Nutritional characterization and chemical composition of Diplazium maximum (D. Don) C. Chr.

Diplazium maximum (D. Don) C. Chr. is a wild edible fern, traditionally consumed in the tribal areas of western Himalayas. The edible part of the plant (young fronds) was analyzed for its nutritional and phytochemical composition. The dried young fronds (DYF) were found to have high contents of dietary fibre (38.32 g/100 g dry basis) and crude protein (25.39 g/100 g dry basis). Branched-chain-essential-amino acids, polyunsaturated fatty acids (PUFA) (constituting more than 50% of total fatty acids), dihomo-gamma-linolenic acid (unique omega-6 PUFA) and phenolics like epicatechin, myricetin, catechin and procatechuic acid were present in nutritionally significant amounts. Hydro-alcoholic extracts of the DYF contained maximum distribution of polyphenols and flavonoids and exhibited high antioxidant capacities. Analysis of functional properties of DYF such as water and oil absorption capacity, dispersibility and swelling capacity indicated its potential application in instant convenience food products such as soup mixes. Sensory scores of soup mix prepared using DYF was similar to that of commercially available soups. In conclusion, D. maximum is nutritious enough to be popularized for domestication, wide consumption and inclusion in the form of instant food products in existing food basket.

Proteome Analysis of the Gametophytes of a Western Himalayan Fern Diplazium maximum Reveals Their Adaptive Responses to Changes in Their Micro-Environment.

Ferns have survived changing habitats and environmental extremes of different eras, wherein, the exploratory haploid gametophytes are believed to have played a major role. Therefore, the proteome of in vitro grown gametophytes of a temperate Himalayan fern, Diplazium maximum in response to 0 (G0), 1 (G1), and 3% (G3) sucrose was studied. A total of 110 differentially abundant protein spots (DAPs) were obtained. Among these, only 67 could be functionally categorized as unique proteins involved in various metabolic processes. Calcium dependent proteins, receptor like kinases, G proteins, proteins related to hormonal signaling and their interaction with other pathways, and regulatory proteins were recorded indicating the involvement of five different signaling pathways. DAPs involved in the activation of genes and transcription factors of signaling and transduction pathways, transport and ion channels, cell-wall and structural proteins, defense, chaperons, energy metabolism, protein synthesis, modification, and turnover were identified. The gametophytes responded to changes in their micro-environment. There was also significant increase in prothallus biomass and conversion of two-dimensional prothalli into three-dimensional prothallus clumps at 3% sucrose. The three-D clumps had higher photosynthetic surface area and also closer proximity for sexual reproduction and sporophyte formation. Highest accumulation of proline, enhanced scavenging of reactive oxygen species (ROS) and DAPs of mostly, abiotic stress tolerance, secondary metabolite synthesis, and detoxification at 3% sucrose indicated an adaptive response of gametophytes. Protein Protein Interaction network and Principal Component analyses, and qRT-PCR validation of genes encoding 12 proteins of various metabolic processes indicated differential adjustment of gametophytes to different levels of sucrose in the culture medium. Therefore, a hypothetical mechanism was proposed to show that even slight changes in the micro-environment of D. maximum gametophytes triggered multiple mechanisms of adaptation. Many DAPs identified in the study have potential use in crop improvement and metabolic engineering programs, phytoremediation and environmental protection.

A simple technique for tracking individual spore and gametophyte development in Adiantum lunulatum Burm. f. using modified extra thin alginate film technique.

A new technique was developed for accurate calculation of percent germination and tracking of individual spores from germination to gametophyte development in Adiantum lunulatum. High percentage of ETAF immobilized spore germination (72.4%) was followed by development of gametophytic clumps. The ETAF immobilized clumps were cut into pieces and multiplied en masse. Apomictic sporophytes developed from the gametophytes. This indicated the potential of ETAF for mass propagation of A. lunulatum without the need to start from spores. Since individual spores can be tracked from germination to gametophyte development, the ETAF technique has the potential to be used for (i) harvesting uniformly developed plants of similar age for extensive experimentations and commercial utilization and (ii) detailed study on developmental and reproductive biology of different ferns and fern allies.