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Two dehydration‐inducible transcripts from the resurrection plant Craterostigma plantagineum encode interacting homeodomain‐leucine zipper proteins
Author(s) -
Frank Wolfgang,
Phillips Jonathan,
Salamini Francesco,
Bartels Dorothea
Publication year - 1998
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1998.00222.x
Subject(s) - leucine zipper , gene , biology , homeobox , gene expression , basic helix loop helix leucine zipper transcription factors , transcription factor , microbiology and biotechnology , genetics , dna binding protein
Summary The molecular dissection of desiccation tolerance in the resurrection plantCraterostigma plantagineumled to the isolation of two dehydration‐stress inducible homeodomain‐leucine zipper genes (CPHB‐1and‐2). When the coding region ofCPHB‐1was used as bait in the yeast two‐hybrid system, the ability of CPHB‐1 to form homodimers was demonstrated. The two‐hybrid system was also used to isolate CPHB‐2, which heterodimerises with CPHB‐1. Both transcripts are inducible by dehydration in leaves and roots, but steady state levels vary in response to exogenously applied ABA. Although expression ofCPHB‐1is not inducible by ABA, the transcript level ofCPHB‐2increases during ABA‐treatment. Both genes are expressed at very early stages of dehydration and thus may be involved in the regulation of gene expression during dehydration.CPHB‐1and ‐2differential expression in response to ABA suggests that they act in different branches of the dehydration‐induced signalling network.In vitrobinding studies revealed that CPHB‐1 specifically binds to the pseudopalindromic sequence CAAT(C/G)ATTG. Using this element forin vitrobinding studies with nuclear proteins from dehydrated leaves, an inducible DNA‐protein complex was identified.