The rice Mybleu transcription factor increases tolerance to oxygen deprivation in Arabidopsis plants.
Mybleu is a natural incomplete transcription factor of rice (Oryza sativa), consisting of a partial Myb repeat followed by a short leucine zipper. We previously showed its localization to the apical region of rice roots and coleoptiles. Specifically, in coleoptiles, Mybleu is expressed under both aerobic and anaerobic conditions, whereas in roots, it is expressed only under aerobic conditions. Mybleu is able to dimerize with canonical leucine zippers and to activate transcription selectively. To investigate Mybleu function in vivo, we transformed Arabidopsis thaliana and evaluated several morphological, physiological and biochemical parameters. In agreement with a hypothesized role of Mybleu in cell elongation in the differentiation zone, we found that the constitutive expression of this transcription factor in Arabidopsis induced elongation in the primary roots and in the internodal region of the floral stem; we also observed a modification of the root apex morphology in transformed lines. Based on the high expression of Mybleu in anaerobic rice coleoptiles, we studied the role of this transcription factor in transgenic plants grown under low-oxygen conditions. We found that overexpression of this transcription factor increased tolerance to oxygen deficit. In transgenic plants, this effect may depend both on the maintenance of a higher metabolism during stress and on the higher expression levels of certain genes involved in the anaerobic response.
Mattana
Monica
M
Istituto di Biologia e Biotecnologia Agraria, CNR, via E Bassini 15, 20133 Milano, Italy.
Vannini
Candida
C
Espen
Luca
L
Bracale
Marcella
M
Genga
Annamaria
A
Marsoni
Milena
M
Iriti
Marcello
M
Bonazza
Veronica
V
Romagnoli
Francesco
F
Baldoni
Elena
E
Coraggio
Immacolata
I
Locatelli
Franca
F
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000444:Aldehyde Dehydrogenase / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D035264:Flowers / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics / Q000502:physiology; D018525:Germination / Q000235:genetics / Q000502:physiology; D012275:Oryza / Q000235:genetics*; D010100:Oxygen / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000502:physiology; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology
D010940:Plant Proteins; D014157:Transcription Factors; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000444:Aldehyde Dehydrogenase; D010100:Oxygen