scholarly journals Genetic Characterization of RRS1, a Recessive Locus in Arabidopsis thaliana that Confers Resistance to the Bacterial Soilborne Pathogen Ralstonia solanacearum

1998 ◽  
Vol 11 (7) ◽  
pp. 659-667 ◽  
Author(s):  
Laurent Deslandes ◽  
Frédéric Pileur ◽  
Laurence Liaubet ◽  
Sylvie Camut ◽  
Canan Can ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Ralstonia Solanacearum ◽  
Recombinant Inbred Lines ◽  
Recessive Trait ◽  
Dependent Manner ◽  
Resistant Accession ◽  
Genetic Cross ◽  
Recessive Locus ◽  
Bacterial Concentrations

The soilborne, vascular pathogen Ralstonia solanacearum, the causative agent of bacterial wilt, was shown to infect a range of Arabidopsis thaliana accessions. The pathogen was capable of infecting the Col-5 accession in an hrp-dependent manner, following root inoculation. Elevated bacterial population levels were found in leaves of Col-5, 4 to 5 days after root inoculation by the GMI1000 strain. Bacteria were found predominantly in the xylem vessels and spread systemically throughout the plant. The Nd-1 accession of A. thaliana was resistant to the GMI1000 strain of R. solanacearum. Bacterial concentrations detected in leaves of Nd-1, inoculated with an hrp+ strain of R. solanacearum, were only slightly higher than those detected in the susceptible accession, Col-5, following inoculation with a strain whose hrp gene cluster was deleted. Leaf inoculation of the GMI1000 strain on the resistant accession Nd-1 induced the formation of lesions in the older leaves of the rosette whereas the same strain of R. solanacearum provoked complete wilting of Col-5. Resistance to strain GMI1000 of R. solanacearum segregated as a simply inherited recessive trait in a genetic cross between Col-5 and Nd-1. F9 recombinant inbred lines generated between these two accessions were used to map a locus, RRS1, that was the major determinant of resistance between restriction fragment length polymorphism markers mi83 and mi61 on chromosome V. This region of the A. thaliana genome is known to contain many other pathogen recognition capabilities.

scholarly journals Characterization of the Interaction Between the Bacterial Wilt Pathogen Ralstonia solanacearum and the Model Legume Plant Medicago truncatula

2007 ◽  
Vol 20 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Fabienne Vailleau ◽  
Elodie Sartorel ◽  
Marie-Françoise Jardinaud ◽  
Fabien Chardon ◽  
Stéphane Genin ◽  
...  
Keyword(s):  
Plant Species ◽  
Medicago Truncatula ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Recombinant Inbred Lines ◽  
Model Legume ◽  
Legume Plant ◽  
Hrp Genes

The soilborne pathogen Ralstonia solanacearum is the causal agent of bacterial wilt and attacks more than 200 plant species, including some legumes and the model legume plant Medicago truncatula. We have demonstrated that M. truncatula accessions Jemalong A17 and F83005.5 are susceptible to R. solanacearum and, by screening 28 R. solana-cearum strains on the two M. truncatula lines, differential interactions were identified. R. solanacearum GMI1000 infected Jemalong A17 line, and disease symptoms were dependent upon functional hrp genes. An in vitro root inoculation method was employed to demonstrate that R. solanacearum colonized M. truncatula via the xylem and intercellular spaces. R. solanacearum multiplication was restricted by a factor greater than 1 × 105 in the resistant line F83005.5 compared with susceptible Jemalong A17. Genetic analysis of recombinant inbred lines from a cross between Jemalong A17 and F83005.5 revealed the presence of major quantitative trait loci for bacterial wilt resistance located on chromosome 5. The results indicate that the root pathosystem for M. truncatula will provide useful traits for molecular analyses of disease and resistance in this model plant species.

scholarly journals The Rice Cation/H+ Exchanger Family Involved in Cd Tolerance and Transport

2021 ◽  
Vol 22 (15) ◽  
pp. 8186
Author(s):  
Wenli Zou ◽  
Jingguang Chen ◽  
Lijun Meng ◽  
Dandan Chen ◽  
Haohua He ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Pcr Analysis ◽  
Dependent Manner ◽  
Rice Varieties ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cd Uptake ◽  
Homologous Genes ◽  
Dose Dependent

Cadmium (Cd), a heavy metal toxic to humans, easily accumulates in rice grains. Rice with unacceptable Cd content has become a serious food safety problem in many rice production regions due to contaminations by industrialization and inappropriate waste management. The development of rice varieties with low grain Cd content is seen as an economic and long-term solution of this problem. The cation/H+ exchanger (CAX) family has been shown to play important roles in Cd uptake, transport and accumulation in plants. Here, we report the characterization of the rice CAX family. The six rice CAX genes all have homologous genes in Arabidopsis thaliana. Phylogenetic analysis identified two subfamilies with three rice and three Arabidopsis thaliana genes in both of them. All rice CAX genes have trans-member structures. OsCAX1a and OsCAX1c were localized in the vacuolar while OsCAX4 were localized in the plasma membrane in rice cell. The consequences of qRT-PCR analysis showed that all the six genes strongly expressed in the leaves under the different Cd treatments. Their expression in roots increased in a Cd dose-dependent manner. GUS staining assay showed that all the six rice CAX genes strongly expressed in roots, whereas OsCAX1c and OsCAX4 also strongly expressed in rice leaves. The yeast (Saccharomyces cerevisiae) cells expressing OsCAX1a, OsCAX1c and OsCAX4 grew better than those expressing the vector control on SD-Gal medium containing CdCl2. OsCAX1a and OsCAX1c enhanced while OsCAX4 reduced Cd accumulation in yeast. No auto-inhibition was found for all the rice CAX genes. Therefore, OsCAX1a, OsCAX1c and OsCAX4 are likely to involve in Cd uptake and translocation in rice, which need to be further validated.

scholarly journals Ca2+-Dependent Protein Kinase 6 Enhances KAT2 Shaker Channel Activity in Arabidopsis thaliana

2021 ◽  
Vol 22 (4) ◽  
pp. 1596
Author(s):  
Elsa Ronzier ◽  
Claire Corratgé-Faillie ◽  
Frédéric Sanchez ◽  
Christian Brière ◽  
Tou Cheu Xiong
Keyword(s):  
Arabidopsis Thaliana ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Physical Interaction ◽  
Fluorescence Lifetime Imaging ◽  
Dependent Manner ◽  
In Planta ◽  
Knock Out ◽  
Calcium Dependent ◽  
Dependent Protein

Post-translational regulations of Shaker-like voltage-gated K+ channels were reported to be essential for rapid responses to environmental stresses in plants. In particular, it has been shown that calcium-dependent protein kinases (CPKs) regulate Shaker channels in plants. Here, the focus was on KAT2, a Shaker channel cloned in the model plant Arabidopsis thaliana, where is it expressed namely in the vascular tissues of leaves. After co-expression of KAT2 with AtCPK6 in Xenopuslaevis oocytes, voltage-clamp recordings demonstrated that AtCPK6 stimulates the activity of KAT2 in a calcium-dependent manner. A physical interaction between these two proteins has also been shown by Förster resonance energy transfer by fluorescence lifetime imaging (FRET-FLIM). Peptide array assays support that AtCPK6 phosphorylates KAT2 at several positions, also in a calcium-dependent manner. Finally, K+ fluorescence imaging in planta suggests that K+ distribution is impaired in kat2 knock-out mutant leaves. We propose that the AtCPK6/KAT2 couple plays a role in the homeostasis of K+ distribution in leaves.

scholarly journals Molecular and Functional Characterization of a ToxR-Regulated Lipoprotein from a Clinical Isolate of Aeromonas hydrophila

2006 ◽  
Vol 74 (7) ◽  
pp. 3742-3755 ◽  
Author(s):  
Lakshmi Pillai ◽  
Jian Sha ◽  
Tatiana E. Erova ◽  
Amin A. Fadl ◽  
Bijay K. Khajanchi ◽  
...  
Keyword(s):  
Virulence Factor ◽  
Aeromonas Hydrophila ◽  
Functional Characterization ◽  
Affinity Column ◽  
Serum Resistance ◽  
Classical Pathway ◽  
Dependent Manner ◽  
T7 Promoter

ABSTRACT Human diseases caused by species of Aeromonas have been classified into two major groups: septicemia and gastroenteritis. In this study, we reported the molecular and functional characterization of a new virulence factor, ToxR-regulated lipoprotein, or TagA, from a diarrheal isolate, SSU, of Aeromonas hydrophila. The tagA gene of A. hydrophila exhibited 60% identity with that of a recently identified stcE gene from Escherichia coli O157:H7, which encoded a protein (StcE) that provided serum resistance to the bacterium and prevented erythrocyte lysis by controlling classical pathway of complement activation by cleaving the complement C1-esterase inhibitor (C1-INH). We purified A. hydrophila TagA as a histidine-tagged fusion protein (rTagA) from E. coli DE3 strain using a T7 promoter-based pET30 expression vector and nickel affinity column chromatography. rTagA cleaved C1-INH in a time-dependent manner. The tagA isogenic mutant of A. hydrophila, unlike its corresponding wild-type (WT) or the complemented strain, was unable to cleave C1-INH, which is required to potentiate the C1-INH-mediated lysis of host and bacterial cells. We indeed demonstrated colocalization of C1-INH and TagA on the bacterial surface by confocal fluorescence microscopy, which ultimately resulted in increased serum resistance of the WT bacterium. Likewise, we delineated the role of TagA in contributing to the enhanced ability of C1-INH to inhibit the classical complement-mediated lysis of erythrocytes. Importantly, we provided evidence that the tagA mutant was significantly less virulent in a mouse model of infection (60%) than the WT bacterium at two 50% lethal doses, which resulted in 100% mortality within 48 h. Taken together, our data provided new information on the role of TagA as a virulence factor in bacterial pathogenesis. This is the first report of TagA characterization from any species of Aeromonas.

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