scholarly journals Stress responses of the oil-producing green microalgaBotryococcus brauniiRace B

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2748 ◽  
Author(s):  
Ivette Cornejo-Corona ◽  
Hem R. Thapa ◽  
Daniel R. Browne ◽  
Timothy P. Devarenne ◽  
Edmundo Lozoya-Gloria
Keyword(s):  
Cell Death ◽  
Stress Responses ◽  
Biomass Accumulation ◽  
Botryococcus Braunii ◽  
Oligosaccharyl Transferase ◽  
Hydrocarbon Production ◽  
Ros Accumulation ◽  
Green Microalga ◽  
Short Times ◽  
Knockout Line

Plants react to biotic and abiotic stresses with a variety of responses including the production of reactive oxygen species (ROS), which may result in programmed cell death (PCD). The mechanisms underlying ROS production and PCD have not been well studied in microalgae. Here, we analyzed ROS accumulation, biomass accumulation, and hydrocarbon production in the colony-forming green microalgaBotryococcus brauniiin response to several stress inducers such as NaCl, NaHCO3, salicylic acid (SA), methyl jasmonate, and acetic acid. We also identified and cloned a single cDNA for theB. brauniiortholog of theArabidopsisgenedefender against cell death 1(DAD1),a gene that is directly involved in PCD regulation. The function ofB. braunii DAD1was assessed by a complementation assay of the yeast knockout line of theDAD1ortholog, oligosaccharyl transferase 2. Additionally, we found thatDAD1transcription was induced in response to SA at short times. These results suggest thatB. brauniiresponds to stresses by mechanisms similar to those in land plants and other  organisms.

scholarly journals Contrasting roles of GmNAC065 and GmNAC085 in natural senescence, plant development, multiple stresses and cell death responses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bruno Paes Melo ◽  
Isabela Tristan Lourenço-Tessutti ◽  
Otto Teixeira Fraga ◽  
Luanna Bezerra Pinheiro ◽  
Camila Barrozo de Jesus Lins ◽  
...  
Keyword(s):  
Cell Death ◽  
Plant Development ◽  
Stress Responses ◽  
Regulatory Networks ◽  
Lower Stress ◽  
Multiple Stresses ◽  
Gene Sets ◽  
Ros Accumulation ◽  
Stress Dependent ◽  
Senescence Associated Genes

AbstractNACs are plant-specific transcription factors involved in controlling plant development, stress responses, and senescence. As senescence-associated genes (SAGs), NACs integrate age- and stress-dependent pathways that converge to programmed cell death (PCD). In Arabidopsis, NAC-SAGs belong to well-characterized regulatory networks, poorly understood in soybean. Here, we interrogated the soybean genome and provided a comprehensive analysis of senescence-associated Glycine max (Gm) NACs. To functionally examine GmNAC-SAGs, we selected GmNAC065, a putative ortholog of Arabidopsis ANAC083/VNI2 SAG, and the cell death-promoting GmNAC085, an ANAC072 SAG putative ortholog, for analyses. Expression analysis of GmNAC065 and GmNAC085 in soybean demonstrated (i) these cell death-promoting GmNACs display contrasting expression changes during age- and stress-induced senescence; (ii) they are co-expressed with functionally different gene sets involved in stress and PCD, and (iii) are differentially induced by PCD inducers. Furthermore, we demonstrated GmNAC065 expression delays senescence in Arabidopsis, a phenotype associated with enhanced oxidative performance under multiple stresses, higher chlorophyll, carotenoid and sugar contents, and lower stress-induced PCD compared to wild-type. In contrast, GmNAC085 accelerated stress-induced senescence, causing enhanced chlorophyll loss, ROS accumulation and cell death, decreased antioxidative system expression and activity. Accordingly, GmNAC065 and GmNAC085 targeted functionally contrasting sets of downstream AtSAGs, further indicating that GmNAC85 and GmNAC065 regulators function inversely in developmental and environmental PCD.

scholarly journals Outdoor open pond batch production of green microalga Botryococcus braunii for high hydrocarbon production: enhanced production with salinity

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Suneerat Ruangsomboon ◽  
Jantra Dimak ◽  
Buppha Jongput ◽  
Itsanun Wiwatanaratanabutr ◽  
Pornthiwa Kanyawongha
Keyword(s):  
Botryococcus Braunii ◽  
Batch Production ◽  
High Hydrocarbon ◽  
Hydrocarbon Production ◽  
Open Pond ◽  
Enhanced Production ◽  
Green Microalga

scholarly journals Combined Production of Astaxanthin and β-Carotene in a New Strain of the Microalga Bracteacoccus aggregatus BM5/15 (IPPAS C-2045) Cultivated in Photobioreactor

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 643
Author(s):  
Konstantin Chekanov ◽  
Daniil Litvinov ◽  
Tatiana Fedorenko ◽  
Olga Chivkunova ◽  
Elena Lobakova
Keyword(s):  
Bubble Column ◽  
Biomass Accumulation ◽  
Natural Antioxidants ◽  
Gas Chromatography Mass Spectrometry ◽  
Stage Scheme ◽  
Green Microalga ◽  
Animal Feeding ◽  
Carotenoid Synthesis ◽  
Bubble Column Photobioreactor ◽  
Β Carotene

Carotenoids astaxanthin and β-carotene are widely used natural antioxidants. They are key components of functional food, cosmetics, drugs and animal feeding. They hold leader positions on the world carotenoid market. In current work, we characterize the new strain of the green microalga Bracteacoccus aggregatus BM5/15 and propose the method of its culturing in a bubble-column photobioreactor for simultaneous production of astaxanthin and β-carotene. Culture was monitored by light microscopy and pigment kinetics. Fatty acid profile was evaluated by tandem gas-chromatography–mass spectrometry. Pigments were obtained by the classical two-stage scheme of autotrophic cultivation. At the first, vegetative, stage biomass accumulation occurred. Maximum specific growth rate and culture productivity at this stage were 100–200 mg∙L−1∙day−1, and 0.33 day−1, respectively. At the second, inductive, stage carotenoid synthesis was promoted. Maximal carotenoid fraction in the biomass was 2.2–2.4%. Based on chromatography data, astaxanthin and β-carotene constituted 48 and 13% of total carotenoid mass, respectively. Possible pathways of astaxanthin synthesis are proposed based on carotenoid composition. Collectively, a new strain B. aggregatus BM5/15 is a potential biotechnological source of two natural antioxidants, astaxanthin and β-carotene. The results give the rise for further works on optimization of B. aggregatus cultivation on an industrial scale.

scholarly journals Long-Term Exposure to Nanosized TiO2 Triggers Stress Responses and Cell Death Pathways in Pulmonary Epithelial Cells

2021 ◽  
Vol 22 (10) ◽  
pp. 5349
Author(s):  
Mayes Alswady-Hoff ◽  
Johanna Samulin Erdem ◽  
Santosh Phuyal ◽  
Oskar Knittelfelder ◽  
Animesh Sharma ◽  
...  
Keyword(s):  
Cell Death ◽  
Epithelial Cells ◽  
Health Effects ◽  
Stress Responses ◽  
Cell Stress ◽  
Lipid Classes ◽  
Long Term Effects ◽  
Cell Death Pathways ◽  
Pulmonary Epithelial Cells

There is little in vitro data available on long-term effects of TiO2 exposure. Such data are important for improving the understanding of underlying mechanisms of adverse health effects of TiO2. Here, we exposed pulmonary epithelial cells to two doses (0.96 and 1.92 µg/cm2) of TiO2 for 13 weeks and effects on cell cycle and cell death mechanisms, i.e., apoptosis and autophagy were determined after 4, 8 and 13 weeks of exposure. Changes in telomere length, cellular protein levels and lipid classes were also analyzed at 13 weeks of exposure. We observed that the TiO2 exposure increased the fraction of cells in G1-phase and reduced the fraction of cells in G2-phase, which was accompanied by an increase in the fraction of late apoptotic/necrotic cells. This corresponded with an induced expression of key apoptotic proteins i.e., BAD and BAX, and an accumulation of several lipid classes involved in cellular stress and apoptosis. These findings were further supported by quantitative proteome profiling data showing an increase in proteins involved in cell stress and genomic maintenance pathways following TiO2 exposure. Altogether, we suggest that cell stress response and cell death pathways may be important molecular events in long-term health effects of TiO2.

scholarly journals Nicotinamide Supplementation Improves Oocyte Quality and Offspring Development by Modulating Mitochondrial Function in an Aged Caenorhabditis elegans Model

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 519
Author(s):  
Hyemin Min ◽  
Mijin Lee ◽  
Kyoung Sang Cho ◽  
Hyunjung Jade Lim ◽  
Yhong-Hee Shim
Keyword(s):  
Caenorhabditis Elegans ◽  
Mitochondrial Function ◽  
Stress Responses ◽  
Oocyte Quality ◽  
Embryonic Lethality ◽  
Reproductive Aging ◽  
Control Female ◽  
Offspring Development ◽  
Developmental Growth ◽  
Ros Accumulation

Aging is associated with a decline in the quality of biological functions. Among the aging processes, reproductive aging is a critical process because of its intergenerational effects. However, the mechanisms underlying reproductive aging remain largely unknown. Female reproductive aging is the primary reason for limited fertility in mammals. Therefore, we attempted to investigate a modulator that can control female reproductive aging using a Caenorhabditis elegans model. In the present study, we examined the role of nicotinamide (NAM) in oocyte quality and offspring development. The levels of reactive oxygen species (ROS) and oxidative stress responses in aged oocytes, embryonic lethality, and developmental growth of the offspring were examined with maternal NAM supplementation. Supplementation with NAM improved oocyte quality, decreased embryonic lethality, and promoted germ cell apoptosis. Furthermore, NAM supplementation in aged mothers reduced ROS accumulation and improved mitochondrial function in oocytes. Consequently, the developmental growth and motility of offspring were improved. These findings suggest that NAM supplementation improves the health of the offspring produced by aged mothers through improved mitochondrial function. Taken together, our results imply that NAM supplementation in the aged mother improves oocyte quality and protects offspring by modulating mitochondrial function.

scholarly journals LONP1 and ClpP cooperatively regulate mitochondrial proteostasis for cancer cell survival

Oncogenesis ◽  
2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Yu Geon Lee ◽  
Hui Won Kim ◽  
Yeji Nam ◽  
Kyeong Jin Shin ◽  
Yu Jin Lee ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Growth ◽  
Cell Survival ◽  
Cancer Cell ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Tca Cycle ◽  
Mitochondrial Matrix ◽  
Mitochondrial Functions ◽  
Cancer Cell Survival

AbstractMitochondrial proteases are key components in mitochondrial stress responses that maintain proteostasis and mitochondrial integrity in harsh environmental conditions, which leads to the acquisition of aggressive phenotypes, including chemoresistance and metastasis. However, the molecular mechanisms and exact role of mitochondrial proteases in cancer remain largely unexplored. Here, we identified functional crosstalk between LONP1 and ClpP, which are two mitochondrial matrix proteases that cooperate to attenuate proteotoxic stress and protect mitochondrial functions for cancer cell survival. LONP1 and ClpP genes closely localized on chromosome 19 and were co-expressed at high levels in most human cancers. Depletion of both genes synergistically attenuated cancer cell growth and induced cell death due to impaired mitochondrial functions and increased oxidative stress. Using mitochondrial matrix proteomic analysis with an engineered peroxidase (APEX)-mediated proximity biotinylation method, we identified the specific target substrates of these proteases, which were crucial components of mitochondrial functions, including oxidative phosphorylation, the TCA cycle, and amino acid and lipid metabolism. Furthermore, we found that LONP1 and ClpP shared many substrates, including serine hydroxymethyltransferase 2 (SHMT2). Inhibition of both LONP1 and ClpP additively increased the amount of unfolded SHMT2 protein and enhanced sensitivity to SHMT2 inhibitor, resulting in significantly reduced cell growth and increased cell death under metabolic stress. Additionally, prostate cancer patients with higher LONP1 and ClpP expression exhibited poorer survival. These results suggest that interventions targeting the mitochondrial proteostasis network via LONP1 and ClpP could be potential therapeutic strategies for cancer.

scholarly journals Analysis of the Oxidative Burst and Its Relevant Signaling Pathways in Leptosphaeria maculans—Brassica napus Pathosystem

2021 ◽  
Vol 22 (9) ◽  
pp. 4812
Author(s):  
Cunchun Yang ◽  
W. G. Dilantha Fernando
Keyword(s):  
Cell Death ◽  
Signaling Pathways ◽  
Oxidative Burst ◽  
Defense Mechanisms ◽  
Leptosphaeria Maculans ◽  
Gene Interaction ◽  
Early Response ◽  
Marker Genes ◽  
Ros Accumulation ◽  
Microbe Interactions

An oxidative burst is an early response of plants to various biotic/abiotic stresses. In plant-microbe interactions, the plant body can induce oxidative burst to activate various defense mechanisms to combat phytopathogens. A localized oxidative burst is also one of the typical behaviors during hypersensitive response (HR) caused by gene-for-gene interaction. In this study, the occurrence of oxidative burst and its signaling pathways was studied from different levels of disease severity (i.e., susceptible, intermediate, and resistant) in the B. napus–L. maculans pathosystem. Canola cotyledons with distinct levels of resistance exhibited differential regulation of the genes involved in reactive oxygen species (ROS) accumulation and responses. Histochemical assays were carried out to understand the patterns of H2O2 accumulation and cell death. Intermediate and resistant genotypes exhibited earlier accumulation of H2O2 and emergence of cell death around the inoculation origins. The observations also suggested that the cotyledons with stronger resistance were able to form a protective region of intensive oxidative bursts between the areas with and without hyphal intrusions to block further fungal advancement to the uninfected regions. The qPCR analysis suggested that different onset patterns of some marker genes in ROS accumulation/programmed cell death (PCD) such as RBOHD, MPK3 were associated with distinct levels of resistance from B. napus cultivars against L. maculans. The observations and datasets from this article indicated the distinct differences in ROS-related cellular behaviors and signaling between compatible and incompatible interactions.

Programmed cell death in the coccoid green microalga Ankistrodesmus densus Korshikov (Sphaeropleales, Selenastraceae)

2021 ◽  
pp. 1-14
Author(s):  
Marcelo M. Barreto Filho ◽  
Pierre M. Durand ◽  
Nathan E. Andolfato ◽  
Anine Jordaan ◽  
Hugo Sarmento ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Green Microalga
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