title: PdEPF1 regulates water-use efficiency and drought tolerance by modulating stomatal density in poplar.
abstract: Water deficiency is a critical environmental condition that is seriously reducing global plant production. Improved water-use efficiency (WUE) and drought tolerance are effective strategies to address this problem. In this study, PdEPF1, a member of the EPIDERMAL PATTERNING FACTOR (EPF) family, was isolated from the fast-growing poplar clone NE-19 [Populus nigra × (Populus deltoides × Populus nigra)]. Significantly, higher PdEPF1 levels were detected after induction by dehydration and abscisic acid. To explore the biological functions of PdEPF1, transgenic triploid white poplars (Populus tomentosa 'YiXianCiZhu B385') overexpressing PdEPF1 were constructed. PdEPF1 overexpression resulted in increased water deficit tolerance and greater WUE. We confirmed that the transgenic lines with greater instantaneous WUE had approximately 30% lower transpiration but equivalent CO2 assimilation. Lower transpiration was associated with a 28% reduction in abaxial stomatal density. PdEPF1 overexpression not only strongly enhanced WUE, but also greatly improved drought tolerance, as measured by the leaf relative water content and water potential, under limited water conditions. In addition, the growth of these oxPdEPF1 plants was less adversely affected by reduced water availability than plants with a higher stomatal density, indicating that plants with a low stomatal density may be well suited to grow in water-scarce environments. Taken together, our data suggest that PdEPF1 improves WUE and confers drought tolerance in poplar; thus, it could be used to breed drought-tolerant plants with increased production under conditions of water deficiency.
authors.affiliation: Nation Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China.
authors.forename: Congpeng
authors.initials: C
authors.lastname: Wang
authors.affiliation: Nation Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China.
authors.forename: Sha
authors.initials: S
authors.lastname: Liu
authors.affiliation: Nation Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China.|Liaoning Forestry Vocational- Technical College, Shenyang, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Nation Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Nation Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China.
authors.forename: Anke
authors.initials: A
authors.lastname: Geng
authors.affiliation: Nation Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China.
authors.forename: Xinli
authors.initials: X
authors.lastname: Xia
authors.affiliation: Nation Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China.
authors.forename: Weilun
authors.initials: W
authors.lastname: Yin
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D003681:Dehydration; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D009929:Organ Size; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D054046:Plant Stomata / Q000033:anatomy & histology / Q000502:physiology* / Q000648:ultrastructure; D018526:Plant Transpiration / Q000502:physiology; D030821:Plants, Genetically Modified; D032107:Populus / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D013312:Stress, Physiological / Q000235:genetics; D014867:Water
chemical_list: D010940:Plant Proteins; D014867:Water
keywords: PdEPF1; drought tolerance; growth rate; poplar; stomatal density; water-use efficiency