Genome wide characterization of WUSCHEL-related homeobox (WOX) gene family in Apostasia shenzhenica, a primeval orchid

In the present study, we report identification and characterization of the plant-specific WUSCHEL-related homeobox (WOX) gene family in Apostasia shenzhenica, a primeval orchid. WOX proteins are DNA-binding WUSCHEL-related homeobox (WOX) encoding transcription factors that play critical role in zygote patterning, embryo development, organogenesis, florigenesis, stress responses etc. Ten putative AsWOX genes were predicted in the A. shenzhenica genome and were characterized by the presence of DNA-binding helix-loop-helix-turn-helix motif. AsWOX proteins were grouped into three clades, ancient, intermediate and WUS on the basis of sequence homology with Arabidopsis thaliana (AtWOX), Oryza sativa (OsWOX), Phalaenopsis equestris (PeWOX) and Dendrobium catenatum (DcWOX) and their phylogenetic relationship was established. Gene structure analysis revealed that three AsWOX genes had two introns, six genes had a single intron, and one gene was intron-less. Expression profiling in a variety of tissue (tubers, seeds and pollens) was analysed in light of the presence of specific cis-regulatory elements in the promoter region and their role in various developmental processes was discussed. Three dimensional structures were predicted for three selected AsWOX proteins representing the three clades. The present study provides insights to the role of AsWOX gene family in various vital developmental processes, establishes phylogenetic relationships with related plant species and provides a platform for functional validation of specific AsWOX genes

ASCORBIC ACID AS A GROWTH ADJUVANT IN ENCAPSULATED PROTOCORM-LIKE-BODIES OF RHYNCHOSTYLIS RETUSA BL. (ORCHIDACEAE)

In the present study, effect of ascorbic acid, a known growth adjuvant on encapsulated protocorm-like-bodies (PLBs) of Rhynchostylis retusa Bl. was investigated. PLBs were encapsulated in calcium alginate (3.5% sodium alginate and 100mM calcium chloride) prepared in Mitra et al. (1976) basal medium and supplemented with different concentration of ascorbic acid (5, 10, 15, 20mM). The encapsulated PLBs were stored at 25°C. Their germination response and germination potential was evaluated after every 4 weeks on basal media. Control set of encapsulated PLBs, failed to germinate after 32 weeks. However, PLBs with 15mM ascorbic acid in the encapsulated matrix showed the best response; nearly 90% germinated even after 32 weeks of storage. The survival and germination frequency was directly proportional to the level of ascorbic acid in the alginate mix upto 15mM level but declined on further increase. Differentiation of PLBs into plantlet was better in synthetic seeds containing lower concentration of ascorbic acid (5mM) as compared to higher levels (15, 20mM) whereas multiplication of secondary PLBs was more pronounced at higher levels. Chlorophyll content was inversely proportional to the level of ascorbic acid in the nutrient mix; lush green PLBs were observed at low concentration of ascorbic acid (5mM). This study highlights the potential of ascorbic acid as an aid to growth and survival of encapsulated PLBs upon storage

In silico identification, characterization and expression profile of WUSCHEL-related homeobox (WOX) gene family in Vanilla planifolia

Vanilla planifolia is an economically important orchid, which is being commercially exploited by the food industry for the highly valued secondary metabolite vanillin. WUSCHEL-related homeobox (WOX) gene family encodes for WUSCHEL-related homeobox (WOX) transcription factors that participate in embryogenesis, organogenesis and florigenesis and in diverse plant developmental processes as well. In the present study, we analysed V. planifolia transcriptome and identified 6 WOX (VpWOX) transcripts, that encode putative WOX (VpWOX) transcription factor proteins. Domain analysis was done which indicates the presence of helix-loop-helix-turn-helix which is identifying feature of WOX gene family proteins. We executed phylogenetic clustering for the VpWOX proteins with their counterpart from the model plant Arabidopsis thaliana (AtWOX) and other closely related orchid species, Phalaenopsis equestris (PeWOX), Dendrobium catenatum (DcWOX) and Apostasia shenzhenica (AsWOX) and established their clade specific grouping. Spatio-temporal expression profile for VpWOX genes was analysed for different plant developmental stages which shows that VpWOX13 is expressing uniformly in all the developmental stages whereas, other genes have tissue specific expression. Based on gene expression patterns, we selected four VpWOX proteins and carried out secondary and tertiary structural analysis which indicates the presence of alpha helix and beta turn in the protein structure. The present study provides basic understanding of the functioning of WOX gene family in V. planifolia and paves the path for functional characterization of selected VpWOX genes in planta and in heterologous system in future for commercial utilization

Essential oils analysis of pseudobulbs of Crepidium acuminatum (D.DON) SZLACH by GC-MS

Objective: To analyse Essential oils of Crepidium acuminatum (D.Don) Szlach. Methods: DCM Extracts were prepared for Essential oil analysis. GC-MS was used for perusal. Results: In the present study, 6 phytoconstituents have been identified from the DCM pseudobulbs extract of Crepidium acuminatum D. Don Szlach by GC-MS analysis. The results showed that DCM extract contains mainly essential oils which are caryophyllene 74.89% ; Eugenol 5.56%; Humulene 5.48% ; phenol, 2,4 bis (1,1 dimethylethyl) 5.57%; Caryophyllene oxide 5.33%; 2,5 Octadecadiynoic acid, methyl ester 3.16%. Analysis and identification of the presence of the compound in the extract were done by using the database of the National Institute of Standards and Technology (NIST) library. Conclusions: Out of various compounds analysed Eugenol has already been reported whereas Caryophyllene, Caryophyllene oxide, Humulene, Phenol, 2,4bis ( 1, 1dimethylethyl) and 2,5 Octadecadiynoic acid, methyl ester are being reported first time. These compounds have immense medicinal potential. Thus, it found to possess significant phytonutrients, which attribute to its medicinal worth