Genetic insights into the regulatory pathways for continuous flowering in a unique orchid Arundina graminifolia

Background Manipulation of flowering time and frequency of blooming is key to enhancing the ornamental value of orchids. Arundina graminifolia is a unique orchid that flowers year round, although the molecular basis of this flowering pattern remains poorly understood. Results We compared the A. graminifolia transcriptome across tissue types and floral developmental stages to elucidate important genetic regulators of flowering and hormones. Clustering analyses identified modules specific to floral transition and floral morphogenesis, providing a set of candidate regulators for the floral initiation and timing. Among candidate floral homeotic genes, the expression of two FT genes was positively correlated with flower development. Assessment of the endogenous hormone levels and qRT-PCR analysis of 32 pathway-responsive genes supported a role for the regulatory networks in floral bud control in A. graminifolia. Moreover, WGCNA showed that flowering control can be delineated by modules of coexpressed genes; especially, MEgreen presented group of genes specific to flowering. Conclusions Candidate gene selection coupled with hormonal regulators brings a robust source to understand the intricate molecular regulation of flowering in precious orchids.

Stage Specificity, the Dynamic Regulators and the Unique Orchid Arundina graminifolia

Orchids take years to reach flowering, but the unique bamboo orchid (Arundina graminifolia) achieves reproductive maturity in six months and then keeps on year round flowering. Therefore, studying different aspects of its growth, development and flowering is key to boost breeding programs for orchids. This study uses transcriptome tools to discuss genetic regulation in five stages of flower development and four tissue types. Stage specificity was focused to distinguish genes specifically expressed in different stages of flower development and tissue types. The top 10 highly expressed genes suggested unique regulatory patterns for each stage or tissue. The A. graminifolia sequences were blasted in Arabidopsis genome to validate stage specific genes and to predict important hormonal and cell regulators. Moreover, weighted gene co-expression network analysis (WGCNA) modules were ascertained to suggest highly influential hubs for early and late stages of flower development, leaf and root. Hormonal regulators were abundant in all data sets, such as auxin (LAX2, GH3.1 and SAUR41), cytokinin (LOG1), gibberellin (GASA3 and YAB4), abscisic acid (DPBF3) and sucrose (SWEET4 and SWEET13). Findings of this study, thus, give a fine sketch of genetic variability in Orchidaceae and broaden our understanding of orchid flower development and the involvement of multiple pathways.

Crystal structure of 7-hydroxy-2,4-dimethoxy-9,10-dihydrophenanthrene from Arundina graminifolia, C16H16O3

C16H16O3, monoclinic, P21/n (no. 14), a = 8.548(3) Å, b = 13.426(4) Å, c = 11.369(3) Å, β = 103.0934°, V = 1270.7(7) Å3, Z = 4, R gt (F) = 0.0421, wR ref (F 2) = 0.1243, T = 296(2) K.

IN VITRO REGENERATION OF ARUNDINA GRAMINIFOLIA (D. DON) HOCHR

We can see Orchids come in a wide variety of shapes, sizes, colours, and textures far beyond the human mind’s imagination. They emerge from seeds in nature, but in the absence of suitable hosts, they do not germinate in sufficient numbers. This problem was solved by using the tissue culture technique for its germination. One of the successful method used for mass propogation of orchid plantlets is in vitro techniques. Therefore, an initial analysis was conducted in order to establish an appropriate procedure for mass multiplication of Arundina graminifolia. MS (Murashige and Skoog) medium was found to be suitable for the asymbiotic seed germination of Arundina graminifolia. Direct protocorm like bodies were induced by using combinations and individual supplement of MS medium with IAA (Indole-3-acetic acid), IBA (Indole-3- butyric acid), BAP (6-Benzylaminopurine) and KIN (Kinetin). Hormone-free MS basal medium was found suitable for the conversion of PLBs (protocorm-like bodies) into complete plantlets

BIOACTIVITY OF ENDEMIC ORCHIDS OF WESTERN GHATS; PHOLIDOTA PALLID LINDL AND ARUNDINA GRAMINIFOLIA (D. DON) HOCHR

Pholidota pallida And Arundina graminifolia is an Endemic orchid species belongs to orchidaceae family. It is mainly found in Western Ghats of India. It is used to treat various diseases such as liver affection, wound healing, rheumatism, abdominal pain, ear pain, diabetes etc. The present study is to identify the phytochemicals, Anticancer, Antioxidant, Antimicrobial and nanoparticle synthesis from leaves extract of Pholidota pallid and Arundina graminifolia. The phytochemical analysis revealed the presence of Alkaloids, Terpenoids, Phenols, Sugar, Saponins, Flavonoids, Quinin’s and Steroids. While comparing Pholidota pallida possess more bioactivity than Arundina graminifolia.

Present and Future Distribution of Two Non-Indigenous Orchids and Their Acquired Enemy in Puerto Rico

Establishment of new populations is contingent on overcoming abiotic and biotic barriers. While this applies to all species, these hurdles are at the forefront of invasion biology where prediction, prevention, eradication, and control strategies depend on an understanding of these processes. Arundina graminifolia and Dendrobium crumenatum are two non-indigenous orchids spreading throughout Puerto Rico. The two species have acquired a native herbivore & seed predator, the orchid-specialist weevil, Stethobaris polita. With recently acquired presence records of the three species, land cover data and BioClim variables, we modeled their potential distributions under current conditions and also those projected under the least and most extreme climate scenarios for 2050 and 2070. We show that D. crumenatum flourishes in urban environments which also provide refugia from S. polita, whereas there is currently limited refugia for A. graminifolia from S. polita attack, as this orchid is sensitive to the same climatic variables as the weevil. Projections into all climate scenarios suggest range retractions for all species, with an equal to or greater proportion of both orchid populations subject to S. polita attack. Thus, we illustrate for island invasions how climate change will likely alter the distribution of acquired biotic interactions.