Deciphering the route of Ralstonia solanacearum colonization in Arabidopsis thaliana roots during a compatible interaction: focus at the plant cell wall

Planta ◽  
2012 ◽  
Vol 236 (5) ◽  
pp. 1419-1431 ◽  
Author(s):  
Catherine Digonnet ◽  
Yves Martinez ◽  
Nicolas Denancé ◽  
Marine Chasseray ◽  
Patrick Dabos ◽  
...  
2005 ◽  
Vol 18 (12) ◽  
pp. 1296-1305 ◽  
Author(s):  
Huanli Liu ◽  
Shuping Zhang ◽  
Mark A. Schell ◽  
Timothy P. Denny

Ralstonia solanacearum, like many phytopathogenic bacteria, makes multiple extracellular plant cell-wall-degrading enzymes (CWDE), some of which contribute to its ability to cause wilt disease. CWDE and many other proteins are secreted to the milieu via the highly conserved type II protein secretion system (T2SS). R. solanacearum with a defective T2SS is weakly virulent, but it is not known whether this is due to absence of all the CWDE or the loss of other secreted proteins that contribute to disease. These alternatives were investigated by creating mutants of wild-type strain GMI1000 lacking either the T2SS or up to six CWDE and comparing them for virulence on tomato plants. To create unmarked deletions, genomic regions flanking the target gene were polymerase chain reaction (PCR)-amplified, were fused using splice overlap extension PCR, were cloned into a suicide plasmid harboring the sacB counter-selectable marker, and then, were site-specifically introduced into the genome. Various combinations of five deletions (δpehA, δpehB, δpehC, δpme, and δegl) and one inactivated allele (cbhA::aphA-3) resulted in 15 mutants missing one to six CWDE. In soil-drench inoculation assays, virulence of mutants lacking only pectic enzymes (PehA, PehB, PehC, and Pme) was not statistically different from GMI1000, but all the mutants lacking one or both cellulolytic enzymes (Egl or CbhA) wilted plants significantly more slowly than did the wild type. The GMI-6 mutant that lacks all six CWDE was more virulent than the mutant lacking only its two cellulolytic enzymes, and both were significantly more virulent than the T2SS mutant (GMI-D). Very similar results were observed in wounded-petiole inoculation assays, so GMI-6 and GMI-D appear to be less capable of colonizing tomato tissues after invasion. Because the T2SS mutant was much less virulent than the sixfold CWDE mutant, we conclude that other secreted proteins contribute substantially to the ability of R. solanacearum GMI1000 to systemically colonize tomato plants.


Plant Science ◽  
2011 ◽  
Vol 180 (3) ◽  
pp. 470-479 ◽  
Author(s):  
Jonatan U. Fangel ◽  
Bent L. Petersen ◽  
Niels B. Jensen ◽  
William G.T. Willats ◽  
Antony Bacic ◽  
...  

2014 ◽  
Vol 79 (3) ◽  
pp. 492-506 ◽  
Author(s):  
Marta Busse‐Wicher ◽  
Thiago C. F. Gomes ◽  
Theodora Tryfona ◽  
Nino Nikolovski ◽  
Katherine Stott ◽  
...  

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1558
Author(s):  
Nathan T. Reem ◽  
Lauran Chambers ◽  
Ning Zhang ◽  
Siti Farah Abdullah ◽  
Yintong Chen ◽  
...  

Pectin is a critical component of the plant cell wall, supporting wall biomechanics and contributing to cell wall signaling in response to stress. The plant cell carefully regulates pectin methylesterification with endogenous pectin methylesterases (PMEs) and their inhibitors (PMEIs) to promote growth and protect against pathogens. We expressed Aspergillus nidulans pectin methylesterase (AnPME) in Arabidopsis thaliana plants to determine the impacts of methylesterification status on pectin function. Plants expressing AnPME had a roughly 50% reduction in methylester content compared with control plants. AnPME plants displayed a severe dwarf phenotype, including small, bushy rosettes and shorter roots. This phenotype was caused by a reduction in cell elongation. Cell wall composition was altered in AnPME plants, with significantly more arabinose and significantly less galacturonic acid, suggesting that plants actively monitor and compensate for altered pectin content. Cell walls of AnPME plants were more readily degraded by polygalacturonase (PG) alone but were less susceptible to treatment with a mixture of PG and PME. AnPME plants were insensitive to osmotic stress, and their susceptibility to Botrytis cinerea was comparable to wild type plants despite their compromised cell walls. This is likely due to upregulated expression of defense response genes observed in AnPME plants. These results demonstrate the importance of pectin in both normal growth and development, and in response to biotic and abiotic stresses.


2013 ◽  
Vol 4 ◽  
Author(s):  
Cécile Albenne ◽  
Hervé Canut ◽  
Elisabeth Jamet

2017 ◽  
Author(s):  
Timo Engelsdorf ◽  
Nora Gigli-Bisceglia ◽  
Manikandan Veerabagu ◽  
Joseph F. McKenna ◽  
Frauke Augstein ◽  
...  

AbstractPlant cells are surrounded by walls, which must often meet opposing functional requirements during plant growth and defense. The cells meet them by modifying wall structure and composition in a tightly controlled and adaptive manner. The modifications seem to be mediated by a dedicated cell wall integrity (CWI) maintenance mechanism. Currently the mode of action of the mechanism is not understood and it is unclear how its activity is coordinated with established plant defense signaling. We investigated responses to induced cell wall damage (CWD) impairing CWI and the underlying mechanism in Arabidopsis thaliana. Interestingly inhibitor- and enzyme-derived CWD induced similar, turgor-sensitive stress responses. Genetic analysis showed that the receptor-like kinase (RLK) FEI2 and the mechano-sensitive, plasma membrane-localized Ca2+- channel MCA1 function downstream of the THE1 RLK in CWD perception. Phenotypic clustering with 27 genotypes identified a core group of RLKs and ion channels, required for activation of CWD responses. By contrast, the responses were repressed by pattern-triggered immune (PTI) signaling components including PEPR1 and 2, the receptors for the immune signaling peptide AtPep1. Interestingly AtPep1 application repressed CWD-induced phytohormone accumulation in a PEPR1/2-dependent manner. These results suggest that PTI suppresses CWD-induced defense responses through elicitor peptide-mediated signaling during defense response activation. If PTI is impaired, the suppression of CWD-induced responses is alleviated, thus compensating for defective PTI.Significance statementStress resistance and plant growth determine food crop yield and efficiency of bioenergy production from ligno-cellulosic biomass. Plant cell walls are essential elements of the biological processes, therefore functional integrity of the cell walls must be maintained throughout. Here we investigate the plant cell wall integrity maintenance mechanism. We characterize its mode of action, identify essential signaling components and show that the AtPep1 signaling peptide apparently coordinates pattern triggered immunity (PTI) and cell wall integrity maintenance in plants. These results suggest how PTI and cell wall modification coordinately regulate biotic stress responses with plants possibly compensating for PTI impairment through enhanced activation of stress responses regulated by the CWI maintenance mechanism.


Author(s):  
M.A. Zhivetiev ◽  
◽  
A.V. Papkina ◽  
I.A. Graskova ◽  
V.K. Voinikov ◽  
...  

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