Deschampsia antarctica is a Poaceae grass that has adapted to and colonized Antarctica. When D. antarctica plants were subjected to cold and dehydration stress both in the Antarctic field and in laboratory experiments, galactinol, a precursor of raffinose family oligosaccharides (RFOs) and raffinose were highly accumulated, which was accompanied by upregulation of galactinol synthase (GolS). The Poaceae monocots have a small family of GolS genes, which are divided into two distinct groups called types I and II. Type II GolSs are highly expanded in cold-adapted monocot plants. Transgenic rice plants, in which type II D. antarctica GolS2 (DaGolS2) and rice GolS2 (OsGolS2) were constitutively expressed, were markedly tolerant to cold and drought stress as compared to the wild-type rice plants. The RFO contents and GolS enzyme activities were higher in the DaGolS2- and OsGolS2-overexpressing progeny than in the wild-type plants under both normal and stress conditions. DaGolS2 and OsGolS2 overexpressors contained reduced levels of reactive oxygen species (ROS) relative to the wild-type plants after cold and drought treatments. Overall, these results suggest that Poaceae type II GolS2s play a conserved role in D. antarctica and rice in response to drought and cold stress by inducing the accumulation of RFO and decreasing ROS levels.
Bibliographical noteFunding Information:
This work was supported by The Polar Genomics 101 Project: Genome analysis of polar organisms and establishment of application platform [PE19080] to H.P., funded by the Korea Polar Research Institute, the Next-Generation BioGreen 21 Program
for Agriculture and Technology Development [project numbers PJ01113801 (NCGC) and PJ01334901 (SSAC)], funded by the Rural Development Administration and the Basic Science Research Program through the National Research Foundation (NRF) [grant number 2018R1A6A1A03025607], funded by the Ministry of Education, Republic of Korea, to W.T.K.
All Science Journal Classification (ASJC) codes
- Plant Science
- Cell Biology