''Erycina pusilla'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s, which is a tiny orchid with an overall size of 2.5 to 3.5 cm from the orchid family,

Orchidaceae Orchids are plants that belong to the family (biology), family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan distribution, cosmopolitan plants that ...

. Its species are native to

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

Belize Belize is a country on the north-eastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a maritime boundary with Honduras to the southeast. P ...

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

and

Trinidad Trinidad is the larger, more populous island of the Republic of Trinidad and Tobago, the country. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is the southernmost island in ...

. The leaves are shaped like a lance head (

lanceolate The following terms are used to describe leaf plant morphology, morphology in the description and taxonomy (biology), taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade ...

) and arranged in a fan. Unlike other similar orchids, ''E. pusilla'' never develops lengthwise folded leaves ( conduplicate leaves) or extra storage organs (

pseudobulbs In botany, a pseudobulb is a storage organ found in many epiphytic and terrestrial sympodial orchids. It is derived from a thickening of the part of a stem between leaf nodes and may be composed of just one internode or several, termed ''heterob ...

). The blooming season is from fall to spring. It produces solitary light-yellow orchid-shaped flowers. In comparison to the overall plant size, these flowers can reach a relatively large size (1 to 2.5 cm). The lateral sepals are united near the flower base. Compared to other orchids, ''E. pusilla'' has a short life cycle (about 17 months). It can reach adulthood in just one season, while the majority of the orchids reach maturity in up to 5 years.

Name

It is commonly known as the tiny psygmorchis, due to its miniature size. The current scientific name is ''Erycina pusilla''. The etymology of its scientific name refers to its beauty and tiny size: ''“Erycina”'' is a

byname An epithet (, ), also a byname, is a descriptive term (word or phrase) commonly accompanying or occurring in place of the name of a real or fictitious person, place, or thing. It is usually literally descriptive, as in Alfred the Great, Suleima ...

of the Roman goddess for beauty,

Venus Venus is the second planet from the Sun. It is often called Earth's "twin" or "sister" planet for having almost the same size and mass, and the closest orbit to Earth's. While both are rocky planets, Venus has an atmosphere much thicker ...

(Venus of Eryx), and '' “pusilla” '' is Latin meaning “very little”. It was formerly classified in the genus ''Psygmorchis'', due to its fan-shaped leaves (“psygmos” Greek for fan).

Synonyms

Homotypic synonyms: * ''Epidendrum pusillum'' L., Sp. Pl. ed. 2: 1352 (1763) * ''Cymbidium pusillum'' (L.) Sw., Nova Acta Regiae Soc. Sci. Upsal. 6: 74 (1799). * ''Oncidium pusillum'' (L.) Mutel, Mém. Soc. Roy. Centr. Agric. Dépt. N. 1835-1836: 84 (1837). * ''Tolumnia pusilla'' (L.) Hoehne, Ic. Orch. Bras.: 231 (1949). * ''Psygmorchis pusilla'' (L.) Dodson & Dressler, Phytologia 24: 288 (1972). Heterotypic synonyms: * ''Oncidium iridifolium'' Kunth in F.W.H.von Humboldt, A.J.A.Bonpland & C.S.Kunth, Nov. Gen. Sp. 1: 344 (1816). * ''Epidendrum ventilabrum'' Vell., Fl. Flumin. 9: t. 32 (1831). * ''Oncidium allemanii'' Barb.Rodr., Gen. Spec. Orchid. 2: 185 (1882). * ''Oncidium pusillum'' var. megalanthum Schltr., Repert. Spec. Nov. Regni Veg. Beih. 27: 115 (1924). * ''Psygmorchis allemanii'' (Barb.Rodr.) Garay & Stacy, Bradea 1: 408 (1974). * ''Erycina allemanii'' (Barb.Rodr.) N.H.Williams & M.W.Chase, Lindleyana 16: 136 (2001).

Distribution and habitat

''Erycina pusilla'' can be found in the

neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeogra ...

region, including South and Central America, the southern Mexican lowlands, the Caribbean islands and southern Florida. Its habitat consists of humid forests at elevations of with temperatures varying from warm to hot. Like many orchids, ''E. pusilla'' grows harmlessly upon other plants. It gets moisture and nutrients from the surroundings without affecting the host plant (

commensalism Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fr ...

). Its quick development permits this orchid to grow on relatively short-lasting sites such as twigs or even leaves of bushes and trees, such as coffee plant or hibiscus. For this reason, it is usually classified as a twig epiphyte.

Use in science

''Erycina pusilla'' is a promising model candidate for ''

Oncidium ''Oncidium'', abbreviated as Onc. in the horticultural trade, is a genus that, , contains about 340 species of orchids from the subtribe Oncidiinae of the orchid family Orchidaceae. It is distributed across tropical and subtropical America from ...

'' research. Its relatively tiny size and its short life cycle, facilitates its cultivation. Additionally, it has the ability to complete its life cycle ''in vitro''. The functional genomic research is easier because ''E. pusilla'' only has 6 chromosomes and a small genome size (1.5 pg 1C nucleus). Another aspect that speaks for the use of this orchid in research, is the rare pollination and production of seeds in nature. This reduces the risk of undesired propagation of transgenic lines. The rapid growth and the low chromosome numbers make ''E. pusilla'' is also an excellent parent for traditional hybridization methods. All these characteristics make ''E. pusilla'' a promising model not only for research, but also for commercial breeding, since it constitutes an excellent parent for traditional hybridization methods. Beyond the use of this orchid for research and commercial purposes, ''E. pusilla'' has also medical applications. The ingestion of whole plant cooked treats colic and stomachache. Additionally, the whole plant boiled is also used as a wash to treat lacerations cuts and wounds.

''In vitro'' cultivation

Sporadic flowering in flasks was first reported by Livingston (1962), although the ''in vitro'' cultivation was just established (2007). The primary culture of ''E. pusilla'' becomes a callus after about one month of cultivation. Three months later it reaches leaf stage and after eight months the flowering stage begins. After two and half months ''E. pusilla'' produces fruits. A new cycle can start from a new primary culture: protocorm-like body (PLB) ''in vitro''.

Genome

The transcriptome sequence of ''E. pusilla'' is available
Orchidstra Database
. Some basic molecular resources were also established, including the sequencing of the chloroplast genome, the

transcriptome The transcriptome is the set of all RNA transcripts, including coding and non-coding, in an individual or a population of cells. The term can also sometimes be used to refer to all RNAs, or just mRNA, depending on the particular experiment. The ...

and the BAC library. The

miRNA Micro ribonucleic acid (microRNA, miRNA, μRNA) are small, single-stranded, non-coding RNA molecules containing 21–23 nucleotides. Found in plants, animals, and even some viruses, miRNAs are involved in RNA silencing and post-transcri ...

database of ''E. pusilla'', including the identification of miRNA biosynthesis-related genes and miRNA families, was established in 2013. The chloroplast genome has been sequenced efficiently and economically by using BAC library and

next-generation sequencing Massive parallel sequencing or massively parallel sequencing is any of several high-throughput approaches to DNA sequencing using the concept of massively parallel processing; it is also called next-generation sequencing (NGS) or second-generation ...

. The chloroplast genome of ''E. pusilla'' is 143.164 bp in size, which contains a pair of inverted repeats (IRa and IRb) of 23.439 bp separated by large and small single copy regions of 84.189 and 12.097 bp, respectively. From these result compare to ''Oncidium'', the gene order of chloroplast genome between ''E. pusilla'' and ''Oncidium'' are similar. In Taiwan, different hybridization compatibility of ''E. pusilla'' with ''Oncidium'', ''Rodriguezia'' and ''Tolumnia'' was found by crossing with several important Oncidiinae orchids.

MADS-box genes

Due to their role in plant growth, the characterization of

MADS-box The MADS box is a conserved sequence motif. The genes which contain this motif are called the MADS-box gene family. The MADS box encodes the DNA-binding MADS domain. The MADS domain binds to DNA sequences of high similarity to the motif CC /TGG ...

genes in ''E. pusilla'' has turned into a hot topic for both researchers and commercial orchid breeders. MADS-box genes encode for MADS-domain proteins, which are generally

transcription factor In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription (genetics), transcription of genetics, genetic information from DNA to messenger RNA, by binding t ...

s. In plants, these proteins control key developmental processes throughout almost all life stages. To date, 28 MADS-box genes were isolated in ''E. pusilla'', namely EpMADS1 to 28. Nearly all of them contain introns greater than 10 kb, which reflects the complexity of the ''E. pusilla'' genome. Many EpMADS genes have expression patterns similar to those MADS-box genes in ''Arabidopsis''. The 28 proteins, encoded by the ''E. pusilla'' MADS-box genes, are classified as type I or type II based on BLASTP analyses.

References

Other sources

* Pridgeon, A.M., Cribb, P.J., Chase, M.A. & Rasmussen, F. eds. (1999). Genera Orchidacearum Vols 1–3. Oxford Univ. Press. * Berg Pana, H. 2005. ''Handbuch der Orchideen-Namen. Dictionary of Orchid Names. Dizionario dei nomi delle orchidee''. Ulmer, Stuttgart. * Establishment of an Agrobacterium-mediated genetic transformation procedure for the experimental model orchid Erycina pusilla. Shu-Hong Lee, Chia-Wen Li, Chia-Hui, Liau Pao-Yi, Chang Li-Jen Liao, Choun-Sea Lin Ming-Tsair Chan, Plant Cell, Tissue and Organ Culture, January 2015, Volume 120, Issue 1, pp 211–220

External links

* * {{Taxonbar, from=Q4038203 Oncidiinae Plant models Orchids of Central America Orchids of Belize