(100-23) Phase Transition and Expression Pattern of Representative Temperature Response Genes in Spring Wheat Under Higher Temperatures in Korea

Body of Abstract: Winter wheat is used for regular cultivation in Korea; however, it becomes harder to plant within the proper time frame in a double cropping system due to summer crops' prolonged ripening period and harvest time. The yield would decrease significantly once the grower lost the chance to plant winter wheat until early November. A choice may be the sowing of spring wheat in early March; however, in that case, the spring wheat encounter the rainy season starts end of June, usually in Korea. That is the reason for yield and quality decrease. There needs to be more time for full ripening. We have investigated the effects of ambient temperature on wheat growth in Korea. The wheat varieties of Joeun and Suan were used in the experiment, and all were alternative types. We have set the daily average temperature of 17℃, 20℃, 23℃, and 26℃ from the tillering stage to the ripening stage. At 26°C treatment, Suan showed etiolation and wilting of the leaves and entered the heading stage; however, Joeun could not enter the heading stage and finally died. The productive tiller number, dry weight, and the size and weight of grains were decreased sharply at 26°C treatment. We carried out quantitative RT-PCR using leaf samples of Suan to understand the response of representative heat-related genes under different temperature conditions. We have analyzed the expression pattern of the genes of the cell cycle, hormone biosynthesis, and signaling. Many heat stress-related genes like HSP90.1-A1, HSP101, HsfA2b, CaM2-3, and DREB2 are up-regulated at higher temperatures; however, ELF3, PHYB, PIF4, VRNA1, VRN2, and PIN are down-regulated.



This work was supported by the Agenda project (PJ015289022023) of the Rural Development Administration, Republic of Korea.