Characterization of stress-related genes can help understand the mechanisms
of plant responses to outside conditions. This study by the team of Yunfei
Yang from University of Adelaide in Australia defined the role of wheat
TaHDZipI-5 gene.

The TaHDZipI-5 gene encodes a stress-responsive transcription factor during
the development of plant tolerance to frost and drought. The researchers
found that the gene was strongly induced by low temperatures. There was also
elevated TaHDZipI-5 expression in flowers and early developing grains under
normal conditions, suggesting that TaHDZipI-5 is involved in regulation of
frost tolerance at flowering.

The overexpression of TaHDZipI-5 in bread wheat significantly enhanced frost
and drought tolerance of transgenic wheat lines. However, undesired
phenotypic features were also present in the transgenics, including reduced
plant size and biomass, delayed flowering, and a decrease in yield.

This gene could be a candidate gene for the development of drought and/or
frost tolerant wheat. However, further studies are still needed to minimize,
if not eliminate, the undesired phenotype caused by its overexpression.

[onlinelibrary.wiley.com]