The Arabidopsis Athb-2 and -4 genes are strongly induced by far-red-rich light

Authors

  • Monica Carabelli,

    1. Centro di studio per gli Acidi Nucleici, c/o Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, P.le Aldo Moro 5, 00185 Rome, Italy
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  • Giovanna Sessa,

    1. Centro di studio per gli Acidi Nucleici, c/o Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, P.le Aldo Moro 5, 00185 Rome, Italy
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  • Simona Baima,

    1. Unità di Nutrizione Sperimentale, Istituto Nazionale della Nutrizione, Via Ardeatina 546, 00178 Rome, Italy
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  • Giorgio Morelli,

    1. Unità di Nutrizione Sperimentale, Istituto Nazionale della Nutrizione, Via Ardeatina 546, 00178 Rome, Italy
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  • Ida Ruberti

    Corresponding author
    1. Centro di studio per gli Acidi Nucleici, c/o Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, P.le Aldo Moro 5, 00185 Rome, Italy
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Abstract

The isolation and characterization of the Athb-2 gene, which codes for a HD-Zip protein in Arabidopsis thaliana is reported. Interestingly, Southern analysis has established that the Arabidopsis genome contains sequences which are highly related to the Athb-2 HD-Zip coding region. One of these genes, designated Athb-4, has been cloned and partially sequenced. Amino acid sequence comparison revealed that Athb-2 and −4 are members of a small family of HD-Zip related proteins. Athb-2 mRNA analysis showed that this gene is expressed during the vegetative and reproductive phases of plant growth. A significant increment in the amount of Athb-2 transcripts was observed in flowering plants. A higher steady-state level of the Athb-2 mRNA was also found in dark-adapted plants. Remarkably, far-red-rich light treatment of Arabidopsis plants results in a rapid and strong induction of the Athb-2 expression. This light treatment also induces the accumulation of Athb-4 transcripts, suggesting a similar role for the two members of this HD-Zip family.

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