidence for the role of the AtAPC7 in regulating cell division, expansion and differentiation, accompanied by an increase in photosynthetic capacity, resulting in enhanced plant biomass and seed yield. AtAPC7-CT might reduce growth-defence trade-offs, enabling plants to simultaneously defend themselves while promoting better growth. Our findings highlight the multifunctional role of AtAPC7, unveiling the potential of its orthologous genes as valuable biotechnological tools in important crops.

Population genomics of a natural Cannabis sativa L. collection from Iran identifies novel genetic loci for flowering time, morphology, sex and chemotyping

BACKGROUND

Future breeding and selection of Cannabis sativa L. for both drug production and industrial purposes require a source of germplasm with wide genetic variation, such as that found in wild relatives and progenitors of highly cultivated plants. Limited directional selection and breeding have occurred in this crop, especially informed by molecular markers.

RESULTS

This study investigated the population genomics of a natural cannabis collection comprising male and female individuals from various climatic zones in Iran. Using Genotyping-By-Sequencing (GBS), we sequenced 228 individuals from 35 populations. The data obtained enabled an association analysis, linking genotypes with key phenotypes such as inflorescence characteristics, flowering time, plant morphology, tetrahydrocannabinol (THC) and cannabidiol (CBD) content, and sex. We detected approximately 23,266 significant high-quality Single Nucleotide Polymorphisms (SNPs), establishing associations between markers and traits. The population structure analysis revealed that Iranian cannabis plants fall into five distinct groups. Additionally, a comparison with global data suggested that the Iranian populations is distinctive and generally closer to marijuana than to hemp, with some populations showing a closer affinity to hemp. The GWAS identified novel genetic loci associated with sex, yield, and chemotype traits in cannabis, which had not been previously reported.

CONCLUSION

The study's findings highlight the distinct genetic structure of Iranian Cannabis populations. The identification of novel genetic loci associated with important traits suggests potential targets for future breeding programs. This research underscores the value of the Iranian cannabis germplasm as a resource for breeding and selection efforts aimed at improving Cannabis for various uses.

Transcriptome-wide Identification of Nine Tandem Repeat Protein Families in Roselle (Hibiscus sabdariffa L.)

Plants are rich in tandem repeats-containing proteins. It is postulated that the occurrence of tandem repeat gene families facilitates the adaptation and survival of plants in adverse environmental conditions. This study intended to identify the tandem repeats in the transcriptome of a high potential tropical horticultural plant, roselle (Hibiscus sabdariffa L.). A total of 92,974 annotated de novo assembled transcripts were analysed using in silico approach, and 6,541 transcripts that encoded proteins containing tandem repeats with length of 20-60 amino acid residues were identified. Domain analysis revealed a total of nine tandem repeat protein families in the transcriptome of roselle, which are the Ankyrin repeats (ANK), Armadillo repeats (ARM), elongation factor-hand domain repeats (EF-hand), Huntingtin, elongation factor 3, protein phosphatase 2A, yeast kinase TOR1 repeats (HEAT), Kelch repeats (Kelch), leucine rich repeats (LRR), pentatricopeptide repeats (PPR), tetratricopeptide repeats (TPR) and WD40 repeats (WD40). Functional annotation analysis further matched 6,236 transcripts to 1,045 known proteins that contained tandem repeats including proteins implicated in plant development, protein-protein interaction, immunity and abiotic stress responses. The findings provide new insights into the occurrence of tandem repeats in the transcriptome and lay the foundation to elucidate the functional associations between tandem peptide repeats (TRs) and proteins in roselle and facilitate the identification of novel biotic and abiotic response related tandem repeats genes that may be useful in breeding improved varieties.

Comparative transcriptomic insights into molecular mechanisms of the susceptibility wheat variety MX169 response to Puccinia striiformis f. sp. tritici (Pst) infection

Stripe rust of wheat is caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst). Breeding durably resistant wheat varieties by disrupting the susceptibility (S) gene has an important impact on the control of wheat stripe rust. Mingxian169 (MX169) showed strong stripe rust susceptibility to all the races of Pst. However, molecular mechanisms and responsive genes underlying susceptibility of the wheat variety MX169 to Pst have not been elucidated. Here, we utilized next-generation sequencing technology to analyze transcriptomics data of "MX169" and high-resistance wheat "Zhong4" at 24, 48, and 120 h post-inoculation (hpi) with Pst. Comparative transcriptome analysis revealed 3,494, 2,831, and 2,700 differentially expressed genes (DEGs) at different time points. We observed an upregulation of DEGs involved in photosynthesis, flavonoid biosynthesis, pyruvate metabolism, thiamine metabolism, and other biological processes, suggesting their involvement in MX169's response to Pst. DEGs encoding transcription factors were also identified. Our study suggested the potential susceptibility gene resources in MX169 related to stripe rust response could be valuable for understanding the mechanisms involved in stripe rust susceptibility and for improving wheat resistance to Pst.

IMPORTANCE

Our study suggests the potential susceptibility gene resources in MX169 related to stripe rust response could be valuable for understanding the mechanisms involved in stripe rust susceptibility and for improving wheat resistance to Pst.

Analysis of 26S Proteasome Activity across Arabidopsis Tissues

Plants utilize the ubiquitin proteasome system (UPS) to orchestrate numerous essential cellular processes, including the rapid responses required to cope with abiotic and biotic stresses. The 26S proteasome serves as the central catalytic component of the UPS that allows for the proteolytic degradation of ubiquitin-conjugated proteins in a highly specific manner. Despite the increasing number of studies employing cell-free degradation assays to dissect the pathways and target substrates of the UPS, the precise extraction methods of highly potent tissues remain unexplored. Here, we utilize a fluorogenic reporting assay using two extraction methods to survey proteasomal activity in different Arabidopsis thaliana tissues. This study provides new insights into the enrichment of activity and varied presence of proteasomes in specific plant tissues.

ZmTDM1 encodes a tetratricopeptide repeat domain protein and is required for meiotic exit in maize

Elaborate cell-cycle control must be adopted to ensure the continuity of the meiotic second division and termination after that. Despite its importance, however, the genetic controls underlying the meiotic cell cycle have not been reported in maize. Here, we characterized a meiotic cell-cycle controller ZmTDM1, which is a homolog of Arabidopsis TDM1 and encodes a canonical tetratricopeptide repeat domain protein in maize. The Zmtdm1 homozygous plants exhibited complete male sterility and severe female abortion. In Zmtdm1 mutants, cell-cycle progression was almost identical to that of wild type from leptotene to anaphase II. However, chromosomes in the tetrad failed meiotic termination at the end of the second division and underwent additional divisions in succession without DNA replication, reducing the ploidy to less than haploid in the product. In addition, two ZmTDM1-like homologs (ZmTDML1 and ZmTDML2) were not functional in meiotic cell-cycle control. Moreover, ZmTDM1 interacted with RING-type E3 ubiquitin ligase, revealing that it acts as a subunit of the APC/C E3 ubiquitin ligase complex. Overall, our results identified a regulator of meiotic cell cycle in maize and demonstrated that ZmTDM1 is essential for meiotic exit after meiosis II.

Genome-Wide Identification and Analysis of APC E3 Ubiquitin Ligase Genes Family in Triticum aestivum

E3 ubiquitin ligases play a pivotal role in ubiquitination, a crucial post-translational modification process. Anaphase-promoting complex (APC), a large cullin-RING E3 ubiquitin ligase, regulates the unidirectional progression of the cell cycle by ubiquitinating specific target proteins and triggering plant immune responses. Several E3 ubiquitin ligases have been identified owing to advancements in sequencing and annotation of the wheat genome. However, the types and functions of APC E3 ubiquitin ligases in wheat have not been reported. This study identified 14 members of the APC gene family in the wheat genome and divided them into three subgroups (CCS52B, CCS52A, and CDC20) to better understand their functions. Promoter sequence analysis revealed the presence of several cis-acting elements related to hormone and stress responses in the APC E3 ubiquitin ligases in wheat. All identified APC E3 ubiquitin ligase family members were highly expressed in the leaves, and the expression of most genes was induced by the application of methyl jasmonate (MeJA). In addition, the APC gene family in wheat may play a role in plant defense mechanisms. This study comprehensively analyzes APC genes in wheat, laying the groundwork for future research on the function of APC genes in response to viral infections and expanding our understanding of wheat immunity mechanisms.

Paternal DNA methylation is remodeled to maternal levels in rice zygote

Epigenetic reprogramming occurs during reproduction to reset the genome for early development. In flowering plants, mechanistic details of parental methylation remodeling in zygote remain elusive. Here we analyze allele-specific DNA methylation in rice hybrid zygotes and during early embryo development and show that paternal DNA methylation is predominantly remodeled to match maternal allelic levels upon fertilization, which persists after the first zygotic division. The DNA methylation remodeling pattern supports the predominantly maternal-biased gene expression during zygotic genome activation (ZGA) in rice. However, parental allelic-specific methylations are reestablished at the globular embryo stage and associate with allelic-specific histone modification patterns in hybrids. These results reveal that paternal DNA methylation is remodeled to match the maternal pattern during zygotic genome reprogramming and suggest existence of a chromatin memory allowing parental allelic-specific methylation to be maintained in the hybrid.

Modelling how plant cell-cycle progression leads to cell size regulation

Populations of cells typically maintain a consistent size, despite cell division rarely being precisely symmetrical. Therefore, cells must possess a mechanism of "size control", whereby the cell volume at birth affects cell-cycle progression. While size control mechanisms have been elucidated in a number of other organisms, it is not yet clear how this mechanism functions in plants. Here, we present a mathematical model of the key interactions in the plant cell cycle. Model simulations reveal that the network of interactions exhibits limit-cycle solutions, with biological switches underpinning both the G1/S and G2/M cell-cycle transitions. Embedding this network model within growing cells, we test hypotheses as to how cell-cycle progression can depend on cell size. We investigate two different mechanisms at both the G1/S and G2/M transitions: (i) differential expression of cell-cycle activator and inhibitor proteins (with synthesis of inhibitor proteins being independent of cell size), and (ii) equal inheritance of inhibitor proteins after cell division. The model demonstrates that both these mechanisms can lead to larger daughter cells progressing through the cell cycle more rapidly, and can thus contribute to cell-size control. To test how these features enable size homeostasis over multiple generations, we then simulated these mechanisms in a cell-population model with multiple rounds of cell division. These simulations suggested that integration of size-control mechanisms at both G1/S and G2/M provides long-term cell-size homeostasis. We concluded that while both size independence and equal inheritance of inhibitor proteins can reduce variations in cell size across individual cell-cycle phases, combining size-control mechanisms at both G1/S and G2/M is essential to maintain size homeostasis over multiple generations. Thus, our study reveals how features of the cell-cycle network enable cell-cycle progression to depend on cell size, and provides a mechanistic understanding of how plant cell populations maintain consistent size over generations.

Genome-wide identification and expression analysis of anaphase promoting complex/cyclosome (APC/C) in rose

The anaphase promoting complex/cyclosome (APC/C) is a large multi-subunit complex, regulating plant development and cell cycle. In plants, the APC/C gene family has been identified in Arabidopsis, rice, and maize. The APC/Cs in rose has not yet been reported. In this study, a total of 19 APC/C genes were identified in rose. Furthermore, we also investigated phylogenetic relationships, chromosomal distribution, gene structure, motif analysis, promoter sequence analysis and expression pattern of RhAPC/C genes. Synteny analysis indicated that AtAPC/Cs and RhAPC/Cs show a high degree of conservation. RhAPC/C promoters contains numerous cis-elements involved in plant morphogenesis, hormone response and stress response. Based on the transcription of RhAPC/Cs in different tissues and developmental stages, it appears that RhAPC/Cs may play a variety of roles in rose growth and development. RhAPC/Cs have limitations in the time and space during which they respond to hormones and abiotic stress. RhAPC5, RhAPC11d, RhAPC13a and RhAPC13c may play a role in rose responding to abiotic stress. The expression of RhAPC10 was altered by infection with fungal pathogen. Our study will serve as a basis for determining the functional role of APC/C genes in roses and help future research on woody plants.

Effect of the At-CDC27a gene on Nicotiana benthamiana phenotype and accumulation of recombinant proteins

In this study the anaphase promoting complex subunit CDC27a from Arabidopsis thaliana was introduced in the genome of Nicotiana benthamiana by Agrobacterium tumefaciens. The presence of the At-CDC27a gene facilitates plant biomass production. Compared to wild type N. benthamiana the leaf mass fraction of the best performing transgenic line At-CDC27a-29 was increased up to 154%. The positive effect of the At-CDC27a expression on leaf biomass accumulation was accompanied by an enlarged total leaf area. Furthermore, the ectopic expression of the At-CDC27a also affected cellular conditions for the production of foreign proteins delivered by the TRBO vector. In comparison to the non-transgenic control, the protein accumulation in the At-CDC27a-29 plant host increased up to 146% for GFP and up to 181% for scFv-TM43-E10. Collectively, the modified N. benthamiana plants developed in this study might be useful to improve the yield of recombinant proteins per biomass unit in closed facilities.

Review: Exploring possible approaches using ubiquitylation and sumoylation pathways in modifying plant stress tolerance

Ubiquitin and similar proteins, such as SUMO, are utilized by plants to modify target proteins to rapidly change their stability and activity in cells. This review will provide an overview of these crucial protein interactions with a focus on ubiquitylation and sumoylation in plants and how they contribute to stress tolerance. The work will also explore possibilities to use these highly conserved pathways for novel approaches to generate more robust crop plants better fit to cope with abiotic and biotic stress situations.

Plant E3 Ligases and Their Role in Abiotic Stress Response

Plants, as sessile organisms, have limited means to cope with environmental changes. Consequently, they have developed complex regulatory systems to ameliorate abiotic stresses im-posed by environmental changes. One such system is the ubiquitin proteasome pathway, which utilizes E3 ligases to target proteins for proteolytic degradation via the 26S proteasome. Plants ex-press a plethora of E3 ligases that are categorized into four major groups depending on their structure. They are involved in many biological and developmental processes in plants, such as DNA repair, photomorphogenesis, phytohormones signaling, and biotic stress. Moreover, many E3 ligase targets are proteins involved in abiotic stress responses, such as salt, drought, heat, and cold. In this review, we will provide a comprehensive overview of E3 ligases and their substrates that have been connected with abiotic stress in order to illustrate the diversity and complexity of how this pathway enables plant survival under stress conditions.

Cycling in a crowd: Coordination of plant cell division, growth, and cell fate

The reiterative organogenesis that drives plant growth relies on the constant production of new cells, which remain encased by interconnected cell walls. For these reasons, plant morphogenesis strictly depends on the rate and orientation of both cell division and cell growth. Important progress has been made in recent years in understanding how cell cycle progression and the orientation of cell divisions are coordinated with cell and organ growth and with the acquisition of specialized cell fates. We review basic concepts and players in plant cell cycle and division, and then focus on their links to growth-related cues, such as metabolic state, cell size, cell geometry, and cell mechanics, and on how cell cycle progression and cell division are linked to specific cell fates. The retinoblastoma pathway has emerged as a major player in the coordination of the cell cycle with both growth and cell identity, while microtubule dynamics are central in the coordination of oriented cell divisions. Future challenges include clarifying feedbacks between growth and cell cycle progression, revealing the molecular basis of cell division orientation in response to mechanical and chemical signals, and probing the links between cell fate changes and chromatin dynamics during the cell cycle.

CAND1 is required for pollen viability in Arabidopsis thaliana-a test of the adaptive exchange hypothesis

The dynamic assembly of SKP1•CUL1•F-box protein (SCF) ubiquitin ligases is important for protein ubiquitination and degradation. This process is enabled by CAND1, which exchanges F-box proteins associated with the common CUL1 scaffold, and thereby, recycles the limited CUL1 core and allows diverse F-box proteins to assemble active SCFs. Previous human cell biological and computational studies have led to the adaptive exchange hypothesis, which suggests that the CAND1-mediated exchange confers plasticity on the SCF system, allowing cells to tolerate large variations in F-box protein expression. Here, we tested this hypothesis using Arabidopsis thaliana, a multicellular organism expressing hundreds of F-box protein genes at variable levels in different tissues. The cand1 null mutant in Arabidopsis is viable but produce almost no seeds. Bioinformatic, cell biological, and developmental analyses revealed that the low fertility in the cand1 mutant is associated with cell death in pollen, where the net expression of F-box protein genes is significantly higher than any other Arabidopsis tissue. In addition, we show that the transmission efficiency of the cand1 null allele was reduced through the male but not the female gametophyte. Our results suggest that CAND1 activity is essential in cells or tissues expressing high levels of F-box proteins. This finding is consistent with the proposed adaptive exchange hypothesis, demonstrating the necessity of the evolutionarily conserved CAND1-mediated exchange system in the development of a multicellular organism.

The Inactivation of Arabidopsis UBC22 Results in Abnormal Chromosome Segregation in Female Meiosis, but Not in Male Meiosis

Protein ubiquitination is important for the regulation of meiosis in eukaryotes, including plants. However, little is known about the involvement of E2 ubiquitin-conjugating enzymes in plant meiosis. Arabidopsis UBC22 is a unique E2 enzyme, able to catalyze the formation of ubiquitin dimers through lysine 11 (K11). Previous work has shown that ubc22 mutants are defective in megasporogenesis, with most ovules having no or abnormally functioning megaspores; furthermore, some mutant plants show distinct phenotypes in vegetative growth. In this study, we showed that chromosome segregation and callose deposition were abnormal in mutant female meiosis while male meiosis was not affected. The meiotic recombinase DMC1, required for homologous chromosome recombination, showed a dispersed distribution in mutant female meiocytes compared to the presence of strong foci in WT female meiocytes. Based on an analysis of F1 plants produced from crosses using a mutant as the female parent, about 24% of female mutant gametes had an abnormal content of DNA, resulting in frequent aneuploids among the mutant plants. These results show that UBC22 is critical for normal chromosome segregation in female meiosis but not for male meiosis, and they provide important leads for studying the role of UBC22 and K11-linked ubiquitination.

Plant CDKs-Driving the Cell Cycle through Climate Change

In a growing population, producing enough food has become a challenge in the face of the dramatic increase in climate change. Plants, during their evolution as sessile organisms, developed countless mechanisms to better adapt to the environment and its fluctuations. One important way is through the plasticity of their body and their forms, which are modulated during plant growth by accurate control of cell divisions. A family of serine/threonine kinases called cyclin-dependent kinases (CDK) is a key regulator of cell divisions by controlling cell cycle progression. In this review, we compile information on the primary response of plants in the regulation of the cell cycle in response to environmental stresses and show how the cell cycle proteins (mainly the cyclin-dependent kinases) involved in this regulation can act as components of environmental response signaling cascades, triggering adaptive responses to drive the cycle through climate fluctuations. Understanding the roles of CDKs and their regulators in the face of adversity may be crucial to meeting the challenge of increasing agricultural productivity in a new climate.

The Anaphase Promoting Complex/Cyclosome Subunit 11 and Its Role in Organ Size and Plant Development

The anaphase promoting complex/cyclosome (APC/C), a member of the E3 ubiquitin ligase family, plays an important role in recognizing the substrates to be ubiquitylated. Progression of anaphase, and therefore, of the cell cycle, is coordinated through cyclin degradation cycles dependent on proteolysis triggered by APC/C. The APC/C activity depends on the formation of a pocket comprising the catalytic subunits, APC2, APC11, and APC10. Among these, the role of APC11 outside the cell division cycle is poorly understood. Therefore, the goal of this work was to analyze the function of APC11 during plant development by characterizing apc11 knock-down mutant lines. Accordingly, we observed decreased apc11 expression in the mutant lines, followed by a reduction in meristem root size based on the cortical cell length, and an overall size diminishment throughout the development. Additionally, crosses of apc11-1 and amiR-apc11 with plants carrying a WUSCHEL-RELATED HOMEOBOX5 (WOX5) fluorescent marker showed a weakening of the green fluorescent protein-positive cells in the Quiescent Center. Moreover, plants with apc11-1 show a decreased leaf area, together with a decrease in the cell area when the shoot development was observed by kinematics analysis. Finally, we observed a decreased APC/C activity in the root and shoot meristems in crosses of pCYCB1;1:D-box-GUS with apc11-1 plants. Our results indicate that APC11 is important in the early stages of development, mediating meristematic architecture through APC/C activity affecting the overall plant growth.