scholarly journals Defense Gene Expression Analysis of Arabidopsis thaliana Parasitized by Orobanche ramosa

2003 ◽  
Vol 93 (4) ◽  
pp. 451-457 ◽  
Author(s):  
C. Vieira Dos Santos ◽  
P. Letousey ◽  
P. Delavault ◽  
P. Thalouarn

The infection of Arabidopsis thaliana roots with the obligate parasite Orobanche ramosa represents a useful model for a study of the molecular events involved in the host plant response to a parasitic plant attack. To avoid analysis problems due to the subterranean development of O. ramosa, we developed two in vitro co-culture systems: O. ramosa seedlings infesting Arabidopsis plantlet roots and callus tissues. We were then able to investigate the expression patterns of some host plant genes selected among genes known to be involved in metabolic pathways and resistance mechanisms activated during several plant-pathogen interactions including ethylene, isoprenoid, phenylpropanoid, and jasmonate biosynthesis pathways, oxidative stress responses, and pathogenesis-related proteins. Molecular analyses were carried out using polymerase chain reaction amplification methods allowing semiquantitative evaluation of transcript accumulation during early (first hours) and late (15 days) stages of infestation, in whole roots or parts close to the parasite attachment site. In A. thaliana, O. ramosa induced most of the general response signaling pathways in a transient manner even before its attachment to A. thaliana roots. However, no salicylic acid-dependent defense is observed because no activation of systemic acquired resistance markers is detectable, whereas genes, co-regulated by jasmonate and ethylene, do display enhanced expression.

2007 ◽  
Vol 189 (14) ◽  
pp. 5302-5313 ◽  
Author(s):  
Simen M. Kristoffersen ◽  
Solveig Ravnum ◽  
Nicolas J. Tourasse ◽  
Ole Andreas Økstad ◽  
Anne-Brit Kolstø ◽  
...  

ABSTRACT Tolerance to bile salts was investigated in forty Bacillus cereus strains, including 17 environmental isolates, 11 dairy isolates, 3 isolates from food poisoning outbreaks, and 9 other clinical isolates. Growth of all strains was observed at low bile salt concentrations, but no growth was observed on LB agar plates containing more than 0.005% bile salts. Preincubation of the B. cereus type strain, ATCC 14579, in low levels of bile salts did not increase tolerance levels. B. cereus ATCC 14579 was grown to mid-exponential growth phase and shifted to medium containing bile salts (0.005%). Global expression patterns were determined by hybridization of total cDNA to a 70-mer oligonucleotide microarray. A general stress response and a specific response to bile salts were observed. The general response was similar to that observed in cultures grown in the absence of bile salts but at a higher (twofold) cell density. Up-regulation of several putative multidrug exporters and transcriptional regulators and down-regulation of most motility genes were observed as part of the specific response. Motility experiments in soft agar showed that motility decreased following bile salts exposure, in accordance with the transcriptional data. Genes encoding putative virulence factors were either unaffected or down-regulated.


2012 ◽  
Vol 92 (7) ◽  
pp. 1267-1282 ◽  
Author(s):  
T. Karuppanapandian ◽  
S-J. Rhee ◽  
E-J. Kim ◽  
B. K. Han ◽  
O. A. Hoekenga ◽  
...  

Karuppanapandian, T., Rhee, S.-J., Kim, E.-J., Han, B. K., Hoekenga, O. A. and Lee, G. P. 2012. Proteomic analysis of differentially expressed proteins in the roots of Columbia-0 and Landsberg erecta ecotypes of Arabidopsis thaliana in response to aluminum-toxicity. Can. J. Plant Sci. 92: 1267–1282. Aluminum (Al) is phytotoxic when solubilized into Al3+ in acidic soils and represents a major constraint for crop production. The present study describes Al-stress responses in roots of Al-tolerant and Al-sensitive Arabidopsis ecotypes, Columbia-0 (Col-0) and Landsberg erecta (Ler), respectively. Comparative proteomic analysis was applied to plants grown in hydroponic solution culture under acidic pH (4.2) conditions. To investigate time-dependent responses, 6-d-old seedlings were treated with 30 µM AlCl3 for 24, 48, or 72 h; total proteins were prepared from roots and separated by two-dimensional gel electrophoresis (2-DE). From 2-DE analysis, were 600 proteins were inspected, 29 proteins were differentially responsive to Al-treatment. The 2-DE patterns were compared and differentially expressed proteins identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Analysis of protein expression patterns revealed that a set of proteins is functionally associated with tricarboxylic acid (TCA) cycle and glycolysis, reactive oxygen quenching and detoxification mechanism, and signal transduction pathways, etc., could play important roles in mediating plant response to Al in Arabidopsis ecotypes. Comparison of the changes in the protein profiles revealed that Al-stress increased Al-tolerance related proteins in Al-tolerant Col-0, but only generic stress responses occurred in Al-sensitive Ler. Specifically, Al up-regulated proteins such as alcohol dehydrogenase, monodehydroascorbate reductase, GTP-binding nuclear protein Ran-2, and leucine aminopeptidase in Col-0 but not in Ler.


2021 ◽  
Vol 22 (19) ◽  
pp. 10341
Author(s):  
Maria Pilarska ◽  
Dorothea Bartels ◽  
Ewa Niewiadomska

Reactive oxygen species (ROS) signalling is crucial in modulating stress responses in plants, and NADPH oxidases (NOXs) are an important component of signal transduction under salt stress. The goal of this research was to investigate whether the regulation of NOX-dependent signalling during mild and severe salinity differs between the halophyte Eutrema salsugineum and the glycophyte Arabidopsis thaliana. Gene expression analyses showed that salt-induced expression patterns of two NOX genes, RBOHD and RBOHF, varied between the halophyte and the glycophyte. Five days of salinity stimulated the expression of both genes in E. salsugineum leaves, while their expression in A. thaliana decreased. This was not accompanied by changes in the total NOX activity in E. salsugineum, while the activity in A. thaliana was reduced. The expression of the RBOHD and RBOHF genes in E. salsugineum leaves was induced by abscisic acid (ABA) and ethephon spraying. The in silico analyses of promoter sequences of RBOHD and RBOHF revealed multiple cis-acting elements related to hormone responses, and their distribution varied between E. salsugineum and A. thaliana. Our results indicate that, in the halophyte E. salsugineum, the maintenance of the basal activity of NOXs in leaves plays a role during acclimation responses to salt stress. The different expression patterns of the RBOHD and RBOHF genes under salinity in E. salsugineum and A. thaliana point to a modified regulation of these genes in the halophyte, possibly through ABA- and/or ethylene-dependent pathways.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Raju Mondal ◽  
Subhankar Biswas ◽  
Akanksha Srivastava ◽  
Suvajit Basu ◽  
Maitri Trivedi ◽  
...  

Abstract Background S-domain receptor-like kinases (SD-RLKs) are an important and multi-gene subfamily of plant receptor-like/pelle kinases (RLKs), which are known to play a significant role in the development and immune responses of Arabidopsis thaliana. The conserved cysteine residues in the extracellular domain of SD-RLKs make them interesting candidates for sensing reactive oxygen species (ROS), assisting oxidative stress mitigation and associated signaling pathways during abiotic stresses. However, how closely SD-RLKs are interrelated to abiotic stress mitigation and signaling remains unknown in A. thaliana. Results This study was initiated by examining the chromosomal localization, phylogeny, sequence and differential expression analyses of 37 SD-RLK genes using publicly accessible microarray datasets under cold, osmotic stress, genotoxic stress, drought, salt, UV-B, heat and wounding. Out of 37 SD-RLKs, 12 genes displayed differential expression patterns in both the root and the shoot tissues. Promoter structure analysis suggested that these 12 SD-RLK genes harbour several potential cis-regulatory elements (CREs), which are involved in regulating multiple abiotic stress responses. Based on these observations, we investigated the expression patterns of 12 selected SD-RLKs under ozone, wounding, oxidative (methyl viologen), UV-B, cold, and light stress at different time points using semi-qRT-PCR. Of these 12 SD-SRKs, the genes At1g61360, At1g61460, At1g61380, and At4g27300 emerged as potential candidates that maintain their expression in most of the stress treatments till exposure for 12 h. Expression patterns of these four genes were further verified under similar stress treatments using qRT-PCR. The expression analysis indicated that the gene At1g61360, At1g61380, and At1g61460 were mostly up-regulated, whereas the expression of At4g27300 either up- or down-regulated in these conditions. Conclusions To summarize, the computational analysis and differential transcript accumulation of SD-RLKs under various abiotic stresses suggested their association with abiotic stress tolerance and related signaling in A. thaliana. We believe that a further detailed study will decipher the specific role of these representative SD-RLKs in abiotic stress mitigation vis-a-vis signaling pathways in A. thaliana.


2019 ◽  
Vol 109 (8) ◽  
pp. 1367-1377 ◽  
Author(s):  
Hamed S. Seifi ◽  
Adel Zarei ◽  
Tom Hsiang ◽  
Barry J. Shelp

Polyamines (PAs) are ubiquitous aliphatic amines that play important roles in growth, development, and environmental stress responses in plants. In this study, we report that exogenous application of spermine (Spm) is effective in the induction of resistance to gray mold disease, which is caused by the necrotrophic fungal pathogen Botrytis cinerea, on tomato (Solanum lycopersicum), bean (Phaseolus vulgaris), and Arabidopsis thaliana. High throughput transcriptome analysis revealed a priming role for the Spm molecule in the genus Arabidopsis, resulting in strong upregulation of several important defense-associated genes, particularly those involved in systemic-acquired resistance. Microscopic analysis confirmed that Spm application potentiates endogenous defense responses in tomato leaves through the generation of reactive oxygen species and the hypersensitive response, which effectively contained B. cinerea growth within the inoculated area. Moreover, co-application of Spm and salicylic acid resulted in a synergistic effect against the pathogen, leading to higher levels of resistance than those induced by separate applications of the two compounds. The Spm plus salicylic acid treatment also reduced infection in systemic nontreated leaves of tomato plants. Our findings suggest that Spm, particularly when applied in combination with salicylic acid, functions as a potent plant defense activator that leads to effective local and systemic resistance against B. cinerea.


2020 ◽  
Author(s):  
Magda Grabsztunowicz ◽  
Marjaana Rantala ◽  
Aiste Ivanauskaite ◽  
Tiina Blomster ◽  
Minna M. Koskela ◽  
...  

2008 ◽  
Vol 21 (2) ◽  
pp. 208-218 ◽  
Author(s):  
V. M. Conn ◽  
A. R. Walker ◽  
C. M. M. Franco

Endophytic actinobacteria, isolated from healthy wheat tissue, which are capable of suppressing a number wheat fungal pathogens both in vitro and in planta, were investigated for the ability to activate key genes in the systemic acquired resistance (SAR) or the jasmonate/ethylene (JA/ET) pathways in Arabidopsis thaliana. Inoculation of A. thaliana (Col-0) with selected endophytic strains induced a low level of SAR and JA/ET gene expression, measured using quantitative polymerase chain reaction. Upon pathogen challenge, endophyte-treated plants demonstrated a higher abundance of defense gene expression compared with the non-endophyte-treated controls. Resistance to the bacterial pathogen Erwinia carotovora subsp. carotovora required the JA/ET pathway. On the other hand, resistance to the fungal pathogen Fusarium oxysporum involved primarily the SAR pathway. The endophytic actinobacteria appear to be able to “prime” both the SAR and JA/ET pathways, upregulating genes in either pathway depending on the infecting pathogen. Culture filtrates of the endophytic actinobacteria were investigated for the ability to also activate defense pathways. The culture filtrate of Micromonospora sp. strain EN43 grown in a minimal medium resulted in the induction of the SAR pathway; however, when grown in a complex medium, the JA/ET pathway was activated. Further analysis using Streptomyces sp. strain EN27 and defense-compromised mutants of A. thaliana indicated that resistance to E. carotovora subsp. carotovora occurred via an NPR1-independent pathway and required salicylic acid whereas the JA/ET signaling molecules were not essential. In contrast, resistance to F. oxysporum mediated by Streptomyces sp. strain EN27 occurred via an NPR1-dependent pathway but also required salicylic acid and was JA/ET independent.


2021 ◽  
Vol 22 (4) ◽  
pp. 1622
Author(s):  
Yanyan Wang ◽  
Zefeng Zhai ◽  
Yueting Sun ◽  
Chen Feng ◽  
Xiang Peng ◽  
...  

B-BOX proteins are zinc finger transcription factors that play important roles in plant growth, development, and abiotic stress responses. In this study, we identified 15 PavBBX genes in the genome database of sweet cherry. We systematically analyzed the gene structures, clustering characteristics, and expression patterns of these genes during fruit development and in response to light and various hormones. The PavBBX genes were divided into five subgroups. The promoter regions of the PavBBX genes contain cis-acting elements related to plant development, hormones, and stress. qRT-PCR revealed five upregulated and eight downregulated PavBBX genes during fruit development. In addition, PavBBX6, PavBBX9, and PavBBX11 were upregulated in response to light induction. We also found that ABA, BR, and GA3 contents significantly increased in response to light induction. Furthermore, the expression of several PavBBX genes was highly correlated with the expression of anthocyanin biosynthesis genes, light-responsive genes, and genes that function in multiple hormone signaling pathways. Some PavBBX genes were strongly induced by ABA, GA, and BR treatment. Notably, PavBBX6 and PavBBX9 responded to all three hormones. Taken together, BBX proteins likely play major roles in regulating anthocyanin biosynthesis in sweet cherry fruit by integrating light, ABA, GA, and BR signaling pathways.


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