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F Van Breusegem

Publications and source records attributed to F Van Breusegem.

4 recordsLinked to original sources
PubMed1998

Processing of a chimeric protein in chloroplasts is different in transgenic maize and tobacco plants.

Transgenic maize (Zea mays L.) and tobacco (Nicotiana tabacum Petit Havana SR1) plants have been generated, which overproduce a mitochondrial Nicotiana plumbaginifolia manganese superoxide dismutase (MnSOD) in chloroplasts. For this, the mature MnSOD-coding sequence was fused to a chloroplast transit peptide from a Pisum sativum ribulose-1,5-bisphosphate carboxylase (Rubisco) gene and expression of the chimeric gene was driven by the cauliflower mosaic virus (CaMV) 35S promoter. The transgenic MnSOD gene product was correctly targeted to the chloroplasts both in maize and tobacco. However, despite the use of the CaMV 35S promoter, the MnSOD was predominantly localized in the chloroplasts of the bundle sheath cells of maize. Furthermore, the transit peptide was cleaved off at a different position in maize and tobacco.

Amino Acid Sequence↗
PubMed1994

Heat-inducible rice hsp82 and hsp70 are not always co-regulated.

We have characterized several heat-shock-induced genes in rice (Oryza sativa L.) and compared their expression under a variety of conditions. Three of these genes, which are analogs of the hsp82/90 family, lie within a cloned 18-kilobase (kb) region of the genome. The middle member of this cluster, designated hsp82B, has been fully sequenced. The gene uses a promoter containing six putative heat-shock elements as well as several unusual sequence motifs including a stretch of 11 thymidines alternating with 11 adenosines. The mRNA for this gene reaches its highest relative level of expression within 120 min after plants are shifted to 42 degrees C; no other conditions induce this gene. By contrast, we found that during heat stress the expression of hsp70 correlates well with increases in internal ion concentrations, and can also be induced by excess salt or ethanol at normal growth temperatures. These results appear to indicate that whereas hsp70 is induced by all stresses that lead to protein denaturation-including heat stress-HSP82 mRNA accumulates only upon heat stress.

Amino Acid Sequence↗