scholarly journals Epsc Involved in the Encoding of Exopolysaccharides Produced by Bacillus amyloliquefaciens FZB42 Act to Boost the Drought Tolerance of Arabidopsis thaliana

2018 ◽  
Vol 19 (12) ◽  
pp. 3795 ◽  
Author(s):  
Xiang Lu ◽  
Shao-Fang Liu ◽  
Liang Yue ◽  
Xia Zhao ◽  
Yu-Bao Zhang ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Drought Tolerance ◽  
Plant Growth ◽  
Mutant Strain ◽  
Root Length ◽  
Bacillus Amyloliquefaciens ◽  
Lateral Root ◽  
Primary Root ◽  
Defense Responses ◽  
Marker Genes

Bacillus amyloliquefaciens FZB42 is a plant growth-promoting rhizobacteria that stimulates plant growth, and enhances resistance to pathogens and tolerance of salt stress. Instead, the mechanistic basis of drought tolerance in Arabidopsis thaliana induced by FZB42 remains unexplored. Here, we constructed an exopolysaccharide-deficient mutant epsC and determined the role of epsC in FZB42-induced drought tolerance in A. thaliana. Results showed that FZB42 significantly enhanced growth and drought tolerance of Arabidopsis by increasing the survival rate, fresh and dry shoot weights, primary root length, root dry weight, lateral root number, and total lateral root length. Coordinated changes were also observed in cellular defense responses, including elevated concentrations of proline and activities of superoxide dismutase and peroxidase, decreased concentrations of malondialdehyde, and accumulation of hydrogen peroxide in plants treated with FZB42. The relative expression levels of drought defense-related marker genes, such as RD29A, RD17, ERD1, and LEA14, were also increased in the leaves of FZB42-treated plants. In addition, FZB42 induced the drought tolerance in Arabidopsis by the action of both ethylene and jasmonate, but not abscisic acid. However, plants inoculated with mutant strain epsC were less able to resist drought stress with respect to each of these parameters, indicating that epsC are required for the full benefit of FZB42 inoculation to be gained. Moreover, the mutant strain was less capable of supporting the formation of a biofilm and of colonizing the A. thaliana root. Therefore, epsC is an important factor that allows FZB42 to colonize the roots and induce systemic drought tolerance in Arabidopsis.

scholarly journals Analysis of plant growth-promoting properties of Bacillus amyloliquefaciens UCMB5113 using Arabidopsis thaliana as host plant

Planta ◽  
2016 ◽  
Vol 245 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Shashidar Asari ◽  
Danuše Tarkowská ◽  
Jakub Rolčík ◽  
Ondřej Novák ◽  
David Velázquez Palmero ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Growth ◽  
Host Plant ◽  
Bacillus Amyloliquefaciens ◽  
Plant Growth Promoting ◽  
Growth Promoting

scholarly journals Bradyrhizobium japonicum IRAT FA3 alters Arabidopsis thaliana root architecture via regulation of auxin efflux transporters PIN2, PIN3, PIN7 and ABCB19

2021 ◽  
Author(s):  
Mercedes Schroeder ◽  
Melissa Y. Gomez ◽  
Nathan K. McLain ◽  
Emma Gachomo
Keyword(s):  
Arabidopsis Thaliana ◽  
Root System ◽  
Root Development ◽  
Bradyrhizobium Japonicum ◽  
Lateral Root ◽  
Plant Root ◽  
Primary Root ◽  
Efflux Transporters ◽  
Loss Of Function ◽  
Lateral Root Primordia

Beneficial rhizobacteria can stimulate changes in plant root development. While root system growth is mediated by multiple factors, the regulated distribution of the phytohormone auxin within root tissues plays a principal role. Auxin transport facilitators help to generate the auxin gradients and maxima that determine root structure. Here, we show that the plant growth-promoting rhizobacterial strain Bradyrhizobium japonicum IRAT FA3 influences specific auxin efflux transporters to alter Arabidopsis thaliana root morphology. Gene expression profiling of host transcripts in control and B. japonicum-inoculated roots of the wild type A. thaliana accession Col-0 confirmed upregulation of PIN2, PIN3, PIN7 and ABCB19 with B. japonicum and identified genes potentially contributing to a diverse array of auxin-related responses. Co-cultivation of the bacterium with loss-of-function auxin efflux transport mutants revealed that B. japonicum requires PIN3, PIN7 and ABCB19 to increase lateral root development and utilizes PIN2 to reduce primary root length. Accelerated lateral root primordia production due to B. japonicum was not observed in single pin3, pin7 or abcb19 mutants, suggesting independent roles for PIN3, PIN7 and ABCB19 during the plant-microbe interaction. Our work demonstrates B. japonicum’s influence over host transcriptional reprogramming during plant interaction with this beneficial microbe and the subsequent alterations to root system architecture.

scholarly journals Role of Volatiles from the Endophytic Fungus Trichoderma asperelloides PSU-P1 in Biocontrol Potential and in Promoting the Plant Growth of Arabidopsis thaliana

2020 ◽  
Vol 6 (4) ◽  
pp. 341
Author(s):  
Nongnat Phoka ◽  
Nakarin Suwannarach ◽  
Saisamorn Lumyong ◽  
Shin-ichi Ito ◽  
Kenji Matsui ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Antifungal Activity ◽  
Plant Growth ◽  
Fungal Pathogens ◽  
Solid Phase ◽  
Defense Responses ◽  
Gas Chromatography Mass Spectrometry ◽  
Plant Host ◽  
Trichoderma Species ◽  
Biocontrol Potential

Fungal volatile organic compounds (VOCs) emitted by Trichoderma species interact with a plant host and display multifaceted mechanisms. In this study, we investigated the antifungal activity of VOCs emitted by Trichoderma asperelloides PSU-P1 against fungal pathogens, as well as the ability of VOCs to activate defense responses and to promote plant growth in Arabidopsis thaliana. The strain’s VOCs had remarkable antifungal activity against fungal pathogens, with an inhibition range of 15.92–84.95% in a volatile antifungal bioassay. The VOCs of T. asperelloides PSU-P1 promoted the plant growth of A. thaliana, thereby increasing the fresh weight, root length, and chlorophyll content in the VOC-treated A. thaliana relative to those of the control. High expression levels of the chitinase (CHI) and β-1,3-glucanase (GLU) genes were found in the VOC-treated A. thaliana by quantitative reverse transcription polymerase chain reaction (RT-PCR). The VOC-treated A. thaliana had higher defense-related enzyme (peroxidase (POD)) and cell wall-degrading enzyme (chitinase and β-1,3-glucanase) activity than in the control. The headspace VOCs produced by PSU-P1, trapped with solid phase microextraction, and tentatively identified by gas chromatography–mass spectrometry, included 2-methyl-1-butanol, 2-pentylfuran, acetic acid, and 6-pentyl-2H-pyran-2-one (6-PP). The results suggest that T. asperelloides PSU-P1 emits VOCs responsible for antifungal activity, for promoting plant growth, and for inducing defense responses in A. thaliana.

scholarly journals Mechanical touch responses of Arabidopsis TCH1-3 mutant roots on inclined hard-agar surface

2016 ◽  
Vol 30 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Guodong Zha ◽  
Bochu Wang ◽  
Junyu Liu ◽  
Jie Yan ◽  
Liqing Zhu ◽  
...  
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Lateral Root ◽  
Plant Root ◽  
Primary Root ◽  
Agar Plate ◽  
Touch Response ◽  
Agar Surface ◽  
Root Growth And Development ◽  
Touch Stimulus

Abstract The gravity-induced mechanical touch stimulus can affect plant root architecture. Mechanical touch responses of plant roots are an important aspect of plant root growth and development. Previous studies have reported that Arabidopsis TCH1-3 genes are involved in mechano-related events, how-ever, the physiological functions of TCH1-3 genes in Arabidopsis root mechanoresponses remain unclear. In the present study, we applied an inclined hard agar plate method to produce mechanical touch stimulus, and provided evidence that altered mechanical environment could influence root growth. Furthermore, tch1-3 Arabidopsis mutants were investigated on inclined agar surfaces to explore the functions of TCH1-3 genes on Arabidopsis root mechanoresponses. The results showed that two tch2 mutants, cml24-2 and cml24-4, exhibited significantly reduced root length, biased skewing, and decreased density of lateral root. In addition, primary root length and density of lateral root of tch3 (cml12-2) was significantly decreased on inclined agar surfaces. This study indicates that the tch2 and tch3 mutants are hypersensitive to mechanical touch stimulus, and TCH2 (CML24-2 and CML24-4) and TCH3 (CML12-2) genes may participate in the mechanical touch response of Arabidopsis roots.

scholarly journals Xylem Colonization by an HrcV¯ Mutant of Ralstonia solanacearum Is a Key Factor for the Efficient Biological Control of Tomato Bacterial Wilt

1998 ◽  
Vol 11 (9) ◽  
pp. 869-877 ◽  
Author(s):  
Christophe Etchebar ◽  
Danièle Trigalet-Demery ◽  
Frédérique van Gijsegem ◽  
Jacques Vasse ◽  
André Trigalet
Keyword(s):  
Mutant Strain ◽  
Ralstonia Solanacearum ◽  
Lateral Root ◽  
Pathogenic Strain ◽  
Staining Procedure ◽  
Bacterial Suspension ◽  
Marker Genes ◽  
Wild Type ◽  
Root Tips ◽  
Challenge Inoculation

Microscopic studies of the colonization of the vascular tissues of tomato by an HrcV¯ (formerly HrpO¯) mutant strain of Ralstonia solanacearum were carried out after either root inoculation of the mutant strain alone or delayed challenge inoculation by a pathogenic strain. The use of two different marker genes, lacZ and uidA, introduced into either mutant or wild-type strains, respectively, permitted histological observation for the presence of both strains simultaneously. In roots, both strains could be found together in infected root tips and in lateral root emergence sites (lateral root cracks), but these bacterial strains subsequently invaded separate xylem vessels in the root system. At the hypocotyl level, a novel staining procedure, in conjunction with bacterial isolation and counting, showed three vascular colonization patterns: exclusive colonization by each of the competitors or simultaneous presence of each strain in separate xylem vessels. The relative frequencies of these patterns depended upon the root inoculation techniques used. The presence of one population always influenced the density of the other challenge-inoculated population. In plants inoculated with both wild-type and mutant strains, the population of the wild-type strain is lower than in plants inoculated with the wild type alone. In contrast, growth of the HrcV¯ mutant strain was significantly increased in the presence of the pathogenic strain. Two agriculturally acceptable techniques for plant inoculation were tested. Inoculation of plants by transplanting them into soil amended with clay micro-granules impregnated with the HrcV¯ mutant strain gave higher and more reproducible colonization of the plants than inoculation by watering a bacterial suspension on the roots. Significant percentages of exclusive colonization by the HrcV¯ mutant strain were only obtained after the clay microgranule inoculation technique. Competition for space in xylem vessels is one of the possible explanations for the protective ability of the HrcV¯ mutant strain against subsequent invasion by a pathogenic strain.

scholarly journals Nitrate Signaling, Functions, and Regulation of Root System Architecture: Insights from Arabidopsis thaliana

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 633 ◽  
Author(s):  
Muhammad Asim ◽  
Zia Ullah ◽  
Fangzheng Xu ◽  
Lulu An ◽  
Oluwaseun Olayemi Aluko ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Root System ◽  
Root Development ◽  
System Architecture ◽  
Lateral Root ◽  
Transcriptional Regulatory Network ◽  
Primary Root ◽  
Root System Architecture ◽  
Nitrate Transporter ◽  
Nitrate Transporters

Root system architecture (RSA) is required for the acquisition of water and mineral nutrients from the soil. One of the essential nutrients, nitrate (NO3−), is sensed and transported by nitrate transporters NRT1.1 and NRT2.1 in the plants. Nitrate transporter 1.1 (NRT1.1) is a dual-affinity nitrate transporter phosphorylated at the T101 residue by calcineurin B-like interacting protein kinase (CIPKs); it also regulates the expression of other key nitrate assimilatory genes. The differential phosphorylation (phosphorylation and dephosphorylation) strategies and underlying Ca2+ signaling mechanism of NRT1.1 stimulate lateral root growth by activating the auxin transport activity and Ca2+-ANR1 signaling at the plasma membrane and the endosomes, respectively. NO3− additionally functions as a signal molecule that forms a signaling system, which consists of a vast array of transcription factors that control root system architecture that either stimulate or inhibit lateral and primary root development in response to localized and high nitrate (NO3−), respectively. This review elucidates the so-far identified nitrate transporters, nitrate sensing, signal transduction, and the key roles of nitrate transporters and its downstream transcriptional regulatory network in the primary and lateral root development in Arabidopsis thaliana under stress conditions.

N-acyl homoserine lactone-mediated modulation of plant growth and defense against Pseudoperonospora cubensis in cucumber

2020 ◽  
Vol 71 (20) ◽  
pp. 6638-6654
Author(s):  
Sercan Pazarlar ◽  
Nedim Cetinkaya ◽  
Melike Bor ◽  
Recep Serdar Kara
Keyword(s):  
Salicylic Acid ◽  
Plant Growth ◽  
Pseudomonas Syringae ◽  
Primary Root ◽  
Homoserine Lactone ◽  
Defense Responses ◽  
Microbial Pathogens ◽  
Transcriptional Analysis ◽  
Pseudoperonospora Cubensis ◽  
Callose Deposition

Abstract N-acyl-homoserine lactones (AHLs), a well-described group of quorum sensing molecules, may modulate plant defense responses and plant growth. However, there is limited knowledge regarding the defense responses of non-model crops to AHLs and the mechanism of action responsible for the modulation of defense responses against microbial pathogens. In the present study, long-chain N-3-oxo-tetradecanoyl-l-homoserine lactone (oxo-C14-HSL) was shown to have a distinct potential to prime cucumber for enhanced defense responses against the biotrophic oomycete pathogen Pseudoperonospora cubensis and the hemibiotrophic bacterium Pseudomonas syringae pv. lachrymans. We provide evidence that AHL-mediated enhanced defense against downy mildew disease is based on cell wall reinforcement by lignin and callose deposition, the activation of defense-related enzymes (peroxidase, β-1,3-glucanase, phenylalanine ammonia-lyase), and the accumulation of reactive oxygen species (hydrogen peroxide, superoxide) and phenolic compounds. Quantitative analysis of salicylic acid and jasmonic acid, and transcriptional analysis of several of genes associated with these phytohormones, revealed that defense priming with oxo-C14-HSL is commonly regulated by the salicylic acid signaling pathway. We also show that treatment with short- (N-hexanoyl-l-homoserine lactone) and medium-chain (N-3-oxo-decanoyl-l-homoserine lactone) AHLs promoted primary root elongation and modified root architecture, respectively, resulting in enhanced plant growth.

scholarly journals Serendipita indica changes host sugar and defense status in Arabidopsis thaliana: cooperation or exploitation?

Planta ◽  
2021 ◽  
Vol 253 (3) ◽  
Author(s):  
Michael W. Opitz ◽  
Roshanak Daneshkhah ◽  
Cindy Lorenz ◽  
Roland Ludwig ◽  
Siegrid Steinkellner ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Endophytic Fungus ◽  
Abiotic Stresses ◽  
Root Colonization ◽  
Growth Promotion ◽  
Sugar Metabolism ◽  
Defense Responses ◽  
Marker Genes ◽  
Wild Type ◽  
Biotic And Abiotic Stresses

Abstract Main conclusion Manipulation of sugar metabolism upon S. indica root colonization triggers changes in sugar pools and defense responses in A. thaliana. Abstract Serendipita indica is an endophytic fungus that establishes mutualistic relationships with many different plants including important crops as well as the model plant A. thaliana. Successful root colonization typically results in growth promotion and enhanced tolerance against various biotic and abiotic stresses. The fungus delivers phosphorus to the host and receives in exchange carbohydrates. There are hints that S. indica prefers hexoses, glucose, and fructose, products of saccharose cleavage driven by invertases (INVs) and sucrose synthases (SUSs). Carbohydrate metabolism in this interaction, however, remains still widely unexplored. Therefore, in this work, the sugar pools as well as the expression of SUSs and cytosolic INVs in plants colonized by S. indica were analyzed. Using sus1/2/3/4 and cinv1/2 mutants the importance of these genes for the induction of growth promotion and proper root colonization was demonstrated. Furthermore, the expression of several defense-related marker genes in both multiple mutants in comparison to the wild-type plants was determined. Our results show that in colonized A. thaliana plants S. indica manipulates the sugar metabolism by altering the expression of host’s INV and SUS and modulates both the sugar pools and plant defense in its favor. We conclude that the interaction A. thaliana–S. indica is a balancing act between cooperation and exploitation, in which sugar metabolism plays a crucial role. Small changes in this mechanism can lead to severe disruption resulting in the lack of growth promotion or altered colonization rate.

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