HsfA1d, a Protein Identified via FOX Hunting Using Thellungiella salsuginea cDNAs Improves Heat Tolerance by Regulating Heat-Stress-Responsive Gene Expression

作者：Higashi Yukari; Ohama Naohiko; Ishikawa Tomoko; Katori Taku; Shimura Ayaka; Kusakabe Kazuya; Yamaguchi Shinozaki Kazuko; Ishida Junko; Tanaka Maho; Seki Motoaki; Shinozaki Kazuo; Sakata Yoichi; Hayashi Takahisa; Taji Teruaki^*

来源：Molecular Plant, 2013, 6(2): 411-422.

DOI：10.1093/mp/sst024

• Thellungiella salsuginea
• heat-stress tolerance
• HsfA1
• FOX hunting

Thellungiella salsuginea, a species closely related to Arabidopsis, is tolerant not only to high salt levels, but also to high temperature. We identified T. salsuginea HsfA1d (TsHsfA1d) as a gene that can confer marked heat tolerance on Arabidopsis via FOX hunting.Thellungiella salsuginea (formerly T. halophila), a species closely related to Arabidopsis (Arabidopsis thaliana), is tolerant not only to high salt levels, but also to chilling, freezing, and ozone. Here, we report that T. salsuginea also shows greater heat tolerance than Arabidopsis. We identified T. salsuginea HsfA1d (TsHsfA1d) as a gene that can confer marked heat tolerance on Arabidopsis. TsHsfA1d was identified via Full-length cDNA Over-eXpressing gene (FOX) hunting from among a collection of heat-stress-related T. salsuginea cDNAs. Transgenic Arabidopsis overexpressing TsHsfA1d showed constitutive up-regulation of many genes in the Arabidopsis AtHsfA1 regulon under normal growth temperature. In Arabidopsis mesophyll protoplasts, TsHsfA1d was localized in both the nucleus and the cytoplasm. TsHsfA1d also interacted with AtHSP90, which negatively regulates AtHsfA1s by forming HsfA1HSP90 complexes in the cytoplasm. It is likely that the partial nuclear localization of TsHsfA1d induced the expression of the AtHsfA1d regulon in the transgenic plants at normal temperature. We also discovered that transgenic Arabidopsis plants overexpressing AtHsfA1d were more heat-tolerant than wild-type plants and up-regulated the expression of the HsfA1d regulon, as was observed in TsHsfA1d-overexpressing plants. We propose that the products of both TsHsfA1d and AtHsfA1d function as positive regulators of Arabidopsis heat-stress response and would be useful for the improvement of heat-stress tolerance in other plants.

• 出版日期2013-3