scholarly journals Ethanol and H2O2 stresses enhance lipid production in an oleaginous Rhodotorula toruloides thermotolerant mutant L1-1

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Chih-Chan Wu ◽  
Takao Ohashi ◽  
Ryo Misaki ◽  
Savitree Limtong ◽  
Kazuhito Fujiyama
Keyword(s):  
Stress Tolerance ◽  
Membrane Lipids ◽  
Lipid Production ◽  
Industrial Applications ◽  
Stress Conditions ◽  
Lipid Productivity ◽  
Ethanol Stress ◽  
Wall Strength ◽  
Thermotolerant Strain ◽  
A Cell

Abstract Stress tolerance is a desired characteristic of yeast strains for industrial applications. Stress tolerance has been well described in Saccharomyces yeasts but has not yet been characterized in oleaginous Rhodotorula yeasts even though they are considered promising platforms for lipid production owing to their outstanding lipogenicity. In a previous study, the thermotolerant strain L1–1 was isolated from R. toruloides DMKU3-TK16 (formerly Rhodosporidium toruloides). In this study, we aimed to further examine the ability of this strain to tolerate other stresses and its lipid productivity under various stress conditions. We found that the L1–1 strain could tolerate not only thermal stress but also oxidative stress (ethanol and H2O2), osmotic stress (glucose) and a cell membrane disturbing reagent (DMSO). Our results also showed that the L1–1 strain exhibited enhanced ability to maintain ROS homeostasis, stronger cell wall strength and increased levels of unsaturated membrane lipids under various stresses. Moreover, we also demonstrated that ethanol-induced stress significantly increased the lipid productivity of the thermotolerant L1–1. The thermotolerant L1–1 was also found to produce a higher lipid titer under the dual ethanol-H2O2 stress than under non-stress conditions. This is the first report to indicate that ethanol stress can induce lipid production in an R. toruloides thermotolerant strain.

scholarly journals Citric Acid-Mediated Abiotic Stress Tolerance in Plants

2021 ◽  
Vol 22 (13) ◽  
pp. 7235
Author(s):  
Md. Tahjib-Ul-Arif ◽  
Mst. Ishrat Zahan ◽  
Md. Masudul Karim ◽  
Shahin Imran ◽  
Charles T. Hunter ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Citric Acid ◽  
Stress Tolerance ◽  
Metabolic Networks ◽  
Abiotic Stress Tolerance ◽  
Heavy Metal Stress ◽  
Stress Conditions ◽  
Growth And Yield ◽  
Antioxidant Defense Systems ◽  
Physiological Outcomes

Several recent studies have shown that citric acid/citrate (CA) can confer abiotic stress tolerance to plants. Exogenous CA application leads to improved growth and yield in crop plants under various abiotic stress conditions. Improved physiological outcomes are associated with higher photosynthetic rates, reduced reactive oxygen species, and better osmoregulation. Application of CA also induces antioxidant defense systems, promotes increased chlorophyll content, and affects secondary metabolism to limit plant growth restrictions under stress. In particular, CA has a major impact on relieving heavy metal stress by promoting precipitation, chelation, and sequestration of metal ions. This review summarizes the mechanisms that mediate CA-regulated changes in plants, primarily CA’s involvement in the control of physiological and molecular processes in plants under abiotic stress conditions. We also review genetic engineering strategies for CA-mediated abiotic stress tolerance. Finally, we propose a model to explain how CA’s position in complex metabolic networks involving the biosynthesis of phytohormones, amino acids, signaling molecules, and other secondary metabolites could explain some of its abiotic stress-ameliorating properties. This review summarizes our current understanding of CA-mediated abiotic stress tolerance and highlights areas where additional research is needed.

scholarly journals Isolation, identification and diversity of oleaginous yeasts from Kuching, Sarawak, Malaysia

2018 ◽  
Vol 19 (4) ◽  
pp. 1266-1272 ◽  
Author(s):  
MICKY VINCENT ◽  
HUANG CHAI HUNG ◽  
PATRICIA ROWENA MARK BARAN ◽  
AFIZUL SAFWAN AZAHARI ◽  
DAYANG SALWANI AWANG ADENI
Keyword(s):  
Candida Parapsilosis ◽  
Yeast Species ◽  
Lipid Production ◽  
Industrial Applications ◽  
Oleaginous Yeasts ◽  
Intracellular Lipids ◽  
Pichia Manshurica ◽  
Sudan Iv ◽  
Scientific Technical ◽  
Polymerase Chain

Vincent M, Hung MC, Baran PRM, Azahari AS, Adeni DSA. 2018. Isolation, identification and diversity of oleaginous yeastsfrom Kuching, Sarawak, Malaysia. Biodiversitas 19: 1266-1272. The present study was performed to isolate, identify and determine thediversity of oleaginous yeasts from various sources in Kuching, Sarawak (Malaysia). Microscopic observations via light and scanningelectron microscope (SEM) indicated that the yeast isolates were in sizes ranging from 2-3 μm in width and 4-8 μm in length, typical ofmost unicellular ascomycotic fungi. Polymerase Chain Reaction (PCR) and molecular identification performed on the yeast isolates,targeting the D1/D2 region of the 26S rDNA, identified 6 yeast species from the 21 isolates, namely Pichia manshurica (5/21), Candidakrusei (8/21), Candida parapsilosis (1/21), Pichia guilliermondii (2/21), Clavispora lusitaniae (1/21) and Kluyveromyces marxianus(4/21). All 21 yeast isolates accumulated intracellular lipids when grown in nitrogen-limited medium, as tested via Sudan IV staining.The present study is the first to document the production of lipids bodies in C. krusei, C. parapsilosis, and C. lusitaniae. Furtherinvestigations to assess the growth kinetics, lipid production efficiencies and lipids profiles of these oleaginous yeasts may provideinsights into the possible utilization of these isolates for a variety of scientific, technical and industrial applications.

scholarly journals Canopy Temperature and Chlorophyll Content are Effective Measures of Drought Stress Tolerance in Durum Wheat

2018 ◽  
Vol 10 (4) ◽  
pp. 575-583 ◽  
Author(s):  
Fereshteh JOKAR ◽  
Rahmatollah KARIMIZADEH ◽  
Asad MASOUMIASL ◽  
Reza AMIRI FAHLIANI
Keyword(s):  
Drought Tolerance ◽  
Durum Wheat ◽  
Stress Tolerance ◽  
Chlorophyll Content ◽  
Geometric Mean ◽  
Canopy Temperature ◽  
Stress Conditions ◽  
Tolerance Index ◽  
Wheat Varieties ◽  
Drought Tolerant

Durum wheat (Triticum durum L.) is used for the preparation of multiple food products, including pasta and bread. Its production is restricted due to diverse environmental stresses i.e. drought and heat stress. Here, comparative analysis of durum wheat varieties was done by studying canopy temperature depression (CTD) and chlorophyll content (CHL), yield and yield contributing traits to evaluate their performance under stress and low stress conditions. Twelve durum wheat genotypes were studied under stressful and low-stress conditions in Gachsaran region of Iran. CTD and CHL were measured at two stages, from the emergence of fifty percent of inflorescence (ZGS 54) to watery ripe stage (ZGS 71). According to stress tolerance index (STI), mean productivity (MP) and geometric mean productivity (GMP) indices, genotype G10 exhibited the most, while genotype G6, the least relative tolerance, respectively. Based on MP and GMP, genotype G10 was found to be drought tolerant, while genotype G2 displayed the lowest amount of MP and GMP. Therefore these genotypes are recommended to be used as genitors in artificial hybridization for improvement of drought tolerance in other cultivars. All indices had high correlation with grain yield under stress and non-stress condition, indicating more suitability of these indices for selection of resistant genotype. Results of the present study showed that among drought tolerance indices, harmonic mean (HM), GMP, CTD and modified STI index (K2STI) can be used as the most suitable indicators for screening drought tolerant cultivars.

scholarly journals The RNA-Binding Protein Hfq of Listeria monocytogenes: Role in Stress Tolerance and Virulence

2004 ◽  
Vol 186 (11) ◽  
pp. 3355-3362 ◽  
Author(s):  
Janne K. Christiansen ◽  
Marianne H. Larsen ◽  
Hanne Ingmer ◽  
Lotte Søgaard-Andersen ◽  
Birgitte H. Kallipolitis
Keyword(s):  
Listeria Monocytogenes ◽  
Stress Tolerance ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Stationary Growth Phase ◽  
Ethanol Stress ◽  
Gram Positive ◽  
Term Survival

ABSTRACT In gram-negative bacteria, the RNA-binding protein Hfq has emerged as an important regulatory factor in a variety of physiological processes, including stress resistance and virulence. In Escherichia coli, Hfq modulates the stability or the translation of mRNAs and interacts with numerous small regulatory RNAs. Here, we studied the role of Hfq in the stress tolerance and virulence of the gram-positive food-borne human pathogen Listeria monocytogenes. We present evidence that Hfq is involved in the ability of L. monocytogenes to tolerate osmotic and ethanol stress and contributes to long-term survival under amino acid-limiting conditions. However, Hfq is not required for resistance to acid and oxidative stress. Transcription of hfq is induced under various stress conditions, including osmotic and ethanol stress and at the entry into the stationary growth phase, thus supporting the view that Hfq is important for the growth and survival of L. monocytogenes in harsh environments. The stress-inducible transcription of hfq depends on the alternative sigma factor σB, which controls the expression of numerous stress- and virulence-associated genes in L. monocytogenes. Infection studies showed that Hfq contributes to pathogenesis in mice, yet plays no role in the infection of cultured cell lines. This study provides, for the first time, information on the role of Hfq in the stress tolerance and virulence of a gram-positive pathogen.

scholarly journals Assessing Genetic Diversity of Rice Varieties under Drought Stress Conditions

2011 ◽  
Vol 3 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Mina ABARSHAHR ◽  
Babak RABIEI ◽  
Habibollah SAMIZADEH LAHIGI
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Stress Tolerance ◽  
Geometric Mean ◽  
Minimum Variance ◽  
Stress Conditions ◽  
Productivity Index ◽  
Stress Index ◽  
Tolerance Index ◽  
Rice Varieties

In order to compare different rice genotypes grown under drought stress conditions a field experiment was conducted. In this study thirty different genotypes of native, breeded and upland cultivars were evaluated. Analysis of variance showed significant differences among genotypes in respect of all vegetative and morphological traits. Genotypes were devided into three groups by cluster analysis based on all studied traits with minimum variance method (Wards Method). The total average indicates significant differences among groups in respect of all morphological and physiological characteristics. In addition, eight drought stress tolerance indices including: sensitivity to stress index (SSI), drought response index (DRI), relative drought index (RDI), tolerance index (TOL), mean productivity index (MP), stress tolerance index (STI), geometric mean productivity index (GMP) and harmonic mean index (HM) were calculated according to their grain yield under drought stress and normal conditions. In general, results of this experimnet revealed that, among rice cultivars Domsephid, Deylamany, Hasansaraei, Sadri, Anbarboo and Domsiah had the highest sensitivity referring to drought stress and produced the lowest grain yield. Also, genotypes of IR24 (breeded of IRRI), Nemat, Sephidroud, Kadoos and Bejar (breeded of Iran) and Vandana, upland cultivar (originally from India) had the highest tolerance to drought stress and produced the highest grain yield. In conclusion, it was suggested that, these cultivars are suitable for drought stress conditions and are appropriate for hybridization with the aim of increasing drought tolerance.

scholarly journals Knockdown of Cytochrome P450 Genes Gh_D07G1197 and Gh_A13G2057 on Chromosomes D07 and A13 Reveals Their Putative Role in Enhancing Drought and Salt Stress Tolerance in Gossypium hirsutum

Genes ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 226 ◽  
Author(s):  
Richard Odongo Magwanga ◽  
Pu Lu ◽  
Joy Nyangasi Kirungu ◽  
Qi Dong ◽  
Xiaoyan Cai ◽  
...  
Keyword(s):  
Salt Stress ◽  
Gossypium Hirsutum ◽  
Stress Tolerance ◽  
Common Property ◽  
Stress Conditions ◽  
Tetraploid Cotton ◽  
Salt Stress Tolerance ◽  
Negative Effects ◽  
Drought And Salt Stress ◽  
Stress Responsive Genes

We identified 672, 374, and 379 CYPs proteins encoded by the CYPs genes in Gossypium hirsutum, Gossypium raimondii, and Gossypium arboreum, respectively. The genes were found to be distributed in all 26 chromosomes of the tetraploid cotton, with chrA05, chrA12, and their homeolog chromosomes harboring the highest number of genes. The physiochemical properties of the proteins encoded by the CYP450 genes varied in terms of their protein lengths, molecular weight, isoelectric points (pI), and even grand hydropathy values (GRAVY). However, over 99% of the cotton proteins had GRAVY values below 0, which indicated that the majority of the proteins encoded by the CYP450 genes were hydrophilic in nature, a common property of proteins encoded by stress-responsive genes. Moreover, through the RNA interference (RNAi) technique, the expression levels of Gh_D07G1197 and Gh_A13G2057 were suppressed, and the silenced plants showed a higher concentration of hydrogen peroxide (H2O2) with a significant reduction in the concentration levels of glutathione (GSH), ascorbate peroxidase (APX), and proline compared to the wild types under drought and salt stress conditions. Furthermore, the stress-responsive genes 1-Pyrroline–5-Carboxylate Synthetase (GhP5CS), superoxide dismutase (GhSOD), and myeloblastosis (GhMYB) were downregulated in VIGS plants, but showed upregulation in the leaf tissues of the wild types under drought and salt stress conditions. In addition, CYP450-silenced cotton plants exhibited a high level of oxidative injury due to high levels of oxidant enzymes, in addition to negative effects on CMS, ELWL, RLWC, and chlorophyll content The results provide the basic foundation for future exploration of the proteins encoded by the CYP450 genes in order to understand the physiological and biochemical mechanisms in enhancing drought and salt stress tolerance in plants.

Genome-Wide Analysis of Phospholipase D Gene Family and Profiling of Phospholipids under Abiotic Stresses in Brassica napus

2019 ◽  
Vol 60 (7) ◽  
pp. 1556-1566 ◽  
Author(s):  
Shaoping Lu ◽  
Tarig Fadlalla ◽  
Shan Tang ◽  
Long Li ◽  
Usman Ali ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Stress Tolerance ◽  
Abiotic Stresses ◽  
Gene Expression Analysis ◽  
Agronomic Traits ◽  
Membrane Lipids ◽  
Protein Structures ◽  
Large Family ◽  
Membrane Phospholipids ◽  
Genome Wide

Abstract Oil crop Brassica napus is subjected to environmental stresses such as drought, cold and salt. Phospholipase Ds (PLDs) have vital roles in regulation of plant growth, development and stress tolerance. In this study, 32 BnaPLD genes were identified and classified into six subgroups depending on the conserved protein structures. High similarity in gene and protein structures exists between BnaPLDs and AtPLDs. Gene expression analysis showed that BnaPLDα1s and BnaPLDδs had higher expression than other PLDs. BnaPLDα1 and BnaPLDδ were significantly induced by abiotic stresses including dehydration, NaCl, abscisic acid (ABA) and 4�C. Lipidomic analysis showed that the content of main membrane phospholipids decreased gradually under stresses, except phosphatidylglycerol increased under the treatment of ABA and phosphatidylethanolamine increased under 4�C. Correspondingly, their product of phosphatidic acid increased often with a transient peak at 8 h. The plant height of mutants of PLDα1 was significantly reduced. Agronomic traits such as yield, seed number, silique number and branches were significantly impaired in PLDα1 mutants. These results indicate that there is a large family of PLD genes in B. napus, especially BnaPLDα1s and BnaPLDδs may play important roles in membrane lipids remodeling and maintaining of the growth and stress tolerance of B. napus.

scholarly journals Unique Roles of Sphingolipids in Selected Malignant and Nonmalignant Lesions of Female Reproductive System

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Paweł Knapp ◽  
Karolina Chomicz ◽  
Magdalena Świderska ◽  
Adrian Chabowski ◽  
Robert Jach
Keyword(s):  
Cancer Biology ◽  
Membrane Lipids ◽  
Malignant Tumors ◽  
Chemotherapeutic Agents ◽  
Self Control ◽  
Cancer Tissue ◽  
Control Mechanisms ◽  
Ceramide Content ◽  
A Cell ◽  
Prevention Of Cancer

Cancer develops as a result of the loss of self-control mechanisms by a cell; it gains the ability to induce angiogenesis, becomes immortal and resistant to cell death, stops responding to growth suppressor signals, and becomes capable of invasion and metastasis. Sphingolipids—a family of membrane lipids—are known to play important roles in the regulation of cell proliferation, the response to chemotherapeutic agents, and/or prevention of cancer. Despite the underlying functions of sphingolipids in cancer biology, their metabolism in different malignant tumors is poorly investigated. Some studies showed marked differences in ceramide content between the tumor and the respective healthy tissue. Interestingly, the level of this sphingolipid could be either low or elevated, suggesting that the alterations in ceramide metabolism in cancer tissue may depend on the biology of the tumor. These processes are indeed related to the type of cancer, its stage, and histology status. In this paper we present the unique roles of bioactive sphingolipid derivative in selected gynecologic malignant and nonmalignant lesions.

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