Dataset Information

Mutants of Arabidopsis thaliana defective in the acquisition of tolerance to high temperature stress.

ABSTRACT: The ability of organisms to acquire thermotolerance to normally lethal high temperatures is an ancient and conserved adaptive response. However, knowledge of cellular factors essential to this response is limited. Acquisition of thermotolerance is likely to be of particular importance to plants that experience daily temperature fluctuations and are unable to escape to more favorable environments. We developed a screen, based on hypocotyl elongation, for mutants of Arabidopsis thaliana that are unable to acquire thermotolerance to high-temperature stress and have defined four separate genetic loci, hot1-4, required for this process. hot1 was found to have a mutation in the heat shock protein 101 (Hsp101) gene, converting a conserved Glu residue in the second ATP-binding domain to a Lys residue, a mutation that is predicted to compromise Hsp101 ATPase activity. In addition to exhibiting a thermotolerance defect as assayed by hypocotyl elongation, 10-day-old hot1 seedlings were also unable to acquire thermotolerance, and hot1 seeds had greatly reduced basal thermotolerance. Complementation of hot1 plants by transformation with wild-type Hsp101 genomic DNA restored hot1 plants to the wild-type phenotype. The hot mutants are the first mutants defective in thermotolerance that have been isolated in a higher eukaryote, and hot1 represents the first mutation in an Hsp in any higher plant. The phenotype of hot1 also provides direct evidence that Hsp101, which is required for thermotolerance in bacteria and yeast, is also essential for thermotolerance in a complex eukaryote.

SUBMITTER: Hong SW

PROVIDER: S-EPMC18252 | biostudies-literature | 2000 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Mutants of Arabidopsis thaliana defective in the acquisition of tolerance to high temperature stress.

Hong S W SW Vierling E E

Proceedings of the National Academy of Sciences of the United States of America 20000401 8

The ability of organisms to acquire thermotolerance to normally lethal high temperatures is an ancient and conserved adaptive response. However, knowledge of cellular factors essential to this response is limited. Acquisition of thermotolerance is likely to be of particular importance to plants that experience daily temperature fluctuations and are unable to escape to more favorable environments. We developed a screen, based on hypocotyl elongation, for mutants of Arabidopsis thaliana that are u ...[more]

PMID: 10760305

Similar Datasets

Project description:Ascophyllum nodosum extract (ANE) contains bioactive compounds that improve the growth of Arabidopsis in experimentally-induced saline conditions; however, the molecular mechanisms through which ANE elicits tolerance to salinity remain largely unexplored. Micro RNAs (miRNAs) are key regulators of gene expression, playing crucial roles in plant growth, development, and stress tolerance. Next generation sequencing of miRNAs from leaves of control Arabidopsis and from plants subjected to three treatments (ANE, NaCl and ANE+NaCl) was used to identify ANE-responsive miRNA in the absence and presence of saline conditions. Differential gene expression analysis revealed that ANE had a strong effect on miRNAs expression in both conditions. In the presence of salinity, ANE tended to reduce the up-regulation or the down-regulation trend induced caused by NaCl in miRNAs such as ath-miR396a-5p, ath-miR399, ath-miR2111b and ath-miR827. To further uncover the effects of ANE, the expression of several target genes of a number of ANE-responsive miRNAs was analyzed by qPCR. NaCl, but not ANE, down-regulated miR396a-5p, which negatively regulated the expression of AtGRF7 leading to a higher expression of AtDREB2a and AtRD29 in the presence of ANE+NaCl, as compared to ANE alone. ANE+NaCl initially reduced and then enhanced the expression of ath-miR169g-5p, while the expression of the target genes AtNFYA1 and ATNFYA2, known to be involved in the salinity tolerance mechanism, was increased as compared to ANE or to NaCl treatments. ANE and ANE+NaCl modified the expression of ath-miR399, ath-miR827, ath-miR2111b, and their target genes AtUBC24, AtWAK2, AtSYG1 and At3g27150, suggesting a role of ANE in phosphate homeostasis. In vivo and in vitro experiments confirmed the improved growth of Arabidopsis in presence of ANE, in saline conditions and in phosphate-deprived medium, further substantiating the influence of ANE on a variety of essential physiological processes in Arabidopsis including salinity tolerance and phosphate uptake.

Dataset Information

Mutants of Arabidopsis thaliana defective in the acquisition of tolerance to high temperature stress.

Publications

Mutants of Arabidopsis thaliana defective in the acquisition of tolerance to high temperature stress.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets