Work

The expression of a tubby-like protein from Malus domestica (MdTLP7) enhances abiotic stress tolerance in Arabidopsis

Year: 2019

Type: article

Abstract: Tubby-like proteins (TLPs), characterized by a signature tubby domain, are widespread in plants and animals. To date, only plant TLPs involved in multifarious stress responses and male gametophyte development have been identified. However, studies on the molecular functions of plant TLPs are largely unknown. In this investigation, the roles of a TLP from Malus domestica ( Md TLP7) in response to abiotic stresses were characterized by expressing it in Arabidopsis. The expression of wild-type full-length Md TLP7 (FL) significantly increased the stress tolerance of Arabidopsis seedlings to osmotic, salt, cold and heat stress, while the expression of truncated Md TLP7 containing only the tubby domain (Tub) also showed some function. Located on a central α helix surrounded by 12 anti-parallel β strands in the tubby domain, the K 190 /R 192 site may be involved in fixation to the plasma membrane, as shown by 3D homology modelling with animal TLPs. This site might play a crucial role in anti-stress functions since site-directed mutagenesis of Md TLP7 reduced stress tolerance. Subcellular localization showed that Md TLP7 was mainly localized in the plasma membrane in plant cells, suggesting that it might participate in the transduction of stress signals. The results of this study showed that Md TLP7 could improve abiotic stress tolerance not only in bacteria but also in plants. The K 190 /R 192 residues in the tubby domain were not only the plasma membrane binding site of Md TLP7 but also played a key role in stress tolerance. These results may provide a basis for further exploring the mechanism of anti-stress functioning and downstream target genes of plant TLPs.

Source: BMC Plant Biology

DOI: 10.1186/s12870-019-1662-9