title: Transgenic poplar expressing Arabidopsis YUCCA6 exhibits auxin-overproduction phenotypes and increased tolerance to abiotic stress.
abstract: YUCCA6, a member of the YUCCA family of flavin monooxygenase-like proteins, is involved in the tryptophan-dependent IAA biosynthesis pathway and responses to environmental cues in Arabidopsis. However, little is known about the role of the YUCCA pathway in auxin biosynthesis in poplar. Here, we generated transgenic poplar (Populus alba × P. glandulosa) expressing the Arabidopsis YUCCA6 gene under the control of the oxidative stress-inducible SWPA2 promoter (referred to as SY plants). Three SY lines (SY7, SY12 and SY20) were selected based on the levels of AtYUCCA6 transcript. SY plants displayed auxin-overproduction morphological phenotypes, such as rapid shoot growth and retarded main root development with increased root hair formation. In addition, SY plants had higher levels of free IAA and early auxin-response gene transcripts. SY plants exhibited tolerance to drought stress, which was associated with reduced levels of reactive oxygen species. Furthermore, SY plants showed delayed hormone- and dark-induced senescence in detached leaves due to higher photosystem II efficiency and less membrane permeability. These results suggest that the conserved IAA biosynthesis pathway mediated by YUCCA family members exists in poplar.
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, South Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon 305-350, South Korea.
authors.forename: Qingbo
authors.initials: Q
authors.lastname: Ke
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, South Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon 305-350, South Korea.
authors.forename: Chang Yoon
authors.initials: CY
authors.lastname: Ji
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, South Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon 305-350, South Korea.
authors.forename: Jae Cheol
authors.initials: JC
authors.lastname: Jeong
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, South Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon 305-350, South Korea.
authors.forename: Haeng-Soon
authors.initials: HS
authors.lastname: Lee
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Hongbing
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Bingcheng
authors.initials: B
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Xiping
authors.initials: X
authors.lastname: Deng
authors.affiliation: Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, South Korea; Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon 305-350, South Korea. Electronic address: sskwak@kribb.re.kr.
authors.forename: Sang-Soo
authors.initials: SS
authors.lastname: Kwak
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000096:biosynthesis* / Q000235:genetics; D007210:Indoleacetic Acids / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000096:biosynthesis* / Q000235:genetics; D030821:Plants, Genetically Modified; D032107:Populus / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D006899:Mixed Function Oxygenases; C562183:YUCCA6 protein, Arabidopsis
keywords: Abiotic stress; AtYUCCA6; Auxin; ROS; Transgenic poplar