title: GDP-D-mannose pyrophosphorylase from Pogonatherum paniceum enhances salinity and drought tolerance of transgenic tobacco.
abstract: Pogonatherum paniceum is a highly drought- and salt-tolerant plant species that is typically used for ecological restoration and the conservation of soil and water in many countries. Understanding the molecular mechanisms underlying plant abiotic stress responses, especially to salinity and drought stresses, in species such as P. paniceum could be important to broader crop improvement efforts. GDP-D-mannose pyrophosphorylase (GMPase) is the limiting enzyme in the synthesis of L-ascorbic acid (AsA), which plays a crucial role in the detoxification of reactive oxygen species (ROS). We have cloned and characterized the cDNA of the PpGMP gene of P. paniceum encoding a GMPase. The full-length cDNA sequence contains 1411 nucleotides encoding a putative protein with 361 amino acid residues and an approximate molecular mass of 39.68 kDa. The GMPase transcript was up-regulated in P. paniceum plants subjected to salinity and drought stress, respectively. Transgenic tobacco expressing PpGMPase exhibited enhanced salinity and drought resistance, a higher seed germination rate, better growth performance, a higher AsA content, a more stable redox state, higher superoxide dismutase (SOD) activity, and lower levels of malonaldehyde (MDA) and H2O2 under drought and salinity stress. Taken together, expression of PpGMPase in tobacco conferred salinity and drought stress tolerance by increasing the content of AsA, thereby enhancing ROS-detoxifying functions. Thus, PpGMP is a potential candidate gene for crop improvement.
authors.forename: Taobo
authors.initials: T
authors.lastname: Ai
authors.forename: Xuehong
authors.initials: X
authors.lastname: Liao
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.forename: Linhong
authors.initials: L
authors.lastname: Fan
authors.forename: Fengxue
authors.initials: F
authors.lastname: Luo
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Shenghua
authors.initials: S
authors.lastname: Wang
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000595:Amino Acid Sequence; D001205:Ascorbic Acid / Q000378:metabolism; D001483:Base Sequence; D055864:Droughts; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D009713:Nucleotidyltransferases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D006109:Poaceae / Q000201:enzymology* / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054712:Salinity; D055051:Salt-Tolerant Plants / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D012965:Sodium Chloride; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D009713:Nucleotidyltransferases; C026917:mannose 1-phosphate guanylyltransferase; D001205:Ascorbic Acid