Mercury‐induced genes in <i>Arabidopsis thaliana</i>: identification of induced genes upon long‐term mercuric ion exposure

Heidenreich, Bernd; Mayer, Klaus; Sandermann, Heinrich; Ernst, D.

doi:10.1046/j.0016-8025.2001.00775.x

Cited by 56 publications

(55 citation statements)

References 41 publications

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“…PMEs modify the properties of cell walls by demethylation of pectin residues, thus creating free carboxylic groups for interaction with divalent cations. Elevated expression of PME has been reported in Arabidopsis in long-term Hg exposure (Heidenreich et al 2001). PME modulates Al sensitivity, since the free carboxylic groups are the major apoplastic binding sites for Al (Schmohl et al 2000).…”

Section: Discussionmentioning

confidence: 99%

Isolation of Zn-responsive genes from two accessions of the hyperaccumulator plant Thlaspi caerulescens

Hassinen

Tervahauta

Halimaa

et al. 2006

Planta

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Several populations with diVerent metal tolerance, uptake and root-to-shoot transport are known for the metal hyperaccumulator plant Thlaspi caerulescens. In this study, genes diVerentially expressed under various Zn exposures were identiWed from the shoots of two T. caerulescens accessions (calaminous and non-calaminous) using Xuorescent diVerential display RT-PCR. cDNA fragments from 16 Zn-responsive genes, including those encoding metallothionein (MT) type 2 and type 3, MRP-like transporter, pectin methylesterase (PME) and Ole e 1-like gene as well as several unknown genes, were eventually isolated. The fulllength MT2 and MT3 sequences diVer from those previously isolated from other Thlaspi accessions, possibly representing new alleles or isoforms. Besides the diVerential expression in Zn exposures, the gene expression was dependent on the accession. Thlaspi homologues of ClpP protease and MRP transporter were induced at high Zn concentrations. MT2 and PME were expressed at higher levels in the calaminous accession. The MTs and MRP transporter expressed in transgenic yeasts were capable of conferring Cu and Cd tolerance, whereas the Ole e 1-like gene enhanced toxicity to these metals. The MTs increased yeast intracellular Cd content. As no signiWcant diVerences were found between Arabidopsis and Thlaspi MTs, they apparently do not diVer in their capacity to bind metals. However, the higher levels of MT2 in the calaminous accession may contribute to the Zn-adapted phenotype.

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Section: Discussionmentioning

confidence: 99%

Isolation of Zn-responsive genes from two accessions of the hyperaccumulator plant Thlaspi caerulescens

Hassinen

Tervahauta

Halimaa

et al. 2006

Planta

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“…Many studies have been conducted to identify and characterize genes that are up-regulated in response to exposure to the various heavy metals other than Pb (Watt 2003;Sahr et al 2004;Heidenreich et al 2001;Weber et al 2005;Louie et al 2003;Fusco et al 2005). Exposure to the heavy metal Cd initially resulted in severe oxidative stress because the low residual glutathione pool was completely oxidized and H 2 O 2 accumulation increased in pine roots (Schützendübel et al 2001).…”

Section: Discussionmentioning

confidence: 98%

“…Overall the mRNA transcripts identiWed in this work have been linked to plant oxidative stress responses, particularly, cold and water stress induced mRNA in response to Al toxicity (Watt 2003) and methyl-jasmonate-elicitor mRNA induced by Hg (Heidenreich et al 2001). This overlap is not surprising considering that in plants stress related transcripts are often not speciWc and they are likely to be aVected by other stress factors such as heavy metals and salts (Heidenreich et al 1999;Reymond et al 2000;Brosche et al 2002).…”

Section: Discussionmentioning

confidence: 99%

“…Genes encoding for ribosomal proteins (SSH-42) were classiWed as expression regulators. The methyl-jasmonate-elicitor protein (SSH-23) found to be induced at the transcriptional level, might suggest a link to lipid peroxidation occurring under photooxidation (Heidenreich et al 2001). One transcript (SSH-17) encoding hemolysin protein with unknown function was also induced by lead nitrate.…”

Section: Analysis Of Lead-induced Cdna Sequencesmentioning

confidence: 96%

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Identification of lead-regulated genes by suppression subtractive hybridization in the heavy metal accumulator Sesbania drummondii

Srivastava

Venkatachalam

Raghothama

et al. 2006

Planta

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Heavy metal contamination of soils is of widespread occurrence as a result of human, agricultural and industrial activities. Among heavy metals, lead is a potential pollutant that readily accumulates in soils and sediments. Although lead is not an essential element for plants, it gets easily absorbed and accumulated in Sesbania drummondii, which exhibits a significant level of tolerance to lead. The response of a metal tolerant plant to heavy metal stress involves a number of biochemical and physiological pathways. To investigate the overall molecular response of a metal-tolerant plant to lead exposure, suppression subtractive hybridization (SSH) was used to construct a cDNA library enriched in lead induced mRNA transcripts from lead-tolerant Sesbania. Screening the library by reverse Northern analysis revealed that between 20 and 25% of clones selected from the library were differentially regulated in lead treated plants. After differential screening, we isolated several differentially expressed cDNA clones, including a type 2 metallothionein (MT) gene which is involved in detoxification and homeostasis and shown to be differentially regulated in lead treated plants. The data from the reverse Northern analysis was further confirmed with conventional Northern analysis of a select group of genes including MT, ACC synthase/oxidase, cold-, water stress-, and other abiotic stress-induced genes, which are up-regulated rapidly in response to lead treatment. The mRNA levels of MT increased substantially after lead treatment indicating a potential role for it under lead stress in Sesbania. The present results show that SSH can serve as an effective tool for isolating genes induced in response to lead heavy metal tolerance in Sesbania. A better understanding of lead induced gene expression in Sesbania should help select candidates associated with remediation of heavy metal toxicity. The possible link between this result and the heavy-metal response of plants is discussed.

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“…In addition, Hg 2+ induces more severe oxidative stress by triggering production of reactive oxygen species (Clemens 2001) and damaging macromolecules (Heidenreich et al 2001;Cargnelutti et al 2006). Thus, Hg 2+ directly damages proteins and DNA and ultimately causes cell death.…”

Section: Introductionmentioning

confidence: 99%

Expression analysis of new Metallothionein2-like protein under mercury stress in tomato seedling

Nagata

2014

Plant Root

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Plants including tomato produce several kinds of chelator proteins such as metallothioneins (MTs) for protection against Hg 2+ toxicity. However, the mechanism of protection from Hg 2+ is not perfectly clear. Hg 2+content subsequently was plateaued from days 1 to 7. Cell death and DNA digestion were not observed in the primary root in the presence of Hg 2+ over the 7 days. The predicted protein sequences of 5 tomato type 2 MT-like (MT2-like) proteins were compared. The coding sequences of accession number Z68185 had no Cys-Cys motif in the N-terminal. However, the Z68185 cDNA genetic recombinant showed high resistance to Hg 2+ in bacteria. In tomato, the expression was observed in the roots, but not in the leaves or stems. mRNA of the MT2-like protein was measured in tomato seedlings exposed to 1 μM Hg 2+ . The expression level did not increase until day 3, but increased expression was observed after day 5. These results suggest that new Metallothionein2-like protein express in root specific and it may trap mercury. Our results indicate that functional identification of an MT2-like protein will be useful for molecular breeding designed to improve plant tolerance to Hg 2+ .

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Mercury‐induced genes in Arabidopsis thaliana: identification of induced genes upon long‐term mercuric ion exposure

Cited by 56 publications

References 41 publications

Isolation of Zn-responsive genes from two accessions of the hyperaccumulator plant Thlaspi caerulescens

Isolation of Zn-responsive genes from two accessions of the hyperaccumulator plant Thlaspi caerulescens

Identification of lead-regulated genes by suppression subtractive hybridization in the heavy metal accumulator Sesbania drummondii

Expression analysis of new Metallothionein2-like protein under mercury stress in tomato seedling

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