SQUAMOSA Promoter Binding Protein-Like7 Is a Central Regulator for Copper Homeostasis in Arabidopsis.

Expression of miR398 is induced in response to copper deficiency and is involved in the degradation of mRNAs encoding copper/zinc superoxide dismutase in Arabidopsis thaliana. We found that SPL7 (for SQUAMOSA promoter binding protein-like7) is essential for this response of miR398. SPL7 is homologous to Copper response regulator1, the transcription factor that is required for switching between plastocyanin and cytochrome c(6) in response to copper deficiency in Chlamydomonas reinhardtii.

A putative peroxisomal polyamine oxidase, AtPAO4, is involved in polyamine catabolism in Arabidopsis thaliana.

We characterized three Arabidopsis polyamine oxidase genes, AtPAO2, AtPAO3 and AtPAO4. Transient expression of these genes as monomeric red fluorescent protein fusion proteins in Arabidopsis root cells revealed that all are peroxisomal proteins. Quantitative analysis of their transcripts in various organs suggested that AtPAO4 is the major isoform in root peroxisomes.

AtMap1: a DNA microarray for genomic deletion mapping in Arabidopsis thaliana.

We have designed a novel tiling array, AtMap1, for genomic deletion mapping. AtMap1 is a 60-mer oligonucleotide microarray consisting of 42 497 data probes designed from the genomic sequence of Arabidopsis thaliana Col-0. The average probe interval is 2.

Cytosolic HSP90 regulates the heat shock response that is responsible for heat acclimation in Arabidopsis thaliana.

Plant survival requires the ability to acclimate to heat. When plants are subjected to heat shock, the expression of various genes is induced, and the plants become tolerant of higher temperatures. We found that transient treatment with geldanamycin and radicicol, two heat shock protein 90 (HSP90) inhibitors, induced heat-inducible genes and heat acclimation in Arabidopsis thaliana seedlings.