scholarly journals Cyanobacteria-Derived Proline Increases Stress Tolerance in Arabidopsis thaliana Root Hairs by Suppressing Programmed Cell Death

2020 ◽  
Vol 11 ◽  
Author(s):  
Alysha Chua ◽  
Orla L. Sherwood ◽  
Laurence Fitzhenry ◽  
Carl K.-Y. Ng ◽  
Paul F. McCabe ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Stress Tolerance ◽  
Root Hair ◽  
Root Hairs ◽  
Biologically Active ◽  
Nostoc Muscorum ◽  
Sensitivity Threshold ◽  
Wild Type

Nitrogen-fixing heterocystous cyanobacteria are used as biofertilizer inoculants for stimulating plant growth but can also alleviate plant stress by exometabolite secretion. However, only a small number of studies have focused on elucidating the identity of said bioactives because of the wide array of exuded compounds. Here, we used the root hair assay (RHA) as a rapid programmed cell death (PCD) screening tool for characterizing the bioactivity of cyanobacteria Nostoc muscorum conditioned medium (CM) on Arabidopsis thaliana root hair stress tolerance. We found that heat-stressed A. thaliana pre-treated with N. muscorum CM fractions exhibited significantly lower root hair PCD levels compared to untreated seedlings. Treatment with CM increased stress tolerance by suppressing PCD in root hairs but not necrosis, indicating the bioactive compound was specifically modulating the PCD pathway and not a general stress response. Based on documented N. muscorum exometabolites, we identified the stress-responsive proline as a compound of interest and strong evidence from the ninhydrin assay and HPLC indicate that proline is present in N. muscorum CM. To establish whether proline was capable of suppressing PCD, we conducted proline supplementation experiments. Our results showed that exogenous proline had a similar effect on root hairs as N. muscorum CM treatment, with comparable PCD suppression levels and insignificant necrosis changes. To verify proline as one of the biologically active compounds in N. muscorum CM, we used three mutant A. thaliana lines with proline transporter mutations (lht1, aap1 and atprot1-1::atprot2-3::atprot3-2). Compared with the wild-type seedlings, PCD-suppression in lht1and aap1 mutants was significantly reduced when supplied with low proline (1–5 μM) levels. Similarly, pre-treatment with N. muscorum CM resulted in elevated PCD levels in all three mutant lines compared to wild-type seedlings. Our results show that plant uptake of cyanobacteria-derived proline alters their root hair PCD sensitivity threshold. This offers evidence of a novel biofertilizer mechanism for reducing stress-induced PCD levels, independent of the existing mechanisms documented in the literature.

scholarly journals “mazEFmediated programmed cell death in Escherichia coli”: is it?

2016 ◽  
Author(s):  
Bhaskar Chandra Mohan Ramisetty ◽  
Swati Raj ◽  
Dimpy Ghosh
Keyword(s):  
Escherichia Coli ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Stress Tolerance ◽  
Type Ii ◽  
Overlapping Genes ◽  
Wild Type ◽  
E Coli ◽  
Typical Type ◽  
Metabolic Fitness

AbstractToxin-antitoxins systems (TAS) are prokaryotic operons containing two small overlapping genes which encode two components referred to as Toxin and Antitoxin. Involvement of TAS in bacterial programmed cell death (PCD) is highly controversial. MazEF, a typical type II TAS, is particularly implicated in mediating PCD inEscherichia coli. Hence, we compared the metabolic fitness and stress tolerance ofE. colistrains (MC4100 and itsmazEF- derivative) which were extensively used by proponents ofmazEF- mediated PCD. We found that both the strains are deficient inrelAgene and that theΔmazEFstrain has lower fitness and stress tolerance compared to wild type MC4100. Furthermore, these strains are likely not isogenic. We could not reproducemazEFmediated PCD which emphasizes the need for skeptic approach to the PCD hypothesis.

scholarly journals An in vivo root hair assay for determining rates of apoptotic-like programmed cell death in plants

Plant Methods ◽  
2011 ◽  
Vol 7 (1) ◽  
pp. 45 ◽  
Author(s):  
Bridget V Hogg ◽  
Joanna Kacprzyk ◽  
Elizabeth M Molony ◽  
Conor O'Reilly ◽  
Thomas F Gallagher ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Root Hair

Proteome and metabolome profiling of wild-type and YCA1 -knock-out yeast cells during acetic acid-induced programmed cell death

2015 ◽  
Vol 128 ◽  
pp. 173-188 ◽  
Author(s):  
Valentina Longo ◽  
Maša Ždralević ◽  
Nicoletta Guaragnella ◽  
Sergio Giannattasio ◽  
Lello Zolla ◽  
...  
Keyword(s):  
Cell Death ◽  
Acetic Acid ◽  
Programmed Cell Death ◽  
Yeast Cells ◽  
Wild Type ◽  
Knock Out ◽  
Metabolome Profiling

Mitochondrial Markers of Programmed Cell Death in Arabidopsis thaliana

2015 ◽  
pp. 211-221 ◽  
Author(s):  
Theresa J. Reape ◽  
Joanna Kacprzyk ◽  
Niall Brogan ◽  
Lee Sweetlove ◽  
Paul F. McCabe
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Mitochondrial Markers

Does the lack of root hairs alter root system architecture of Zea mays?

2021 ◽  
Author(s):  
Steffen Schlüter ◽  
Eva Lippold ◽  
Maxime Phalempin ◽  
Doris Vetterlein
Keyword(s):  
Zea Mays ◽  
Root System ◽  
Root Hair ◽  
System Architecture ◽  
Volume Fraction ◽  
Root Hairs ◽  
Root System Architecture ◽  
Root Diameter ◽  
Wild Type ◽  
Defective Mutant

<p>Root hairs are one root trait among many which enables plants to adapt to environmental conditions. How different traits are coordinated and whether some are mutually exclusive is currently poorly understood. Comparing a root hair defective mutant with its corresponding wild-type we explored if and how the mutant exhibited root growth adaption strategies and as to how far this depended on the substrate.</p><p>Zea mays root hair defective mutant (rth3) and the corresponding wild-type siblings were grown on two substrates with contrasting texture and hence nutrient mobility. Root system architecture was investigated over time using repeated X-ray computed tomography.</p><p>There was no plastic adaption of root system architecture to the lack of root hairs, which resulted in lower uptake in particular in the substrate with low P mobility. The function of the root hairs for anchoring did not result in different depth profiles of the root length density between genotypes. Both maize genotypes showed a marked response to substrate. This was well reflected in the spatiotemporal development of rhizosphere volume fraction but especially in the strong response of root diameter to substrate, irrespective of genotype.</p><p>The most salient root plasticity trait was root diameter in response to substrate, whereas coping mechanisms for missing root hairs were less evident. Further experiments are required to elucidate whether observed differences can be explained by mechanical properties beyond mechanical impedance, root or microbiome ethylene production or differences in diffusion processes within the root or the rhizosphere.</p>

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