scholarly journals Arabidopsis V-ATPase d2 Subunit Plays a Role in Plant Responses to Oxidative Stress

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 701 ◽  
Author(s):  
Shuang Feng ◽  
Yun Peng ◽  
Enhui Liu ◽  
Hongping Ma ◽  
Kun Qiao ◽  
...  

Vacuolar-type H+-ATPase (V-ATPase), a multisubunit proton pump located on the endomembrane, plays an important role in plant growth. The Arabidopsis thaliana V-ATPase d subunit (VHA-d) consists of two isoforms; AtVHA-d1 and AtVHA-d2. In this study, the function of AtVHA-d2 was investigated. Histochemical analysis revealed that the expression of AtVHA-d1 and AtVHA-d2 was generally highly overlapping in multiple tissues at different developmental stages of Arabidopsis. Subcellular localization revealed that AtVHA-d2 was mainly localized to the vacuole. AtVHA-d2 expression was significantly induced by oxidative stress. Analysis of phenotypic and H2O2 content showed that the atvha-d2 mutant was sensitive to oxidative stress. The noninvasive microtest monitoring demonstrated that the net H+ influx in the atvha-d2 roots was weaker than that in the wild-type under normal conditions. However, oxidative stress resulted in the H+ efflux in atvha-d2 roots, which was significantly different from that in the wild-type. RNA-seq combined with qPCR analysis showed that the expression of several members of the plasma membrane H+-ATPase gene (AtAHA) family in atvha-d2 was significantly different from that in the wild-type. Overall, our results indicate that AtVHA-d2 plays a role in Arabidopsis in response to oxidative stress by affecting H+ flux and AtAHA gene expression.

2020 ◽  
Author(s):  
Shuang Feng ◽  
Yun Peng ◽  
Enhui Liu ◽  
Hongping Ma ◽  
Kun Qiao ◽  
...  

Abstract Background: Vacuolar-type H + -ATPase (V-ATPase) is a multisubunit proton pump located on the endomembranes, which plays an important role in plant growth. The Arabidopsis V-ATPase d subunit consists of two isoforms, AtVHA-d1 and AtVHA-d2. Results: In this study, the function of the AtVHA-d2 gene was investigated. Histochemical analysis revealed that the AtVHA-d1 and AtVHA-d2 genes were generally and highly overlapping expressed in multiple tissues at different developmental stages of Arabidopsis. Subcellular localization showed that AtVHA-d2 was mainly localized to the vacuole. The AtVHA-d2 expression was significantly induced by oxidative stress. Furthermore, the phenotypic analysis showed that the atvha-d2 mutant was sensitive to oxidative stress. The non-invasive micro-test measurement demonstrated that the net H + influx in the atvha-d2 roots was weaker than that of the wild type under normal conditions. However, oxidative stress resulted in the H + efflux in atvha-d2 roots, which was significantly different from the wild type. RNA-seq combined with qPCR analysis showed that the expression of several members of the plasma membrane H + -ATPase gene ( AtAHA ) family in atvha-d2 were significant different from wild type under normal and oxidative stress. Conclusion: Overall, our results indicate that AtVHA-d2 plays a role in Arabidopsis in response to oxidative stress by affecting H + flux and AtAHA gene expression.


Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 439-446 ◽  
Author(s):  
Masaaki Onda ◽  
Katsuhiro Hanada ◽  
Hirokazu Kawachi ◽  
Hideo Ikeda

Abstract DNA damage by oxidative stress is one of the causes of mutagenesis. However, whether or not DNA damage induces illegitimate recombination has not been determined. To study the effect of oxidative stress on illegitimate recombination, we examined the frequency of λbio transducing phage in the presence of hydrogen peroxide and found that this reagent enhances illegitimate recombination. To clarify the types of illegitimate recombination, we examined the effect of mutations in mutM and related genes on the process. The frequency of λbio transducing phage was 5- to 12-fold higher in the mutM mutant than in the wild type, while the frequency in the mutY and mutT mutants was comparable to that of the wild type. Because 7,8-dihydro-8-oxoguanine (8-oxoG) and formamido pyrimidine (Fapy) lesions can be removed from DNA by MutM protein, these lesions are thought to induce illegitimate recombination. Analysis of recombination junctions showed that the recombination at Hotspot I accounts for 22 or 4% of total λbio transducing phages in the wild type or in the mutM mutant, respectively. The preferential increase of recombination at nonhotspot sites with hydrogen peroxide in the mutM mutant was discussed on the basis of a new model, in which 8-oxoG and/or Fapy residues may introduce double-strand breaks into DNA.


Development ◽  
1993 ◽  
Vol 118 (3) ◽  
pp. 751-764 ◽  
Author(s):  
H. Tsukaya ◽  
S. Naito ◽  
G. P. Redei ◽  
Y. Komeda

We isolated and analyzed mutants of Arabidopsis thaliana, acaulis, with flower stalks that are almost absent or are much reduced in length. The mutations are divided between two loci, acaulis1 (acl1) and acaulis2 (acl2). The acl1-1 mutation has been assigned to linkage group 4 in the vicinity of locus ap2. The acl1-1 mutant showed premature arrest of the inflorescence meristem after the onset of reproductive development, followed by consequent reduction in the number of flower-bearing phytomers and therefore flowers. The apical meristem of the inflorescences was morphologically normal but its radius was about half that of the wild type. The acl1 mutants are also defective in the development of foliage leaves. Both defects could be rescued by growth at a specific temperature (28°C). The length of the cells in acl1-3 mutant was less than that in the wild type but the numbers of cells in leaves and internodes of acl1 mutants were calculated to be the same as those of the wild type. Thus, the defects in inflorescences and leaves were attributed to defects in the process of elongation (maturation) of these cells. Temperature-shift experiments showed that the Acl1+ product was necessary at all developmental stages. A critical stage was shown to exist for recovery from the cessation of development of inflorescence meristems that was caused by the acl1-1 mutation. Grafting experiments showed that the acl1-1 mutation does not affect diffusible substances. An analysis of double mutants carrying both acl1-1 and one of developmental mutations, ap1, clv1, lfy, or tfl1, showed that ACL1 is a new class of gene.


2019 ◽  
Vol 20 (16) ◽  
pp. 3930 ◽  
Author(s):  
Komivi Dossa ◽  
Marie A. Mmadi ◽  
Rong Zhou ◽  
Tianyuan Zhang ◽  
Ruqi Su ◽  
...  

Sesame is a source of a healthy vegetable oil, attracting a growing interest worldwide. Abiotic stresses have devastating effects on sesame yield; hence, studies have been performed to understand sesame molecular responses to abiotic stresses, but the core abiotic stress-responsive genes (CARG) that the plant reuses in response to an array of environmental stresses are unknown. We performed a meta-analysis of 72 RNA-Seq datasets from drought, waterlogging, salt and osmotic stresses and identified 543 genes constantly and differentially expressed in response to all stresses, representing the sesame CARG. Weighted gene co-expression network analysis of the CARG revealed three functional modules controlled by key transcription factors. Except for salt stress, the modules were positively correlated with the abiotic stresses. Network topology of the modules showed several hub genes predicted to play prominent functions. As proof of concept, we generated over-expressing Arabidopsis lines with hub and non-hub genes. Transgenic plants performed better under drought, waterlogging, and osmotic stresses than the wild-type plants but did not tolerate the salt treatment. As expected, the hub gene was significantly more potent than the non-hub gene. Overall, we discovered several novel candidate genes, which will fuel investigations on plant responses to multiple abiotic stresses.


1996 ◽  
Vol 319 (3) ◽  
pp. 767-773 ◽  
Author(s):  
Estrella SÁNCHEZ-GÓNGORA ◽  
John G. PASTORINO ◽  
Luis ALVAREZ ◽  
María A. PAJARES ◽  
Concepción GARCÍA ◽  
...  

Chinese hamster ovary cells were stably transfected with rat liver S-adenosylmethionine synthetase cDNA. As a result, S-adenosylmethionine synthetase activity increased 2.3-fold, an effect that was accompanied by increased S-adenosylmethionine, a depletion of ATP and NAD levels, elevation of the S-adenosylmethionine/S-adenosylhomocysteine ratio (the methylation ratio), increased DNA methylation and polyamine levels (spermidine and spermine), and normal GSH levels. By contrast, the transfected cells showed normal growth curves and morphology. Exposure to an oxidative stress by the addition of H2O2 resulted in a greater consumption of ATP and NAD in the transfected cells than in the wild-type cells. In turn, cell killing by H2O2 was greater in the transfected cells than in the wild-type cells. This killing of Chinese hamster ovary cells by H2O2 involved the activation of poly(ADP-ribose) polymerase with the resultant loss of NAD and ATP. 3-Aminobenzamide, an inhibitor of poly(ADP-ribose) polymerase, but not the antioxidant N,N´-diphenylphenylenediamine, prevented the killing of Chinese hamster ovary cells by H2O2 and maintained the contents of NAD and ATP. The results of this study indicate that a moderate activation of the synthesis of S-adenosylmethionine leads to ATP and NAD depletion and to a greater sensitivity to cell killing by oxidative stress.


Author(s):  
João Anes ◽  
Katherine Dever ◽  
Athmanya Eshwar ◽  
Scott Nguyen ◽  
Yu Cao ◽  
...  

AbstractIn bacteria, the defense system deployd to counter oxidative stress is orchestrated by three transcriptional factors – SoxS, SoxR, and OxyR. Although the regulon that these factors control is known in many bacteria, similar data is not available for Klebsiella pneumoniae. To address this data gap, oxidative stress was artificially induced in K. pneumoniae MGH 78578 using paraquat and the corresponding oxidative stress regulon recorded using RNA-seq. The soxS gene was significantly induced during oxidative stress and a knock-out mutant was constructed, to explore its functionality. The wild-type and mutant were grown in the presence of paraquat and subjected to RNA-seq to elucidate the soxS regulon in K. pneumoniae MGH78578. Genes that are commonly regulated both in the oxidative stress regulon and soxS regulon were identified and denoted as the ‘oxidative SoxS regulon’ – these included a stringent group of genes specifically regulated by SoxS. Efflux pump encoding genes such as acrAB-tolC, acrE, and global regulators such as marRAB were identified as part of this regulon. Consequently, the isogenic soxS mutant was found to exhibit a reduction in the minimum bactericidal concentration against tetracycline compared to that of the wild type. Impaired efflux activity, allowing tetracycline to be accumulated in the cytoplasm to bactericidal levels, was further evaluated using a tetraphenylphosphonium (TPP+) accumulation assay. The soxS mutant was also susceptible to tetracycline in vivo, in a zebrafish embryo model. We conclude that the soxS gene could be considered as a genetic target against which an inhibitor could be developed in the future and used in combinatorial therapy with tetracycline to combat infections associated with multi-drug resistant K. pneumoniae.


2019 ◽  
Author(s):  
Sareh Yousefirad ◽  
Hassan Soltanloo ◽  
Sayad Sanaz Ramezanpour ◽  
Khalil Zaynalinezhad ◽  
Vahid Shariati

Abstract Regarding the complexity of the mechanisms of salinity tolerance, the use of isogenic lines or mutants that have the same genetic background but show different tolerance to salinity is a suitable method to reduce the analytical complexity to study these mechanisms. In the current study, whole transcriptome analysis was evaluated using RNA-seq method between a salt-tolerant mutant line “73-M4-30” and its wild-type “Zarjou” cultivar at a seedling stage after six hours of exposure to salt stress (300 mM NaCl). Transcriptome sequencing yielded 20 million reads for each genotype. A total number of 7116 transcripts with differential expression were identified, 1586 and 1479 of which were obtained with significantly increased expression in the mutant and the wild-type, respectively. In addition, the families of WRKY, ERF, AP2/EREBP, NAC, CTR/DRE, AP2/ERF, MAD, MIKC, HSF, and bZIP were identified as the important transcription factors with specific expression in the mutant genotype. The RNA-seq results were confirmed in several time points using qRT-PCR of some important salt-responsive genes. In general, the results revealed that the mutant compared to its wild-type via fast stomach closure and consequently transpiration reduction under the salt stress, saved more sodium ion in the root and decreased its transfer to the shoot, and increased the amount of potassium ion leading to the maintenance a high ratio [K+]/­[Na+] in the shoot. Moreover, it caused a reduction in photosynthesis and respiration, resulting in the use of the stored energy and the carbon for maintaining the plant tissues, which is a mechanism of salt tolerance in plants. Up-regulation of catalase, peroxidase, and ascorbate peroxidase genes, which was probably due to the more accumulation of H2O2 in the wild-type compared to the mutant. Therefore, the wild-type initiated rapid ROS signals lead to less oxidative scavenging than the mutant. The mutant increased expression in the ion transporters and the channels related to the salinity to retain the ion homeostasis. Totally, the results demonstrated that the mutant responded better to the salt stress under both the osmotic and the ionic stress phases. Less damage was observed in the mutant compared to its wild-type under the salt stress.


2010 ◽  
Vol 78 (11) ◽  
pp. 4850-4859 ◽  
Author(s):  
Miranda Lo ◽  
Gerald L. Murray ◽  
Chen Ai Khoo ◽  
David A. Haake ◽  
Richard L. Zuerner ◽  
...  

ABSTRACT Leptospirosis is a globally significant zoonosis caused by Leptospira spp. Iron is essential for growth of most bacterial species. Since iron availability is low in the host, pathogens have evolved complex iron acquisition mechanisms to survive and establish infection. In many bacteria, expression of iron uptake and storage proteins is regulated by Fur. L. interrogans encodes four predicted Fur homologs; we have constructed a mutation in one of these, la1857. We conducted microarray analysis to identify iron-responsive genes and to study the effects of la1857 mutation on gene expression. Under iron-limiting conditions, 43 genes were upregulated and 49 genes were downregulated in the wild type. Genes encoding proteins with predicted involvement in inorganic ion transport and metabolism (including TonB-dependent proteins and outer membrane transport proteins) were overrepresented in the upregulated list, while 54% of differentially expressed genes had no known function. There were 16 upregulated genes of unknown function which are absent from the saprophyte L. biflexa and which therefore may encode virulence-associated factors. Expression of iron-responsive genes was not significantly affected by mutagenesis of la1857, indicating that LA1857 is not a global regulator of iron homeostasis. Upregulation of heme biosynthetic genes and a putative catalase in the mutant suggested that LA1857 is more similar to PerR, a regulator of the oxidative stress response. Indeed, the la1857 mutant was more resistant to peroxide stress than the wild type. Our results provide insights into the role of iron in leptospiral metabolism and regulation of the oxidative stress response, including genes likely to be important for virulence.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yimei Xi ◽  
Liang Yin ◽  
Zhan you Chi ◽  
Guanghong Luo

AbstractMicroalgae have received significant attention as potential next-generation microbiologic cell factories for biofuels. However, the production of microalgal biofuels is not yet sufficiently cost-effective for commercial applications. To screen higher lipid-producing strains, heavy carbon ion beams are applied to induce a genetic mutant. An RNA-seq technology is used to identify the pathways and genes of importance related to photosynthesis and biofuel production. The deep elucidation of photosynthesis and the fatty acid metabolism pathway involved in lipid yield is valuable information for further optimization studies. This study provided the photosynthetic efficiency and transcriptome profiling of a unicellular microalgae, Scenedesmus obliqnus mutant SO120G, with enhanced lipid production induced by heavy carbon ion beams. The lipid yield (52.5 mg L−1) of SO120G mutant were enhanced 2.4 fold compared with that of the wild strain under the nitrogen deficient condition. In addition, the biomass and growth rate were 57% and 25% higher, respectively, in SO120G than in the wild type, likely owing to an improved maximum quantum efficiency (Fv/Fm) of photosynthesis. As for the major pigment compositions, the content of chlorophyll a and carotenoids was higher in SO120G than in the wild type. The transcriptome data confirmed that a total of 2077 genes with a change of at least twofold were recognized as differential expression genes (DEGs), of which 1060 genes were up-regulated and 1017 genes were down-regulated. Most of the DEGs involved in lipid biosynthesis were up-regulated with the mutant SO120G. The expression of the gene involved in the fatty acid biosynthesis and photosynthesis of SO120G was upregulated, while that related to starch metabolism decreased compared with that of the wild strain. This work demonstrated that heavy-ion irradiation is an promising strategy for quality improvement. In addition, the mutant SO120G was shown to be a potential algal strain for enhanced lipid production. Transcriptome sequencing and annotation of the mutant suggested the possible genes responsible for lipid biosynthesis and photosynthesis, and identified the putative target genes for future genetic manipulation and biotechnological applications.


2021 ◽  
Vol 12 ◽  
Author(s):  
Wenxu Wang ◽  
Jiaojiao Zhang ◽  
Lijuan Ai ◽  
Dan Wu ◽  
Bing Li ◽  
...  

We previously reported the involvement of cyclic nucleotide-gated ion channel 6 (CNGC6) and hydrogen peroxide (H2O2) in plant responses to heat shock (HS). To demonstrate their relationship with plant thermotolerance, we assessed the effect of HS on several groups of Arabidopsis (Arabidopsis thaliana) seedlings: wild-type, cngc6 mutant, and its complementation line. Under exposure to HS, the level of H2O2 was lower in the cngc6 mutant seedlings than in the wild-type (WT) seedlings but obviously increased in the complementation line. The treatment of Arabidopsis seeds with calcium ions (Ca2+) increased the H2O2 levels in the seedlings under HS treatment, whereas treatment with a Ca2+ chelator (EGTA) inhibited it, indicating that CNGC6 may stimulate the accumulation of H2O2 in a manner dependent on an increase in cytosolic Ca2+ ([Ca2+]cyt). This point was verified by phenotypic observations and thermotolerance testing with transgenic plants overexpressing AtRbohB and AtRbohD (two genes involved in HS-responsive H2O2 production), respectively, in a cngc6 background. Real-time reverse transcription-polymerase chain reactions and Western blotting suggested that CNGC6 enhanced the gene transcription of HS factors (HSFs) and the accumulation of HS proteins (HSPs) via H2O2. These upon results indicate that H2O2 acts downstream of CNGC6 in the HS signaling pathway, increasing our understanding of the initiation of plants responses to high temperatures.


Sign in / Sign up

Export Citation Format

Share Document