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MADS transcription factors are master regulators of plant reproduction and flower development. The SEPALLATA (SEP) subfamily of MADS transcription factors is required for the development of floral organs and plays roles in inflorescence architecture and development of the floral meristem. SEPALLATAs act as organizers of MADS complexes, forming both heterodimers and heterotetramers in vitro. To date, the MADS complexes characterized in angiosperm floral organ development contain at least 1 SEPALLATA protein. Whether DNA binding by SEPALLATA-containing dimeric MADS complexes is sufficient for launching floral organ identity programs, however, is not clear as only defects in floral meristem determinacy were observed in tetramerization-impaired SEPALLATA mutant proteins. Here, we used a combination of genome-wide-binding studies, high-resolution structural studies of the SEP3/AGAMOUS (AG) tetramerization domain, structure-based mutagenesis and complementation experiments in Arabidopsis (Arabidopsis thaliana) sep1 sep2 sep3 and sep1 sep2 sep3 ag-4 plants transformed with versions of SEP3 encoding tetramerization mutants. We demonstrate that while SEP3 heterodimers can bind DNA both in vitro and in vivo and recognize the majority of SEP3 wild-type-binding sites genome-wide, tetramerization is required not only for floral meristem determinacy but also for floral organ identity in the second, third, and fourth whorls., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The evolution of the MADS-box gene family is essential for the rapid differentiation of floral organs and fruit types in angiosperms. Two key processes drive the evolution of gene families: gene duplication and functional differentiation. Duplicated copies provide the material for variation, while advantageous mutations can confer new functions on gene copies. In this study, we selected the Rosaceae family, which includes a variety of fruit types and flower organs, as well as species that existed before and after whole-genome duplication (WGD). The results indicate that different fruit types are associated with different copies of MADS-box gene family duplications and WGD events. While most gene copies derived from WGD have been lost, MADS-box genes not only retain copies derived from WGD but also undergo further gene duplication. The sequences, protein structures, and expression patterns of these gene copies have undergone significant differentiation. This work provides a clear example of MADS-box genes in the context of gene duplication and functional differentiation, offering new insights into the evolution of fruit types and floral organs.

Key Message: Approximately 119 MADS-box genes have been identified in durian. Moreover, DzAGL6-1 primarily expressed during fruit development, activates the DzPSY promoter. Transient expression of DzAGL6-1 in tomatoes influences carotenoid production. MADS-box transcription factors play a crucial role in regulating plant biological processes, including fruit ripening and associated events. This study aimed to comprehend the mechanisms involved in durian fruit development and ripening and carotenoid production by conducting a genome-wide analysis of MADS-box proteins in durian (Durio zibethinus L.), an economically important fruit in Southeast Asia. A total of 119 durian MADS-box proteins were identified from the genome of the 'Musang King' cultivar. Based on the phylogenetic analysis, the proteins were classified into types I and II, which exhibited similar conserved motif compositions. Notably, only 16 durian MADS-box genes exhibited fruit-specific expression patterns. Among these genes, DzAGL6-1 was predominantly expressed during fruit development, a stage at which carotenoid biosynthesis is activated. Transient expression of DzAGL6-1 in tomato fruit increased the transcript level of the carotenoid biosynthetic gene phytoene synthase (PSY) and the β-carotene content. Furthermore, DzAGL6-1 activated the promoter activity of DzPSY, as demonstrated by a dual-luciferase assay. These findings provide insights into the role of MADS-box transcription factors in regulating carotenoid biosynthesis during durian fruit development., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: In Angiosperms, the continuation of plant species is intricately dependent on the funiculus multifaceted role in nutrient transport, mechanical support, and dehiscence of seeds. SEEDSTICK (STK) is a MADS-box transcription factor involved in seed size and abscission, and one of the few genes identified as affecting funiculus growth. Given the importance of the funiculus to a correct seed development, allied with previous phenotypic observations of stk mutants, we performed a transcriptomic analysis of stk funiculi from floral stage 17, using RNA-sequencing, to infer on the deregulated networks of genes., Results: The generated dataset of differentially expressed genes was enriched with cell wall biogenesis, cell cycle, sugar metabolism and transport terms, all in accordance with stk phenotype observed in funiculi from floral stage 17. We selected eight differentially expressed genes for transcriptome validation using qPCR and/or promoter reporter lines. Those genes were involved with abscission, seed development or novel functions in stk funiculus, such as hormones/secondary metabolites transport., Conclusion: Overall, the analysis performed in this study allowed delving into the STK-network established in Arabidopsis funiculus, fulfilling a literature gap. Simultaneously, our findings reinforced the reliability of the transcriptome, making it a valuable resource for candidate genes selection for functional genetic studies in the funiculus. This will enhance our understanding on the regulatory network controlled by STK, on the role of the funiculus and how seed development may be affected by them., (© 2024. The Author(s).)

Plants flower in response to environmental signals. These signals change the shape and developmental identity of the shoot apical meristem (SAM), causing it to form flowers and inflorescences. We show that the increases in SAM width and height during floral transition correlate with changes in size of the central zone (CZ), defined by CLAVATA3 expression, and involve a transient increase in the height of the organizing center (OC), defined by WUSCHEL expression. The APETALA2 (AP2) transcription factor is required for the rapid increases in SAM height and width, by maintaining the width of the OC and increasing the height and width of the CZ. AP2 expression is repressed in the SAM at the end of floral transition, and extending the duration of its expression increases SAM width. Transcriptional repression by SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) represents one of the mechanisms reducing AP2 expression during floral transition. Moreover, AP2 represses SOC1 transcription, and we find that reciprocal repression of SOC1 and AP2 contributes to synchronizing precise changes in meristem shape with floral transition., (© 2024. The Author(s).)

Evolution of unisexual flowers involves extreme changes in floral development. Spinach is one of the species to discern the formation and evolution of dioecy. MADS-box gene family is involved in regulation of floral organ identity and development and in many other plant developmental processes. However, there is no systematic analysis of MADS-box family genes in spinach. A comprehensive genome-wide analysis and transcriptome profiling of MADS-box genes were undertaken to understand their involvement in unisexual flower development at different stages in spinach. In total, 54 MADS-box genes found to be unevenly located across 6 chromosomes and can be divided into type I and type II genes. Twenty type I MADS-box genes are subdivided into Mα, Mβ and Mγ subgroups. While thirty-four type II SoMADSs consist of 3 MIKC*, and 31 MIKC C -type genes including sixteen floral homeotic MADS-box genes that are orthologous to the proposed Arabidopsis ABCDE model of floral organ identity determination, were identified in spinach. Gene structure, motif distribution, physiochemical properties, gene duplication and collinearity analyses for these genes are performed in detail. Promoters of both types of SoMADS genes contain mainly MeJA and ABA response elements. Expression profiling indicated that MIKCc genes exhibited more dynamic and intricate expression patterns compared to M-type genes and the majority of type-II genes AP1, SVP, and SOC1 sub-groups showed female flower-biased expression profiles, suggesting their role in carpel development, while PI showed male-biased expression throughout flower developmental stages, suggesting their role in stamen development. These results provide genomic resources and insights into spinach dioecious flower development and expedite spinach improvement., (© 2024. The Author(s).)

Flowering time and maturity are crucial agronomic traits that affect the regional adaptability of soybean plants. The development of soybean cultivars with early maturity adapted to longer days and colder climates of high latitudes is very important for ensuring normal ripening before frost begins. FUL belongs to the MADS-box transcription factor family and has several duplicated members in soybeans. In this study, we observed that overexpression of GmFULc in the Dongnong 50 cultivar promoted soybean maturity, while GmFULc knockout mutants exhibited late maturity. Chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) revealed that GmFULc could bind to the CArG, bHLH and homeobox motifs. Further investigation revealed that GmFULc could directly bind to the CArG motif in the promoters of the GmZTL3 and GmZTL4 genes. Overexpression of GmZTL4 promoted soybean maturity, whereas the ztl4 mutants exhibited delayed maturity. Moreover, we found that the cis element box 4 motif of the GmZTL4 promoter, a motif of light response elements, played an important role in controlling the growth period. Deletion of this motif shortened the growth period by increasing the expression levels of GmZTL4. Functional investigations revealed that short-day treatment promoted the binding of GmFULc to the promoter of GmZTL4 and inhibited the expression of E1 and E1Lb, ultimately resulting in the promotion of flowering and early maturation. Taken together, these findings suggest a novel photoperiod regulatory pathway in which GmFULc directly activates GmZTL4 to promote earlier maturity in soybean., (© 2024 Institute of Botany, Chinese Academy of Sciences.)

Grain weight, grain number per panicle, and the number of panicles are the three factors that determine rice (Oryza sativa L.) yield. Of these, grain weight, which not only directly determines rice yield but also influences appearance and quality, is often considered the most important for rice production. Here, we describe OsNF-YC1, a member of the NF-Y transcription factor family that regulates rice grain size. OsNF-YC1 knockout plants (osnf-yc1), obtained using CRISPR-Cas9 technology, showed reduced grain weight due to reduced width and thickness, with no change in grain length, leading to a slenderer grain shape. Downregulation of OsNF-YC1 using RNA interference resulted in similar grain phenotypes as osnf-yc1. OsNF-YC1 affects grain formation by regulating both cell proliferation and cell expansion. OsNF-YC1 localizes in both the nucleus and cytoplasm, has transcriptional activation activity at both the N-terminus and C-terminus, and is highly expressed in young panicles. OsNF-YC1 interacts with OsMADS1 both in vivo and in vitro. Further analysis showed that the histone-like structural CBFD-NFYB-HMF domain of OsNF-YC1 conserved in the OsNF-YC transcription factor family can directly interact with the MADS-box domain of OsMADS1 to enhance its transcriptional activation activity. This interaction positively regulates the expression of OsMADS55, the direct downstream target of OsMADS1. Therefore, this paper reveals a potential grain size regulation pathway controlled by an OsNF-YC1-OsMADS1-OsMADS55 module in rice., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

Epigenetic modifications, such as histone alterations, play crucial roles in regulating the flowering process in Arabidopsis, a typical long-day model plant. Histone modifications are notably involved in the intricate regulation of FLC, a key inhibitor of flowering. Although sirtuin-like protein and NAD + -dependent deacetylases play an important role in regulating energy metabolism, plant stress responses, and hormonal signal transduction, the mechanisms underlying their developmental transitions remain unclear. Thus, this study aimed to reveal how Arabidopsis NAD  +  -dependent deacetylase AtSRT1 affects flowering by regulating the expression of flowering integrators. Genetic and molecular evidence demonstrated that AtSRT1 mediates histone deacetylation by directly binding near the transcriptional start sites (TSS) of the flowering integrator genes FT and SOC1 and negatively regulating their expression by modulating the expression of the downstream gene LFY to inhibit flowering. Additionally, AtSRT1 directly down-regulates the expression of TOR, a glucose-driven central hub of energy signaling, which controls cell metabolism and growth in response to nutritional and environmental factors. This down-regulation occurs through binding near the TSS of TOR, facilitating the addition of H3K27me3 marks on FLC via the TOR-FIE-PRC2 pathway, further repressing flowering. These results uncover a multi-pathway regulatory network involving deacetylase AtSRT1 during the flowering process, highlighting its interaction with TOR as a hub for the coordinated regulation of energy metabolism and flowering initiation. These findings significantly enhance understanding of the complexity of histone modifications in the regulation of flowering., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

In wheat, the transition of the inflorescence meristem to a terminal spikelet (IM→TS) determines the spikelet number per spike (SNS), an important yield component. In this study, we demonstrate that the plant-specific transcription factor LEAFY (LFY) physically and genetically interacts with WHEAT ORTHOLOG OF APO1 (WAPO1) to regulate SNS and floret development. Loss-of-function mutations in either or both genes result in significant and similar reductions in SNS, as a result of a reduction in the rate of spikelet meristem formation per day. SNS is also modulated by significant genetic interactions between LFY and the SQUAMOSA MADS-box genes VRN1 and FUL2, which promote the IM→TS transition. Single-molecule fluorescence in situ hybridization revealed a downregulation of LFY and upregulation of the SQUAMOSA MADS-box genes in the distal part of the developing spike during the IM→TS transition, supporting their opposite roles in the regulation of SNS in wheat. Concurrently, the overlap of LFY and WAPO1 transcription domains in the developing spikelets contributes to normal floret development. Understanding the genetic network regulating SNS is a necessary first step to engineer this important agronomic trait., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Most of the studied MADS box members are linked to flowering and fruit traits. However, higher volumes of studies on type II of the two types so far suggest that the florigenic effect of the gene members could just be the tip of the iceberg. In the current study, we used a systematic approach to obtain a general overview of the MADS box members' cross-trait and multifactor associations, and their pleiotropic potentials, based on a manually curated local reference database. While doing so, we screened for the co-occurrence of terms of interest within the title or abstract of each reference, with a threshold of three hits. The analysis results showed that our approach can retrieve multi-faceted information on the subject of study (MADS box gene members in the current case), which could otherwise have been skewed depending on the authors' expertise and/or volume of the literature reference base. Overall, our study discusses the roles of MADS box members in association with plant organs and trait-linked factors among plant species. Our assessment showed that plants with most of the MADS box member studies included tomato, apple, and rice after Arabidopsis. Furthermore, based on the degree of their multi-trait associations, FLC , SVP , and SOC1 are suggested to have relatively higher pleiotropic potential among others in plant growth, development, and flowering processes. The approach devised in this study is expected to be applicable for a basic understanding of any study subject of interest, regardless of the depth of prior knowledge.

Plants consist of fundamental units of growth called phytomers (leaf or bract, axillary bud, node, and internode), which are repeated and modified throughout shoot development to give plants plasticity for survival and adaptation. One phytomer modification is the suppression or outgrowth of bracts, the leaves subtending the flowers. The floral meristem identity regulator LEAFY (LFY) and the organ boundary genes BLADE-ON-PETIOLE1 (BOP1) and BOP2 have been shown to suppress bract development in Arabidopsis, as mutations in these genes result in bract outgrowth. However, much less is known about the mechanisms that promote bract outgrowth in Arabidopsis mutants such as these. Further understanding of this mechanism may provide a potential tool for modifying leaf development. Here, we showed that the MADS-box genes SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1), FRUITFUL (FUL), and AGAMOUS-LIKE24 (AGL24) play more important roles than BOP1/2 and LFY in bract suppression, and that AINTEGUMENTA (ANT) and the partially redundant AINTEGUMENTA-LIKE6 (AIL6) are necessary for bract outgrowth in these mutant backgrounds. We also demonstrated that misexpression of AIL6 alone is sufficient for bract outgrowth. Our data reveal a mechanism for bract suppression and outgrowth and provide insight into phytomer plasticity., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Proper timing of flowering under different environmental conditions is critical for plant propagation. Light quality is a pivotal environmental cue that plays a critical role in flowering regulation. Plants tend to flower late under light with a high red (R)/far-red (FR) light ratio but early under light with a low R/FR light ratio. However, how plants fine-tune flowering in response to changes in light quality is not well understood. Here, we demonstrate that F-box of Flowering 2 (FOF2), an autonomous pathway-related regulator, physically interacts with VASCULAR PLANT ONE-ZINC FINGER 1 and 2 (VOZ1 and VOZ2), which are direct downstream factors of the R/FR light receptor phytochrome B (PHYB). We show that PHYB physically interacts with FOF2, mediates stabilization of the FOF2 protein under FR light and end-of-day FR light, and enhances FOF2 binding to VOZ2, which leads to degradation of VOZ2 by SCF FOF2 E3 ligase. By contrast, PHYB mediates degradation of FOF2 protein under R light and end-of-day R light. Genetic interaction studies demonstrated that FOF2 functions downstream of PHYB to promote FLC expression and inhibit flowering under both high R/FR light and simulated shade conditions, processes that are partially dependent on VOZ proteins. Taken together, our findings suggest a novel mechanism whereby plants fine-tune flowering time through a PHYB-FOF2-VOZ2 module that modulates FLC expression in response to changes in light quality., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The MADS-box gene family is widely distributed in the plant kingdom, and its members typically encoding transcription factors to regulate various aspects of plant growth and development. In particular, the MIKC-type MADS-box genes play a crucial role in the determination of floral organ development and identity recognition. As a type of androdioecy plant, Chionanthus retusus have unique gender differentiation. Manifested as male individuals with only male flowers and female individuals with only bisexual flowers. However, due to the lack of reference genome information, the characteristics of MIKC-type MADS-box genes in C. retusus and its role in gender differentiation of C. retusus remain largely unknown. Therefore, it is necessary to identify and characterize the MADS-box gene family within the genome of the C. retusus., Results: In this study, we performed a genome-wide identification and analysis of MIKC-type MADS-box genes in C. retusus (2n = 2x = 46), utilizing the latest reference genome, and studied its expression pattern in individuals of different genders. As a result, we identified a total of 61 MIKC-type MADS-box genes in C. retusus. 61 MIKC-type MADS-box genes can be divided into 12 subfamilies and distributed on 18 chromosomes. Genome collinearity analysis revealed their conservation in evolution, while gene structure, domains and motif analysis indicated their conservation in structure. Finally, based on their expression patterns in floral organs of different sexes, we have identified that CrMADS45 and CrMADS60 may potentially be involved in the gender differentiation of C. retusus., Conclusions: Our studies have provided a general understanding of the conservation and characteristics of the MIKC-type MADS-box genes family in C. retusus. And it has been demonstrated that members of the AG subfamily, CrMADS45 and CrMADS60, may play important roles in the gender differentiation of C. retusus. This provides a reference for future breeding efforts to improve flower types in C. retusus and further investigate the role of MIKC-type MADS-box genes in gender differentiation., (© 2024. The Author(s).)

The development of floral organs, crucial for the establishment of floral symmetry and morphology in higher plants, is regulated by MADS-box genes. In sunflower, the capitulum is comprised of ray and disc florets with various floral organs. In the sunflower long petal mutant ( lpm ), the abnormal disc (ray-like) floret possesses prolongated petals and degenerated stamens, resulting in a transformation from zygomorphic to actinomorphic symmetry. In this study, we investigated the effect of MADS-box genes on floral organs, particularly on petals, using WT and lpm plants as materials. Based on our RNA-seq data, 29 MADS-box candidate genes were identified, and their roles on floral organ development, especially in petals, were explored, by analyzing the expression levels in various tissues in WT and lpm plants through RNA-sequencing and qPCR. The results suggested that HaMADS3 , HaMADS7 , and HaMADS8 could regulate petal development in sunflower. High levels of HaMADS3 that relieved the inhibition of cell proliferation, together with low levels of HaMADS7 and HaMADS8 , promoted petal prolongation and maintained the morphology of ray florets. In contrast, low levels of HaMADS3 and high levels of HaMADS7 and HaMADS8 repressed petal extension and maintained the morphology of disc florets. Their coordination may contribute to the differentiation of disc and ray florets in sunflower and maintain the balance between attracting pollinators and producing offspring. Meanwhile, Pearson correlation analysis between petal length and expression levels of MADS-box genes further indicated their involvement in petal prolongation. Additionally, the analysis of cis -acting elements indicated that these three MADS-box genes may regulate petal development and floral symmetry establishment by regulating the expression activity of HaCYC2c . Our findings can provide some new understanding of the molecular regulatory network of petal development and floral morphology formation, as well as the differentiation of disc and ray florets in sunflower., Competing Interests: The authors declare that they have no competing interests., (© 2024 Wang et al.)

MADS-box genes are known to play important roles in diverse aspects of growth/devolopment and stress response in several plant species. However, no study has yet examined about MADS-box genes in P. vulgaris. In this study, a total of 79 PvMADS genes were identified and classified as type I and type II according to the phylogenetic analysis. While both type I and type II PvMADS classes were found to contain the MADS domain, the K domain was found to be present only in type II PvMADS proteins, in agreement with the literature. All chromosomes of the common bean were discovered to contain PvMADS genes and 17 paralogous gene pairs were identified. Only two of them were tandemly duplicated gene pairs (PvMADS-19/PvMADS-23 and PvMADS-20/PvMADS-24), and the remaining 15 paralogous gene pairs were segmentally duplicated genes. These duplications were found to play an important role in the expansion of type II PvMADS genes. Moreover, the RNAseq and RT-qPCR analyses showed the importance of PvMADS genes in response to drought stress in P. vulgaris., (© 2024. The Author(s).)

Spatiotemporal regulation of gene expression by polycomb repressive complex 2 (PRC2) is critical for animal and plant development. The Arabidopsis fertilization independent seed (FIS)-PRC2 complex functions specifically during plant reproduction from gametogenesis to seed development. After a double fertilization event, triploid endosperm proliferates early, followed by the growth of a diploid embryo, which replaces the endosperm in Arabidopsis and many dicots. Key genes critical for endosperm proliferation such as IKU2 and MINI3 are activated after fertilization. Here we report that two MADS-box AGAMOUS-LIKE (AGL) proteins associate with the key endosperm proliferation loci and recruit the FIS-PRC2 repressive complex at 4-5 days after pollination (DAP). Interestingly, AGL9 and AGL15 only accumulate toward the end of endosperm proliferation at 4-5 DAP and promote the deposition of H3K27me3 marks at key endosperm proliferation loci. Disruption of AGL9 and AGL15 or overexpression of AGL9 or AGL15 significantly influence endosperm proliferation and cellularization. Genome-wide analysis with cleavage Under Targets and tagmentation (CUT&Tag) sequencing and RNA sequencing revealed the landscape of endosperm H3K27me3 marks and gene expression profiles in Col-0 and agl9 agl15. CUT&Tag qPCR also demonstrated the occupancy of the two MADS-box proteins and FIS-PRC2 on a few representative target loci. Our studies suggest that MADS-box proteins could potentially recruit PRC2 to regulate many other developmental processes in plants or even in fungi and animals., (Copyright © 2024 The Author. Published by Elsevier Inc. All rights reserved.)

Cellular behavior, cell differentiation and ontogenetic development in eukaryotes result from complex interactions between epigenetic and classic molecular genetic mechanisms, with many of these interactions still to be elucidated. Histone deacetylase enzymes (HDACs) promote the interaction of histones with DNA by compacting the nucleosome, thus causing transcriptional repression. MADS-domain transcription factors are highly conserved in eukaryotes and participate in controlling diverse developmental processes in animals and plants, as well as regulating stress responses in plants. In this work, we focused on finding out putative interactions of Arabidopsis thaliana HDACs and MADS-domain proteins using an evolutionary perspective combined with bioinformatics analyses and testing the more promising predicted interactions through classic molecular biology tools. Through bioinformatic analyses, we found similarities between HDACs proteins from different organisms, which allowed us to predict a putative protein-protein interaction between the Arabidopsis thaliana deacetylase HDA15 and the MADS-domain protein XAANTAL1 (XAL1). The results of two-hybrid and Bimolecular Fluorescence Complementation analysis demonstrated in vitro and in vivo HDA15-XAL1 interaction in the nucleus. Likely, this interaction might regulate developmental processes in plants as is the case for this type of interaction in animals.

Adjusting the timing of floral transition is essential for reproductive success in plants. A number of flowering regulators integrate internal and external signals to precisely determine the time to flower. We here report that the AGAMOUS-LIKE 6 (AGL6) - EARLY FLOWERING 3 (ELF3) module regulates flowering in the FLOWERING LOCUS T (FT)-dependent pathway in Arabidopsis . The AGL6 transcriptional repressor promotes floral transition by directly suppressing ELF3 , which in turn directly represses FT expression that acts as a floral integrator. Indeed, ELF3 is epistatic to AGL6 in the control of floral transition. Overall, our findings propose that the AGL6-ELF3 module contributes to fine-tuning flowering time in plants.

High temperature (HT) is an environmental factor that considerably affects plant physiology, development, crop yield, and economic value. HT can cause diseases and early bolting of leaf lettuce, thereby reducing the yield and quality of leaf lettuce. Herein, we used two leaf lettuce (Lactuca sativa L.) cultivars (bolting-resistant 'S24' and bolting-sensitive 'S39') to investigate the key factors and molecular mechanism impacting bolting. We found that 14 MADS-box genes implicated in bolting and flowering, LsMADS54 (also referred to as L. sativa FRUITFULL, LsFUL), was significantly up-regulated 1000 times after 5-d HT treatment and that HT-induced up-regulation of LsFUL was higher in bolting-sensitive than in resistant cultivars. The overexpression lines of LsFUL exhibited an earlier bolting time than that in the non-transformed 'S39'(CK). However, the RNA interference, and CRISPR-Cas9-mediated knockout lines of LsFUL exhibited a later bolting time than that in CK. In addition, we found that L. sativa SUPPRESSORS OF MEC-8 AND UNC-52 PROTEIN 2 (LsSMU2) and L. sativa CONSTANS-LIKE PROTEIN 5 (LsCOL5) interact with LsFUL, and these interactions could stimulate or prevent bolting. We observed that elevated temperature stimulated the abundance of LsSMU2 in the stem, which collaborated with LsFUL to accelerate bolting. Conversely, room temperature (RT) condition led to relatively more stable LsCOL5, which worked with LsFUL to postpone bolting. In summary, our findings demonstrate a molecular regulatory module of LsSMU2-LsFUL associated with HT-induced premature bolting, which serves as a reference for understanding HT-induced premature bolting phenomenon in leaf lettuce., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024. Published by Elsevier B.V.)

Fragaria chiloensis is a Chilean native species that softens intensively during its ripening. Its softening is related to cell wall disassembly due to the participation of cell wall degrading enzymes. Softening of F. chiloensis fruit can be accelerated by ABA treatment which is accompanied by the increment in the expression of key cell wall degrading genes, however the molecular machinery involved in the transcriptional regulation has not been studied until now. Therefore, the participation of two MADS-box transcription factors belonging to different subfamilies, FchAGL9 and FchSHP, was addressed. Both TFs are members of type-II MADS-box family (MIKC-type) and localized in the nucleus. FchAGL9 and FchSHP are expressed only in flower and fruit tissues, rising as the fruit softens with the highest expression level at C3-C4 stages. EMSA assays demonstrated that FchAGL9 binds to CArG sequences of RIN and SQM, meanwhile FchSHP interacts only with RIN. Bimolecular fluorescence complementation and yeast two-hybrid assays confirmed FchAGL9-FchAGL9 and FchAGL9-FchSHP interactions. Hetero-dimer structure was built through homology modeling concluding that FchSHP monomer binds to DNA. Functional validation by Luciferase-dual assays indicated that FchAGL9 transactivates FchRGL and FchPG's promoters, meanwhile FchSHP transactivates those of FchEXP2, FchRGL and FchPG. Over-expression of FchAGL9 in C2 F. chiloensis fruit rises FchEXP2 and FchEXP5 transcripts, meanwhile the over-expression of FchSHP also increments FchXTH1 and FchPL; in both cases there is a down-regulation of FchRGL and FchPG. In summary, we provided evidence of FchAGL9 and FchSHP participating in the transcription regulation associated to F. chiloensis's softening., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

A novel MADS-box transcription factor from Pinus radiata D. Don was characterized. PrMADS11 encodes a protein of 165 amino acids for a MADS-box transcription factor belonging to group II, related to the MIKC protein structure. PrMADS11 was differentially expressed in the stems of pine trees in response to 45° inclination at early times (1 h) . Arabidopsis thaliana was stably transformed with a 35S::PrMADS11 construct in an effort to identify the putative targets of PrMADS11 . A massive transcriptome analysis revealed 947 differentially expressed genes: 498 genes were up-regulated, and 449 genes were down-regulated due to the over-expression of PrMADS11 . The gene ontology analysis highlighted a cell wall remodeling function among the differentially expressed genes, suggesting the active participation of cell wall modification required during the response to vertical stem loss. In addition, the phenylpropanoid pathway was also indicated as a PrMADS11 target, displaying a marked increment in the expression of the genes driven to the biosynthesis of monolignols. The EMSA assays confirmed that PrMADS11 interacts with CArG-box sequences. This TF modulates the gene expression of several molecular pathways, including other TFs, as well as the genes involved in cell wall remodeling. The increment in the lignin content and the genes involved in cell wall dynamics could be an indication of the key role of PrMADS11 in the response to trunk inclination.

The mechanisms and timescales controlling de novo establishment of chromatin-mediated transcriptional silencing by Polycomb repressive complex 2 (PRC2) are unclear. Here, we investigate PRC2 silencing at Arabidopsis FLOWERING LOCUS C (FLC), known to involve co-transcriptional RNA processing, histone demethylation activity, and PRC2 function, but so far not mechanistically connected. We develop and test a computational model describing proximal polyadenylation/termination mediated by the RNA-binding protein FCA that induces H3K4me1 removal by the histone demethylase FLD. H3K4me1 removal feeds back to reduce RNA polymerase II (RNA Pol II) processivity and thus enhance early termination, thereby repressing productive transcription. The model predicts that this transcription-coupled repression controls the level of transcriptional antagonism to PRC2 action. Thus, the effectiveness of this repression dictates the timescale for establishment of PRC2/H3K27me3 silencing. We experimentally validate these mechanistic model predictions, revealing that co-transcriptional processing sets the level of productive transcription at the locus, which then determines the rate of the ON-to-OFF switch to PRC2 silencing., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

The interconnections between co-transcriptional regulation, chromatin environment, and transcriptional output remain poorly understood. Here, we investigate the mechanism underlying RNA 3' processing-mediated Polycomb silencing of Arabidopsis FLOWERING LOCUS C (FLC). We show a requirement for ANTHESIS PROMOTING FACTOR 1 (APRF1), a homolog of yeast Swd2 and human WDR82, known to regulate RNA polymerase II (RNA Pol II) during transcription termination. APRF1 interacts with TYPE ONE SERINE/THREONINE PROTEIN PHOSPHATASE 4 (TOPP4) (yeast Glc7/human PP1) and LUMINIDEPENDENS (LD), the latter showing structural features found in Ref2/PNUTS, all components of the yeast and human phosphatase module of the CPF 3' end-processing machinery. LD has been shown to co-associate in vivo with the histone H3 K4 demethylase FLOWERING LOCUS D (FLD). This work shows how the APRF1/LD-mediated polyadenylation/termination process influences subsequent rounds of transcription by changing the local chromatin environment at FLC., Competing Interests: Declaration of interests L.A.P. is on the advisory board for Molecular Cell., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

The development of perennial crops holds great promise for sustainable agriculture and food security. However, the evolution of the transition between perenniality and annuality is poorly understood. Here, using two Brassicaceae species, Crucihimalaya himalaica and Erysimum nevadense, as polycarpic perennial models, we reveal that the transition from polycarpic perennial to biennial and annual flowering behavior is a continuum determined by the dosage of three closely related MADS-box genes. Diversification of the expression patterns, functional strengths, and combinations of these genes endows species with the potential to adopt various life-history strategies. Remarkably, we find that a single gene among these three is sufficient to convert winter-annual or annual Brassicaceae plants into polycarpic perennial flowering plants. Our work delineates a genetic basis for the evolution of diverse life-history strategies in plants and lays the groundwork for the generation of diverse perennial Brassicaceae crops in the future., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Basic helix-loop-helix (bHLH) transcription factors play various important roles in plant growth and development. In this study, a AabHLH48 was identified in the floral organ of Adonis amurensis, a perennial herb that can naturally complete flowering at extreme low temperatures. AabHLH48 was widely expressed in various tissues or organs of A. amurensis and was localized in the nucleus. Overexpression of AabHLH48 promotes early flowering in Arabidopsis under both photoperiod (12 h light/12 h dark and 16 h light/8 h dark) and temperature (22 and 18 °C) conditions. Transcriptome sequencing combined with quantitative real-time PCR analysis showed that overexpression of AabHLH48 caused a general upregulation of genes involved in floral development in Arabidopsis, especially for AtAGAMOUS-LIKE 8/FRUITFULL (AtAGL8/FUL). The yeast one-hybrid assay revealed that AabHLH48 has transcriptional activating activity and can directly bind to the promoter region of AtAGL8/FUL. These results suggest that the overexpression of AabHLH48 promoting early flowering in Arabidopsis is associated with the upregulated expression of AtAGL8/FUL activated by AabHLH48. This indicates that AabHLH48 can serve as an important genetic resource for improving flowering-time control in other ornamental plants or crops., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Histone 2B ubiquitination (H2Bub) and trimethylation of H3 at lysine 4 (H3K4me3) are associated with transcription activation. However, the function of these modifications in transcription in plants remains largely unknown. Here, we report that coordination of H2Bub and H3K4me3 deposition with the binding of the RNA polymerase-associated factor VERNALIZATION INDEPENDENCE2 (VIP2) to FLOWERING LOCUS C (FLC) modulates flowering time in Arabidopsis. We found that RING domain protein HISTONE MONOUBIQUITINATION1 (HUB1) and HUB2 (we refer as HUB1/2), which are responsible for H2Bub, interact with ARABIDOPSIS TRITHORAX1 (ATX1), which is required for H3K4me3 deposition, to promote the transcription of FLC and repress the flowering time. The atx1-2 hub1-10 hub2-2 triple mutant in FRIGIDIA (FRI) background displayed early flowering like FRI hub1-10 hub2-2 and overexpression of ATX1 failed to rescue the early flowering phenotype of hub1-10 hub2-2. Mutations in HUB1 and HUB2 reduced the ATX1 enrichment at FLC, indicating that HUB1 and HUB2 are required for ATX1 recruitment and H3K4me3 deposition at FLC. We also found that the VIP2 directly binds to HUB1, HUB2, and ATX1 and that loss of VIP2 in FRI hub1-10 hub2-2 and FRI atx1-2 plants resulted in early flowering like that observed in FRI vip2-10. Loss of function of HUB2 and ATX1 impaired VIP2 enrichment at FLC, and reduced the transcription initiation and elongation of FLC. In addition, mutations in VIP2 reduced HUB1 and ATX1 enrichment and H2Bub and H3K4me3 levels at FLC. Together, our findings revealed that HUB1/2, ATX1, and VIP2 coordinately modulate H2Bub and H3K4me3 deposition, FLC transcription, and flowering time., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

The petals of rose (Rosa sp.) flowers determine the ornamental and industrial worth of this species. The number of petals in roses was previously shown to be subject to fluctuations in ambient temperature. However, the mechanisms by which rose detects and responds to temperature changes are not entirely understood. In this study, we identified short interstitial telomere motifs (telo boxes) in the second intron of AGAMOUS (RcAG) from China rose (Rosa chinensis) that play an essential role in precise temperature perception. The second intron of RcAG harbors two telo boxes that recruit telomere repeat binding factors (RcTRBs), which interact with CURLY LEAF (RcCLF) to compose a repressor complex. We show that this complex suppresses RcAG expression when plants are subjected to low temperatures via depositing H3K27me3 marks (trimethylation of lysine 27 on histone H3) over the RcAG gene body. This regulatory mechanism explains the low-temperature-dependent decrease in RcAG transcript levels, leading to the production of more petals under these conditions. Our results underscore an interesting intron-mediated regulatory mechanism governing RcAG expression, enabling rose plants to perceive temperature cues and establish petal numbers., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

The plant MADS-box transcription factor family is a major regulator of plant flower development and reproduction, and the AGAMOUS-LIKE11/SEEDSTICK (AGL11/STK) subfamily plays conserved functions in the seed development of flowering plants. Camellia japonica is a world-famous ornamental flower, and its seed kernels are rich in highly valuable fatty acids. Seed abortion has been found to be common in C. japonica , but little is known about how it is regulated during seed development. In this study, we performed a genome-wide analysis of the MADS-box gene the in C. japonica genome and identified 126 MADS-box genes. Through gene expression profiling in various tissue types, we revealed the C/D-class MADS-box genes were preferentially expressed in seed-related tissues. We identified the AGL11/STK-like gene, CjSTK , and showed that it contained a typical STK motif and exclusively expressed during seed development. We found a significant increase in the CjSTK expression level in aborted seeds compared with normally developing seeds. Furthermore, overexpression of CjSTK in Arabidopsis thaliana caused shorter pods and smaller seeds. Taken together, we concluded that the fine regulation of the CjSTK expression at different stages of seed development is critical for ovule formation and seed abortion in C. japonica . The present study provides evidence revealing the regulation of seed development in Camellia .

Main Conclusion: TaAGL66, a MADS-box transcription factor highly expressed in fertile anthers of KTM3315A, regulates anther and/or pollen development, as well as male fertility in wheat with Aegilops kotschyi cytoplasm. Male sterility, as a string of sophisticated biological processes in higher plants, is commonly regulated by transcription factors (TFs). Among them, MADS-box TFs are mainly participated in the processes of floral organ formation and pollen development, which are tightly related to male sterility, but they have been little studied in the reproductive development in wheat. In our study, TaAGL66, a gene that was specifically expressed in spikes and highly expressed in fertile anthers, was identified by RNA sequencing and the expression profiles data of these genes, and qRT-PCR analyses, which was localized to the nucleus. Silencing of TaAGL66 under fertility condition in KTM3315A, a thermo-sensitive male sterile line with Ae. kotschyi cytoplasm, displayed severe fertility reduction, abnormal anther dehiscence, defective pollen development, decreased viability, and low seed-setting. It can be concluded that TaAGL66 plays an important role in wheat pollen development in the presence of Ae. kotschyi cytoplasm, providing new insights into the utilization of male sterility., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Cellular mRNA levels, particularly under stress conditions, can be finely regulated by the coordinated action of transcription and degradation processes. Elements of the 5'-3' mRNA degradation pathway, functionally associated with the exonuclease Xrn1, can bind to nuclear chromatin and modulate gene transcription. Within this group are the so-called decapping activators, including Pat1, Dhh1, and Lsm1. In this work, we have investigated the role of Pat1 in the yeast adaptive transcriptional response to cell wall stress. Thus, we demonstrated that in the absence of Pat1, the transcriptional induction of genes regulated by the Cell Wall Integrity MAPK pathway was significantly affected, with no effect on the stability of these transcripts. Furthermore, under cell wall stress conditions, Pat1 is recruited to Cell Wall Integrity-responsive genes in parallel with the RNA Pol II complex, participating both in pre-initiation complex assembly and transcriptional elongation. Indeed, strains lacking Pat1 showed lower recruitment of the transcription factor Rlm1, less histone H3 displacement at Cell Wall Integrity gene promoters, and impaired recruitment and progression of RNA Pol II. Moreover, Pat1 and the MAPK Slt2 occupied the coding regions interdependently. Our results support the idea that Pat1 and presumably other decay factors behave as transcriptional regulators of Cell Wall Integrity-responsive genes under cell wall stress conditions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The MADS-box gene family is a transcription factor family that is widely expressed in plants. It controls secondary metabolic processes in plants and encourages the development of tissues like roots and flowers. However, the phylogenetic analysis and evolutionary model of MADS-box genes in Fagopyrum species has not been reported yet. This study identified the MADS-box genes of three buckwheat species at the whole genome level, and conducted systematic evolution and physicochemical analysis. The results showed that these genes can be divided into four subfamilies, with fragment duplication being the main way for the gene family expansion. During the domestication process from golden buckwheat to tartary buckwheat and the common buckwheat, the Ka/Ks ratio indicated that most members of the family experienced strong purification selection pressure, and with individual gene pairs experiencing positive selection. In addition, we combined the expression profile data of the MADS genes, mGWAS data, and WGCNA data to mine genes FdMADS28/48/50 that may be related to flavonoid metabolism. The results also showed that overexpression of FdMADS28 could increase rutin content by decreasing Kaempferol pathway content in hairy roots, and increase the resistance and growth of hairy roots to PEG and NaCl. This study systematically analyzed the evolutionary relationship of MADS-box genes in the buckwheat species, and elaborated on the expression patterns of MADS genes in different tissues under biotic and abiotic stresses, laying an important theoretical foundation for further elucidating their role in flavonoid metabolism., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Areca catechu L., a monocot belonging to the palm family, is monoecious, with female and male flowers separately distributed on the same inflorescence. To discover the molecular mechanism of flower development in Areca, we sequenced different floral samples to generate tissue-specific transcriptomic profiles. We conducted a comparative analysis of the transcriptomic profiles of apical sections of the inflorescence with male flowers and the basal section of the inflorescence with female flowers. Based on the RNA sequencing dataset, we applied weighted gene co-expression network analysis (WGCNA) to identify sepal, petal, stamen, stigma and other specific modules as well as hub genes involved in specific floral organ development. The syntenic and expression patterns of AcMADS-box genes were analyzed in detail. Furthermore, we analyzed the open chromatin regions and transcription factor PI binding sites in male and female flowers by assay for transposase-accessible chromatin sequencing (ATAC-seq) assay. Heterologous expression revealed the important role of AcMADS17 and AcMADS23 in floral organ development. Our results provide a valuable genomic resource for the functional analysis of floral organ development in Areca., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Many plant populations exhibit synchronous flowering, which can be advantageous in plant reproduction. However, molecular mechanisms underlying flowering synchrony remain poorly understood. We studied the role of known vernalization-response and flower-promoting pathways in facilitating synchronized flowering in Arabidopsis thaliana. Using the vernalization-responsive Col-FRI genotype, we experimentally varied germination dates and daylength among individuals to test flowering synchrony in field and controlled environments. We assessed the activity of flowering regulation pathways by measuring gene expression across leaves produced at different time points during development and through a mutant analysis. We observed flowering synchrony across germination cohorts in both environments and discovered a previously unknown process where flower-promoting and repressing signals are differentially regulated between leaves that developed under different environmental conditions. We hypothesized this mechanism may underlie synchronization. However, our experiments demonstrated that signals originating from sources other than leaves must also play a pivotal role in synchronizing flowering time, especially in germination cohorts with prolonged growth before vernalization. Our results suggest flowering synchrony is promoted by a plant-wide integration of flowering signals across leaves and among organs. To summarize our findings, we propose a new conceptual model of vernalization-induced flowering synchrony and provide suggestions for future research in this field., (© 2024 The Authors. New Phytologist © 2024 New Phytologist Foundation.)

Brassica juncea (mustard) is a vegetable crop of Brassica , which is widely planted in China. The yield and quality of stem mustard are greatly influenced by the transition from vegetative growth to reproductive growth, i.e., flowering. The WRKY transcription factor family is ubiquitous in higher plants, and its members are involved in the regulation of many growth and development processes, including biological/abiotic stress responses and flowering regulation. WRKY71 is an important member of the WRKY family. However, its function and mechanism in mustard have not been reported. In this study, the BjuWRKY71-1 gene was cloned from B . juncea . Bioinformatics analysis and phylogenetic tree analysis showed that the protein encoded by BjuWRKY71-1 has a conserved WRKY domain, belonging to class Ⅱ WRKY protein, which is closely related to BraWRKY71-1 in Brassica rapa . The expression abundance of BjuWRKY71-1 in leaves and flowers was significantly higher than that in roots and stems, and the expression level increased gradually along with plant development. The result of subcellular localization showed that BjuWRKY71-1 protein was located in nucleus. The flowering time of overexpressing BjuWRKY71-1 Arabidopsis plants was significantly earlier than that of the wild type. Yeast two-hybrid assay and dual-luciferase reporter assay showed that BjuWRKY71-1 interacted with the promoter of the flowering integrator BjuSOC1 and promoted the expression of its downstream genes. In conclusion, BjuWRKY71-1 protein can directly target BjuSOC1 to promote plant flowering. This discovery may facilitate further clarifying the molecular mechanism of BjuWRKY71-1 in flowering time control, and creating new germplasm with bolting and flowering tolerance in mustard.

Monocarpic plants have a single reproductive phase in their life. Therefore, flower and fruit production are restricted to the length of this period. This reproductive strategy involves the regulation of flowering cessation by a coordinated arrest of the growth of the inflorescence meristems, optimizing resource allocation to ensure seed filling. Flowering cessation appears to be a regulated phenomenon in all monocarpic plants. Early studies in several species identified seed production as a major factor triggering inflorescence proliferative arrest. Recently, genetic factors controlling inflorescence arrest, in parallel to the putative signals elicited by seed production, have started to be uncovered in Arabidopsis, with the MADS-box gene FRUITFULL (FUL) playing a central role in the process. However, whether the genetic network regulating arrest is also at play in other species is completely unknown. Here, we show that this role of FUL is not restricted to Arabidopsis but is conserved in another monocarpic species with a different inflorescence structure, field pea, strongly suggesting that the network controlling the end of flowering is common to other plants. Moreover, field trials with lines carrying mutations in pea FUL genes show that they could be used to boost crop yield., Competing Interests: Competing interests statement:The authors declare no competing interest.

Competing Interests: Conflict of interest statement: None declared.

Background: Proper flowering time is important for the growth and development of plants, and both too early and too late flowering impose strong negative influences on plant adaptation and seed yield. Thus, it is vitally important to study the mechanism underlying flowering time control in plants. In a previous study by the authors, genome-wide association analysis was used to screen the candidate gene SISTER OF FCA (SSF) that regulates FLOWERING LOCUS C (FLC), a central gene encoding a flowering suppressor in Arabidopsis thaliana., Results: SSF physically interacts with Protein arginine methyltransferase 5 (PRMT5, SKB1). Subcellular co-localization analysis showed that SSF and SKB1 interact in the nucleus. Genetically, SSF and SKB1 exist in the same regulatory pathway that controls FLC expression. Furthermore, RNA-sequencing analysis showed that both SSF and SKB1 regulate certain common pathways., Conclusions: This study shows that PRMT5 interacts with SSF, thus controlling FLC expression and facilitating flowering time control., (© 2024. The Author(s).)

The members of MADS-box gene family have important roles in regulating the growth and development of plants. MADS-box genes are highly regarded for their potential to enhance grain yield and quality under shifting global conditions. Wild emmer wheat (Triticum turgidum subsp. dicoccoides) is a progenitor of common wheat and harbors valuable traits for wheat improvement. Here, a total of 117 MADS-box genes were identified in the wild emmer wheat genome and classified to 90 MIKCC, 3 MIKC*, and 24 M-type. Furthermore, a phylogenetic analysis and expression profiling of the emmer wheat MADS-box gene family was presented. Although some MADS-box genes belonging to SOC1, SEP1, AGL17, and FLC groups have been expanded in wild emmer wheat, the number of MIKC-type MADS-box genes per subgenome is similar to that of rice and Arabidopsis. On the other hand, M-type genes of wild emmer wheat is less frequent than that of Arabidopsis. Gene expression patterns over different tissues and developmental stages agreed with the subfamily classification of MADS-box genes and was similar to common wheat and rice, indicating their conserved functionality. Some TdMADS-box genes are also differentially expressed under drought stress. The promoter region of each of the TdMADS-box genes harbored 6 to 48 responsive elements, mainly related to light, however hormone, drought, and low-temperature related cis-acting elements were also present. In conclusion, the results provide detailed information about the MADS-box genes of wild emmer wheat. The present work could be useful in the functional genomics efforts toward breeding for agronomically important traits in T. dicoccoides., Competing Interests: The author have declared that no competing interests exist., (Copyright: © 2024 Ghader Mirzaghaderi. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The AGL6 (AGMOUSE LIKE 6) gene is a member of the SEP subfamily and functions as an E-class floral homeotic gene in the development of floral organs. In this study, we cloned IiAGL6, the orthologous gene of AGL6 in Isatis indigotica. The constitutive expression of IiAGL6 in Arabidopsis thaliana resulted in a late-flowering phenotype and the development of curly leaves during the vegetative growth period. Abnormal changes in floral organ development were observed during the reproductive stage. In woad plants, suppression of IiAGL6 using TRV-VIGS (tobacco rattle virus-mediated virus-induced gene silencing) decreased the number of stamens and led to the formation of aberrant anthers. Similar changes in stamen development were also observed in miRNA-AGL6 transgenic Arabidopsis plants. Yeast two-hybrid and BiFC tests showed that IiAGL6 can interact with other MADS-box proteins in woad; thus, playing a key role in defining the identities of floral organs, particularly during stamen formation. These findings might provide novel insights and help investigate the biological roles of MADS transcription factors in I. indigotica., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The tomato (Solanum lycopersicum) ripening inhibitor (rin) mutation is known to completely repress fruit ripening. The heterozygous (RIN/rin) fruits have extended shelf life, ripen normally, but have inferior taste/flavour. To address this, we used genome editing to generate newer alleles of RIN (rin CR ) by targeting the K-domain. Unlike previously reported CRISPR alleles, the rin CR alleles displayed delayed onset of ripening, suggesting that the mutated K-domain represses the onset of ripening. The rin CR fruits had extended shelf life and accumulated carotenoids at an intermediate level between rin and progenitor line. Besides, the metabolites and hormonal levels in rin CR fruits were more akin to rin. To overcome the negative attributes of rin, we crossed the rin CR alleles with Nps1, a dominant-negative phototropin1 mutant, which enhances carotenoid levels in tomato fruits. The resulting Nps1/rin CR hybrids had extended shelf life and 4.4-7.1-fold higher carotenoid levels than the wild-type parent. The metabolome of Nps1/rin CR fruits revealed higher sucrose, malate, and volatiles associated with tomato taste and flavour. Notably, the boosted volatiles in Nps1/rin CR were only observed in fruits bearing the homozygous Nps1 mutation. The Nps1 introgression into tomato provides a promising strategy for developing cultivars with extended shelf life, improved taste, and flavour., (© 2023 The Authors. New Phytologist © 2023 New Phytologist Foundation.)

The MADS-box gene family controls plant flowering and floral organ development; therefore, it is particularly important in ornamental plants. To investigate the genes associated with the MADS-box family in Clematis courtoisii, we performed full-length transcriptome sequencing on C. courtoisii using the PacBio Sequel third-generation sequencing platform, as no reference genome data was available. A total of 12.38 Gb of data, containing 9,476,585 subreads and 50,439 Unigenes were obtained. According to functional annotation, a total of 37,923 Unigenes (75.18% of the total) were assigned with functional annotations, and 50 Unigenes were identified as MADS-box related genes. Subsequently, we employed hmmerscan to perform protein sequence similarity search for the translated Unigene sequences and successfully identified 19 Unigenes associated with the MADS-box gene family, including MIKC*(1) and MIKCC (18) genes. Furthermore, within the MIKCC group, six subclasses can be further distinguished., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Chen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Identification and understanding of the genetic basis of natural variations in plants are essential for comprehending their phenotypic adaptation. Here, we report a genome-wide association study (GWAS) of FLOWERING LOCUS C (FLC) expression in 727 Arabidopsis accessions. We identified B LYMPHOMA MOLONEY MURINE LEUKEMIA VIRUS INSERTION REGION 1 HOMOLOG 1A (BMI1A) as a causal gene for one of the FLC expression quantitative trait loci (QTLs). Loss of function in BMI1A increases FLC expression and delays flowering time at 16 °C significantly compared with the wild type (Col-0). BMI1A activity is required for histone H3 lysine 27 trimethylation (H3K27me3) accumulation at the FLC, MADS AFFECTING FLOWERING 4 (MAF4), and MAF5 loci at low ambient temperature. We further uncovered two BMI1A haplotypes associated with the natural variation in FLC expression and flowering time at 16 °C, and demonstrated that polymorphisms in the BMI1A promoter region are the main contributor. Different BMI1A haplotypes are strongly associated with geographical distribution, and the low ambient temperature-sensitive BMI1A variants are associated with a lower mean temperature of the driest quarter of their collection sites compared with the temperature-non-responsive variants, indicating that the natural variations in BMI1A have adaptive functions in FLC expression and flowering time regulation. Therefore, our results provide new insights into the natural variations in FLC expression and flowering time diversity in plants., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The transition from vegetative to reproductive growth, known as flowering, is a critical developmental process in flowering plants to ensure reproductive success. This process is strictly controlled by various internal and external cues; however, the underlying molecular regulatory mechanisms need to be further characterized. Here, we report a plant-specific protein, FCS-LIKE ZINC FINGER PROTEIN 13 (FLZ13), which functions as a hitherto unknown negative modulator of flowering time in Arabidopsis thaliana. Biochemical analysis showed that FLZ13 directly interacts with FLOWERING LOCUS C (FLC), a major flowering repressor, and that FLZ13 largely depends on FLC to repress the transcription of two core flowering integrators: FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1. In addition, FLZ13 works together with ABSCISIC ACID INSENSITIVE 5 to activate FLC expression to delay flowering. Taken together, our findings suggest that FLZ13 is an important component of the gene regulatory network for flowering time control in plants., (© 2023 The Authors. New Phytologist © 2023 New Phytologist Foundation.)

The MADS-box protein is an important transcription factor in plants and plays an important role in regulating the plant abiotic stress response. In this study, a total of 94 MADS-box genes were predicted in the litchi genome, and these genes were widely distributed on all the chromosomes. The LcMADS-box gene family was divided into six subgroups (Mα, Mβ, Mγ, Mδ, MIKC, and UN) based on their phylogenetical relationships with Arabidopsis , and the closely linked subgroups exhibited more similarity in terms of motif distribution and intron/exon numbers. Transcriptome analysis indicated that LcMADS-box gene expression varied in different tissues, which can be divided into universal expression and specific expression. Furthermore, we further validated that LcMADS-box genes can exhibit different responses to various stresses using quantitative real-time PCR (qRT-PCR). Moreover, physicochemical properties, subcellular localization, collinearity, and cis -acting elements were also analyzed. The findings of this study provide valuable insights into the MADS-box gene family in litchi, specifically in relation to stress response. The identification of hormone-related and stress-responsive cis -acting elements in the MADS-box gene promoters suggests their involvement in stress signaling pathways. This study contributes to the understanding of stress tolerance mechanisms in litchi and highlights potential regulatory mechanisms underlying stress responses.

Seasonal changes are crucial in shifting the developmental stages from the vegetative phase to the reproductive phase in plants, enabling them to flower under optimal conditions. Plants grown at different latitudes sense and interpret these seasonal variations, such as changes in day length (photoperiod) and exposure to cold winter temperatures (vernalization). These environmental factors influence the expression of various genes related to flowering. Plants have evolved to stimulate a rapid response to environmental conditions through genetic and epigenetic mechanisms. Multiple epigenetic regulation systems have emerged in plants to interpret environmental signals. During the transition to the flowering phase, changes in gene expression are facilitated by chromatin remodeling and small RNAs interference, particularly in annual and perennial plants. Key flowering regulators, such as FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT), interact with various factors and undergo chromatin remodeling in response to seasonal cues. The Polycomb silencing complex (PRC) controls the expression of flowering-related genes in photoperiodic flowering regulation. Under vernalization-dependent flowering, FLC acts as a potent flowering suppressor by downregulating the gene expression of various flower-promoting genes. Eventually, PRCs are critically involved in the regulation of FLC and FT locus interacting with several key genes in photoperiod and vernalization. Subsequently, PRCs also regulate Epigenetical events during gametogenesis and seed development as a driving force. Furthermore, DNA methylation in the context of CHG, CG, and CHH methylation plays a critical role in embryogenesis. DNA glycosylase DME (DEMETER) is responsible for demethylation during seed development. Thus, the review briefly discusses flowering regulation through light signaling, day length variation, temperature variation and seed development in plants., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The nuclear pore complex (NPC) has multiple functions beyond the nucleo-cytoplasmic transport of large molecules. Subnuclear compartmentalization of chromatin is critical for gene expression in animals and yeast. However, the mechanism by which the NPC regulates gene expression is poorly understood in plants. Here we report that the Y-complex (Nup107-160 complex, a subcomplex of the NPC) self-maintains its nucleoporin homeostasis and modulates FLOWERING LOCUS C (FLC) transcription via changing histone modifications at this locus. We show that Y-complex nucleoporins are intimately associated with FLC chromatin through their interactions with histone H2A at the nuclear membrane. Fluorescence in situ hybridization assays revealed that Nup96, a Y-complex nucleoporin, enhances FLC positioning at the nuclear periphery. Nup96 interacted with HISTONE DEACETYLASE 6 (HDA6), a key repressor of FLC expression via histone modification, at the nuclear membrane to attenuate HDA6-catalyzed deposition at the FLC locus and change histone modifications. Moreover, we demonstrate that Y-complex nucleoporins interact with RNA polymerase II to increase its occupancy at the FLC locus, facilitating transcription. Collectively, our findings identify an attractive mechanism for the Y-complex in regulating FLC expression via tethering the locus at the nuclear periphery and altering its histone modification., Competing Interests: Conflict of interest statement. The authors declare no competing interests., (© The Author(s) 2023. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Noncoding transcription induces chromatin changes that can mediate environmental responsiveness, but the causes and consequences of these mechanisms are still unclear. Here, we investigate how antisense transcription (termed COOLAIR ) interfaces with Polycomb Repressive Complex 2 (PRC2) silencing during winter-induced epigenetic regulation of Arabidopsis FLOWERING LOCUS C ( FLC ). We use genetic and chromatin analyses on lines ineffective or hyperactive for the antisense pathway in combination with computational modeling to define the mechanisms underlying FLC repression. Our results show that FLC is silenced through pathways that function with different dynamics: a COOLAIR transcription-mediated pathway capable of fast response and in parallel a slow PRC2 switching mechanism that maintains each allele in an epigenetically silenced state. Components of both the COOLAIR and PRC2 pathways are regulated by a common transcriptional regulator (NTL8), which accumulates by reduced dilution due to slow growth at low temperature. The parallel activities of the regulatory steps, and their control by temperature-dependent growth dynamics, create a flexible system for registering widely fluctuating natural temperature conditions that change year on year, and yet ensure robust epigenetic silencing of FLC., Competing Interests: Competing interests statement:The authors declare no competing interest.

Plants can record external stimuli in mobile mRNAs and systemically deliver them to distal tissues to adjust development. Despite the identification of thousands of mobile mRNAs, the functional relevance of mobile mRNAs remains limited. Many mobile mRNAs are synthesized in the source cells that perceive environmental stimuli, but specifically exert their functions upon transportation to the recipient cells. However, the translation of mobile mRNA-encoded protein in the source cells could locally activate downstream target genes. How plants avoid ectopic functions of mobile mRNAs in the source cells to achieve tissue specificity remains to be elucidated. Here, we show that Arabidopsis AGAMOUS-LIKE 24 (AGL24) is a mobile mRNA whose movement is necessary and sufficient to specify floral organ identity. Although AGL24 mRNA is expressed in vegetative tissues, AGL24 protein exclusively accumulates in the shoot apex. In leaves, AGL24 proteins are degraded to avoid ectopically activating its downstream target genes. Our results reveal how selective protein degradation in source cells provides a strategy to limit the local effects associated with proteins encoded by mobile mRNAs, which ensures that mobile mRNAs specifically trigger systemic responses only in recipient tissues., (© 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.)

Lilium is a commercially important genus of bulbous flowers, investigating the flowering molecular mechanisms is important for flowering regulation of lily. MADS-box SHORT VEGETATIVE PHASE (SVP) orthologs are involved in the flowering transition and floral organ differentiation in many plants. In this study, we identified an SVP ortholog from L. × formolongi (LfSVP), which was closely related to Arabidopsis SVP according to phylogenetic analysis. Tissue-specific expression patterns indicated that LfSVP expression levels peaked in the leaves and showed low expression levels in flowering tepals. Stage-dependent expression patterns of LfSVP showed high transcription level in the flowering induction stage under different photoperiods and exhibited transcription peak in the floral budding development stage under long days. Overexpressed LfSVP led to delayed flowering and floral organ defects in Arabidopsis independent of photoperiod. Tobacco rattle virus -induced gene silencing of LfSVP caused a strongly earlier flowering time and floral organ defects of L. × formolongi. Moreover, LfSVP can interact with L. × formolongi APETALA1 (AP1) in both yeast and tobacco cells, and the two may interact to regulate floral organ differentiation. In conclusion, LfSVP is a flowering repressor and may be involved in the regulation of floral organ differentiation. This study will be helpful for the molecular breeding of short-life-period and rich floral patterns lily varieties., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Yufan Li reports financial support was provided by Subproject of National Key research and development program., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)