A metabolomic snapshot through NMR revealed differences in phase transition during the induction of reproduction in Ulva ohnoi (Chlorophyta).

The present study deals with the metabolomic status of Ulva cells undergoing phase transition (vegetative, determination and differentiation) when exposed to different abiotic conditions. The objective was to study whether metabolite changes occurring during the phase transition reveal any commonality among differential abiotic conditions. The phase transition was followed through microscopic observations and 1H NMR characterization at 0 h, 24 h, and 48 h after the incubation of the thallus under abiotic conditions, such as different salinities (20-35 psu), temperatures (20-35 °C), photoperiods (18 : 6, 12 : 12, and 6 : 18 D/N), light intensities (220, 350, and 500 µmol photons m-2 s-1), nitrate (0.05-0.2 g L-1) and phosphate (0.05-0.2 g L-1) concentrations. Microscopic analysis revealed the role of all abiotic conditions except variable salinity and phosphate concentration in phase transition. NMR analysis revealed that glucose increased in the determination phase [7.58 to 9.62 normalized intensity (AU)] and differentiation phase (5.85 to 6.41 AU) from 20 °C to 25 °C temperature. Coniferyl aldehyde increased in vegetative (5.79 to 6.83 AU) and differentiation (6.66 to 7.40 AU) phases from 20 °C to 30 °C temperature. The highest average (22.97) was found in photoperiod (average range = 0-122.91) and the highest SD (24.73) in salinity (SD range = 1.86-57.04) in region 9 (creatinine and cysteine) of the differentiation phase. A total of 30 metabolites were identified under the categories of sugars, amino acids, and aromatic compounds. The present study will aid in understanding the mechanisms underlying cell differentiation during reproduction. The result may serve as an important reference point for future studies, besides helping in controlling seedling preparation for commercial farming as well as the management of rapid green tide formation.

Biology, farming and applications of economically important red seaweed Gracilaria edulis (S. G. Gmelin) P. C. Silva: A concise review.

Gracilaria edulis is one of the most studied agarophytes, especially in tropical regions like India because of its natural abundance. Apart from the Indian peninsula, it is widely distributed in tropical and subtropical regions. The taxonomy of G. edulis is evolving; currently G. edulis is the taxonomically accepted name, however several phylogenetic and morphological investigations supported its inclusion in the genus Hydropuntia. In addition to the conventional farming methods like the tube net and raft methods which use clonally propagated seed material, spore-based planting materials like carpospores have been employed to cultivate G. edulis. Co-cultivation with shrimp farm wastewater has also been practised to make the cultivation economically viable and environmentally sustainable as the seaweed could provide an efficient ecosystem service by up taking nitrogen from the shrimp waste. Like other seaweed cultivation systems, farming of G. edulis is also infested by various epiphytes like Ulva, Cladophora, Ceramium, Centroceras, Hypnea and Padina as well as grazed by fishes like Monodactylus, Pelates and Pteroscirtes which decrease the growth and ultimately result in low yield of agar, seaweed sap and other value added products. Food grade agar produced by this seaweed is an important resource and the current review focusses on the latest extraction technologies. Further, there also is evidence based application of plant bio-stimulant derived from G. edulis feedstock which has proven to be highly effective in enhancing the yield by 10-33% in field trials of nine cash crops. Supplementary Information: The online version contains supplementary material available at 10.1007/s10811-023-02955-8.

Modulation of BRCA1 mediated DNA damage repair by deregulated ER-α signaling in breast cancers.

BRCA1 mutation carriers have a greater risk of developing cancers in hormone-responsive tissues like breasts and ovaries. However, this tissue-specific incidence of BRCA1 related cancers remains elusive. The majority of the BRCA1 mutated breast cancers exhibit typical histopathological features of high-grade tumors, with basal epithelial phenotype, classified as triple-negative molecular subtype and have a higher percentage of DNA damage and chromosomal abnormality. Though there are many studies relating BRCA1 with ER-α (Estrogen receptor-α), it has not been reported whether E2 (Estrogen) -ER-α signaling can modulate the DNA repair activities of BRCA1. The present study analyzes whether deregulation of ER-α signaling, arising as a result of E2/ER-α deficiency, could impact the BRCA1 dependent DDR (DNA Damage Response) pathways, predominantly those of DNA-DSB (Double Strand break) repair and oxidative damage response. We demonstrate that E2/E2-stimulated ER-α can augment BRCA1 mediated high fidelity repairs like HRR (Homologous Recombination Repair) and BER (Base Excision Repair) in breast cancer cells. Conversely, a condition of ER-α deficiency itself or any interruption in ligand-dependent ER-α transactivation resulted in delayed DNA damage repair, leading to persistent activation of γH2AX and retention of unrepaired DNA lesions, thereby triggering tumor progression. ER-α deficiency not only limited the HRR in cells but also facilitated the DSB repair through error prone pathways like NHEJ (Non Homologous End Joining). ER-α deficiency associated persistence of DNA lesions and reduced expression of DDR proteins were validated in human mammary tumors.

Marine macroalga Caulerpa: role of its metabolites in modulating cancer signaling.

Cancer, the leading causes of death worldwide, causes multiple metabolic and physiological alterations, leading to an unregulated proliferation of cells. The existing anticancer therapies are usually nonspecific with side effects and or are extremely expensive, thus hunt for better therapeutics is still on, specially efforts are made to look for naturally occurring molecules. Sea harbors several organisms which are unexplored for their biological potentials. Green macroalga genus, Caulerpa, is one such invaluable repository of bioactive metabolites like alkaloids, terpenoids, flavonoids, steroids and tannins with reported bioactivities against many diseases including cancer. Anti-cancerous metabolites of Caulerpa like caulerpenyne (Cyn), caulerpin, caulersin, and racemosin C, possess unique structural moieties and are known to exhibit distinct effects on cancer cells. Theses metabolites are reported to affect microtubule dynamics, unfolded protein response, mitochondrial health, cell cycle progression, metabolic and stress pathways by their cross-talk with signalling proteins like AMPK, GRP78, GADD153, Bid, Bax, AIF, Bcl2, P21, cyclin D, cyclin E, caspase 9, and PTP1B. Targeting of multiple cancer hallmarks by Caulerpa metabolites, with concomitant modulations of multiple signalling cascades, displays its multifactorial approach against cancer. Evaluation of anti-cancer properties of this genus is particularly important as Caulerpa species are widely edible and utilized in several delicacies in the coastal countries. This is the first review article providing a consolidated information about the role of Caulerpa in cancer with major contributing metabolites and plausible modulations in cancer signaling and prospects.

Strong Endemism of bloom-forming tubular Ulva in Indian West Coast, with description of Ulva paschima Sp. Nov. (Ulvales, Chlorophyta).

Ulva intestinalis and Ulva compressa are two bloom-forming morphologically-cryptic species of green seaweeds widely accepted as cosmopolitan in distribution. Previous studies have shown that these are two distinct species that exhibit great morphological plasticity with changing seawater salinity. Here we present a phylogeographic assessment of tubular Ulva that we considered belonging to this complex collected from various marine and estuarine green-tide occurrences in a ca. 600 km stretch of the Indian west coast. Maximum Likelihood and Bayesian Inference phylogenetic reconstructions using ITS nrDNA revealed strong endemism of Indian tubular Ulva, with none of the Indian isolates forming part of the already described phylogenetic clades of either U. compressa or U. intestinalis. Due to the straightforward conclusion that Indian isolates form a robust and distinct phylogenetic clade, a description of a new bloom-forming species, Ulva paschima Bast, is formally proposed. Our phylogenetic reconstructions using Neighbor-Joining method revealed evolutionary affinity of this new species with Ulva flexuosa. This is the first molecular assessment of Ulva from the Indian Subcontinent.

DNA barcoding of a new record of epi-endophytic green algae Ulvella leptochaete (Ulvellaceae, Chlorophyta) in India.

Epi-endophytic green algae comprise one of the most diverse and phylogenetically primitive groups of green algae and are considered to be ubiquitous in the world's oceans; however, no reports of these algae exist from India. Here we report the serendipitous discovery of Ulvella growing on intertidal green algae Cladophora glomerata and benthic red algae Laurencia obtusa collected from India. DNA barcodes at nuclear ribosomal DNA Internal Transcriber Spacer (nrDNA ITS) 1 and 2 regions for Indian isolates from the west and east coasts have been generated for the first time. Based on morphology and DNA barcoding, isolates were identified as Ulvella leptochaete. Phylogenetic reconstruction of concatenated dataset using Maximum Likelihood method differentiated Indian isolates from other accessions of this alga available in Genbank, albeit with low bootstrap support. Monophyly of Ulvella leptochaete was obvious in both of our phylogenetic analyses. With this first report of epi-endophytic algae from Indian territorial waters, the dire need to catalogue its cryptic diversity is highlighted and avenues of future research are discussed.