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Background: Paeonia section Moutan DC. is a significant perennial subshrub, the ornamental value of which heavily depends on the type of flower it possesses. MADS-box transcription factors have a particular impact on the intricate process of floral organ development and differentiation. The release of the whole-genome data from Paeonia ostii now allows us to conduct a thorough investigation of the tree peony MADS-box gene family. Results: In this study, we identified 110 MADS-box genes in Paeonia ostii that were classified into 5 subgroups. Gene structure, domain and motif analyses revealed the conservation of the structure of these subgroups. Analysis of the cis-acting elements revealed that the 110 PoMADS genes contained different kinds of hormones and stress-related cis-acting elements in their promoter regions. Quantitative real-time PCR analysis was employed to validate the expression patterns of some PoMADS genes related to floral organ development. Genome collinearity analysis with Arabidopsis and grape revealed the conservation of PoMADS genes during evolution. A total of 857 SSRs were identified by analysing the genome sequences of identified genes. We additionally created protein‒protein interaction networks for PoMADS proteins and analysed proteins that could interact among PoMADSs in Arabidopsis thaliana and grape. Conclusion: These findings offer fundamental insights for understanding the function of the MADS-box gene family, which can aid in the selection and breeding of tree peony varieties with high ornamental value in addition to supporting the understanding of the process of tree peony floral organogenesis. [ABSTRACT FROM AUTHOR]

Flowers, serving as the reproductive structures of angiosperms, perform an integral role in plant biology and are fundamental to understanding plant evolution and taxonomy. The growth and organogenesis of flowers are driven by numerous factors, such as external environmental conditions and internal physiological processes, resulting in diverse traits across species or even within the same species. Among these factors, genes play a central role, governing the entire developmental process. The regulation of floral genesis by these genes has become a significant focus of research. In the AE model of floral development, the five structural whorls (calyx, corolla, stamens, pistils, and ovules) are controlled by five groups of genes: A, B, C, D, and E. These genes interact to give rise to a complex control system that governs the floral organsgenesis. The activation or suppression of specific gene categories results in structural modifications to floral organs, with variations observed across different species. The present article examines the regulatory roles of key genes, including genes within the MADS-box and AP2/ERF gene clusters, such as AP1, AP2, AP3, AG, STK, SHP, SEP, PI, and AGL6, as well as other genes, like NAP, SPL, TGA, PAN, and WOX, in shaping floral organ genesis. In addition, it analyzes the molecular-level effects of these genes on floral organ formation. The findings offer a deeper understanding of the genetic governance of floral organ genesis across plant species. [ABSTRACT FROM AUTHOR]

Paeonia have diverse flower colors, rich flower types, varying bloom periods, and delightful fragrances, rendering them highly valuable for both ornamental and economic purposes in horticulture. Investigating the developmental mechanisms of morphology, flower color, flowering and floral fragrance in Paeonia holds significant value for enhancing their ornamental traits and conducting germplasm improvement. This review provides an overview of research progress on Paeonia flower morphology (including flower bud differentiation, classification, omics applications in shape studies, and functional genes regulating flower morphology), flower colors (omics applications in color research and functional genes regulating flower colors), bloom periods (flower bud dormancy, flowering time), and fragrances (preparation, analysis, components, and molecular biology research of flower fragrances) within the Paeonia. Additionally, it offers a comprehensive analysis of current research challenges and future directions. [ABSTRACT FROM AUTHOR]

Background: The differing floret opening times between subsp. indica and subsp. japonica in rice limit the potential for increased hybrid seed production. Objectives: To elucidate the physiological basis underlying the differences in floret opening time between indica and japonica rice. Materials: A comparative analysis involved nine indica and ten japonica rice varieties. Methods: Using paraffin sectioning, transcriptome sequencing, RT-PCR, and endogenous substance quantification, we investigated the structural variations in floral organs, the differences in the initiation timing of floret opening regulatory pathways, and endogenous regulators. Results: The results indicated insignificant differences in lemma thickness, lodicule thickness, lodicule area, and the coupling-lodicule length between indica and japonica rice. However, japonica rice exhibited larger lodicule-lemma gaps and more vascular bundles compared to indica rice. Within the 9:00 a.m. to 10:00 a.m. interval, the expression of OsAOS1 in α-linolenic acid metabolism and OsISA3 in starch and sucrose metabolism notably increased in indica rice, with no significant change in japonica rice. Additionally, the endogenous JA and α-amylase surged more significantly in indica rice than in japonica rice. The increase in soluble carbohydrate in indica rice is greater than in japonica rice, but the difference is not significant. Conclusions: These findings suggest that in the process of the floret opening, the α-linolenic acid metabolism and starch and sucrose metabolism are initiated earlier in indica rice, accompanied by a more pronounced elevation in endogenous JA and α-amylase. Furthermore, the smaller lodicule-lemma gap in indica rice contributes to earlier floret opening compared to japonica rice. [ABSTRACT FROM AUTHOR]

Siberian apricot (Prunus sibirica) is an important ecological and commercial woody plant that is negatively affected by spring frosts. However, the mechanisms that control gene expression in adaptation to freezing remain largely unknown. In this work, we investigated the physiological, molecular, and phenotypic characteristics of pistils of two P. sibirica clones that differ in their ability to withstand freezing stress. A total of 14,717 unigenes categorized into 38 functional groups were identified. Additionally, the two P. sibirica clones included 3931 up-regulated and 2070 down-regulated differentially expressed genes (DEGs). Many DEGs are related to Ca2+ and MAPK signaling, carbohydrate biosynthesis and metabolism, plant hormone signal transduction, biosynthesis of amino acids, and photosynthesis. The metabolism of carbohydrates, amino acids, lipids, secondary metabolites, plant hormone signal transduction, and terpenoid metabolism were the transcriptome modifications most significantly altered by freezing stress. Real-time quantitative PCR (RT-qPCR) was used to verify the precision of the RNA-seq data. PsbHLH18, PsMYB4, PsMYB44, PsPOD1, and PsCDPK5 may play important roles in the freezing tolerance of the P. sibirica floral organ. This study provides a foundation for further studies on the complex mechanisms of freezing stress response in P. sibirica. [ABSTRACT FROM AUTHOR]

Summary: Abscission is the shedding of plant organs in response to developmental and environmental cues. Abscission involves cell separation between two neighboring cell types, residuum cells (RECs) and secession cells (SECs) in the floral abscission zone (AZ) in Arabidopsis thaliana. However, the regulatory mechanisms behind the spatial determination that governs cell separation are largely unknown.The class I KNOTTED‐like homeobox (KNOX) transcription factor BREVIPEDICELLUS (BP) negatively regulates AZ cell size and number in Arabidopsis. To identify new players participating in abscission, we performed a genetic screen by activation tagging a weak complementation line of bp‐3. We identified the mutant ebp1 (enhancer of BP1) displaying delayed floral organ abscission.The ebp1 mutant showed a concaved surface in SECs and abnormally stacked cells on the top of RECs, in contrast to the precisely separated surface in the wild‐type. Molecular and histological analyses revealed that the transcriptional programming during cell differentiation in the AZ is compromised in ebp1. The SECs of ebp1 have acquired REC‐like properties, including cuticle formation and superoxide production.We show that SEPARATION AFFECTING RNA‐BINDING PROTEIN1 (SARP1) is upregulated in ebp1 and plays a role in the establishment of the cell separation layer during floral organ abscission in Arabidopsis. [ABSTRACT FROM AUTHOR]

SUMMARY: BARENTSZ (BTZ), a core component of the exon junction complex, regulates diverse developmental processes in animals. However, its evolutionary and developmental roles in plants remain elusive. Here, we revealed that three groups of paralogous BTZ genes existed in Poaceae, and Group 2 underwent loss‐of‐function mutations during evolution. They showed surprisingly low (~33%) sequence identities, implying functional divergence. Two genes retained in rice, OsBTZ1 and OsBTZ3, were edited; however, the resultant osbtz1 and osbtz3 mutants showed similar floral morphological and functional defects at a low frequency. When growing under low‐temperature conditions, developmental abnormalities became pronounced, and new floral variations were induced. In particular, stamen and carpel functionality was impaired in these rice btz mutants. The double‐gene mutant osbtz1/3 shared these floral defects with an increased frequency, which was further induced under low‐temperature conditions. OsBTZs interacted with OsMADS7 and OsMADS8, and the floral expressions of the OsTGA10 and MADS‐box genes were correlatively altered in these osbtz mutants and responded to low‐temperature treatment. These novel findings demonstrate that two highly diverged OsBTZs are required to maintain floral developmental stability under low‐temperature conditions, and play an integral role in male and female fertility, thus providing new insights into the indispensable roles of BTZ genes in plant development and adaptive evolution. Significance Statement: Two highly diverged rice BTZ genes are required for floral developmental stability under low‐temperature conditions, suggesting their roles in plant development and adaptive evolution. [ABSTRACT FROM AUTHOR]

Abstract 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.

SUMMARY: Abscisic acid (ABA) signaling interacts frequently with auxin signaling when it regulates plant development, affecting multiple physiological processes; however, to the best of our knowledge, their interaction during tomato development has not yet been reported. Here, we found that type 2C protein phosphatase (SlPP2C2) interacts with both flavin monooxygenase FZY, an indole‐3‐acetic acid (IAA) biosynthetic enzyme, and small auxin upregulated RNA (SAUR) of an IAA signaling protein and regulates their activity, thereby affecting the expression of IAA‐responsive genes. The expression level of SlPP2C2 was increased by exogenous ABA, IAA, NaCl, or dehydration treatment of fruits, leaves, and seeds, and it decreased in imbibed seeds. Manipulating SlPP2C2 with overexpression, RNA interference, and CRISPR/Cas9‐mediated genome editing resulted in pleiotropic changes, such as morphological changes in leaves, stem trichomes, floral organs and fruits, accompanied by alterations in IAA and ABA levels. Furthermore, the RNA‐seq analysis indicated that SlPP2C2 regulates the expression of auxin‐/IAA‐responsive genes in different tissues of tomato. The results demonstrate that SlPP2C2‐mediated ABA signaling regulates the development of both vegetative and reproductive organs via interaction with FZY/SAUR, which integrates the cross‐talk of ABA and auxin signals during development and affects the expressions of development‐related genes in tomato. Significance Statement: SlPP2C2 regulates tomato development by integrating ABA and auxin signals through interaction with FZY/SAUR. This finding extends our knowledge of ABA signal cross talk in regulation of tomato development. [ABSTRACT FROM AUTHOR]

Maize develops separate ear and tassel inflorescences with initially similar morphology but ultimately different architecture and sexuality. The detailed regulatory mechanisms underlying these changes still remain largely unclear. In this study, through analyzing the time-course meristem transcriptomes and floret single-cell transcriptomes of ear and tassel, we revealed the regulatory dynamics and pathways underlying inflorescence development and sex differentiation. We identified 16 diverse gene clusters with differential spatiotemporal expression patterns and revealed biased regulation of redox, programmed cell death, and hormone signals during meristem differentiation between ear and tassel. Notably, based on their dynamic expression patterns, we revealed the roles of two RNA-binding proteins in regulating inflorescence meristem activity and axillary meristem formation. Moreover, using the transcriptional profiles of 53 910 single cells, we uncovered the cellular heterogeneity between ear and tassel florets. We found that multiple signals associated with either enhanced cell death or reduced growth are responsible for tassel pistil suppression, while part of the gibberellic acid signal may act non-cell-autonomously to regulate ear stamen arrest during sex differentiation. We further showed that the pistil-protection gene SILKLESS 1 (SK1) functions antagonistically to the known pistil-suppression genes through regulating common molecular pathways, and constructed a regulatory network for pistil-fate determination. Collectively, our study provides a deep understanding of the regulatory mechanisms underlying inflorescence development and sex differentiation in maize, laying the foundation for identifying new regulators and pathways for maize hybrid breeding and improvement. This study explores meristem transcriptomes and floret single-cell transcriptomes in maize ear and tassel, revealing the molecular features and pathways underlying inflorescence development and sex differentiation. Key findings include the roles of two RNA-binding proteins in inflorescence development, several major signals regulating sex differentiation, and the model for pistil-fate determination. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Paeonia have diverse flower colors, rich flower types, varying bloom periods, and delightful fragrances, rendering them highly valuable for both ornamental and economic purposes in horticulture. Investigating the developmental mechanisms of morphology, flower color, flowering and floral fragrance in Paeonia holds significant value for enhancing their ornamental traits and conducting germplasm improvement. This review provides an overview of research progress on Paeonia flower morphology (including flower bud differentiation, classification, omics applications in shape studies, and functional genes regulating flower morphology), flower colors (omics applications in color research and functional genes regulating flower colors), bloom periods (flower bud dormancy, flowering time), and fragrances (preparation, analysis, components, and molecular biology research of flower fragrances) within the Paeonia. Additionally, it offers a comprehensive analysis of current research challenges and future directions.

Abstract Passiflora is a plant genus known for its extremely distinctive and colorful flowers and a wide range of genome size variation. However, how genome characteristics are related to flower traits among Passiflora species remains poorly understood. Here, we assembled a chromosome-scale genome of P. foetida, which belongs to the same subgenus as the commercial passionfruit P. edulis. The genome of P. foetida is smaller (424.16 Mb) and contains fewer copies of long terminal repeat retrotransposons (LTR-RTs). The disparity in LTR-RTs is one of the main contributors to the differences in genome sizes between these two species and possibly in floral traits. Additionally, we observed variation in insertion times and copy numbers of LTR-RTs across different transposable element (TE) lineages. Then, by integrating transcriptomic data from 33 samples (eight floral organs and flower buds at three developmental stages) with phylogenomic and metabolomic data, we conducted an in-depth analysis of the expression, phylogeny, and copy number of MIKC-type MADS-box genes and identified essential biosynthetic genes responsible for flower color and scent from glandular bracts and other floral organs. Our study pinpoints LRT-RTs as an important player in genome size variation in Passiflora species and provides insights into future genetic improvement. Graphical Abstract

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Flower development, as the basis for plant seed development, is principally conserved in angiosperms. At present, a number of genes regulating flower organ differentiation have been identified, and an ABCDE model has also been proposed. In contrast, the mechanism that regulates the development of the sterile lemma remains unclear. In this study, we identified and characterized a rice floral organ mutant, M15, in which the sterile lemma transformed into a lemma-like organ. Positional cloning combined with a complementary experiment demonstrated that the mutant phenotype was restored by LONG STERILE LEMMA1/(G1). G1 was expressed constitutively in various tissues, with the highest expression levels detected in the sterile lemma and young panicle. G1 is a nucleus-localized protein and functions as a homomer. Biochemical assays showed that G1 physically interacted with OsMADS1 both in vitro and in vivo. Interestingly, the expression of G1 in M15 decreased, while the expression level of OsMADS1 increased compared with the wild type. We demonstrate that G1 plays a key role in sterile lemma development through cooperating with OsMADS1. The above results have implications for further research on the molecular mechanisms underlying flower development and may have potential applications in crop improvement strategies. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Passiflora is a plant genus known for its extremely distinctive and colorful flowers and a wide range of genome size variation. However, how genome characteristics are related to flower traits among Passiflora species remains poorly understood. Here, we assembled a chromosome-scale genome of P. foetida, which belongs to the same subgenus as the commercial passionfruit P. edulis. The genome of P. foetida is smaller (424.16 Mb) and contains fewer copies of long terminal repeat retrotransposons (LTR-RTs). The disparity in LTR-RTs is one of the main contributors to the differences in genome sizes between these two species and possibly in floral traits. Additionally, we observed variation in insertion times and copy numbers of LTR-RTs across different transposable element (TE) lineages. Then, by integrating transcriptomic data from 33 samples (eight floral organs and flower buds at three developmental stages) with phylogenomic and metabolomic data, we conducted an in-depth analysis of the expression, phylogeny, and copy number of MIKC-type MADS-box genes and identified essential biosynthetic genes responsible for flower color and scent from glandular bracts and other floral organs. Our study pinpoints LRT-RTs as an important player in genome size variation in Passiflora species and provides insights into future genetic improvement. [ABSTRACT FROM AUTHOR]

Gramineous crops have undergone a diversification in floral architecture, with distinguished variations in their spikelets, florets, and inner hull-like organ patterns occurring during cereal domestication. Significant advancements have enhanced our comprehension of domesticated footprints and the molecular mechanisms associated with major regulators involved in cereal threshability. The miRNA172-AP2/ERF and miRNA156/TCP-SBP regulatory modules, functionally differentiated MADS-box transcription factors, and G protein pathways compose an intricate regulatory network functioning in floral organ initiation, differentiation, and specification. The molecular design of summarized gene resources, facilitated by genome-editing technologies, can expedite de novo domestication and advance the breeding of easy-threshing grains in cereals. Hulled grains, while providing natural protection for seeds, pose a challenge to manual threshing due to the pair of glumes tightly encasing them. Based on natural evolution and artificial domestication, gramineous crops evolved various hull-like floral organs. Recently, progress has been made in uncovering novel domesticated genes associated with cereal threshability and deciphering common regulatory modules pertinent to the specification of hull-like floral organs. Here we review morphological similarities, principal regulators, and common mechanisms implicated in the easy-threshing traits of crops. Understanding the shared and unique features in the developmental process of cereal threshability may not only shed light on the convergent evolution of cereals but also facilitate the de novo domestication of wild cereal germplasm resources through genome-editing technologies. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is an indispensable nutrient for seed germination, but the seeds always store excessive P over demand. High-P seeds of feeding crops lead to environmental and nutrition issues, because phytic acid (PA), the major form of P in seeds, cannot be digested by mono-gastric animals. Therefore, reduction of P level in seeds has become an imperative task in agriculture. Our study here suggested that both VPT1 and VPT3, two vacuolar phosphate transporters responsible for vacuolar Pi sequestration, were downregulated in leaves during the flowering stage, which led to less Pi accumulated in leaves and more Pi allocated to reproductive organs, and thus high-P containing seeds. To reduce the total P content in seeds, we genetically regulated VPT1 during the flowering stage and found that overexpression of VPT1 in leaves could reduce P content in seeds without affecting the production and seed vigor. Therefore, our finding provides a potential strategy to reduce the P level of the seeds to prevent the nutrition over-accumulation pollution.

SEPALLATA (SEP) genes encode E-class floral homeotic transcriptional factors involved in regulation of flowering. In the present work, artificial microRNA (amiRNA) technology was adopted to downregulate the expression levels of SEP3-2, SEP3-3 and SEP4. Silencing of SEP3-2 and SEP3-3 did not generate obvious phenotypic changes in the four types of floral organs. However, knockdown of SEP3-2 and SEP3-3 resulted in suppression of FLOWERING LOCUS T (FT) and GIGANTEA (GI), accompanied by a delay in flowering time. SEP3-2 can directly bind to CArG-boxes existing in the promoter of AGL17, AGL20, AGL42, CCA1, FT, TCP3, TCP12, while SEP3-3 can directly interact with CArG-boxes existing in the promoter of AGL15, AGL24, CUC2, MAF5 and TCP2, indicating the encoded products of two alternative splicing variants of SEP3 can affect distinct target genes. These results suggest that SEP3-2 and SEP3-3 are probably involved in controlling different developmental processes. Compared to wild-type plants, the vegetative growth of amiRNA-SEP3-2 and amiRNA-SEP3-3 transgenic plants was more vigorous, and the morphology of leaves was changed significantly, including a widening the blade, increased surface area, longer petiole and serrated margin. In amiRNA-SEP4 transgenic plants, sepals were converted into petaloid structures, and the number of floral organs in the outside three whorls was reduced. In addition, amiRNA-SEP4 transgenic plants presented a late-flowering phenotype, illustrating the important roles of SEP4 in floral transition. These results showed that SEP3-2 and SEP3-3, two splicing variants of SEP3, involved in morphogenesis of leaves and floral organ development by conferring transcriptional activity. Moreover, SEP4 genes participate in development of sepals, petals, stamens and carpels. All these results indicated that SEPALLATA genes of Arabidopsis possessed diversified functions. In addition to the roles in reproductive growth, these genes can also influence the vegetative growth. [ABSTRACT FROM AUTHOR]

Flower development, as the basis for plant seed development, is principally conserved in angiosperms. At present, a number of genes regulating flower organ differentiation have been identified, and an ABCDE model has also been proposed. In contrast, the mechanism that regulates the development of the sterile lemma remains unclear. In this study, we identified and characterized a rice floral organ mutant, M15, in which the sterile lemma transformed into a lemma-like organ. Positional cloning combined with a complementary experiment demonstrated that the mutant phenotype was restored by LONG STERILE LEMMA1/(G1). G1 was expressed constitutively in various tissues, with the highest expression levels detected in the sterile lemma and young panicle. G1 is a nucleus-localized protein and functions as a homomer. Biochemical assays showed that G1 physically interacted with OsMADS1 both in vitro and in vivo. Interestingly, the expression of G1 in M15 decreased, while the expression level of OsMADS1 increased compared with the wild type. We demonstrate that G1 plays a key role in sterile lemma development through cooperating with OsMADS1. The above results have implications for further research on the molecular mechanisms underlying flower development and may have potential applications in crop improvement strategies.

MADS-box genes encode transcription factors that affect plant growth and development. Camellia chekiangoleosa is an oil tree species with ornamental value, but there have been few molecular biological studies on the developmental regulation of this species. To explore their possible role in C. chekiangoleosa and lay a foundation for subsequent research, 89 MADS-box genes were identified across the whole genome of C. chekiangoleosa for the first time. These genes were present on all the chromosomes and were found to have expanded by tandem duplication and fragment duplication. Based on the results of a phylogenetic analysis, the 89 MADS-box genes could be divided into either type I (38) or type II (51). Both the number and proportion of the type II genes were significantly greater than those of Camellia sinensis and Arabidopsis thaliana, indicating that C. chekiangoleosa type II genes experienced a higher duplication rate or a lower loss rate. The results of both a sequence alignment and a conserved motif analysis suggest that the type II genes are more conserved, meaning that they may have originated and differentiated earlier than the type I genes did. At the same time, the presence of extra-long amino acid sequences may be an important feature of C. chekiangoleosa. Gene structure analysis revealed the number of introns of MADS-box genes: twenty-one type I genes had no introns, and 13 type I genes contained only 1~2 introns. The type II genes have far more introns and longer introns than the type I genes do. Some MIKCC genes have super large introns (≥15 kb), which are rare in other species. The super large introns of these MIKCC genes may indicate richer gene expression. Moreover, the results of a qPCR expression analysis of the roots, flowers, leaves and seeds of C. chekiangoleosa showed that the MADS-box genes were expressed in all those tissues. Overall, compared with that of the type I genes, the expression of the type II genes was significantly higher. The CchMADS31 and CchMADS58 genes (type II) were highly expressed specifically in the flowers, which may in turn regulate the size of the flower meristem and petals. CchMADS55 was expressed specifically in the seeds, which might affect seed development. This study provides additional information for the functional characterization of the MADS-box gene family and lays an important foundation for in-depth study of related genes, such as those involved in the development of the reproductive organs of C. chekiangoleosa. [ABSTRACT FROM AUTHOR]

Most bamboos die after flowering, and the molecular mechanisms responsible for flowering is poorly understood. The MIKCc-type MADS-box family gene is involved in the flowering process. To explore the mechanism of the MIKCc-type MADS-box gene and phytohormone regulation in the flowering of Dendrocalamus latiflorus Munro (D. latiflorus), characterized by extremely rapid growth and widely cultivated woody bamboo, we initially did a genome-wide analysis of the MIKCc-type MADS-box gene in D. latiflorus. In the meantime, transcriptome analysis was performed using the floral organs. A total of 170 MIKCc-Type MADS-Box genes were identified and divided into 15 categories. The cis-acting element analysis in promoters regions revealed that MIKC-type MADS-box family genes were associated with hormones, including auxin, abscisic acid (ABA), gibberellin (GA) and jasmonic acid (JA), which was found at 79, 476, 96, 486 sites and cover 61, 103, 73, 128 genes. Genome synteny analysis showed subgenome AA and BB were better than CC and obtained 49, 40, 39 synteny genes compared with Oryza sativa (O. sativa). In transcriptome analysis of floral organs, the enriched pathway from DEGs included circadian, vernalization and gibberellin pathways associated with the flowering process. We found that the jasmonic acid synthesis gene is highly expressed in the pistil, which may be the cause of Ma bamboo pollen abortion. The expression profile showed that most MIKC-type MADS-box genes exhibited high expression in flower organs. The consequences of this study will provide insight into the irregular flowering and low pollen counts of Ma bamboo. [ABSTRACT FROM AUTHOR]

Flowering is an important factor to ensure the success of plant reproduction, and reasonable flowering time is crucial to the crop yield. BBX transcription factors can regulate several growth and development processes. However, there is little research on whether BBX is involved in flower formation and floral organ development of pineapple. In this study, AcBBX5, a BBX family gene with two conserved B-box domains, was identified from pineapple. Subcellular localization analysis showed that AcBBX5 was located in the nucleus. Transactivation analysis indicated that AcBBX5 had no significant toxic effects on the yeast system and presented transcriptional activation activity in yeast. Overexpression of AcBBX5 delayed flowering time and enlarged flower morphology in Arabidopsis. Meanwhile, the expression levels of AtFT, AtSOC1, AtFUL and AtSEP3 were decreased, and the transcription levels of AtFLC and AtSVP were increased in AcBBX5-overexpressing Arabidopsis, which might lead to delayed flowering of transgenic plants. Furthermore, transcriptome data and QRT-PCR results showed that AcBBX5 was expressed in all floral organs, with the high expression levels in stamens, ovaries and petals. Yeast one-hybrid and dual luciferase assay results showed that AcBBX5 bound to AcFT promoter and inhibited AcFT gene expression. In conclusion, AcBBX5 was involved in flower bud differentiation and floral organ development, which provides an important reference for studying the functions of BBX and the molecular regulation of flower. [ABSTRACT FROM AUTHOR]

MADS-box genes play crucial roles in plant vegetative and reproductive growth, better development of inflorescences, flower, and fruit. Pineapple is a typical collective fruit, and a comprehensive analysis of the MADS-box gene family in the development of floral organs of pineapple is still lacking. In this study, the wholegenome survey and expression profiling of the MADS-box family in pineapple were introduced. Forty-four AcMADS genes were identified in pineapple, 39 of them were located on 18 chromosomes and five genes were distributed in five scaffolds. Twenty-two AcMADS genes were defined as 15 pairs of segmental duplication events. Most members of the type II subfamily of AcMADS genes had higher expression levels in floral organs compared with type I subfamily, thereby suggesting that AcMADS of type II may play more crucial roles in the development of floral organs of pineapple. Six AcMADS genes have significant tissue-specificity expression, thereby suggesting that they may participate in the formation of one or more floral organs. This study provides valuable insights into the role of MADS-box gene family in the floral organ development of pineapple. [ABSTRACT FROM AUTHOR]

Abstract Background Cymbidium goeringii, belonging to the Orchidaceae family, is an important ornamental plant with striking petals and lips. Extremely diversified floral patterns and morphologies make C. goeringii good research material to examine floral development of orchids. However, no floral organ-specific protein has been identified yet. To screen floral development associated proteins, four proteomes from petal (PE), lip (LI), gynostemium (GY), and sepal (SE) were analyzed using Tandem Mass Tag-based proteomic analysis. Results A total of 6626 unique peptides encoding 2331 proteins were identified in our study. Proteins in several primary metabolic pathways, including amino acid metabolism, energy metabolism, and lipid metabolism, were identified as differentially expressed proteins. Interestingly, most of the energy metabolism-related proteins highly expressed in SE, indicating that SE is an important photosynthetic organ of C. goeringii flower. Furthermore, a number of phytohormone-related proteins and transcription factors (TFs) were identified in C. goeringii flowers. Expression analysis showed that 1-aminocyclopropane-1-carboxylate oxidase highly expressed in GY, IAA-amino acid hydrolase ILR1-like 4 and gibberellin receptor 1 C greatly expressed in LI, and auxin-binding protein ABP20 significantly expressed in SE, suggesting a significant role of hormones in the regulation of flower morphogenesis and development. For TFs, GY-highly expressed bHLH13, PE-highly expressed WRKY33, and GY-highly expressed VIP1, were identified. Conclusions Mining of floral organ differential expressed enzymes and TFs helps us to excavate candidate proteins related to floral organ development and to accelerate the breeding of Cymbidium plants.

This study aimed to investigate the flowering biological characteristics, floral organ characteristics, and pollen morphology of Camellia weiningensis Y.K. Li. These features of adult C. weiningensis plants were observed via light microscopy and scanning electron microscopy (SEM). Pollen viability and stigma receptivity were detected using 2,3,5-triphenyltetrazole chloride (TTC) staining and the benzidine–hydrogen peroxide reaction method. C. weiningensis is monoecious, with alternate leaves and glabrous branchlets. Its flowering period lasts 2 to 4 months, and the flowering time of individual plants lasts ≈50 days, with the peak flowering period from the end of February to the middle of March. It is a “centralized flowering” plant that attracts a large number of pollinators. Individual flowers are open for 12 to 13 days, mostly between 1230 and 1630 hr, and include four to six sepals, six to eight petals, ≈106 stamens, an outer ring of ≈24.6-mm-long stamens, an inner ring of ≈13.4-mm-long stamens, one pistil, and nine to 12 ovules. The flowers are light pink. The style is two- to three-lobed and 16.6 mm long, showing a curly “Y” shape. The contact surface of the style is covered with papillary cells and displays abundant secretory fluid and a full shape, facilitating pollen adhesion. The pollen is rhombohedral cone-shaped, and there are germ pores (tremoids). The groove of the germ pore is slender and extends to the two poles (nearly reaching the two poles). The pollen is spherical in equatorial view and trilobate in polar view. The pollen vitality was highest at the full flowering stage, and the stigma receptivity was greatest on days 2 to 3 of flowering. The best concentration of sucrose medium for pollen germination was 100 g/L. The number of pollen grains per anther was ≈2173, and the pollen-to-ovule ratio was 23,034:1. C. weiningensis is cross-pollinated. Seventy-two hours after cross-pollination, the pollen tube reached the base, and a small part entered the ovary. The time when the pollen tube reached the base after pollination was later than that in commonly grown Camellia oleifera. The results of this study might lay an important foundation for the flowering management, pollination time selection, and cross-breeding of C. weiningensis.

S. chinensis is a typical monoecious plant, and the number and development of female flowers determines the yield of S. chinensis. Due to a lack of genetic information, the molecular mechanism of sex differentiation in S. chinensis remains unclear. In this study, the combination of scanning electron microscopy (SEM) and RNA sequencing (RNA-seq) was used to understand the way of sex differentiation of S. chinensis and to mine the related genes of sex determination. The result shows the development of male and female S. chinensis flowers was completed at the same time, the unisexual S. chinensis flowers did not undergo a transition stage between sexes, and sex may have been determined at an early stage in flower development. The results of the gene function analysis of the plant hormone signaling pathway and sucrose metabolism pathway suggest that auxin and JA could be the key hormones for sex differentiation in S. chinensis, and sucrose may promote pollen maturation at the later stage of male flower development. Two AGAMOUS (GAG) genes, 10 AGAMOUS-like MADS-box (AGLs) genes, and the MYB, NAC, WRKY, bHLH, and Trihelix transcription factor families may play important roles in sex determination in S. chinensis. Taken together, the present findings provide valuable genetic information on flower development and sex determination in S. chinensis. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Barley (Hordeum vulgare) is the fourth most highly produced cereal in the world after wheat, rice and maize and is mainly utilized as malts and for animal feed. Barley, a model crop of the tribe Triticeae, is important in comparative analyses of Poaceae. However, molecular understanding about the developmental processes is limited in barley. Our previous work characterized one of two WUSCHEL-RELATED HOMEOBOX 3 (WOX3) genes present in the barley genome: NARROW LEAFED DWARF1 (NLD1). We demonstrated that NLD1 plays a pivotal role in the development of lateral organs. In the present study, we describe a bifurcated palea (bip) mutant of barley focusing on flower and leaf phenotypes. The palea in the bip mutant was split into two and develop towards inside the lemma surrounding the carpels and anthers. The bip mutant is devoid of lodicules, which develop in a pair at the base of the stamen within the lemma in normal barley. bip also exhibited malformations in leaves, such as narrow leaf due to underdeveloped leaf-blade width, and reduced trichome density. Map-based cloning and expression analysis indicated that BIP is identical to another barley WOX3 gene, named HvWOX3. The bip nld1 double mutant presented a more severe reduction in leaf-blade width and number of trichomes. By comparing the phenotypes and gene expression patterns of various WOX3 mutants, we concluded that leaf bilateral outgrowth and trichome development are promoted by both NLD1 and HvWOX3 , but that HvWOX3 serves unique and pivotal functions in barley development that differ from those of NLD1. [ABSTRACT FROM AUTHOR]

This study was conducted to explore the mechanism of soybean cytoplasmic-nuclear male sterility. [Methods] With soybean cytoplasmic-nuclear male sterile line JLCMS9A and its homotype maintainer line JLCMS9B as experimental materials, the activity of superoxide dismutase ( SOD), peroxidase (POD) and catalase (CAT), malondialdehyde (MDA ) content, starch content, soluble protein content, soluble sugar content and free proline content in flower buds, alabastrums and mature flowers were determined, and the contents and changes of auxin (IAA), gibberellin (GA3), isopentenyl adenosine (iPA) and abscisic acid ( ABA) at the three stages were analyzed. [Results] The activity of SOD and CAT and the contents of MDA and free proline in the sterile line at the flower bud stage were lower than those of the maintainer line, but the opposite was true at the alabastrum stage and the flowering stage, and their values were higher than those of the maintainer line; the POD activity of the sterile line was significantly lower than that of the maintainer line at the flower bud stage, and the opposite was true at the alabastrum stage and the flowering stage, and its values were higher than those of the maintainer line; and the starch content and soluble sugar content of sterile line 9A showed an overall upward trend, and were significantly lower than those of the maintainer line 9B at the alabastrum stage and the flowering stage. During the whole development process of floral organs, the content of IAA in sterile line 9 A showed a trend of first increasing and then decreasing, and the content of iP A increased gradually. The contents of hormones in the sterile line were lower than those in the maintainer line. The ratios of IAA/ABA, IAA/ GA3, IAA/ iPA and ABAIGA3 in the sterile line were significantly different from those in the maintainer line. It is inferred that the abnormal physiological characteristics of floral organ development are related to the cytoplasmic-nuclear male sterility of soybean. The alabastrum stage may be a critical period for the occurrence of abnormal physiological and biochemical indexes in the floral organs of soybean cytoplasmic-nuclear male sterile lines. [Conclusion] This study provides a theoretical basis for the breeding of fine sterile lines of soybean and the research on the mechanism of sterility. [ABSTRACT FROM AUTHOR]

Orchids are some of the most popular ornamental plants worldwide. Orchid floral morphology has increasingly attracted horticultural and commercial attention. Although multiple genes have been shown to be involved in the formation of the orchid flower, the underlying multi-level regulatory networks are largely unknown. In this study, we analyzed the ontogeny of flower development in Cymbidium ensifolium, a traditional orchid in the tropical and subtropical regions of Asia, by performing deep sequencing of the transcriptome of individual flower organs to discover organ-specific genes potentially involved in their growth. We identified 3,017 differentially-expressed genes (DEGs) during the development of various flower organs, and observed over-representation of GROWTH-REGULATING FACTORS (GRFs) specific to flower column (gynostemium). Eleven C. ensifolium GRFs (CeGRFs) from our transcriptome data clustered into five phylogenetic subgroups. Ten of these GRFs shared a region complementary to C. ensifolium microRNA396 (Ce-miR396), and degradome sequencing confirmed the cleavage of transcripts derived from seven CeGRFs. We cloned Ce-miR396 and used a protoplast-based transient expression system to overexpress it in Cymbidium protoplasts. We observed a significant decrease in the transcripts of several CeGRFs in flowers and leaves, indicating a potential role for miR396–GRF module in organ development through the cleavage of distinct CeGRFs. Temporal and spatial expression analysis indicated that most CeGRF transcripts accumulated in flower buds and column tissues, where Ce-miR396 expression was the lowest. Expression dynamics in wild type and floral-defective mutants further confirmed a strong correlation between Ce-miR396, CeGRFs, and flower organ development and column specification. Moreover, overexpression of Ce-miR396 in Nicotiana tabacum resulted in curved pistils and reduced fertility, implying that the conserved role of Ce-miR396 in floral development. These results provide tools to better understand the biological roles of GRFs in orchid development, and open new avenues for the diversification of orchid floral patterns.

The identity of the floral organs is defined by a small group of transcriptional regulators, and the activities of these proteins can specify the feature of the different whorls in flowers. In the last thirty years, formation of the floral organs remained as the main research subject in plant, especially in Arabidopsis thaliana. By using A. thaliana as material, relevant research works have established a basic architecture for the development of floral organs in higher plants, and it was named as the ABCDE model. In accordance with this model, the identity of the different floral organs can be confirmed by the specific combinations of A-, B-, C-, D-, or E-class floral homeotic genes. SEP-like genes encode MADS transcription factors required for the development of all the four whorls of floral organs and for the determinacy of the floral meristems. In ABCDE model, these genes are defined as E-class floral homeotic genes. A great deal of studies have shown that the proteins encoding by these genes are the main regulators of flower development and act pivotal parts not only in organ identification but also in organ morphogenesis. In this paper, the functions of the E-class floral homeotic genes in dicotyledons are reviewed, and the progress that has been made in characterization of the floral organ identity factors in A. thaliana and other dicotyledons is discussed. [ABSTRACT FROM AUTHOR]

Orchids are some of the most popular ornamental plants worldwide. Orchid floral morphology has increasingly attracted horticultural and commercial attention. Although multiple genes have been shown to be involved in the formation of the orchid flower, the underlying multi-level regulatory networks are largely unknown. In this study, we analyzed the ontogeny of flower development in Cymbidium ensifolium , a traditional orchid in the tropical and subtropical regions of Asia, by performing deep sequencing of the transcriptome of individual flower organs to discover organ-specific genes potentially involved in their growth. We identified 3,017 differentially-expressed genes (DEGs) during the development of various flower organs, and observed over-representation of GROWTH-REGULATING FACTORS (GRFs) specific to flower column (gynostemium). Eleven C. ensifolium GRFs (CeGRFs) from our transcriptome data clustered into five phylogenetic subgroups. Ten of these GRFs shared a region complementary to C. ensifolium microRNA396 (Ce -miR396), and degradome sequencing confirmed the cleavage of transcripts derived from seven CeGRFs. We cloned Ce- miR396 and used a protoplast-based transient expression system to overexpress it in Cymbidium protoplasts. We observed a significant decrease in the transcripts of several CeGRFs in flowers and leaves, indicating a potential role for miR396–GRF module in organ development through the cleavage of distinct CeGRFs. Temporal and spatial expression analysis indicated that most CeGRF transcripts accumulated in flower buds and column tissues, where Ce -miR396 expression was the lowest. Expression dynamics in wild type and floral-defective mutants further confirmed a strong correlation between Ce -miR396, CeGRFs , and flower organ development and column specification. Moreover, overexpression of Ce -miR396 in Nicotiana tabacum resulted in curved pistils and reduced fertility, implying that the conserved role of Ce -miR396 in floral development. These results provide tools to better understand the biological roles of GRFs in orchid development, and open new avenues for the diversification of orchid floral patterns. [ABSTRACT FROM AUTHOR]

Summary: The AGAMOUS‐LIKE6 (AGL6)‐like genes are ancient MADS‐box genes and are functionally studied in a few model plants. The knowledge of these genes in wheat remains limited. Here, by studying a 'double homoeolog mutant' of the AGL6 gene in tetraploid wheat, we showed that AGL6 was required for the development of all four whorls of floral organs with dosage‐dependent effect on floret fertility. Yeast two‐hybrid analyses detected interactions of AGL6 with all classes of MADS‐box proteins in the ABCDE model for floral organ development. AGL6 was found to interact with several additional proteins, including the G protein β and γ (DEP1) subunits. Analysis of the DEP1‐B mutant showed a significant reduction in spikelet number per spike in tetraploid wheat, while overexpression of AGL6 in common wheat increased the spikelet number per spike and hence the grain number per spike. RNA‐seq analysis identified the regulation of several meristem activity genes by AGL6, such as FUL2 and TaMADS55. Our work therefore extensively updated the wheat ABCDE model and proposed an alternative approach to improve wheat grain yield by manipulating the AGL6 gene. [ABSTRACT FROM AUTHOR]

Lotus (Nelumbo nucifera) is a highly recognized flower with high ornamental value. Flower color and flower morphology are two main factors for flower lotus breeding. Petaloidy is a universal phenomenon in lotus flowers. However, the genetic regulation of floral organ petaloidy in lotus remains elusive. In this study, the transcriptomic analysis was performed among three organs, including petal, carpel petaloidy, and carpel in lotus. A total of 1,568 DEGs related to carpel petaloidy were identified. Our study identified one floral homeotic gene encoded by the MADS-box transcription factor, AGAMOUS (AG) as the candidate gene for petaloid in lotus. Meanwhile, a predicted labile boundary in floral organs of N. nucifera was hypothesized. In summary, our results explored the candidate genes related to carpel petaloidy, setting a theoretical basis for the molecular regulation of petaloid phenotype.

Background: Cymbidium goeringii, belonging to the Orchidaceae family, is an important ornamental plant with striking petals and lips. Extremely diversified floral patterns and morphologies make C. goeringii good research material to examine floral development of orchids. However, no floral organ-specific protein has been identified yet. To screen floral development associated proteins, four proteomes from petal (PE), lip (LI), gynostemium (GY), and sepal (SE) were analyzed using Tandem Mass Tag-based proteomic analysis. Results: A total of 6626 unique peptides encoding 2331 proteins were identified in our study. Proteins in several primary metabolic pathways, including amino acid metabolism, energy metabolism, and lipid metabolism, were identified as differentially expressed proteins. Interestingly, most of the energy metabolism-related proteins highly expressed in SE, indicating that SE is an important photosynthetic organ of C. goeringii flower. Furthermore, a number of phytohormone-related proteins and transcription factors (TFs) were identified in C. goeringii flowers. Expression analysis showed that 1-aminocyclopropane-1-carboxylate oxidase highly expressed in GY, IAA-amino acid hydrolase ILR1-like 4 and gibberellin receptor 1 C greatly expressed in LI, and auxin-binding protein ABP20 significantly expressed in SE, suggesting a significant role of hormones in the regulation of flower morphogenesis and development. For TFs, GY-highly expressed bHLH13, PE-highly expressed WRKY33, and GY-highly expressed VIP1, were identified. Conclusions: Mining of floral organ differential expressed enzymes and TFs helps us to excavate candidate proteins related to floral organ development and to accelerate the breeding of Cymbidium plants. [ABSTRACT FROM AUTHOR]

Cotton is an important economic crop and the main source of natural fiber in the world. The budding, flowering and bolling during cotton growth and development directly affect the yield and quality of cotton fiber that are the main economic traits of cotton. In this study, we found a flower organ mutant (named 182-9) in transgenic cottons, which displayed the floral organ petaloid feature. PCR and Southern blotting confirmed that the foreign T-DNA was integrated into the 182-9 genome with a single copy. Comparative analysis of the resequencing data revealed that the exogenic T-DNA was inserted in the 182-9 on chromosome A11: 59086840. The insertion site was further verified by PCR and southern blot. According to the gene annotation of cotton genome, there were three candidate genes of GH A11G2251, GHA11G2252, and GH_ A11G2253, near to the insertion site. GH_A11G2251 encoded AP2 genes controlling the formation of sepals and petals in the ABC model of flower organs as previous report. qRT-PCR showed that there were significant differences in the expression level of GHA11G2251 in petals, pistil and stamens of transgenic receptor W0 and mutant 182-9. Our study provided the basis for further study of molecular mechanism in cotton floral organ development. [ABSTRACT FROM AUTHOR]

The Hemerocallis accessions is widely consumed as nutritious vegetable and traditional medicine in eastern Asia and used as an ornamental flower worldwide. Compared with most other horticultural products, its flower is richer in polyphenols, flavonoids, carotenoids, and anthocyanins. Therefore, the flower has strong antioxidant activity that inhibits cancer cell proliferation, which could used for health and pharmaceutical purposes. The flavonoids composition and distribution in the flowers, and the content varied between different accssions is still unclear. In this context, eight flavonols, two flavones, and two anthocyanins were determined in Hemerocallis flower by high-performance liquid chromatography (HPLC) coupled with photodiode array and mass spectrometric detectors. Rutin was the most abundant flavonols and cyanidin 3,5-glucoside and cyanidin 3-rutinoside were the major anthocyanins in Hemerocallis tepals, resulting in flower petal coloration, and their content in the petal was higher than that of the sepal. Hierarchical cluster analysis grouped the 42 accessions into four groups, and they were significantly different (p < 0.05) from each other in the ten significant compounds by One-way ANOVA. Overall, the qualitative and quantitative analysis of flavonoid constituents in six floral parts of 42 Hemerocallis accessions were elucidated, which could be helpful for the food and pharmaceutical industries, and lay the foundation for the Hemerocallis flower color research.

Trihelix transcription factors with helix–loop–helix–loop–helix characteristics are essential in plant growth, development, and response to adversity. Several potential functions of Trihelix have been studied in multiple plant species, but little is known about the features and functions of Trihelix genes in pineapple. In this study, 23 Trihelix members were identified and classified into 5 groups and were unevenly distributed in 17 chromosomes of pineapple. The results revealed that six fragment duplication events and one tandem duplication event were found through gene duplication analysis. Moreover, 4, 10, 21, and 23 homologous gene pairs were found between pineapple and Arabidopsis, grape, banana, and rice, respectively. The promoters of Trihelix have many cis-elements, especially in light and hormone response. The expression characteristics of AcTrihelix members showed obvious tissue specificities in different tissues. The expressions of AcTrihelix3, AcTrihelix8, AcTrihelix16, AcTrihelix19, AcTrihelix20, and AcTrihelix23 were maintained at high levels during the late stage of flower bud development. In floral organs, the expression of different members was very different. In conclusion, some AcTrihelix members may play important roles during the floral development of pineapple, and they provide resources for further studies of the function of Trihelix and the molecular mechanism during pineapple flower formation.

The Hemerocallis accessions is widely consumed as nutritious vegetable and traditional medicine in eastern Asia and used as an ornamental flower worldwide. Compared with most other horticultural products, its flower is richer in polyphenols, flavonoids, carotenoids, and anthocyanins. Therefore, the flower has strong antioxidant activity that inhibits cancer cell proliferation, which could used for health and pharmaceutical purposes. The flavonoids composition and distribution in the flowers, and the content varied between different accssions is still unclear. In this context, eight flavonols, two flavones, and two anthocyanins were determined in Hemerocallis flower by high-performance liquid chromatography (HPLC) coupled with photodiode array and mass spectrometric detectors. Rutin was the most abundant flavonols and cyanidin 3,5-glucoside and cyanidin 3-rutinoside were the major anthocyanins in Hemerocallis tepals, resulting in flower petal coloration, and their content in the petal was higher than that of the sepal. Hierarchical cluster analysis grouped the 42 accessions into four groups, and they were significantly different (p < 0.05) from each other in the ten significant compounds by One-way ANOVA. Overall, the qualitative and quantitative analysis of flavonoid constituents in six floral parts of 42 Hemerocallis accessions were elucidated, which could be helpful for the food and pharmaceutical industries, and lay the foundation for the Hemerocallis flower color research. [ABSTRACT FROM AUTHOR]

Boron (B) is an essential micronutrient for the plant normal growth. In Arabidopsis , NIP6;1 is a boric acid channel required for the proper distribution of boric acid, especially in the nodal regions of shoots. BnaA02.NIP6;1a , a homologous gene of AtNIP6;1 in Brassica napus , was reported to play a key role in B transport activity. However, little is known about the other functions of BnaA02.NIP6;1a in Brassica napus. In this study, we found that BnaA02.NIP6; 1a was localized in both plasma membrane and cytoplasm, which was different from that in Arabidopsis. The transgenic Arabidopsis plant containing a BnaA02.NIP6;1a promoter driven GUS reporter gene displayed strong GUS activity in roots, stems, leaves, especially in buds and open flowers, which are different from the expression pattern from its homologous gene in Arabidopsis. Silencing BnaA02.NIP6;1a repressed vegetative growth under B-deficient condition in Brassica napus. More importantly, knockdown of BnaA02.NIP6;1a in rapeseed resulted in the reduction of boron accumulation in the flower under boron deficiency and lead to severe sterility, which has not yet been reported before. Furthermore, nip6;1 mutant in Arabidopsis only showed the loss of apical dominance phenotype under boron deficiency at reproductive stage, whereas BnaA02.NIP6;1 RNAi lines exhibited large amounts of abnormal development of the inflorescence as compared with the wild type under boron limitation. Taken together, our results demonstrate that BnaA02.NIP6;1a encodes a boron transporter required for plant development under boron deficiency in Brassica napus , which shows its novel and diverse function in rapeseed compared with model plant Arabidopsis. • Distinct BnaA02.NIP6;1a GUS activity was observed in Arabidopsis compared with that of Arabidopsis NIP6;1. • Overexpressing BnaA02.NIP6;1a rescued the seedling phenotype of nip6;1-3 in Arabidopsis under B limitation. • Knockdown of BnaA02.NIP6;1a in Brassica napus increased the sensitivity of the RNAi line seedlings to B deficiency. • Novel role of B transporter BnaA02.NIP6; 1a for the inflorescence development in Brassica napus. • Knockdown of BnaA02.NIP6;1a inhibits the cell enlargement of floral organs in Brassica napus. [ABSTRACT FROM AUTHOR]

Lumnitzera littorea (Jack) Voigt is among the most endangered mangrove species in China. The morphology and evolution of L. littorea flowers have received substantial attention for their crucial reproductive functions. However, little is known about the genomic regulation of flower development in L. littorea. In this study, we characterized the morphology of two kinds of L. littorea flowers and performed comparative analyses of transcriptome profiles of the two different flowers. Morphological observation showed that some flowers have a column embedded in the petals while others produce a stretched flower style during petal unfolding in flowering. By using RNA-seq, we obtained 138,857 transcripts that were assembled into 82,833 unigenes with a mean length of 1055.48 bp. 82,834 and 34,997 unigenes were assigned to 52 gene ontology (GO) functional groups and 364 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. A total of 4,267 differentially expressed genes (DEGs), including 1,794 transcription factors (TFs), were identified between two types of flowers. These TFs are mainly involved in bHLH, B3, bZIP, MYB-related, and NAC family members. We further validated that 12 MADS-box genes, including 4 MIKC-type and 8 M-type TFs, were associated with the pollinate of L. littorea by herkogamy. Our current results provide valuable information for genetic analysis of L. littorea flowering and may be useful for illuminating its adaptive evolutionary mechanisms.

Abstract Background MADS-box genes encode a large family of transcription factors that play significant roles in plant growth and development. Bamboo is an important non-timber forest product worldwide, but previous studies on the moso bamboo (Phyllostachys edulis) MADS-box gene family were not accurate nor sufficiently detailed. Results Here, a complete genome-wide identification and characterization of the MADS-box genes in moso bamboo was conducted. There was an unusual lack of type-I MADS-box genes in the bamboo genome database (http://202.127.18.221/bamboo/index.php), and some of the PeMADS sequences are fragmented and/or inaccurate. We performed several bioinformatics techniques to obtain more precise sequences using transcriptome assembly. In total, 42 MADS-box genes, including six new type-I MADS-box genes, were identified in bamboo, and their structures, phylogenetic relationships, predicted conserved motifs and promoter cis-elements were systematically investigated. An expression analysis of the bamboo MADS-box genes in floral organs and leaves revealed that several key members are involved in bamboo inflorescence development, like their orthologous genes in Oryza. The ectopic overexpression of one MADS-box gene, PeMADS5, in Arabidopsis triggered an earlier flowering time and the development of an aberrant flower phenotype, suggesting that PeMADS5 acts as a floral activator and is involved in bamboo flowering. Conclusion We produced the most comprehensive information on MADS-box genes in moso bamboo. Additionally, a critical PeMADS gene (PeMADS5) responsible for the transition from vegetative to reproductive growth was identified and shown to be related to bamboo floral development.

Abstract Background Flower morphology, a phenomenon regulated by a complex network, is one of the vital ornamental features in Nelumbo nucifera. Stamen petaloid is very prevalent in lotus flowers. However, the mechanism underlying this phenomenon is still obscure. Results Here, the comparative transcriptomic analysis was performed among petal, stamen petaloid and stamen through RNA-seq. Using pairwise comparison analysis, a large number of genes involved in hormonal signal transduction pathways and transcription factors, especially the MADS-box genes, were identified as candidate genes for stamen petaloid in lotus. Conclusions Taken together, these results provide an insight into the molecular networks underlying lotus floral organ development and stamen petaloid.

Developmentally programmed cell death (dPCD) is a tightly controlled biological process. In recent years, vital roles of dPCD on regulating floral organ growth and development have been reported. It is well known that flower is an essential organ for reproduction and a turning point of plants' life cycle. Hence, uncovering the complex molecular networks which regulates dPCD processes in floral organs is utmost important. So far, our understanding of dPCD on floral organ growth and development is just starting. Herein, we summarize the important factors that involved in the tapetal degeneration, pollen tube rupture, receptive synergid cell death, nucellar degradation, and antipodal cell degradation. Meanwhile, the known factors that involved in transmitting tract formation and self-incompatibility-induced PCD were also introduced. Furthermore, the genes that associated with anther dehiscence and petal senescence and abscission were reviewed as well. The functions of various types of factors involved in floral dPCD processes are highlighted principally. The regulatory panorama described here can provide us some insights about flower-specific dPCD process. • Developmentally programmed cell death (dPCD) plays essential roles in floral organ growth, development, and senescence. • dPCD process was observed in nine types of floral organs. • Regulatory networks of dPCD in floral organs were delineated in this review. [ABSTRACT FROM AUTHOR]

Lumnitzera littorea (Jack) Voigt is among the most endangered mangrove species in China. The morphology and evolution of L. littorea flowers have received substantial attention for their crucial reproductive functions. However, little is known about the genomic regulation of flower development in L. littorea. In this study, we characterized the morphology of two kinds of L. littorea flowers and performed comparative analyses of transcriptome profiles of the two different flowers. Morphological observation showed that some flowers have a column embedded in the petals while others produce a stretched flower style during petal unfolding in flowering. By using RNA-seq, we obtained 138,857 transcripts that were assembled into 82,833 unigenes with a mean length of 1055.48 bp. 82,834 and 34,997 unigenes were assigned to 52 gene ontology (GO) functional groups and 364 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. A total of 4,267 differentially expressed genes (DEGs), including 1,794 transcription factors (TFs), were identified between two types of flowers. These TFs are mainly involved in bHLH, B3, bZIP, MYB-related, and NAC family members. We further validated that 12 MADS-box genes, including 4 MIKC-type and 8 M-type TFs, were associated with the pollinate of L. littorea by herkogamy. Our current results provide valuable information for genetic analysis of L. littorea flowering and may be useful for illuminating its adaptive evolutionary mechanisms. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)