RESUMO
Plant-microbe associations have been regarded as an exciting topic of research due to their potential as environment friendly alternatives for stimulating crop growth and development. Seeds of Tamarindus indica L. have been chosen for the present study as seed endophytes prefer larger or nutritive cotyledon and hard seed coats for their colonization. The main objectives of our study were to isolate and identify the seed endophytes, their bioefficacy, and responsible chemical compounds. In a dose-dependent experiment, tamarind seed exudates (TSE) showed plant growth-promoting properties on Oryza sativa (53-81%), Daucus carota (10-31%), and Raphanus sativa (21-42%). Identification of the bacterial load in TSE through 16S rRNA sequencing revealed the existence of two bacterial species, Acinetobacter johnsonii and Niallia nealsonii. This is the first report of these two bacteria as seed endophytes of Tamarindus indica L. HRLC-MS analysis of TSE confirmed the presence of indole derivatives, primarily indole-3-lactic acid (ILA). The quantitative phytochemical estimation of bacterial culture filtrates revealed that indole-like substances were present in the extracts only in A. johnsonii at a concentration of 0.005 mg/ml of indole acetic acid equivalent. Experimental results suggested that the stimulatory activity of TSE was caused by the presence of A. johnsonii, a potential plant growth-promoting bacteria that produced indole-like compounds. This study suggests tamarind seed exudates with its endophytic microbiota as a potent plant growth-promoting agent that may find use as a cheap and sustainable source of metabolites useful in the agro-industries.
Assuntos
Acinetobacter , Tamarindus , Tamarindus/química , Endófitos , RNA Ribossômico 16S/genética , Sementes/microbiologia , Plantas , Bactérias/genéticaRESUMO
Two pigment producing fungi, Talaromyces atroroseus and Penicillium choerospondiatis, were isolated and identified from infected fruits of Phyllanthus emblica L. based on amplification and sequencing of internal transcribed spacer region and beta-tubulin gene. This is the first occurrence report of these two fungi from fruits of P. emblica. Culture extract containing metabolites of T. atroroseus and P. choerospondiatis contained phenolics of 26.35 mg and 30.89 mg GAE/g dry extract respectively; whereas no significant amount of flavonoids and tannins were detected. P. choerospondiatis metabolites extract showed higher DPPH and ABTS activity with IC50 values of 21.94 mg/ml and 27.03 mg/ml respectively than T. atroroseus. LC-HRMS analysis of metabolites extract of T. atroroseus revealed presence of trimethyl-isopropyl-butanamide, perlolyrine, N-hexadecanoylpyrrolidine etc. whereas P. choerospondiatis displayed presence of tangeraxanthin, ugaxanthone, daphniphylline, etc. Therefore, fungal metabolites are rich natural sources of diversified compounds that can be utilized in dyeing industries, cosmetics and novel drug development.
Assuntos
Phyllanthus emblica , Ribes , Phyllanthus emblica/química , Phyllanthus emblica/metabolismo , Frutas/química , Taninos/análise , Extratos Vegetais/química , FungosRESUMO
Coconut (Cocos nucifera) leaves, an unutilized resource, enriched with valuable bioactive compounds. Spectral analysis of purified pentane fraction of coconut leaves revealed the presence of a squalene analog named 4,4'-diapophytofluene or in short 4,4'-DPE (C30H46). Pure squalene standard (PSQ) showed cytotoxicity after 8 µg/ml concentration whereas 4,4'-DPE exhibited no cytotoxic effects up to 16 µg/ml concentration. On senescence-induced WI38 cells, 4,4'-DPE displayed better percentage of cell viability (164.5% at 24 h, 159.4% at 48 h and 148% at 72 h) compared to PSQ and BSQ (bio-source squalene) with same time duration. Similar trend of result was found in HaCaT cells. SA-ß-gal assay showed that number of ß-galactosidase positive cells were significantly decreased in senescent cells (WI38 and HaCaT) after treated with 4,4'-DPE than PSQ, BSQ. Percentage of ROS was increased to 60% in WI38 cells after olaparib treatment. When PSQ, BSQ and 4,4'-DPE were applied separately on these oxidative-stress-induced cells for 48 h, the overall percentage of ROS was decreased to 39.3%, 45.6% and 19.3% respectively. This 4,4'-DPE was found to be more effective in inhibiting senescence by removing ROS as compared to squalene. Therefore, this 4,4'-DPE would be new potent senotherapeutic agent for pharmaceuticals and dermatological products.