scholarly journals Volatile-Mediated Killing ofArabidopsis thalianaby Bacteria Is Mainly Due to Hydrogen Cyanide

2010 ◽  
Vol 77 (3) ◽  
pp. 1000-1008 ◽  
Author(s):  
Dirk Blom ◽  
Carlotta Fabbri ◽  
Leo Eberl ◽  
Laure Weisskopf
Keyword(s):  
Plant Growth ◽  
Hydrogen Cyanide ◽  
Alternative Oxidase ◽  
Clinical Strain ◽  
Oxygen Species ◽  
Physiological Changes ◽  
Significant Extent ◽  
Environmental Strain ◽  
Growth Inhibiting ◽  
Bacterial Volatiles

ABSTRACTThe volatile-mediated impact of bacteria on plant growth is well documented, and contrasting effects have been reported ranging from 6-fold plant promotion to plant killing. However, very little is known about the identity of the compounds responsible for these effects or the mechanisms involved in plant growth alteration. We hypothesized that hydrogen cyanide (HCN) is a major factor accounting for the observed volatile-mediated toxicity of some strains. Using a collection of environmental and clinical strains differing in cyanogenesis, as well as a defined HCN-negative mutant, we demonstrate that bacterial HCN accounts to a significant extent for the deleterious effects observed when growingArabidopsis thalianain the presence of certain bacterial volatiles. The environmental strainPseudomonas aeruginosaPUPa3 was less cyanogenic and less plant growth inhibiting than the clinical strainP. aeruginosaPAO1. Quorum-sensing deficient mutants ofC. violaceumCV0,P. aeruginosaPAO1, andP. aeruginosaPUPa3 showed not only diminished HCN production but also strongly reduced volatile-mediated phytotoxicity. The double treatment of providing plants with reactive oxygen species scavenging compounds and overexpressing the alternative oxidase AOX1a led to a significant reduction of volatile-mediated toxicity. This indicates that oxidative stress is a key process in the physiological changes leading to plant death upon exposure to toxic bacterial volatiles.

scholarly journals C4 Bacterial Volatiles Improve Plant Health

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 682
Author(s):  
Bruno Henrique Silva Dias ◽  
Sung-Hee Jung ◽  
Juliana Velasco de Castro Oliveira ◽  
Choong-Min Ryu
Keyword(s):  
Plant Growth ◽  
Volatile Compounds ◽  
Large Scale ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Health ◽  
Systemic Resistance ◽  
Potential Applications ◽  
Plant Growth Promoting ◽  
Bacterial Volatiles

Plant growth-promoting rhizobacteria (PGPR) associated with plant roots can trigger plant growth promotion and induced systemic resistance. Several bacterial determinants including cell-wall components and secreted compounds have been identified to date. Here, we review a group of low-molecular-weight volatile compounds released by PGPR, which improve plant health, mostly by protecting plants against pathogen attack under greenhouse and field conditions. We particularly focus on C4 bacterial volatile compounds (BVCs), such as 2,3-butanediol and acetoin, which have been shown to activate the plant immune response and to promote plant growth at the molecular level as well as in large-scale field applications. We also disc/ uss the potential applications, metabolic engineering, and large-scale fermentation of C4 BVCs. The C4 bacterial volatiles act as airborne signals and therefore represent a new type of biocontrol agent. Further advances in the encapsulation procedure, together with the development of standards and guidelines, will promote the application of C4 volatiles in the field.

scholarly journals Recapitulation of the Function and Role of ROS Generated in Response to Heat Stress in Plants

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 371
Author(s):  
Emily Medina ◽  
Su-Hwa Kim ◽  
Miriam Yun ◽  
Won-Gyu Choi
Keyword(s):  
Heat Stress ◽  
Plant Growth ◽  
Intracellular Signaling ◽  
Oxygen Species ◽  
Natural Ecosystems ◽  
Signaling Molecule ◽  
Signaling Systems ◽  
Cell Compartments ◽  
Tropical Area

In natural ecosystems, plants are constantly exposed to changes in their surroundings as they grow, caused by a lifestyle that requires them to live where their seeds fall. Thus, plants strive to adapt and respond to changes in their exposed environment that change every moment. Heat stress that naturally occurs when plants grow in the summer or a tropical area adversely affects plants’ growth and poses a risk to plant development. When plants are subjected to heat stress, they recognize heat stress and respond using highly complex intracellular signaling systems such as reactive oxygen species (ROS). ROS was previously considered a byproduct that impairs plant growth. However, in recent studies, ROS gained attention for its function as a signaling molecule when plants respond to environmental stresses such as heat stress. In particular, ROS, produced in response to heat stress in various plant cell compartments such as mitochondria and chloroplasts, plays a crucial role as a signaling molecule that promotes plant growth and triggers subsequent downstream reactions. Therefore, this review aims to address the latest research trends and understandings, focusing on the function and role of ROS in responding and adapting plants to heat stress.

scholarly journals Complete Genome Sequences of Two Plant Growth-Inhibiting Bacteria, Acinetobacter ursingii M3 and Asticcacaulis excentricus M6, Isolated from Duckweed (Lemna minor)

2018 ◽  
Vol 7 (12) ◽  
Author(s):  
Hidehiro Ishizawa ◽  
Masashi Kuroda ◽  
Daisuke Inoue ◽  
Michihiko Ike
Keyword(s):  
Plant Growth ◽  
Complete Genome ◽  
Lemna Minor ◽  
Genome Sequences ◽  
Content Type ◽  
Pacbio Rs Ii ◽  
Growth Inhibiting

Acinetobacter ursingii M3 and Asticcacaulis excentricus M6 are plant growth-inhibiting bacteria that reduce the yield of the duckweed Lemna minor. We report here the complete genome sequences of A. ursingii M3 and A. excentricus M6, sequenced using the PacBio RS II platform.

scholarly journals Plant growth inhibiting effcts of Cotoneaster salicifolius, Spiraea thunbergii and S. prunifolia

2002 ◽  
Vol 47 (Supplement) ◽  
pp. 146-147
Author(s):  
S. Morita ◽  
Y. Fujii ◽  
S. Hiradate ◽  
J. Harada
Keyword(s):  
Plant Growth ◽  
Growth Inhibiting

Alterations in the transcriptional landscape allows differential desiccation tolerance in different strains of Cronobacter sakazakii

2021 ◽  
Author(s):  
Yu Cao ◽  
Katherine Dever ◽  
Sathesh Kumar Sivasankaran ◽  
Scott V. Nguyen ◽  
Guerrino Macori ◽  
...  
Keyword(s):  
Infant Formula ◽  
Desiccation Tolerance ◽  
Growth Conditions ◽  
Evolutionary Strategies ◽  
Clinical Strain ◽  
Powdered Infant Formula ◽  
Cronobacter Sakazakii ◽  
Rna Seq ◽  
Environmental Strain ◽  
Different Strains

Cronobacter sakazakii is a typical example of a xerotolerant bacterium. It is epidemiologically linked to low moisture foods like powdered infant formula (PIF) and is associated with high fatality rates among neonates. We characterized the xerotolerance in a clinically isolated strain, C. sakazakii ATCC™29544 T , and compared the desiccation tolerance with an environmental strain, C. sakazakii SP291, whose desiccation tolerance was previously characterized. We found that, although the clinical strain was desiccation-tolerant, the level of tolerance was compromised when compared to the environmental strain. RNA-seq based deep transcriptomic characterization identified a unique transcriptional profile in the clinical strain compared to what was already known for the environmental strain. As RNA-seq was also carried out in different TSB growth conditions, genes that were expressed specifically under desiccated conditions were identified and denoted as desiccation responsive genes (DRGs). Interestingly, these DRGs included transcriptomic factors like fnr , ramA, and genes associated with inositol metabolism, a phenotype as yet unreported in C. sakazakii . Further, the clinical strain did not express the proP gene, which was previously reported to be very important for desiccation survival and persistence. Interestingly, analysis of the plasmid genes showed that the iron metabolism in desiccated C. sakazakii ATCC™29544 T cells specifically involved the siderophore cronobactin encoded by the iucABCD genes. Confirmatory studies using qRT-PCR determined that, though the secondary desiccation response genes were upregulated in C. sakazakii ATCC™29544 T , the level of up-regulation was lower compared to that in C. sakazakii SP291. All these factors could collectively contribute to the compromised desiccation tolerance in the clinical strain. IMPORTANCE Cronobacter sakazakii has in past led to outbreaks, particularly associated with food that are low in moisture content. This species has adapted to survive in low water conditions and can survive in such environments for long periods. These characteristics have enabled the pathogen to contaminate powder infant formula, a food matrix with which the pathogen has been epidemiologically associated. Even though clinically adapted strains can also be isolated, there is no information on how the clinical strains adapt to low moisture environments. Our research assessed the adaptation of a clinically isolated strain to low moisture survival on sterile stainless steel coupons and compared the survival to a highly desiccation-tolerant environmental strain. We found that, even though the clinical strain is desiccation-tolerant, the rate of tolerance was compromised compared to the environmental strain. A deeper investigation using RNA-seq identified that the clinical strain used pathways different from that of the environmental strain to adapt to low moisture conditions. This shows that the adaptation to desiccation conditions, at least for C. sakazakii , is strain-specific and that different strains have used different evolutionary strategies for adaptation.

scholarly journals MgONPs Can Boost Plant Growth: Evidence from Increased Seedling Growth, Morpho-Physiological Activities, and Mg Uptake in Tobacco (Nicotiana tabacum L.)

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3375 ◽  
Author(s):  
Lin Cai ◽  
Minghong Liu ◽  
Zhongwei Liu ◽  
Huikuan Yang ◽  
Xianchao Sun ◽  
...  
Keyword(s):  
Plant Growth ◽  
Chlorophyll Content ◽  
Germination Rate ◽  
Paraffin Section ◽  
Growth Stimulation ◽  
Physiological Changes ◽  
Tobacco Plants ◽  
Tobacco Roots ◽  
The Impact ◽  
Mg Content

In this study, we documented the impact of magnesium oxide nanoparticles (MgONPs) on the various morpho-physiological changes by root irrigation in tobacco plants in the matrix media, as well as the uptake and accumulation of the NPs over a range of concentrations (50–250 μg/mL). Our results showed that the seed germination rate was not affected following exposure to MgONPs for 5 days. Enhanced plant growth together with increased peroxidase activity (39.63 U mg−1 protein in the 250 μg/mL MgONPs treatment, 36.63 U mg−1 protein in the control), superoxide dismutase activity (30.15 U mg−1 protein compared to 26.95 U mg−1 protein in the control), and chlorophyll content (the chlorophyll a and b contents in 0 and 250 μg/mL of MgONPs were 0.21, 0.12 μg/g to 1.21, 0.67 μg/g, respectively) were observed after 30 days of MgONP treatment. However, the malondialdehyde, protein, and relative water contents did not differ significantly, indicating that the NPs in the test concentrations had no phytotoxicity and even promoted plant growth. Scanning electron microscopy and paraffin section observations indicated that the MgONPs did not affect the plant tissue structures and cells. In addition, an elevated Mg content was detected in the plant tissues exposed to MgONPs, suggesting that the Mg was taken up by the tobacco roots and translocated to the shoots and leaves, which were probably the most important tools to cause an increase in the chlorophyll content and stimulate growth. In particular, compared with the controls, a substantially higher Mg content was observed in the leaves (12.93 mg/g in the MgONPs treatment, 9.30 mg/g in the control) exposed to 250 μg/mL MgONPs, especially in the lower and middle leaves. This result confirmed that the contents of plant Mg-element in the old leaves were increased by MgONPs. In summary, this study investigated increased Mg uptake and growth stimulation, as well as the induction of various positive morpho-physiological changes to tobacco plants when exposed to MgONPs. Results elucidate the promotional impact of the NPs on plant health and their implications for agricultural safety and security.

scholarly journals Comparative Physiological and Biochemical Changes in Tomato (Solanum lycopersicum L.) Under Salt Stress and Recovery: Role of Antioxidant Defense and Glyoxalase Systems

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 350 ◽  
Author(s):  
Parvin ◽  
Hasanuzzaman ◽  
Bhuyan ◽  
Nahar ◽  
Mohsin ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Plant Growth ◽  
Solanum Lycopersicum ◽  
Nutrient Solution ◽  
Stress Responses ◽  
Antioxidant Defense ◽  
Oxygen Species ◽  
Tomato Plants ◽  
Solanum Lycopersicum L ◽  
Post Stress

Salinity toxicity and the post-stress restorative process were examined to identify the salt tolerance mechanism in tomato, with a focus on the antioxidant defense and glyoxalase systems. Hydroponically grown 15 day-old tomato plants (Solanum lycopersicum L. cv. Pusa Ruby) were treated with 150 and 250 mM NaCl for 4 days and subsequently grown in nutrient solution for a further 2 days to observe the post-stress responses. Under saline conditions, plants showed osmotic stress responses that included low leaf relative water content and high proline content. Salinity induced oxidative stress by the over-accumulation of reactive oxygen species (H2O2 and O2•−) and methylglyoxal. Salinity also impaired the non-enzymatic and enzymatic components of the antioxidant defense system. On the other hand, excessive Na+ uptake induced ionic stress which resulted in a lower content of other minerals (K+, Ca2+, and Mg2+), and a reduction in photosynthetic pigment synthesis and plant growth. After 2 days in the normal nutrient solution, the plants showed improvements in antioxidant and glyoxalase system activities, followed by improvements in plant growth, water balance, and chlorophyll synthesis. The antioxidant and glyoxalase systems worked in concert to scavenge toxic reactive oxygen species (ROS), thereby reducing lipid peroxidation and membrane damage. Taken together, these findings indicate that tomato plants can tolerate salinity and show rapid post-stress recovery by enhancement of their antioxidant defense and glyoxalase systems.

scholarly journals Silicon Alleviates Copper Toxicity in Flax Plants by Up-Regulating Antioxidant Defense and Secondary Metabolites and Decreasing Oxidative Damage

2020 ◽  
Vol 12 (11) ◽  
pp. 4732 ◽  
Author(s):  
Hossam S. El-Beltagi ◽  
Mahmoud R. Sofy ◽  
Mohammed I. Aldaej ◽  
Heba I. Mohamed
Keyword(s):  
Lipid Peroxidation ◽  
Plant Growth ◽  
Oxidative Damage ◽  
Antioxidant Defense ◽  
Growth Yield ◽  
Enzymatic Antioxidants ◽  
Oxygen Species ◽  
Total Chlorophyll ◽  
Yield Attributes ◽  
Cu Toxicity

In recent years, nutrient management has gained much attention as a way to mitigate heavy metal stress. Silicon (Si) promotes plant defense responses against toxic metal stresses. In this study, we evaluated the effects of silicon (Si) on copper (Cu) toxicity in two flax genotypes (Sakha 1 and Sakha 2) as it relates to plant growth, yield attributes, total chlorophyll, nucleic acid content, enzymatic and non-enzymatic antioxidants, oxidative damage, lipid peroxidation, copper and silicon content, and fatty acid composition. The results showed that Cu (100 and 200 µM) inhibited plant growth and increased Cu accumulation in soil, roots, and shoots. Cu significantly decreased the yield attributes, total chlorophyll by 9.5% and 22% in Sakha 1 and by 22.5% and 29% in Sakha 2, and enhanced the accumulation of non-enzymatic (tocopherol), enzymatic antioxidants such as superoxide dismnutase, peroxidase, ascorbate peroxidase and catalase) and secondary metabolites (phenol and flavonoids). The DNA content significantly decreased in stressed plants with 100 and 200 µM Cu about 22% and 44%, respectively, in Sakha 1 and about 21.6% and 34.7% in Sakha 2, and RNA content also decreased by about 20% and 29%, respectively, in Sakha 1 and by about 2% and 13% in Sakha 2 compared to the control plant. Furthermore, Cu stress accelerated the generation of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2) and induced cellular oxidative injury caused by lipid peroxidation. In parallel, Cu induced a change in the composition of fatty acids, resulting in lower unsaturated fatty acid levels and increased saturated fatty acids (increased saturation/unsaturation ratio for both genotypes). Treating the flax plants with irrigation three times with Si protected the plants from Cu toxicity. Si treatment decreased the uptake and the transport of Cu to the shoots and harvested seeds and promoted plant growth, yield attributes, and antioxidant defense systems by reducing Cu accumulation, lipid peroxidation, and the generation of H2O2. In addition, the alleviation of Cu toxicity correlated with increased Si accumulation in the roots and shoots. In conclusion, Si can be used to improve the resistance of flax plants to Cu toxicity by up-regulating the antioxidant defense system such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and catalase (CAT) and decreasing the oxidative damage caused by reactive oxygen species (ROS).

scholarly journals The Mechanisms Involved in Seed Dormancy Alleviation by Hydrogen Cyanide Unravel the Role of Reactive Oxygen Species as Key Factors of Cellular Signaling during Germination

2009 ◽  
Vol 150 (1) ◽  
pp. 494-505 ◽  
Author(s):  
Krystyna Oracz ◽  
Hayat El-Maarouf-Bouteau ◽  
Ilse Kranner ◽  
Renata Bogatek ◽  
Françoise Corbineau ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Seed Dormancy ◽  
Hydrogen Cyanide ◽  
Cellular Signaling ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Key Factors
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