title: Transcriptomic Profiling of Soybean in Response to High-Intensity UV-B Irradiation Reveals Stress Defense Signaling.
abstract: The depletion of the ozone layer in the stratosphere has led to a dramatic spike in ultraviolet B (UV-B) intensity and increased UV-B light levels. The direct absorption of high-intensity UV-B induces complex abiotic stresses in plants, including excessive light exposure, heat, and dehydration. However, UV-B stress signaling mechanisms in plants including soybean (Glycine max[L.]) remain poorly understood. Here, we surveyed the overall transcriptional responses of two soybean genotypes, UV-B-sensitive Cheongja 3 and UV-B-resistant Buseok, to continuous UV-B irradiation for 0 (control), 0.5, and 6 h using RNA-seq analysis. Homology analysis using UV-B-related genes fromArabidopsis thalianarevealed differentially expressed genes (DEGs) likely involved in UV-B stress responses. Functional classification of the DEGs showed that the categories of immune response, stress defense signaling, and reactive oxygen species (ROS) metabolism were over-represented. UV-B-resistant Buseok utilized phosphatidic acid-dependent signaling pathways (based on subsequent reactions of phospholipase C and diacylglycerol kinase) rather than phospholipase D in response to UV-B exposure at high fluence rates, and genes involved in its downstream pathways, such as ABA signaling, mitogen-activated protein kinase cascades, and ROS overproduction, were upregulated in this genotype. In addition, the DEGs for TIR-NBS-LRR and heat shock proteins are positively activated. These results suggest that defense mechanisms against UV-B stress at high fluence rates are separate from the photomorphogenic responses utilized by plants to adapt to low-level UV light. Our study provides valuable information for deep understanding of UV-B stress defense mechanisms and for the development of resistant soybean genotypes that survive under high-intensity UV-B stress.
authors.affiliation: Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National University Seoul, South Korea.
authors.forename: Min Young
authors.initials: MY
authors.lastname: Yoon
authors.affiliation: Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National UniversitySeoul, South Korea; Plant Genomics and Breeding Institute, Seoul National UniversitySeoul, South Korea.
authors.forename: Moon Young
authors.initials: MY
authors.lastname: Kim
authors.affiliation: Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National University Seoul, South Korea.
authors.forename: Sangrae
authors.initials: S
authors.lastname: Shim
authors.affiliation: Center for Applied Genetic Technologies, University of Georgia Athens, GA, USA.
authors.forename: Kyung Do
authors.initials: KD
authors.lastname: Kim
authors.affiliation: Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National UniversitySeoul, South Korea; Plant Genomics and Breeding Institute, Seoul National UniversitySeoul, South Korea.
authors.forename: Jungmin
authors.initials: J
authors.lastname: Ha
authors.affiliation: Center for Applied Genetic Technologies, University of Georgia Athens, GA, USA.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Shin
authors.affiliation: Department of Crop Science and Biotechnology, Dankook University Cheonan, South Korea.
authors.forename: Sungtaeg
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National UniversitySeoul, South Korea; Plant Genomics and Breeding Institute, Seoul National UniversitySeoul, South Korea.
authors.forename: Suk-Ha
authors.initials: SH
authors.lastname: Lee
keywords: TIR-NBS-LRR; UV-B stress resistance; diacylglycerol kinase; phosphatidic acid; soybean; transcriptomic profiling