Poaceae Type II Galactinol Synthase 2 from Antarctic Flowering Plant Deschampsia antarctica and Rice Improves Cold and Drought Tolerance by Accumulation of Raffinose Family Oligosaccharides in Transgenic Rice Plants

• Published in: Plant and Cell Physiology
• Main Authors: Cui, Li Hua, Byun, Mi Young, Oh, Hyeong Geun, Kim, Sung Jin, Lee, Jungeun, Park, Hyun, Lee, Hyoungseok, Kim, Woo Taek
• Other Authors: The Polar Genomics 101 Project: Genome analysis, Korea Polar Research Institute, Next-Generation BioGreen 21 Program for Agriculture and Technology Development, Rural Development Administration and the Basic Science Research Program, National Research Foundation, NRF, Ministry of Education, Republic of Korea
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP) 2019
• Subjects: Antarctic; The Antarctic; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1093/pcp/pcz180; http://academic.oup.com/pcp/advance-article-pdf/doi/10.1093/pcp/pcz180/30123552/pcz180.pdf; http://academic.oup.com/pcp/article-pdf/61/1/88/32500138/pcz180.pdf

Abstract 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.