Hypobaric Biology: Arabidopsis Gene Expression at Low Atmospheric Pressure

Paul, Anna‐Lisa; Schuerger, Andrew C.; Popp, Michael P.; Richards, Jeffrey T.; Manak, Michael S.; Ferl, Robert J.

doi:10.1104/pp.103.032607

Cited by 88 publications

(73 citation statements)

References 47 publications

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“…We amplified the mRNA by two cycles of reverse transcription/in vitro transcription according to the Affymetrix protocol for small samples (GeneChip Eukaryotic Small Sample Target Labeling Assay Version II) prior to labeling, fragmentation, and hybridization. To halt transcription and other cellular activities at the precise time points and preserve RNA profile of each sample, we submerged plants in RNAlater (Ambion, Austin, TX;Paul et al, 2004). RNAlater penetrated the roots in less than 3 s as demonstrated by trypan blue viability staining (Fig.…”

Section: Resultsmentioning

confidence: 99%

The Fast and Transient Transcriptional Network of Gravity and Mechanical Stimulation in the Arabidopsis Root Apex

et al. 2004

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Plant root growth is affected by both gravity and mechanical stimulation . A coordinated response to both stimuli requires specific and common elements. To delineate the transcriptional response mechanisms, we carried out whole-genome microarray analysis of Arabidopsis root apices after gravity stimulation (reorientation) and mechanical stimulation and monitored transcript levels of 22,744 genes in a time course during the first hour after either stimulus. Rapid, transient changes in the relative abundance of specific transcripts occurred in response to gravity or mechanical stimulation, and these transcript level changes reveal clusters of coordinated events. Transcriptional regulation occurs in the root apices within less than 2 min after either stimulus. We identified genes responding specifically to each stimulus as well as transcripts regulated in both signal transduction pathways. Several unknown genes were specifically induced only during gravitropic stimulation (gravity induced genes). We also analyzed the network of transcriptional regulation during the early stages of gravitropism and mechanical stimulation.Plants adapt their growth in response to environmental cues. Gravity is a constant force that guides the direction of plant growth. Mechanical stimuli such as wind, rain, and obstacles in the soil trigger changes in growth patterns (Braam and Davis, 1990;. Gravitropic and mechanical stimulation in the root are interactive processes, mutually influencing differential growth (Mullen et al., 2000;Fasano et al., 2002;. The mechanisms of sensing and signal transduction for either stimulus are not well understood, but it has been shown that the transcript levels of specific genes are regulated early during signal transduction after either stimulus Braam and Davis, 1990).It is widely accepted that gravitropic stimulation by reorientation is perceived by sedimentation of starchcontaining plastids (statoliths) in the columella cells of the root tip (Kiss et al., 1989(Kiss et al., , 1996Juniper et al., 1966;Blancaflor et al., 1998). Columella cells show differences in their contribution toward gravity perception and in the velocity of sedimentation of their statoliths (Blancaflor et al., 1998). While complete sedimentation of the statoliths requires at least 5 min (Blancaflor et al., 1998;MacCleery and Kiss, 1999), the presentation time (duration of the stimulus that is required to establish a response) was estimated at only approximately 1 min for wild-type Arabidopsis root tips (Blancaflor et al., 1998). Statolith sedimentation is postulated to disrupt the actin-based cytoskeletal network and its links to plasma membrane receptors in some regions of the cell cortex (Yoder et al., 2001). Other groups hypothesized that statoliths are directly connected to the cytoskeleton, activating membrane proteins anchored to the filaments upon dislocation or activation of mechanosensitive ion channels (Evans et al., 1986;Pickard and Ding, 1993;Collings et al., 2001;Blancaflor, 2002).The transduction of the physical alt...

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Section: Resultsmentioning

confidence: 99%

The Fast and Transient Transcriptional Network of Gravity and Mechanical Stimulation in the Arabidopsis Root Apex

et al. 2004

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“…Arabidopsis seeds were planted aseptically on the surface of 10 cm 2 solid media plates (Paul et al, 2004). The samples come from a collection of three Arabidopsis lines.…”

Section: Plant Growth and Harvest On The Issmentioning

confidence: 99%

Spaceflight Induces Specific Alterations in the Proteomes of Arabidopsis

Ferl

Koh²,

Denison³

et al. 2015

Astrobiology

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Life in spaceflight demonstrates remarkable acclimation processes within the specialized habitats of vehicles subjected to the myriad of unique environmental issues associated with orbital trajectories. To examine the response processes that occur in plants in space, leaves and roots from Arabidopsis (Arabidopsis thaliana) seedlings from three GFP reporter lines that were grown from seed for 12 days on the International Space Station and preserved on orbit in RNAlater were returned to Earth and analyzed by using iTRAQ broad-scale proteomics procedures. Using stringent criteria, we identified over 1500 proteins, which included 1167 leaf proteins and 1150 root proteins we were able to accurately quantify. Quantification revealed 256 leaf proteins and 358 root proteins that showed statistically significant differential abundance in the spaceflight samples compared to ground controls, with few proteins differentially regulated in common between leaves and roots. This indicates that there are measurable proteomics responses to spaceflight and that the responses are organspecific. These proteomics data were compared with transcriptome data from similar spaceflight samples, showing that there is a positive but limited relationship between transcriptome and proteome regulation of the overall spaceflight responses of plants. These results are discussed in terms of emergence understanding of plant responses to spaceflight particularly with regard to cell wall remodeling, as well as in the context of deriving multiple omics data sets from a single on-orbit preservation and operations approach.

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“…For example, Mercury, Gemini and Apollo vehicles have been produced to form a pressure of 34 kPa (pure oxygen) for astronauts in space. Also, Skylab has been produced pressure of 34 kPa (70% O 2 /30% N 2 gas mixture) (Waligora et al, 1991;Massimo, 1992;Paul et al, 2004).…”

Section: Discussionmentioning

confidence: 99%

Effects of Hypobaric Conditions on Apoptosis Signalling Pathways in HeLa Cells

Arıcan

Khalilia²,

Serbes³

et al. 2014

Asian Pacific Journal of Cancer Prevention

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Nowadays increasing effectiveness in cancer therapy and investigation of formation of new strategies that enhance antiproliferative activity against target organs has become a subject of interest. Although the molecular mechanisms of apoptosis can not be fully explained, it is known that cell suicide program existing in their memory genetically is activated by pathophysiological conditions and events such as oxidative stress. Low pressure (hypobaric) conditions that create hypoxia promote apoptosis by inhibiting cell cycling. In this study, determination of the effects of fractional hypobaric applications at different times on HeLa cells at cellular and molecular levels were targeted. Experiments were carried out under hypobaric conditions (35.2 kPa) in a specially designed hypobaric cabin including 2% O 2 and 98% N. Application of fractional hypobaric conditions was repeated two times for 3 hours with an interval of 24 hours. At the end of the implementation period cells were allowed to incubate for 24 hours for activation of repair mechanisms. Cell kinetic parameters such as growth rate (MTT) and apoptotic index were used in determination of the effect of hypobaric conditions on HeLa cells. Also in our study expression levels of the Bcl-2 gene family that have regulatory roles in apoptosis were determined by the RT-PCR technique to evaluate molecular mechanisms. The results showed that antiproliferative effect of hypobaric conditions on HeLa cells started three hours from the time of application and increased depending on the period of exposure. While there was a significant decrease in growth rate values, there was a significant increase in apoptotic index values (p<0.01). Also molecular studies showed that hypobaric conditions caused a significant increase in expression level of proapoptotic gene Bax and significant decrease in antiapoptotic Bfl-1. Consequently fractional application of hypobaric conditions on HeLa cell cultures increased both antiproliferative and apoptotic effects and these effects were triggered by the Bax gene.

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Hypobaric Biology: Arabidopsis Gene Expression at Low Atmospheric Pressure

Cited by 88 publications

References 47 publications

The Fast and Transient Transcriptional Network of Gravity and Mechanical Stimulation in the Arabidopsis Root Apex

The Fast and Transient Transcriptional Network of Gravity and Mechanical Stimulation in the Arabidopsis Root Apex

Spaceflight Induces Specific Alterations in the Proteomes of Arabidopsis

Effects of Hypobaric Conditions on Apoptosis Signalling Pathways in HeLa Cells

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