Carlos Alberto Dezar

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The HD-Zip family of transcription factors is unique to the plant kingdom. These proteins exhibit the singular combination of a homeodomain with a leucine zipper acting as a dimerization motif. They can be classified into four subfamilies, according to a set of distinctive features that include DNA-binding specificities, gene structures, additional common(More)
Homeodomain-leucine zipper proteins constitute a family of transcription factors found only in plants. Hahb-4 is a member of Helianthus annuus (sunflower) subfamily I. It is regulated at the transcriptional level by water availability and abscisic acid. In order to establish if this gene plays a functional role in drought responses, transgenic Arabidopsis(More)
Hahb-4 is a member of the Helianthusannuus (sunflower) subfamily I of HD-Zip proteins that is transcriptionally regulated by water availability and abscisic acid. Transgenic Arabidopsis thaliana plants overexpressing this transcription factor (TF) exhibit a characteristic phenotype that includes a strong tolerance to water stress. Here we show that this TF(More)
The Helianthus annuus (sunflower) HAHB4 transcription factor belongs to the HD-Zip family and its transcript levels are strongly induced when sunflower plants are attacked by herbivores, mechanically damaged or treated with methyl-jasmonic acid (MeJA) or ethylene (ET). Promoter fusion analysis, in Arabidopsis and in sunflower, demonstrated that induction of(More)
Homeodomain-leucine zipper type I (HD-Zip I) proteins are plant-specific transcription factors associated with the regulation of growth and development in response to changes in the environment. Nicotiana attenuata NaHD20 was identified as an HD-Zip I-coding gene whose expression was induced by multiple stress-associated stimuli including drought and(More)
HAHB4 belongs to the sunflower subfamily I of HD-Zip proteins and is involved in drought-tolerance response and ethylene-mediated senescence. Cross-talk between these two processes through this transcription factor was recently described. In this study it is shown that the expression of HAHB4 is induced in darkness and quickly disappears when plants are(More)
Homeodomain-leucine zipper proteins constitute a family of transcription factors found only in plants. Expression patterns of the sunflower homeobox-leucine zipper gene Hahb-10 (Helianthus annuus homeobox-10), that belongs to the HD-Zip II subfamily, were analysed. Northern blots showed that Hahb-10 is expressed primarily in mature leaves, although(More)
Hahb-4 is a member of Helianthus annuus (sunflower) subfamily I of HD-Zip proteins. Transgenic Arabidopsis thaliana plants constitutively expressing this gene exhibit a strong tolerance of water stress in concert with morphological defects and a delay in development. In order to obtain a drought-tolerant phenotype without morphological associated phenotype,(More)
Three cDNA clones, HaPI, HaAG and HaAP3, were isolated from sunflower inflorescences at the R2 stage of development. The cDNAs share high sequence similarity with the PISTILLATA, AGAMOUS, and APETALA3 genes from Arabidopsis, respectively, which contain a MADS-box and are involved in floral organ development. Expression of the corresponding genes was(More)
The transcription factor HAHB10 belongs to the sunflower (Helianthus annuus) HD-Zip II subfamily and it has been previously associated with the induction of flowering. In this study it is shown that HAHB10 is expressed in sunflower leaves throughout the vegetative stage and in stamens during the reproductive stage. In short-day inductive conditions the(More)