Maize DBF1-interactor protein 1 containing an R3H domain is a potential regulator of DBF1 activity in stress responses.

The maize dehydration-responsive element (DRE)-binding factor, DBF1, is a member of the Apetala 2/Ethylene Response Factor transcription factors family and is involved in the regulation of the ABA-responsive gene rab17 through the DRE in an ABA-dependent pathway. In this study we analysed the functionality of DBF1 in abiotic stress responses and found that Arabidopsis plants over-expressing DBF1 were more tolerant to osmotic stress than control plants. In yeast two-hybrid analyses, DBF1 interacted with DBF1-interactor protein 1 (DIP1), a protein containing a conserved R3H single-strand DNA-binding domain.

Isolation and functional characterisation of two new bZIP maize regulators of the ABA responsive gene rab28.

The plant hormone abscisic acid regulates gene expression in response to growth stimuli and abiotic stress. Previous studies have implicated members of the bZIP family of transcription factors as mediators of abscisic acid dependent gene expression through the ABRE cis-element. Here, we identify two new maize bZIP transcription factors, EmBP-2 and ZmBZ-1 related to EmBP-1 and OsBZ-8 families.

Characterization of a strawberry cDNA clone homologous to calcium-dependent protein kinases that is expressed during fruit ripening and affected by low temperature.

A full-length cDNA clone (FaCDPK1) encoding a calcium-dependent protein kinase (CDPK) has been isolated from a strawberry fruit cDNA library. FaCDPK1 contains the basic features of CDPKs: a catalytic kinase domain linked to a regulatory calmodulin-like domain by a junction sequence that has been shown to act as an autoinhibitory pseudosubstrate. Although the calmodulin-like domain of CDPKs typically contains four EF-hand calcium-binding motifs, FaCDPK1 was predicted to contain only three EF-hand motifs.

Characterization of two divergent endo-beta-1,4-glucanase cDNA clones highly expressed in the nonclimacteric strawberry fruit.

Two cDNAs clones (Cel1 and Cel2) encoding divergent endo-beta-1, 4-glucanases (EGases) have been isolated from a cDNA library obtained from ripe strawberry (Fragaria x ananassa Duch) fruit. The analysis of the amino acid sequence suggests that Cel1 and Cel2 EGases have different secondary and tertiary structures and that they differ in the presence of potential N-glycosylation sites. By in vitro translation we show that Cel1 and Cel2 bear a functional signal peptide, the cleavage of which yields mature proteins of 52 and 60 kD, respectively.

A cDNA clone highly expressed in ripe banana fruit shows homology to pectate lyases.

A cDNA clone (Ban17), encoding a protein homologous to pectate lyase, has been isolated from a cDNA library from climacteric banana fruit by means of differential screening. Northern analysis showed that Ban17 mRNA is first detected in early climacteric fruit, reaches a steady-state maximum at the climacteric peak, and declines thereafter in overripe fruit. Accumulation of the Ban17 transcript can be induced in green banana fruit by exogenous application of ethylene.