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Chen Y, Shen Q, Lyu P, Lin R, Sun C. Identification and expression profiling of selected MADS-box family genes in Dendrobium officinale. Genetica 2019; 147:303-313. [PMID: 31292836 DOI: 10.1007/s10709-019-00071-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/05/2019] [Indexed: 11/24/2022]
Abstract
Dendrobium officinale, a herb with highly medicinal and ornamental value, is widely distributed in China. MADS-box genes encode transcription factors that regulate various growth and developmental processes in plants, particular in flowering. However, the MADS-box genes in D. officinale are largely unknown. In our study, expression profiling analyses of selected MADS-box genes in D. officinale were performed. In total, 16 DnMADS-box genes with full-length ORF were identified and named according to their phylogenetic relationships with model plants. The transient expression of eight selected MADS-box genes in the epidermal cells of tobacco leaves showed that these DnMADS-box proteins localized to the nucleus. Tissue-specific expression analysis pointed out eight flower-specific expressed MADS-box genes in D. officinale. Furthermore, expression patterns of DnMADS-box genes were investigated during the floral transition process. DnMADS3, DnMADS8 and DnMADS22 were significantly up-regulated in the reproductive phase compared with the vegetative phase, suggesting putative roles of these DnMADS-box genes in flowering. Our data showed that the expressions of MADS-box genes in D. officinale were controlled by diverse exogenous phytohormones. Together, these findings will facilitate further studies of MADS-box genes in Orchids and broaden our understanding of the genetics of flowering.
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Affiliation(s)
- Yue Chen
- Institute of Horticulture, Zhejiang Academy of Agriculture Science, Hangzhou, Zhejiang, People's Republic of China.,Key laboratory of creative Agriculture, Ministry of Agriculture, Hangzhou, People's Republic of China
| | - Qi Shen
- Plant Protection and Microbiology, Zhejiang Academy of Agricultural Science, Hangzhou, Zhejiang, People's Republic of China
| | - Ping Lyu
- Lin'an Agricultural & Forestry Technology Extension Center, Hangzhou, Zhejiang, People's Republic of China
| | - Renan Lin
- Yueqing Forestry Varieties Tech Center, Yueqing, Zhejiang, People's Republic of China
| | - Chongbo Sun
- Institute of Horticulture, Zhejiang Academy of Agriculture Science, Hangzhou, Zhejiang, People's Republic of China. .,Key laboratory of creative Agriculture, Ministry of Agriculture, Hangzhou, People's Republic of China.
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2
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The MADS-box genes expressed in the inflorescence of Orchis italica (Orchidaceae). PLoS One 2019; 14:e0213185. [PMID: 30822337 PMCID: PMC6396907 DOI: 10.1371/journal.pone.0213185] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 02/15/2019] [Indexed: 11/21/2022] Open
Abstract
The Orchidaceae family, which is one of the most species-rich flowering plant families, includes species with highly diversified and specialized flower shapes. The aim of this study was to analyze the MADS-box genes expressed in the inflorescence of Orchis italica, a wild Mediterranean orchid species. MADS-box proteins are transcription factors involved in various plant biological processes, including flower development. In the floral tissues of O. italica, 29 MADS-box genes are expressed that are classified as both class I and II. Class I MADS-box genes include one Mβ-type gene, thereby confirming the presence of this type of MADS-box genes in orchids. The class II MIKC* gene is highly expressed in the column, which is consistent with the conserved function of the MIKC* genes in gametophyte development. In addition, homologs of the SOC, SVP, ANR1, AGL12 and OsMADS32 genes are expressed. Compared with previous knowledge on class II MIKCC genes of O. italica involved in the ABCDE model of flower development, the number of class B and D genes has been confirmed. In addition, 4 class A (AP1/FUL) transcripts, 2 class E (SEP) transcripts, 2 new class C (AG) transcripts and 1 new AGL6 transcript have been identified. Within the AP1/FUL genes, the sequence divergence, relaxation of purifying selection and expression profiles suggest a possible functional diversification within these orchid genes. The detection of only two SEP transcripts in O. italica, in contrast with the 4 genes found in other orchids, suggests that only two SEP genes could be present in the subfamily Orchidoideae. The expression pattern of the MIKCC genes of O. italica indicates that low levels at the boundary of the domain of a given MADS-box gene can overlap with the expression of genes belonging to a different functional A-E class in the adjacent domain, thereby following a “fading borders” model.
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Valoroso MC, Sobral R, Saccone G, Salvemini M, Costa MMR, Aceto S. Evolutionary Conservation of the Orchid MYB Transcription Factors DIV, RAD, and DRIF. FRONTIERS IN PLANT SCIENCE 2019; 10:1359. [PMID: 31736999 PMCID: PMC6838138 DOI: 10.3389/fpls.2019.01359] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/02/2019] [Indexed: 05/02/2023]
Abstract
The MYB transcription factors DIVARICATA (DIV), DIV-and-RAD-Interacting-Factor (DRIF), and the small interfering peptide RADIALIS (RAD) can interact, forming a regulatory module that controls different plant developmental processes. In the snapdragon Antirrhinum majus, this module, together with the TCP transcription factor CYCLOIDEA (CYC), is responsible for the establishment of floral dorsoventral asymmetry. The spatial gene expression pattern of the OitDIV, OitDRIF, and OitRAD homologs of Orchis italica, an orchid with zygomorphic flowers, has suggested a possible conserved role of these genes in bilateral symmetry of the orchid flower. Here, we have identified four DRIF genes of orchids and have reconstructed their genomic organization and evolution. In addition, we found snapdragon transcriptional cis-regulatory elements of DIV and RAD loci generally conserved within the corresponding orchid orthologues. We have tested the biochemical interactions among OitDIV, OitDRIF1, and OitRAD of O. italica, showing that OitDRIF1 can interact both with OitDIV and OitRAD, whereas OitDIV and OitRAD do not directly interact, as in A. majus. The analysis of the quantitative expression profile of these MYB genes revealed that in zygomorphic orchid flowers, the DIV, DRIF1, and RAD transcripts are present at higher levels in the lip than in lateral inner tepals, whereas in peloric orchid flowers they show similar expression levels. These results indicate that MYB transcription factors could have a role in shaping zygomorphy of the orchid flower, potentially enriching the underlying orchid developmental code.
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Affiliation(s)
| | - Rómulo Sobral
- BioSystems & Integrative Sciences Institute (BioISI), Plant Functional Biology Centre, University of Minho, Campus de Gualtar, Braga, Portugal
| | - Giuseppe Saccone
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Marco Salvemini
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Maria Manuela Ribeiro Costa
- BioSystems & Integrative Sciences Institute (BioISI), Plant Functional Biology Centre, University of Minho, Campus de Gualtar, Braga, Portugal
| | - Serena Aceto
- Department of Biology, University of Naples Federico II, Naples, Italy
- *Correspondence: Serena Aceto,
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Wang SL, Viswanath KK, Tong CG, An HR, Jang S, Chen FC. Floral Induction and Flower Development of Orchids. FRONTIERS IN PLANT SCIENCE 2019; 10:1258. [PMID: 31649713 PMCID: PMC6795766 DOI: 10.3389/fpls.2019.01258] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 09/10/2019] [Indexed: 05/19/2023]
Abstract
Orchids comprise one of the largest, most highly evolved angiosperm families, and form an extremely peculiar group of plants. Various orchids are available through traditional breeding and micro-propagation since they are valuable as potted plants and/or cut flowers in horticultural markets. The flowering of orchids is generally influenced by environmental signals such as temperature and endogenous developmental programs controlled by genetic factors as is usual in many flowering plant species. The process of floral transition is connected to the flower developmental programs that include floral meristem maintenance and floral organ specification. Thanks to advances in molecular and genetic technologies, the understanding of the molecular mechanisms underlying orchid floral transition and flower developmental processes have been widened, especially in several commercially important orchids such as Phalaenopsis, Dendrobium and Oncidium. In this review, we consolidate recent progress in research on the floral transition and flower development of orchids emphasizing representative genes and genetic networks, and also introduce a few successful cases of manipulation of orchid flowering/flower development through the application of molecular breeding or biotechnology tools.
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Affiliation(s)
- Shan-Li Wang
- Biotechnology Center in Southern Taiwan (BCST) of the Agricultural Biotechnology Research Center (ABRC), Academia Sinica, Tainan, Taiwan
| | - Kotapati Kasi Viswanath
- Department of Plant Industry, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Chii-Gong Tong
- Biotechnology Center in Southern Taiwan (BCST) of the Agricultural Biotechnology Research Center (ABRC), Academia Sinica, Tainan, Taiwan
| | - Hye Ryun An
- National Institute of Horticultural and Herbal Science (NIHHS), Rural Development Administration (RDA), Wanju-gun, South Korea
| | - Seonghoe Jang
- World Vegetable Center Korea Office (WKO), Wanju-gun, South Korea
- *Correspondence: Seonghoe Jang, ; Fure-Chyi Chen,
| | - Fure-Chyi Chen
- Department of Plant Industry, National Pingtung University of Science and Technology, Pingtung, Taiwan
- *Correspondence: Seonghoe Jang, ; Fure-Chyi Chen,
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Valoroso MC, De Paolo S, Iazzetti G, Aceto S. Transcriptome-Wide Identification and Expression Analysis of DIVARICATA- and RADIALIS-Like Genes of the Mediterranean Orchid Orchis italica. Genome Biol Evol 2017; 9:3852528. [PMID: 28541415 PMCID: PMC5499889 DOI: 10.1093/gbe/evx101] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2017] [Indexed: 02/01/2023] Open
Abstract
Bilateral symmetry of flowers is a relevant novelty that has occurred many times throughout the evolution of flowering plants. In Antirrhinum majus, establishment of flower dorso-ventral asymmetry is mainly due to interaction of TCP (CYC and DICH) and MYB (DIV, RAD, and DRIF) transcription factors. In the present study, we characterized 8 DIV-, 4 RAD-, and 2 DRIF-like genes from the transcriptome of Orchis italica, an orchid species with bilaterally symmetric and resupinate flowers. We found a similar number of DIV- and RAD-like genes within the genomes of Phalaenopsis equestris and Dendrobium catenatum orchids. Orchid DIV- and RAD-like proteins share conserved motifs whose distribution reflects their phylogeny and analysis of the genomic organization revealed a single intron containing many traces of transposable elements. Evolutionary analysis has shown that purifying selection acts on the DIV- and RAD-like coding regions in orchids, with relaxation of selective constraints in a branch of the DIV-like genes. Analysis of the expression patterns of DIV- and RAD-like genes in O. italica revealed possible redundant functions for some of them. In the perianth of O. italica, the ortholog of DIV and DRIF of A. majus are expressed in all tissues, whereas RAD is mainly expressed in the outer tepals and lip. These data allow for proposal of an evolutionary conserved model in which the expression of the orthologs of the DIV, RAD, and DRIF genes might be related to establishment of flower bilateral symmetry in the nonmodel orchid species O. italica.
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Affiliation(s)
| | - Sofia De Paolo
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Giovanni Iazzetti
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Serena Aceto
- Department of Biology, University of Naples Federico II, Naples, Italy
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6
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De Paolo S, Gaudio L, Aceto S. Analysis of the TCP genes expressed in the inflorescence of the orchid Orchis italica. Sci Rep 2015; 5:16265. [PMID: 26531864 PMCID: PMC4632031 DOI: 10.1038/srep16265] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/13/2015] [Indexed: 11/09/2022] Open
Abstract
TCP proteins are plant-specific transcription factors involved in many different processes. Because of their involvement in a large number of developmental pathways, their roles have been investigated in various plant species. However, there are almost no studies of this transcription factor family in orchids. Based on the available transcriptome of the inflorescence of the orchid Orchis italica, in the present study we identified 12 transcripts encoding TCP proteins. The phylogenetic analysis showed that they belong to different TCP classes (I and II) and groups (PCF, CIN and CYC/TB1), and that they display a number of conserved motifs when compared with the TCPs of Arabidopsis and Oryza. The presence of a specific cleavage site for the microRNA miRNA319, an important post-transcriptional regulator of several TCP genes in other species, was demonstrated for one transcript of O. italica, and the analysis of the expression pattern of the TCP transcripts in different inflorescence organs and in leaf tissue suggests that some TCP transcripts of O. italica exert their role only in specific tissues, while others may play multiple roles in different tissues. In addition, the evolutionary analysis showed a general purifying selection acting on the coding region of these transcripts.
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Affiliation(s)
- Sofia De Paolo
- Department of Biology, University of Naples Federico II, Napoli, Italy
| | - Luciano Gaudio
- Department of Biology, University of Naples Federico II, Napoli, Italy
| | - Serena Aceto
- Department of Biology, University of Naples Federico II, Napoli, Italy
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Sasaki K, Yamaguchi H, Nakayama M, Aida R, Ohtsubo N. Co-modification of class B genes TfDEF and TfGLO in Torenia fournieri Lind. alters both flower morphology and inflorescence architecture. PLANT MOLECULAR BIOLOGY 2014; 86:319-34. [PMID: 25082268 DOI: 10.1007/s11103-014-0231-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 07/23/2014] [Indexed: 05/27/2023]
Abstract
The class B genes DEFICIENS (DEF)/APETALA3 (AP3) and GLOBOSA (GLO)/PISTILLATA (PI), encoding MADS-box transcription factors, and their functions in petal and stamen development have been intensely studied in Arabidopsis and Antirrhinum. However, the functions of class B genes in other plants, including ornamental species exhibiting floral morphology different from these model plants, have not received nearly as much attention. Here, we examine the cooperative functions of TfDEF and TfGLO on floral organ development in the ornamental plant torenia (Torenia fournieri Lind.). Torenia plants co-overexpressing TfDEF and TfGLO showed a morphological alteration of sepals to petaloid organs. Phenotypically, these petaloid sepals were nearly identical to petals but had no stamens or yellow patches like those of wild-type petals. Furthermore, the inflorescence architecture in the co-overexpressing torenias showed a characteristic change in which, unlike the wild-types, their flowers developed without peduncles. Evaluation of the petaloid sepals showed that these attained a petal-like nature in terms of floral organ phenotype, cell shape, pigment composition, and the expression patterns of anthocyanin biosynthesis-related genes. In contrast, torenias in which TfDEF and TfGLO were co-suppressed exhibited sepaloid petals in the second whorl. The sepaloid petals also attained a sepal-like nature, in the same way as the petaloid sepals. The results clearly demonstrate that TfDEF and TfGLO play important cooperative roles in petal development in torenia. Furthermore, the unique transgenic phenotypes produced create a valuable new way through which characteristics of petal development and inflorescence architecture can be investigated in torenia.
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Affiliation(s)
- Katsutomo Sasaki
- NARO Institute of Floricultural Science (NIFS), National Agriculture and Food Research Organization (NARO), Fujimoto 2-1, Tsukuba, Ibaraki, 305-8519, Japan
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8
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De Paolo S, Salvemini M, Gaudio L, Aceto S. De novo transcriptome assembly from inflorescence of Orchis italica: analysis of coding and non-coding transcripts. PLoS One 2014; 9:e102155. [PMID: 25025767 PMCID: PMC4099010 DOI: 10.1371/journal.pone.0102155] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 06/16/2014] [Indexed: 01/09/2023] Open
Abstract
The floral transcriptome of Orchis italica, a wild orchid species, was obtained using Illumina RNA-seq technology and specific de novo assembly and analysis tools. More than 100 million raw reads were processed resulting in 132,565 assembled transcripts and 86,079 unigenes with an average length of 606 bp and N50 of 956 bp. Functional annotation assigned 38,984 of the unigenes to records present in the NCBI non-redundant protein database, 32,161 of them to Gene Ontology terms, 15,775 of them to Eukaryotic Orthologous Groups (KOG) and 7,143 of them to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The in silico expression analysis based on the Fragments Per Kilobase of transcript per Million mapped reads (FPKM) was confirmed by real-time RT-PCR experiments on 10 selected unigenes, which showed high and statistically significant positive correlation with the RNA-seq based expression data. The prediction of putative long non-coding RNAs was assessed using two different software packages, CPC and Portrait, resulting in 7,779 unannotated unigenes that matched the threshold values for both of the analyses. Among the predicted long non-coding RNAs, one is the homologue of TAS3, a long non-coding RNA precursor of trans-acting small interfering RNAs (ta-siRNAs). The differential expression pattern observed for the selected putative long non-coding RNAs suggests their possible functional role in different floral tissues.
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Affiliation(s)
- Sofia De Paolo
- Department of Biology, University of Naples Federico II, Napoli, Italy
| | - Marco Salvemini
- Department of Biology, University of Naples Federico II, Napoli, Italy
| | - Luciano Gaudio
- Department of Biology, University of Naples Federico II, Napoli, Italy
| | - Serena Aceto
- Department of Biology, University of Naples Federico II, Napoli, Italy
- * E-mail:
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The analysis of the inflorescence miRNome of the orchid Orchis italica reveals a DEF-like MADS-box gene as a new miRNA target. PLoS One 2014; 9:e97839. [PMID: 24832004 PMCID: PMC4022656 DOI: 10.1371/journal.pone.0097839] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 04/25/2014] [Indexed: 01/08/2023] Open
Abstract
Plant microRNAs (miRNAs) are small, regulatory non-coding RNAs involved in a wide range of biological processes, from organ development to response to stimuli. In recent years, an increasing number of studies on model plant species have highlighted the evolutionary conservation of a high number of miRNA families and the existence of taxon-specific ones. However, few studies have examined miRNAs in non-model species such as orchids, which are characterized by highly diversified floral structures and pollination strategies. Therefore, we analysed a small RNA library of inflorescence tissue of the Mediterranean orchid Orchis italica to increase the knowledge on miRNAs in a non-model plant species. The high-throughput sequencing and analysis of a small RNA library of inflorescence of O. italica revealed 23 conserved and 161 putative novel miRNA families. Among the putative miRNA targets, experimental validation demonstrated that a DEF-like MADS-box transcript is cleaved by the homolog of miR5179 of O. italica. The presence of conserved miRNA families in the inflorescence of O. italica indicates that the basic developmental flower regulatory mechanisms mediated by miRNAs are maintained through evolution. Because, according to the "orchid code" theory, DEF-like genes exert a key function in the diversification of tepals and lip, the cleavage-mediated inhibitory activity of miR5179 on a OitaDEF-like transcript suggests that, in orchids, miRNAs play an important role in the diversification of the perianth organs.
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Su CL, Chen WC, Lee AY, Chen CY, Chang YCA, Chao YT, Shih MC. A modified ABCDE model of flowering in orchids based on gene expression profiling studies of the moth orchid Phalaenopsis aphrodite. PLoS One 2013; 8:e80462. [PMID: 24265826 PMCID: PMC3827201 DOI: 10.1371/journal.pone.0080462] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 10/02/2013] [Indexed: 12/21/2022] Open
Abstract
Previously we developed genomic resources for orchids, including transcriptomic analyses using next-generation sequencing techniques and construction of a web-based orchid genomic database. Here, we report a modified molecular model of flower development in the Orchidaceae based on functional analysis of gene expression profiles in Phalaenopsis aphrodite (a moth orchid) that revealed novel roles for the transcription factors involved in floral organ pattern formation. Phalaenopsis orchid floral organ-specific genes were identified by microarray analysis. Several critical transcription factors including AP3, PI, AP1 and AGL6, displayed distinct spatial distribution patterns. Phylogenetic analysis of orchid MADS box genes was conducted to infer the evolutionary relationship among floral organ-specific genes. The results suggest that gene duplication MADS box genes in orchid may have resulted in their gaining novel functions during evolution. Based on these analyses, a modified model of orchid flowering was proposed. Comparison of the expression profiles of flowers of a peloric mutant and wild-type Phalaenopsis orchid further identified genes associated with lip morphology and peloric effects. Large scale investigation of gene expression profiles revealed that homeotic genes from the ABCDE model of flower development classes A and B in the Phalaenopsis orchid have novel functions due to evolutionary diversification, and display differential expression patterns.
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Affiliation(s)
- Chun-lin Su
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Wan-Chieh Chen
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Ann-Ying Lee
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Chun-Yi Chen
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Yao-Chien Alex Chang
- Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei, Taiwan
| | - Ya-Ting Chao
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Ming-Che Shih
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
- * E-mail:
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Salemme M, Sica M, Iazzetti G, Gaudio L, Aceto S. The AP2-like gene OitaAP2 is alternatively spliced and differentially expressed in inflorescence and vegetative tissues of the orchid Orchis italica. PLoS One 2013; 8:e77454. [PMID: 24204832 PMCID: PMC3804621 DOI: 10.1371/journal.pone.0077454] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 09/02/2013] [Indexed: 11/23/2022] Open
Abstract
The AP2/ERF proteins are plant-specific transcription factors involved in multiple regulatory pathways, from plant organ development to response to various environmental stresses. One of the mechanisms that regulates the AP2-like genes involves the microRNA miR172, which controls their activity at the post-transcriptional level. Extensive studies on AP2-like genes are available in many different species; however, in orchids, one of the largest plant families, studies are restricted to a few species, all belonging to the Epidendroideae subfamily. In the present study, we report the isolation of an AP2-like gene in the Mediterranean orchid Orchis italica (Orchidoideae). The OitaAP2 locus includes 10 exons and 9 introns, and its transcript is alternatively spliced, resulting in the long OitaAP2 and the short OitaAP2_ISO isoforms, with the latter skipping exon 9. Both isoforms contain the conserved target site for miR172, whose action is demonstrated by the presence of cleaved OitaAP2 mRNA. The OitaAP2 and OitaAP2_ISO mRNAs are present in the tepals and lip before and after anthesis at different expression levels. In addition, the OitaAP2_ISO isoform is expressed in the ovary before pollination and in the root and stem. The isoform-specific expression pattern suggests a functional differentiation of the OitaAP2 alternatively spliced transcripts. The expression profile of miR172 is complementary to that of the OitaAP2 isoforms in inflorescence tissues before anthesis, whereas after anthesis and in ovary tissue before and after pollination, this relationship disappears, suggesting the existence of OitaAP2 inhibitory mechanisms in these tissues that differ from that involving miR172.
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Affiliation(s)
- Marinella Salemme
- Department of Biology, University of Naples Federico II, Napoli, Italy
| | - Maria Sica
- Department of Biology, University of Naples Federico II, Napoli, Italy
| | - Giovanni Iazzetti
- Department of Biology, University of Naples Federico II, Napoli, Italy
| | - Luciano Gaudio
- Department of Biology, University of Naples Federico II, Napoli, Italy
| | - Serena Aceto
- Department of Biology, University of Naples Federico II, Napoli, Italy
- * E-mail:
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12
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Salemme M, Sica M, Gaudio L, Aceto S. The OitaAG and OitaSTK genes of the orchid Orchis italica: a comparative analysis with other C- and D-class MADS-box genes. Mol Biol Rep 2013; 40:3523-35. [PMID: 23277396 DOI: 10.1007/s11033-012-2426-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 12/18/2012] [Indexed: 10/27/2022]
Abstract
According to the ABCDE model of flower development, the C- and D- class MADS box genes are involved in the formation of male and female reproductive organs (fused to form the column in orchids) and in ovule maturation (triggered by fertilization in orchids). In the present study, we report the isolation of the Orchis italica genes OitaAG and OitaSTK, homologs of the C-class AGAMOUS and the D-class SEEDSTICK genes of Arabidopsis, respectively. Analysis of their expression profiles reveals high levels of mRNA in columns and ovaries, particularly after pollination. However, weak expression is also detectable in the inner tepals (OitaAG) and the lip and root (OitaSTK). This expression profile is only partially overlapping with those reported in other orchid species and may be the consequence of a different evolutionary history of these functional gene classes in orchids. The genomic characterization of the OitaAG and OitaSTK genes shows that a high number of traces of mobile elements are present in introns and could have contributed to the size expansion of some of them (e.g., intron 2 and 3 of OitaAG and intron 3, 4 and 5 of OitaSTK). Nucleotide sequences of intron 1 of the OitaSTK gene and other STK-like genes do not share regulatory motifs, whereas sequence comparison of intron 2 of the OitaAG gene with that of intron 2 of other AG-like genes reveals, for the first time in an orchid species, the presence of conserved cis-regulatory boxes and binding sites for transcription factors that positively (e.g., LEAFY and WUSCHEL) or negatively (e.g., BELLRINGER) regulate the expression of the AG homologs in dicots and monocots.
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Affiliation(s)
- Marinella Salemme
- Department of Biological Sciences, University of Naples Federico II, via Mezzocannone 8, 80134 Naples, Italy
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13
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Chen YY, Lee PF, Hsiao YY, Wu WL, Pan ZJ, Lee YI, Liu KW, Chen LJ, Liu ZJ, Tsai WC. C- and D-class MADS-box genes from Phalaenopsis equestris (Orchidaceae) display functions in gynostemium and ovule development. PLANT & CELL PHYSIOLOGY 2012; 53:1053-67. [PMID: 22499266 DOI: 10.1093/pcp/pcs048] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Gynostemium and ovule development in orchid are unique developmental processes in the plant kingdom. Characterization of C- and D-class MADS-box genes could help reveal the molecular mechanisms underlying gynostemium and ovule development in orchids. In this study, we isolated and characterized a C- and a D-class gene, PeMADS1 and PeMADS7, respectively, from Phalaenopsis equestris. These two genes showed parallel spatial and temporal expression profiles, which suggests their cooperation in gynostemium and ovule development. Furthermore, only PeMADS1 was ectopically expressed in the petals of the gylp (gynostemium-like petal) mutant, whose petals were transformed into gynostemium-like structures. Protein-protein interaction analyses revealed that neither PeMADS1 and PeMADS7 could form a homodimer or a heterodimer. An E-class protein was needed to bridge the interaction between these two proteins. A complementation test revealed that PeMADS1 could rescue the phenotype of the AG mutant. Overexpression of PeMADS7 in Arabidopsis caused typical phenotypes of the D-class gene family. Together, these results indicated that both C-class PeMADS1 and D-class PeMADS7 play important roles in orchid gynostemium and ovule development.
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MESH Headings
- Amino Acid Sequence
- DNA, Plant/genetics
- DNA, Plant/metabolism
- Gene Expression Profiling
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Plant
- Genes, Plant
- Genetic Complementation Test
- MADS Domain Proteins/genetics
- MADS Domain Proteins/metabolism
- Microscopy, Electron, Scanning
- Molecular Sequence Data
- Orchidaceae/anatomy & histology
- Orchidaceae/genetics
- Orchidaceae/growth & development
- Ovule/genetics
- Ovule/growth & development
- Ovule/ultrastructure
- Phenotype
- Phylogeny
- Plant Proteins/genetics
- Plant Proteins/metabolism
- Plants, Genetically Modified/anatomy & histology
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/growth & development
- Pollination
- Protein Interaction Mapping
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Affiliation(s)
- You-Yi Chen
- Institute of Tropical Plant Sciences, National Cheng Kung University, Tainan 701, Taiwan
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