The over-expression of phasin and regulator genes promoting the synthesis of polyhydroxybutyrate in Cupriavidus necator H16 under non-stress conditions

2021 ◽  
Author(s):  
Ruohao Tang ◽  
Xiaowei Peng ◽  
Caihong Weng ◽  
Yejun Han
Keyword(s):  
Bacterial Growth ◽  
Stress Condition ◽  
Stress Conditions ◽  
Comparative Transcriptome ◽  
Low Oxygen ◽  
Oxygen Stress ◽  
Percentage Content ◽  
Over Expression ◽  
Phb Production ◽  
Regulator Genes

Cupriavidus necator H16 is an ideal strain for polyhydroxybutyrate (PHB) production from CO 2 . Low-oxygen-stress can induce PHB synthesis in C. necator H16 while reducing bacterial growth under chemoautotrophic culture. The optimum growth and PHB synthesis of C. necator H16 cannot be achieved simultaneously, which restricts PHB production. The present study was initiated to address the issue through comparative transcriptome and gene function analysis. Firstly, the comparative transcriptome of C. necator H16 chemoautotrophically cultured under low-oxygen-stress and non-stress conditions was studied. Three types of transcription different genes were discovered: PHB enzymatic synthesis, PHB granulation, and regulators. Under low-oxygen-stress condition, acetoacetyl-CoA reductase gene phaB2 , PHB synthase gene phaC2 , phasins genes phaP1 and phaP2 , regulators genes uspA and rpoN were up-regulated 3.0, 2.5, 1.8, 2.7, 3.5, 1.6 folds, respectively. Secondly, the functions of up-regulated genes and their applications in PHB synthesis were further studied. It was found that the over-expression of phaP1 , phaP2 , uspA , and rpoN can induce PHB synthesis under non-stress condition, while phaB2 and phaC2 have no significant effect. Under the optimum condition, PHB percentage content in C. necator H16 was respectively increased by 37.2%, 28.4%, 15.8%, and 41.0% with the over-expression of phaP1 , phaP2 , uspA , and rpoN , and the corresponding PHB production increased by 49.8%, 42.9%, 47.0%, and 77.5% under non-stress chemoautotrophic conditions. Similar promotion by phaP1 , phaP2 , uspA , and rpoN was observed in heterotrophically cultured C. necator H16. The PHB percentage content and PHB production were respectively increased by 54.4% and 103.1% with the over-expression of rpoN under non-stress heterotrophic conditions. Importance Microbial fixation of CO 2 is an effective way to reduce greenhouse gases. Some microbes such as C. necator H16 usually accumulate PHB when they grow under stress. Low-oxygen-stress can induce PHB synthesis when C. necator H16 is autotrophically cultured with CO 2 , H 2 , and O 2 , while under stress, growth is restricted and total PHB yield is reduced. Achieving the optimal bacterial growth and PHB synthesis at the same time is an ideal condition for transforming CO 2 into PHB by C. necator H16. The present study was initiated to clarify the molecular basis of low-oxygen-stress promoting PHB accumulation and to realize the optimal PHB production by C. necator H16. Genes up-regulated under non-stress conditions were identified through comparative transcriptome analysis and over-expression of phasin and regulator genes were demonstrated to promote PHB synthesis in C. necator H16.

Dynamic changes of antioxidants and fermentative metabolites in apple peel in relation to storage, controlled atmosphere, and initial low oxygen stress

2021 ◽  
Vol 288 ◽  
pp. 110312
Author(s):  
Marina Buccheri ◽  
Valentina Picchi ◽  
Maurizio Grassi ◽  
Davide Gandin ◽  
Giulia Bianchi ◽  
...  
Keyword(s):  
Controlled Atmosphere ◽  
Low Oxygen ◽  
Dynamic Changes ◽  
Oxygen Stress ◽  
Apple Peel

The CRZ-1 Transcription Factor Regulates Hsp 80 Involves in the Acquisition of Thermotolerance, and NCA-2 for Calcium Stress Tolerance in Neurospora Crassa

2021 ◽  
Author(s):  
Avishek Roy ◽  
Ranjan Tamuli
Keyword(s):  
Transcription Factor ◽  
Heat Shock ◽  
Neurospora Crassa ◽  
Stress Condition ◽  
Stress Conditions ◽  
Start Codon ◽  
Expression Levels ◽  
Heat Shock Stress ◽  
Shock Proteins ◽  
Shock Stress

Abstract Heat shock proteins (Hsps) are molecular chaperones and required for survival of organisms under heat stress conditions. In this study, we studied Hsp80, a member of the Hsp90 family, in Neurospora crassa. The expression of hsp80 was severely reduced in the N. crassa calcineurin B subunit RIP-mutant (cnb-1RIP) strains under the heat shock conditions. Furthermore, the expression levels of cnb-1, hsp60, hsp80, and the calcineurin-regulated transcription factor crz-1 were increased, but expression levels were reduced in the presence of the calcineurin inhibitor FK506 under the heat shock stress in the N. crassa wild type. Therefore, the calcineurin-crz-1 signaling pathway transcriptionally regulates hsp60 and hsp80 under the heat shock stress condition in N. crassa. In addition, the transcript levels of trm-9 and nca-2, a Ca2+ sensor and a Ca2+ ATPase, respectively, were increased under the heat shock stress condition. Moreover, the expression of the hsp80, but not the hsp60, was reduced in the Δtrm-9, Δnca-2, and the Δtrm-9 Δnca-2 double mutants. These results suggested that hsp80, trm-9, and nca-2 play a role in coping the heat shock stress in N. crassa. We found that CRZ-1 binds to 5ʹ-CCTTCACA-3ʹ and 5ʹ-AGCGGAGC-3ʹ 8 bp nucleotide sequences, located about 1075 bp and 679 bp upstream of the ATG start codon, respectively, of hsp80. We also found that CRZ-1 binds to an 8 bp nucleotide sequence 5ʹ-ACCGCGCC-3ʹ, located 234 bp upstream of the ATG start codon of nca-2 under Ca2+ stress condition. Thus, cnb-1, hsp60, hsp80, and crz-1 are involved in the heat shock stress response in N. crassa. Moreover, CRZ-1 upregulates the expressions of hsp80 and nca-2 under the heat shock stress and Ca2+ stress conditions, respectively, in N. crassa.

A PDMS-Based Interdigitated Platform for Trophoblast Invasion Study Under Oxygen Stress Conditions

2021 ◽  
Author(s):  
Hyeran Cho ◽  
Ahmed Fuwad ◽  
Gun Ko ◽  
Gi Jin Kim ◽  
Tae-Joon Jeon ◽  
...  
Keyword(s):  
Stress Conditions ◽  
Trophoblast Invasion ◽  
Oxygen Stress

Response of pomegranate arils (cv. Wonderful) to low oxygen stress under active modified atmosphere condition

2018 ◽  
Vol 99 (3) ◽  
pp. 1088-1097 ◽  
Author(s):  
Zinash A Belay ◽  
Oluwafemi J Caleb ◽  
Pramod V Mahajan ◽  
Umezuruike L Opara
Keyword(s):  
Modified Atmosphere ◽  
Low Oxygen ◽  
Oxygen Stress ◽  
Pomegranate Arils

scholarly journals Vigor and alpha-amylase activity in common bean seeds under salt stress conditions

2021 ◽  
Vol 42 (6supl2) ◽  
pp. 3633-3650
Author(s):  
Matheus Santin Padilha ◽  
◽  
Cileide Maria Medeiros Coelho ◽  
Natalia Carolina Moraes Ehrhardt-Brocardo ◽  
◽  
...  
Keyword(s):  
Salt Stress ◽  
Common Bean ◽  
Stress Condition ◽  
Amylase Activity ◽  
Reduction Rate ◽  
Stress Conditions ◽  
Alpha Amylase ◽  
Reserve Mobilization ◽  
Relationship Of ◽  
The Relationship

Seeds with high vigor have greater capacity for hydrolysis and mobilization of stored reserves, which results in the formation of vigorous seedlings, and this behavior is observed under abiotic stress conditions. This study proposes to investigate the relationship of the enzyme alpha-amylase in lots of common-bean seeds with contrasting vigor, when subjected to the absence and presence of salt stress, aiming to identify the relationship of this enzyme with the vigor of the seed lot under these conditions. Seven common-bean cultivars were used. Physiological quality was determined by germination, vigor index and seedling length. The mobilization of reserves was evaluated under absence and presence of salt stress simulated with a NaCl solution with a concentration of 50 mmol L-1. The analyzed variables regarding reserve mobilization were reserve reduction, reserve reduction rate, seedling dry weight, reserve mobilization rate, starch, starch reduction rate and alpha-amylase activity. Results showed that the stress condition negatively affected all the evaluated variables; however, the cultivars classified as having greater vigor showed better physiological performance under stress. Salt stress in common-bean seeds affects seedling performance and reduces alpha-amylase activity during germination, and high-vigor seed lots exhibited higher enzyme activity in the no-stress condition.

scholarly journals Heritability and mode of gene action determination for grain filling rate and relative water content in hexaploid wheat

Genetika ◽  
2012 ◽  
Vol 44 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ahmad Golparvar
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
Relative Water Content ◽  
Stress Condition ◽  
Gene Action ◽  
Grain Filling ◽  
Stress Conditions ◽  
Filling Rate ◽  
Grain Filling Rate ◽  
Relative Water

Mode of gene action, heritability and determination of the effective breeding strategy for improvement of physiological and traits specifically in drought stress conditions is very important. Therefore, this study was conducted by using two drought susceptible and tolerant wheat cultivars. Cultivars Sakha8 (tolerant) and Pishtaz (susceptible) as parents along with F1, F2, BC1 and BC2 generations were sown in a randomized complete block design with three replications in drought stress conditions. Results of analysis of variance indicated significant difference between generations as well as degree of dominance revealed over-dominance for the both traits. Fitting simple additive-dominance model designated that this model was not able to account for changes of traits relative water content and mean of grain filling rate. It was revealed that m-d-h-i-j model for relative water content and m-d-h-i model for mean of grain filling rate are the best models. Estimation of heritability and mode of gene action indicated that selection for improvement of traits studied in stress condition and specifically in early generations have medium genetic gain. In conclusion, grain filling rate is better than relative water content as indirect selection criteria to improve plant grain yield in drought stress condition.

Pyrophosphate as an alternative energy currency in plants

2021 ◽  
Vol 478 (8) ◽  
pp. 1515-1524
Author(s):  
Abir U. Igamberdiev ◽  
Leszek A. Kleczkowski
Keyword(s):  
Metabolic Pathways ◽  
Energy Efficient ◽  
Alternative Energy ◽  
Plant Cells ◽  
Atp Synthesis ◽  
Continuous Operation ◽  
Low Oxygen ◽  
Pyruvate Phosphate Dikinase ◽  
Oxygen Stress ◽  
Membrane Bound

In the conditions of [Mg2+] elevation that occur, in particular, under low oxygen stress and are the consequence of the decrease in [ATP] and increase in [ADP] and [AMP], pyrophosphate (PPi) can function as an alternative energy currency in plant cells. In addition to its production by various metabolic pathways, PPi can be synthesized in the combined reactions of pyruvate, phosphate dikinase (PPDK) and pyruvate kinase (PK) by so-called PK/PPDK substrate cycle, and in the reverse reaction of membrane-bound H+-pyrophosphatase, which uses the energy of electrochemical gradients generated on tonoplast and plasma membrane. The PPi can then be consumed in its active forms of MgPPi and Mg2PPi by PPi-utilizing enzymes, which require an elevated [Mg2+]. This ensures a continuous operation of glycolysis in the conditions of suppressed ATP synthesis, keeping metabolism energy efficient and less dependent on ATP.

Sign in / Sign up

Export Citation Format

Share Document