scholarly journals Enhancement of Low pH Stress Tolerance in Anthocyanin-Enriched Transgenic Petunia Overexpressing RsMYB1 Gene

2018 ◽  
Vol 9 ◽  
Author(s):  
Aung H. Naing ◽  
Deuk B. Lee ◽  
Trinh N. Ai ◽  
Ki B. Lim ◽  
Chang K. Kim
Keyword(s):  
Stress Tolerance ◽  
Low Ph ◽  
Ph Stress ◽  
Transgenic Petunia

High environmental temperature and low pH stress alter the gill phenotypic plasticity of Hoven's carp Leptobarbus hoevenii

2021 ◽  
Author(s):  
Suhaini Mohamad ◽  
Hon Jung Liew ◽  
Rabiatul Adawiyyah Zainuddin ◽  
Sharifah Rahmah ◽  
Khor Waiho ◽  
...  
Keyword(s):  
Phenotypic Plasticity ◽  
Environmental Temperature ◽  
Low Ph ◽  
High Environmental Temperature ◽  
Ph Stress

scholarly journals Streptococcus mutans Lacking sufCDSUB Is Viable, but Displays Major Defects in Growth, Stress Tolerance Responses and Biofilm Formation

2021 ◽  
Vol 12 ◽  
Author(s):  
Kassapa Ellepola ◽  
Xiaochang Huang ◽  
Ryan P. Riley ◽  
Jacob P. Bitoun ◽  
Zezhang Tom Wen
Keyword(s):  
Stress Tolerance ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Nitrosative Stress ◽  
Growth Stress ◽  
Low Ph ◽  
Luciferase Reporter ◽  
Deficient Mutant ◽  
Oxidative And Nitrosative Stress ◽  
Isoleucine Leucine

Streptococcus mutans appears to possess a sole iron-sulfur (Fe-S) cluster biosynthesis system encoded by the sufCDSUB cluster. This study was designed to examine the role of sufCDSUB in S. mutans physiology. Allelic exchange mutants deficient of the whole sufCDSUB cluster and in individual genes were constructed. Compared to the wild-type, UA159, the sufCDSUB-deficient mutant, Δsuf::kanr, had a significantly reduced growth rate, especially in medium with the absence of isoleucine, leucine or glutamate/glutamine, amino acids that require Fe-S clusters for biosynthesis and when grown with medium adjusted to pH 6.0 and under oxidative and nitrosative stress conditions. Relative to UA159, Δsuf::kanr had major defects in stress tolerance responses with reduced survival rate of > 2-logs following incubation at low pH environment or after hydrogen peroxide challenge. When compared to UA159, Δsuf::kanr tended to form aggregates in broth medium and accumulated significantly less biofilm. As shown by luciferase reporter fusion assays, the expression of sufCDSUB was elevated by > 5.4-fold when the reporter strain was transferred from iron sufficient medium to iron-limiting medium. Oxidative stress induced by methyl viologen increased sufCDSUB expression by > 2-fold, and incubation in a low pH environment led to reduction of sufCDSUB expression by > 7-fold. These results suggest that lacking of SufCDSUB in S. mutans causes major defects in various cellular processes of the deficient mutant, including growth, stress tolerance responses and biofilm formation. In addition, the viability of the deficient mutant also suggests that SUF, the sole Fe-S cluster machinery identified is non-essential in S. mutans, which is not known in any other bacterium lacking the NIF and/or ISC system. However, how the bacterium compensates the Fe-S deficiency and if any novel Fe-S assembly systems exist in this bacterium await further investigation.

Transcriptional profiling reveals molecular basis and the role of arginine in response to low-pH stress in Pichia kudriavzevii

2019 ◽  
Author(s):  
Hao Ji ◽  
Xiameng Dong ◽  
Kailun Zhang ◽  
Libo Jin ◽  
Renyi Peng ◽  
...  
Keyword(s):  
Organic Acids ◽  
Molecular Basis ◽  
Transcriptional Profiling ◽  
Cell Aggregation ◽  
Membrane Lipid ◽  
Low Ph ◽  
Pichia Kudriavzevii ◽  
Ph Stress ◽  
Ph Conditions

Abstract BackgroundThe non-conventional yeast Pichia kudriavzevii possesses a unique ability to tolerate various environmental stresses particularly low-pH stress. Thus, it is considered to be a promising biotechnological host for the production of various organic acids under low-pH conditions. However, little is known about the low-pH stress response in P. kudriavzevii, which significantly restricts its future development. ResultsIn this study, P. kudriavzevii JLY1107 showed great tolerance to low-pH stress, but its cell aggregation upon acidic conditions is unfavorable for the development of low-pH fermentation. To explore the molecular basis, we conducted RNA-Seq to compare global gene expression in response to low-pH. Among the 429 differentially expressed genes, the genes associated with regulation of membrane lipid composition, filamentous growth and arginine metabolism were selected for in-depth discussions. The up-regulation of genes associated with arginine uptake and degradation suggests a potential role of arginine in response to low-pH strsss. We therefore present data supporting the hypothesis that P. kudriavzevii maintains intracellular homeostasis by using the ammonia produced by arginine catabolism. Furthermore, external addition of arginine significantly enhances growth and reduces cell aggregation of P. kudriavzevii under low-pH conditions.ConclusionsArginine was demonstrated to be a promising molecule for improving cell growth and preventing cell aggregation under extremely low-pH conditions. Our study is a step towards developing the non-conventional yeast P. kudriavzevii as a platform host for the production of organic acids under low-pH conditions.

Transcriptomic response to low pH stress in gills of the pacific white shrimp, Litopenaeus vannamei

2019 ◽  
Vol 51 (1) ◽  
pp. 175-186
Author(s):  
Hongmei Li ◽  
Qilin Meng ◽  
Ting Chen ◽  
Chunhua Ren ◽  
Wen Huang ◽  
...  
Keyword(s):  
Litopenaeus Vannamei ◽  
Low Ph ◽  
Pacific White Shrimp ◽  
White Shrimp ◽  
Transcriptomic Response ◽  
Ph Stress ◽  
The Pacific

Growth and functional responses of different cultivars of Lotus corniculatus to aluminum and low pH stress

2009 ◽  
Vol 166 (14) ◽  
pp. 1479-1487 ◽  
Author(s):  
Ján Pavlovkin ◽  
Peter Pal’ove-Balang ◽  
Lukáš Kolarovič ◽  
Veronika Zelinová
Keyword(s):  
Lotus Corniculatus ◽  
Low Ph ◽  
Functional Responses ◽  
Ph Stress

scholarly journals Exploring the mitochondrial response to oxidative DNA damage in octocorals

2017 ◽  
Author(s):  
Gaurav G Shimpi ◽  
Sergio Vargas ◽  
Gert Wörheide
Keyword(s):  
Climate Change ◽  
Oxidative Stress ◽  
Copy Number ◽  
Low Ph ◽  
Host Cells ◽  
Climate Change Scenarios ◽  
Gene Repertoire ◽  
Mtdna Copy Number ◽  
Mtdna Damage ◽  
Ph Stress

Mitochondrial response to oxidative stress is intricately related to cellular homeostasis due to the high susceptibility of the mitochondrial genome to oxidative damage. Octocoral mitogenomes possess a unique DNA repair gene, mtMutS, potentially capable of counteracting the effects of oxidative stress induced mtDNA damage. Despite this unique feature, the response of octocoral mitochondria to increased oxidative stress remains unexplored. Here we explore the response of the octocoral Sinularia cf. cruciata to elevated temperature and low-pH stress and its ability to reverse acute oxidative mtDNA damage caused by exogenous agents like hydrogen peroxide (H2O2). The differential transcriptional response to these climate change-related stresses was recorded for two mtDNA-encoded genes and three stress biomarkers. Only HSP70 was significantly upregulated during thermal stress whereas significant reduction in the expression levels of HSP70, GPX, and COI was observed along with an increased number of mtMutS transcripts during low-pH stress. Damage to mtDNA was evident, accompanied by changes in mtDNA copy number. Damage caused by H2O2 toxicity was reversed within 5 hours and initial mtDNA copy number apparently influenced damage reversal. Our results indicate that different stress-specific resilience strategies are used by this octocoral species and its mitochondria to reverse oxidative stress and associated mtDNA damage. These experiments provide the first account on the response of octocoral mitochondria with its unique gene repertoire among animals to different stressors and highlight its potential role in conferring resilience to the host cells during different climate change scenarios.

Soil—Plant Nutrient Relationships at Low pH Stress

1990 ◽  
pp. 475-507 ◽  
Author(s):  
N.K. FAGERIA ◽  
V.C. BALIGAR ◽  
D.G. EDWARDS
Keyword(s):  
Low Ph ◽  
Plant Nutrient ◽  
Ph Stress

scholarly journals Overexpression of RsMYB1 enhances heavy metal stress tolerance in transgenic petunia by elevating the transcript levels of stress tolerant and antioxidant genes

2018 ◽  
Author(s):  
Trinh Ngoc Ai ◽  
Aung Htay Naing ◽  
Byung-Wook Yun ◽  
Chang Kil Kim
Keyword(s):  
Heavy Metal ◽  
Stress Tolerance ◽  
Sequence Similarity ◽  
Abiotic Stress Tolerance ◽  
Heavy Metal Stress ◽  
Metal Stress ◽  
Antioxidant Genes ◽  
Resultant Increase ◽  
Anthocyanin Production ◽  
Transgenic Petunia

AbstractThe RsMYB1 transcription factor (TF) controls the regulation of anthocyanin in radish (Raphanus sativus), and its overexpression in tobacco and petunia strongly enhances anthocyanin production. However, no data exists on whether RsMYB1 is involved in the mechanism that leads to abiotic stress tolerance. Under normal conditions, transgenic petunia plants expressing RsMYB1 and WT were able to thrive by producing well-developed broad leaves and regular roots. In contrast, a reduction in plant growth was observed when they were exposed to heavy metals (CuSO4, ZnSO4, MnSO4, and K2Cr2O7). However, RsMYB1-overexpressing plants were found to be more tolerant to the stresses than the WT plants because the expressions of stress tolerant genes (GSH and PCs) and antioxidant genes (SOD, CAT, and POX) were enhanced. In addition, according to the phylogenetic analysis, RsMYB1 has a strong sequence similarity with other MYB TFs that confer different abiotic stresses. These results suggest that overexpression of RsMYB1 enhances the expression levels of metal-induced stress tolerance genes and antioxidant genes, and the resultant increase in gene expression improves heavy metal stress tolerance in petunia.

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