The unusual Arabidopsis extensin gene atExt1 is expressed throughout plant development and is induced by a variety of biotic and abiotic stresses

Merkouropoulos, Georgios; Shirsat, A. H.

doi:10.1007/s00425-003-1002-y

Cited by 69 publications

(49 citation statements)

References 59 publications

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“…A general role for extensin in response to different stresses, including senescence and abscission, was corroborated and detailed (Merkouropoulos and Shirsat, 2003).…”

Section: The Extensin Superfamily Over 5 Decadesmentioning

confidence: 70%

Role of the Extensin Superfamily in Primary Cell Wall Architecture

et al. 2011

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“…A general role for extensin in response to different stresses, including senescence and abscission, was corroborated and detailed (Merkouropoulos and Shirsat, 2003).…”

Section: The Extensin Superfamily Over 5 Decadesmentioning

confidence: 70%

Role of the Extensin Superfamily in Primary Cell Wall Architecture

et al. 2011

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“…Up-regulation of extensin encoding transcripts was first observed in roots (within 2 h of K 1 resupply), whereas increase of transcript levels in shoots appeared with a delay. Extensin expression has also been shown to be increased in response to wounding, pathogen infection, and exogenous application of methyl JA and other hormones (Merkouropoulos and Shirsat, 2003).…”

Section: Extensinsmentioning

confidence: 99%

The Potassium-Dependent Transcriptome of Arabidopsis Reveals a Prominent Role of Jasmonic Acid in Nutrient Signaling

2004

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Full genome microarrays were used to assess transcriptional responses of Arabidopsis seedlings to changing external supply of the essential macronutrient potassium (K+). Rank product statistics and iterative group analysis were employed to identify differentially regulated genes and statistically significant coregulated sets of functionally related genes. The most prominent response was found for genes linked to the phytohormone jasmonic acid (JA). Transcript levels for the JA biosynthetic enzymes lipoxygenase, allene oxide synthase, and allene oxide cyclase were strongly increased during K+ starvation and quickly decreased after K+ resupply. A large number of well-known JA responsive genes showed the same expression profile, including genes involved in storage of amino acids (VSP), glucosinolate production (CYP79), polyamine biosynthesis (ADC2), and defense (PDF1.2). Our findings highlight a novel role of JA in nutrient signaling and stress management through a variety of physiological processes such as nutrient storage, recycling, and reallocation. Other highly significant K+-responsive genes discovered in our study encoded cell wall proteins (e.g. extensins and arabinogalactans) and ion transporters (e.g. the high-affinity K+ transporter HAK5 and the nitrate transporter NRT2.1) as well as proteins with a putative role in Ca2+ signaling (e.g. calmodulins). On the basis of our results, we propose candidate genes involved in K+ perception and signaling as well as a network of molecular processes underlying plant adaptation to K+ deficiency.

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“…Similar root hair phenotypes are seen in plants lacking Pro 4-hydroxylase activity due to reduced Pro hydroxylation and O-arabinosylation of extensins, suggesting that these posttranslationally modified proteins influence root hair growth (Velasquez et al, 2011). There are 51 genes annotated as encoding extensins or extensinlike proteins in the Arabidopsis genome (Showalter et al, 2010), and it appears likely from their specific expression patterns that they are involved in a range of growth, developmental, and stress responses (Merkouropoulos and Shirsat, 2003), although plants manipulated to produce abnormally high levels of EXT1 appear to develop normally with the exception of having thicker stems (Roberts and Shirsat, 2006). Physiological roles in aerial tissues remain elusive and the failure to identify a function for extensins and indeed other HRGPs in shoots is likely to be due to redundancy within this large gene family, a common problem in plant cell wall protein studies.…”

mentioning

confidence: 91%

Formation of the Stomatal Outer Cuticular Ledge Requires a Guard Cell Wall Proline-Rich Protein

et al. 2017

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(K.S.); 0000-0002-6438-9188 (R.S.); 0000-0002-9703-0745 (A.J.F.); 0000-0001-9972-5156 (J.E.G.).Stomata are formed by a pair of guard cells which have thickened, elastic cell walls to withstand the large increases in turgor pressure that have to be generated to open the pore that they surround. We have characterized FOCL1, a guard cell-expressed, secreted protein with homology to Hyp-rich cell wall proteins. FOCL1-GFP localizes to the guard cell outer cuticular ledge and plants lacking FOCL1 produce stomata without a cuticular ledge. Instead the majority of stomatal pores are entirely covered over by a continuous fusion of the cuticle, and consequently plants have decreased levels of transpiration and display drought tolerance. The focl1 guard cells are larger and less able to reduce the aperture of their stomatal pore in response to closure signals suggesting that the flexibility of guard cell walls is impaired. FOCL1 is also expressed in lateral root initials where it aids lateral root emergence. We propose that FOCL1 acts in these highly specialized cells of the stomata and root to impart cell wall strength at high turgor and/or to facilitate interactions between the cell wall and the cuticle.

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The unusual Arabidopsis extensin gene atExt1 is expressed throughout plant development and is induced by a variety of biotic and abiotic stresses

Cited by 69 publications

References 59 publications

Role of the Extensin Superfamily in Primary Cell Wall Architecture

Role of the Extensin Superfamily in Primary Cell Wall Architecture

The Potassium-Dependent Transcriptome of Arabidopsis Reveals a Prominent Role of Jasmonic Acid in Nutrient Signaling

Formation of the Stomatal Outer Cuticular Ledge Requires a Guard Cell Wall Proline-Rich Protein

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