Floral Ontogeny of<i>Telipogon</i>spp. (Orchidaceae) and Insights on the Perianth Symmetry in the Family

Pabón‐Mora, Natalia; González, Favio

doi:10.1086/591982

Cited by 19 publications

(7 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These modes of initiation can coexist in the same family or even the same species; for example, Viola odorata L. has bidirectional sepal initiation and unidirectional petal initiation (Mayers & Lord, 1984). It should be noted that the presence of strictly lateral organs is necessary to make a distinction between unidirectional, bidirectional and reverse bidirectional; these three modes are essentially the same for trimerous whorls (e.g., the Orchidaceae species described by Pabón-Mora & González, 2008) or tetramerous whorls that initiate organs two by two (e.g., the sepals of Veronica speciosa R.Cunn. ex A.Cunn.…”

Section: Cardiopteris Quinquelobamentioning

confidence: 99%

Perianth symmetry changed at least 199 times in angiosperm evolution

Reyes

Sauquet

Nadot

2016

TAXON

View full text Add to dashboard Cite

Perianth bilateral symmetry (zygomorphy) has evolved repeatedly from radial symmetry (actinomorphy) throughout angiosperms. Zygomorphy has previously been linked with plant‐pollinator specialization and higher species diversification. However, the exact number of transitions to and from zygomorphy has remained so far unknown. We recorded perianth symmetry from 761 species, selected to represent all 61 orders and 426 currently accepted families of angiosperms and to include all presumed origins of perianth zygomorphy. We then reconstructed the evolution of perianth symmetry on a consensus backbone tree, using parsimony. We found perianth zygomorphy in 32 orders and 110 families. There was a minimum of 130 origins, almost double of what was previously estimated, and 69 reversals to actinomorphy. Among the origins, 2 were in magnoliids, 29 in monocots, 17 in basal eudicots, 35 in superrosids and 47 in superasterids. Among the reversals, 8 were in monocots, 4 in basal eudicots, 18 in superrosids and 39 in superasterids. This study shows that there has been many more origins of perianth zygomorphy and reversals to actinomorphy than previously shown. We then use this new framework to review the developmental evidence of changes in floral symmetry, showing convergence in the early stages of zygomorphy across angiosperms at the developmental level. We also review the evidence on the genetic control of floral symmetry, suggesting that a restricted number of genes has been recruited multiple times independently to achieve zygomorphy. In contrast to its relative homogeneity at the early developmental and molecular level, zygomorphy appears to be highly variable in its morphological expression at anthesis, involving various processes such as perianth part displacement and differentiation. We then review recent hypotheses on the relationship between floral symmetry, floral orientation, and pollination mode in terms of selective advantages and constraints. Our comprehensive angiosperm‐wide reconstruction of floral symmetry evolution provides a new context for future studies on the developmental, functional, and macroevolutionary aspects of floral symmetry.

show abstract

Section: Cardiopteris Quinquelobamentioning

confidence: 99%

Perianth symmetry changed at least 199 times in angiosperm evolution

Reyes

Sauquet

Nadot

2016

TAXON

View full text Add to dashboard Cite

show abstract

“…With approximately 25,000 species, the Orchidaceae is one of the most diversified families of flowering plants. Orchid flowers exhibit predominantly bilateral symmetry as a result of the elaborated medial petal (called the lip) and the congenital fusion of one (rarely 3) stamens with the stigmas into a gynostemium (Pabón-Mora and González, 2008;Hsu et al, 2015). Such floral complexity is translated into exceedingly variable arrays of form, color and size which appeals the market for ornamental plants (Teixeira da Silva, 2013;Teixeira da Silva et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Evolution and Expression of Reproductive Transition Regulatory Genes FT/TFL1 With Emphasis in Selected Neotropical Orchids

et al. 2020

View full text Add to dashboard Cite

Flowering is a rigorously timed and morphologically complex shift in plant development. This change depends on endogenous as well as environmental factors. FLOWERING LOCUS T (FT) integrates several cues from different pathways acting as a flowering promoter. Contrary to the role of FT, its paralog TERMINAL FLOWER 1 (TFL1) delays floral transition. Although FT/TFL1 homologs have been studied in model eudicots and monocots, scarce studies are available in non-model monocots like the Orchidaceae. Orchids are very diverse and their floral complexity is translated into a unique aesthetic display, which appeals the ornamental plant market. Nonetheless, orchid trade faces huge limitations due to their long vegetative phase and intractable indoor flowering seasons. Little is known about the genetic basis that control reproductive transition in orchids and, consequently, manipulating their flowering time remains a challenge. In order to contribute to the understanding of the genetic bases that control flowering in orchids we present here the first broad-scale analysis of FT/TFL1-like genes in monocots with an expanded sampling in Orchidaceae. We also compare expression patterns in three selected species and propose hypotheses on the putative role of these genes in their reproductive transition. Our findings show that FT-like genes are by far more diversified than TFL1-like genes in monocots with six subclades in the former and only one in the latter. Within MonFT1, the comparative protein sequences of MonFT1A and MonFT1B suggest that they could have recruited functional roles in delaying flowering, a role typically assigned to TFL1-like proteins. On the other hand, MonFT2 proteins have retained their canonical motifs and roles in promoting flowering transition. This is also shown by their increased expression levels from the shoot apical meristem (SAM) and leaves to inflorescence meristems (IM) and floral buds (FBs). Finally, TFL1-like genes are retained as single copy and often times are lost. Their loss could be linked to the parallel recruitment of MonFT1A and MonFT1B homologs in delaying flowering and maintaining indeterminacy of the inflorescence meristem. These hypotheses lay the foundation for future functional validation in emerging model orchid species and comparative analyses in orchids with high horticultural potential in the market.

show abstract

“…Conversely, orchid flowers are variously bilateral and undergo extreme elaboration of some organs, including differentiation of perianth parts, stamen abortion, and fusion of floral parts from the same whorl or from different whorls (Rudall, 2002). In the bilateral resupinated orchid flowers the two dorsal petals are very similar to each other, whereas the ventral one (the lip or labellum) often undergoes extreme elaboration in shape, color, size and epidermal specializations (Rudall and Bateman, 2004; Pabón-Mora and González, 2008; Mondragón-Palomino and Theißen, 2009; Rudall et al, 2013; Endress, 2016). In the inner floral whorls bilateral symmetry is evident by the formation of a gynostemium that results from the congenital fusion between the single fertile stamen (sometimes two fertile stamens) and stigmas (Rudall and Bateman, 2002; Pabón-Mora and González, 2008; Endress, 2016).…”

Section: Introductionmentioning

confidence: 99%

“…In the bilateral resupinated orchid flowers the two dorsal petals are very similar to each other, whereas the ventral one (the lip or labellum) often undergoes extreme elaboration in shape, color, size and epidermal specializations (Rudall and Bateman, 2004; Pabón-Mora and González, 2008; Mondragón-Palomino and Theißen, 2009; Rudall et al, 2013; Endress, 2016). In the inner floral whorls bilateral symmetry is evident by the formation of a gynostemium that results from the congenital fusion between the single fertile stamen (sometimes two fertile stamens) and stigmas (Rudall and Bateman, 2002; Pabón-Mora and González, 2008; Endress, 2016). Such floral elaboration has been linked to extremely specialized pollination mechanisms and the exceedingly high diversification rates in Orchidaceae (Gong and Huang, 2009; Mondragón-Palomino and Theißen, 2009; Mondragón-Palomino, 2013).…”

Section: Introductionmentioning

confidence: 99%

Evolution and Expression Patterns of TCP Genes in Asparagales

2017

View full text Add to dashboard Cite

CYCLOIDEA-like genes are involved in the symmetry gene network, limiting cell proliferation in the dorsal regions of bilateral flowers in core eudicots. CYC-like and closely related TCP genes (acronym for TEOSINTE BRANCHED1, CYCLOIDEA, and PROLIFERATION CELL FACTOR) have been poorly studied in Asparagales, the largest order of monocots that includes both bilateral flowers in Orchidaceae (ca. 25.000 spp) and radially symmetrical flowers in Hypoxidaceae (ca. 200 spp). With the aim of assessing TCP gene evolution in the Asparagales, we isolated TCP-like genes from publicly available databases and our own transcriptomes of Cattleya trianae (Orchidaceae) and Hypoxis decumbens (Hypoxidaceae). Our matrix contains 452 sequences representing the three major clades of TCP genes. Besides the previously identified CYC specific core eudicot duplications, our ML phylogenetic analyses recovered an early CIN-like duplication predating all angiosperms, two CIN-like Asparagales-specific duplications and a duplication prior to the diversification of Orchidoideae and Epidendroideae. In addition, we provide evidence of at least three duplications of PCF-like genes in Asparagales. While CIN-like and PCF-like genes have multiplied in Asparagales, likely enhancing the genetic network for cell proliferation, CYC-like genes remain as single, shorter copies with low expression. Homogeneous expression of CYC-like genes in the labellum as well as the lateral petals suggests little contribution to the bilateral perianth in C. trianae. CIN-like and PCF-like gene expression suggests conserved roles in cell proliferation in leaves, sepals and petals, carpels, ovules and fruits in Asparagales by comparison with previously reported functions in core eudicots and monocots. This is the first large scale analysis of TCP-like genes in Asparagales that will serve as a platform for in-depth functional studies in emerging model monocots.

show abstract

Floral Ontogeny ofTelipogonspp. (Orchidaceae) and Insights on the Perianth Symmetry in the Family

Cited by 19 publications

References 27 publications

Perianth symmetry changed at least 199 times in angiosperm evolution

Perianth symmetry changed at least 199 times in angiosperm evolution

Evolution and Expression of Reproductive Transition Regulatory Genes FT/TFL1 With Emphasis in Selected Neotropical Orchids

Evolution and Expression Patterns of TCP Genes in Asparagales

Contact Info

Product

Resources

About