Local Root Apex Hypoxia Induces NO-Mediated Hypoxic Acclimation of the Entire Root

Mugnai, S.; Azzarello, Elisa; Baluška, Frantǐsek; Mancuso, Stefano

doi:10.1093/pcp/pcs034

Cited by 55 publications

(48 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Sun et al (2014) have also reported that in wheat root NO burst induced by aluminium 3 h after the treatment was mediated through the nitrate reductase activity. Similarly to Cd-induced NO generation in roots, the hypoxia-induced NO production in maize seedlings was detected within a few minutes and was strictly associated with the transition zone of root apex (Mugnai et al 2012).…”

Section: Discussionmentioning

confidence: 87%

Enhanced nitric oxide generation in root transition zone during the early stage of cadmium stress is required for maintaining root growth in barley

et al. 2015

View full text Add to dashboard Cite

Background and Aims The objective of this study was to analyse the role of nitric oxide (NO) in relation to reactive oxygen species (ROS) production and root growth inhibition in the early response of barley root tip to cadmium. Methods We used cell-permeable NO-binding dye DAF-2DA for the NO localization and cellimpermeable dye DAR-4M for the quantification of NO in barley root apex. Results A considerable increase in NO production was detected in the transition zone of root tips already 30 min after the immersion of barley roots into 15 μM Cd. This Cd-induced NO generation further increased during the recovery period and reached its maximum level 2 h after the short-term treatment. At this stage an enhanced Cd-induced NO generation was observed in the meristematic, transition and in the beginning of elongation zone in comparison with control roots. Inhibitor of NO synthase activity markedly reduced root growth in control seedlings and had a synergistic growth inhibitory effect with Cd. On the contrary, this Cdinduced root growth inhibition was markedly alleviated by the NO donor. Exposure of roots to Cd markedly increased the production of ROS in the proximal elongation zone of root. While NO did not affect ROS generation, inhibition of its synthesis slightly decreased ROS generation in both control and Cd-treated roots. Conclusions Our results revealed that enhanced NO production is a very early response of barley root to Cd stress and it is involved in the regulation of root growth mitigating Cd-induced root growth inhibition.

show abstract

Section: Discussionmentioning

confidence: 87%

Enhanced nitric oxide generation in root transition zone during the early stage of cadmium stress is required for maintaining root growth in barley

et al. 2015

View full text Add to dashboard Cite

show abstract

“…50 A recent study conducted on maize demonstrated that the transition zone plays central roles in both sensing and adapting to root hypoxia. 51 The authors also observed that the oxygen deprivation of roots induces local NO emission in the TZ, that is essential for the successful acclimation of the entire maize root to oxygen deprivation. 51 A number of experimental data globally indicates that the transition zone of the root may be considered as a sort of sensory center, enabling the root apex to continuously monitor environment parameters and to trigger appropriate responses.…”

Section: The Root Transition Zonementioning

confidence: 95%

“…51 A number of experimental data globally indicates that the transition zone of the root may be considered as a sort of sensory center, enabling the root apex to continuously monitor environment parameters and to trigger appropriate responses. [51][52][53][54][55][56][57][58][59][60][61][62][63] Future studies will be needed to deepen the role of this unique root zone in translating the external stimuli in motoric responses.…”

Section: The Root Transition Zonementioning

confidence: 99%

NO signaling is a key component of the root growth response to nitrate inZea maysL.

Trevisan

Manoli

Quaggiotti

2014

Plant Signaling & Behavior

View full text Add to dashboard Cite

To search for nutrients and water, roots need to efficiently explore large soil volumes. To this aim they generate complex root systems, allowing them to maximize their resource allocation efficiency. 1 Despite the vital importance of roots, the difficulty in accessing intact root systems for analysis, particularly under field conditions, have slowed down the breeding programs for plant's adaptation to environmental restrictions. 2,3 The capacity of plants to take up nutrients and water is mainly determined by changes in the architecture of the root system. 1 Three major processes affect the overall architecture of the root system: the rate of cell division, the rate of cell differentiation, and the extent of expansion and elongation of cells. [4][5][6] Disturbs in any of these 3 processes can affect the whole root-system architecture and the capacity of plants to survive and develop in adverse environments (Giehl et al. 7 and references therein).The root system results from the coordinated control of both genetic endogenous programs (regulating growth and organogenesis) and the action of abiotic and biotic environmental stimuli. 8,9 The dynamic control of the overall root system architecture (RSA) throughout time finally determines root plasticity and allows plants to efficiently adapt to environmental constraints. 10 The soil-environment from which plants extract nutrients and water is extremely heterogeneous, both spatially and temporally. 11 Among the nutrients present in soil, nitrate (NO 3 − ) may vary by an order of magnitude within centimeters or over the course of a day. 12 The effects of NO 3 − on the root system are complex and depend on several factors, such as the concentration available to the plant, the endogenous nitrogen status and the sensitivity of the species. 10,13,14 A considerable part of the studies aimed to unravel the mechanisms controlling RSA growth and development in response to nitrate have been focused on lateral roots (LR), 8,13,[15][16][17][18][19][20] while the nitrate-regulation of the primary root growth is still unclear. Beside NO 3 − , auxin has been demonstrated to strongly affect and control the LR development, [21][22][23][24] and an increasing number of studies suggests an overlap between auxin and NO 3 − signaling pathways in controlling LR development. [25][26][27][28][29][30][31][32][33] NO 3 -has a Doubtful Role in Regulating the Growth of Primary RootsDespite the high amount of reports published on nitrate effects on root elongation, the lack of univocal results makes it difficult to clearly decipher this response ( Table 1). In Arabidopsis thaliana, inhibition of primary root growth has been observed when nitrate is applied homogeneously at high concentrations (50 mM) for 7 d, but not in a range between 0.1 and 10 mM. 35 On the contrary, in this same species Linkohr et al. 36 showed an inhibition of primary root elongation with the increase of nitrate concentration already beyond 0.01 mM, but in this case seedlings were IAA, indole-3-acetic acid; SNP, sodium n...

show abstract

“…Unlike seedlings grown on vertical agar plates that experience a normoxic-to-hypoxic transition, in our system, submerged roots transition from hypoxic to severely hypoxic conditions . Interestingly, it has been shown that low oxygen in the root tip only is sufficient to activate low-oxygenresponsive genes throughout the entire root (Mugnai et al, 2012). In active meristems, hypoxia is a common event during periods of high activity (van Dongen and Licausi, 2015).…”

Section: Organ-specific Transcriptome Reconfiguration and Oxygen-depementioning

confidence: 99%

Transcriptomes of eight Arabidopsis thaliana accessions reveal core conserved, genotype- and organ-specific responses to flooding stress

et al. 2016

View full text Add to dashboard Cite

ORCID IDs: 0000-0002-6709-6436 (S.H.); 0000-0001-6777-6565 (M.E.S.); 0000-0002-8568-7125 (J.B.-S.); 0000-0002-6940-0657 (R.S.).Climate change has increased the frequency and severity of flooding events, with significant negative impact on agricultural productivity. These events often submerge plant aerial organs and roots, limiting growth and survival due to a severe reduction in light reactions and gas exchange necessary for photosynthesis and respiration, respectively. To distinguish molecular responses to the compound stress imposed by submergence, we investigated transcriptomic adjustments to darkness in air and under submerged conditions using eight Arabidopsis (Arabidopsis thaliana) accessions differing significantly in sensitivity to submergence. Evaluation of root and rosette transcriptomes revealed an early transcriptional and posttranscriptional response signature that was conserved primarily across genotypes, although flooding susceptibility-associated and genotype-specific responses also were uncovered. Posttranscriptional regulation encompassed darkness-and submergence-induced alternative splicing of transcripts from pathways involved in the alternative mobilization of energy reserves. The organ-specific transcriptome adjustments reflected the distinct physiological status of roots and shoots. Root-specific transcriptome changes included marked up-regulation of chloroplast-encoded photosynthesis and redox-related genes, whereas those of the rosette were related to the regulation of development and growth processes. We identified a novel set of tolerance genes, recognized mainly by quantitative differences. These included a transcriptome signature of more pronounced gluconeogenesis in tolerant accessions, a response that included stress-induced alternative splicing. This study provides organ-specific molecular resolution of genetic variation in submergence responses involving interactions between darkness and low-oxygen constraints of flooding stress and demonstrates that early transcriptome plasticity, including alternative splicing, is associated with the ability to cope with a compound environmental stress.

show abstract

Local Root Apex Hypoxia Induces NO-Mediated Hypoxic Acclimation of the Entire Root

Cited by 55 publications

References 78 publications

Enhanced nitric oxide generation in root transition zone during the early stage of cadmium stress is required for maintaining root growth in barley

Enhanced nitric oxide generation in root transition zone during the early stage of cadmium stress is required for maintaining root growth in barley

NO signaling is a key component of the root growth response to nitrate inZea maysL.

Transcriptomes of eight Arabidopsis thaliana accessions reveal core conserved, genotype- and organ-specific responses to flooding stress

Contact Info

Product

Resources

About