Ectopic expression of a wheat MYB transcription factor gene, TaMYB73, improves salinity stress tolerance in Arabidopsis thaliana

Abstract

MYB transcription factors (TFs) play pivotal roles in the abiotic stress response in plants, but their characteristics and functions in wheat (Triticum aestivum L.) have not been fully investigated. A novel wheat MYB TF gene, TaMYB73, is reported here based on the observation that its targeting probe showed the highest salinity-inducibility level among all probes annotated as MYB TFs in the cDNA microarray. TaMYB73 is a R2R3 type MYB protein with transactivation activity, and binds with types I, II, and IIG MYB binding motifs. The gene was induced by NaCl, dehydration, and several phytohormones, as well as some stress-, ABA-, and GA-responsive cis-elements present in its promoter region. Its over-expression in Arabidopsis enhanced the tolerance to NaCl as well as to LiCl and KCl, whereas it had no contribution to mannitol tolerance. The over-expression lines had superior germination ability under NaCl and ABA treatments. The expression of many stress signalling genes such as AtCBF3 and AtABF3, as well as downstream responsive genes such as AtRD29A and AtRD29B, was improved in these over-expression lines, and TaMYB73 can bind with promoter sequences of AtCBF3 and AtABF3. Taken together, it is suggested that TaMYB73, a novel MYB transcription factor gene, participates in salinity tolerance based on improved ionic resistance partly via the regulation of stress-responsive genes.

Overexpression of a novel SbMYB15 from Salicornia brachiata confers salinity and dehydration tolerance by reduced oxidative damage and improved photosynthesis in transgenic tobacco

“…A yeast-one-hybrid assay was performed to study the transcriptional activation as described by He et al (2012). Full-length SbMYB15 cDNA was cloned in pGBKT7 followed by transformation in AH109 cells.…”

LcSAIN1, a Novel Salt-Induced Gene from SheepGrass, Confers Salt Stress Tolerance in Transgenic Arabidopsis and Rice

“…Plant stress tolerance is controlled by at least six signal transduction pathways (three ABA dependent and three ABA independent) in response to drought, high salinity and cold stress (Shinozaki and Yamaguchi-Shinozaki 2007). Both ABA-dependent and ABAindependent regulatory systems induce the expression of early response transcriptional activators, which then activate downstream stress tolerance genes (Zhu 2002, He et al 2012, Puranik et al 2012. Previous studies have characterized members of the APETELA2 (AP2), bZIP, NAC and MYB families of transcription factors in Arabidopsis and rice for their regulatory roles in response to abiotic stresses in plants (Abe et al 2003, Sakuma et al 2006, Hu et al 2008, Yang et al 2012, and additional studies demonstrated that transgenic plants that overexpress genes encoding transcription factors can greatly enhance the tolerance of plants to various abiotic stresses, such as salinity, cold and drought (Dubouzet et al 2003, Nakashima et al 2007, Xiang et al 2008, Hao et al 2011, He et al 2012).…”

“…Both ABA-dependent and ABAindependent regulatory systems induce the expression of early response transcriptional activators, which then activate downstream stress tolerance genes (Zhu 2002, He et al 2012, Puranik et al 2012. Previous studies have characterized members of the APETELA2 (AP2), bZIP, NAC and MYB families of transcription factors in Arabidopsis and rice for their regulatory roles in response to abiotic stresses in plants (Abe et al 2003, Sakuma et al 2006, Hu et al 2008, Yang et al 2012, and additional studies demonstrated that transgenic plants that overexpress genes encoding transcription factors can greatly enhance the tolerance of plants to various abiotic stresses, such as salinity, cold and drought (Dubouzet et al 2003, Nakashima et al 2007, Xiang et al 2008, Hao et al 2011, He et al 2012). In addition, many genes are activated by transcription factors, such as late embryogenesis abundant (LEA) class genes (RD29B and RAB18) and proline biosynthetic genes (P5CS), and the activation of these genes can protect plants from oxidative damage due to osmotic stress, ionic toxicity and oxidative stress (Strizhov et al 1997, Bartels and Sunkar 2005, Szabados and Savouré 2010.…”

Molecular cloning and expression profile of an abiotic stress and hormone responsive MYB transcription factor gene from <italic>Panax ginseng</italic>

“…In Arabidopsis, AtMYB15 was demonstrated to be associated with cold stress tolerance [18]. TaMYB33 and TaMYB73 from Triticum aestivum exhibited enhanced salinity tolerance [19,20]. AtMYB13, AtMYB15, AtMYB33, and AtMYB101 of Arabidopsis were implicated in phytohormone ABA-mediated responses to environmental signals [21].…”