A Myb transcription factor (<i>TaMyb1</i>) from wheat roots is expressed during hypoxia: roles in response to the oxygen concentration in root environment and abiotic stresses

Abstract

Oxygen deficiency is one of the major stresses to plants under waterlogging. A low‐oxygen‐signaling pathway is the most important mechanism for adaptation and survival under anaerobic conditions. To find genes related to the oxygen concentration in root environment in common wheat roots, we investigated the transcriptional expression in vitro for low‐oxygen treatment. Dramatic increases in the transcripts of a TaMyb1 ( Triticum aestivum Myb transcription factor 1) gene occurred under hypoxia. Presence of TaMyb1 on the 3BL was confirmed by using Chinese Spring aneuploid accessions including nullisomic–tetrasomic and ditelosomic lines. The transcriptional expression of TaMyb1 was continued until approximate anoxia, being enhanced by light under hypoxia, but little expression during anoxia could be shown by Northern hybridization. The TaMyb1 expression was high in the epidermis, endodermis and the cortex adjacent to the endodermis under hypoxia but undetectable in the vascular tissues or cortex, which contained aerenchyma. TaMyb1 transcription levels in roots gradually increased as the result of treatment with NaCl. Slight increases in expression were noted during the early stages of exogenous treatment of with both abscisic acid and polyethylene glycol. Little and constant expressions were detected as the result of citric acid treatment. Our data suggested that the expression of TaMyb1 in roots could be strongly related to the oxygen concentration in root environment and the wheat plant responses to abiotic stresses.