title: Isolation and functional characterization of a salt responsive transcriptional factor, LrbZIP from lotus root (Nelumbo nucifera Gaertn).
abstract: Basic leucine zipper transcription factor (bZIP) is involved in signaling transduction for various stress responses. Here we reported a bZIP transcription factor (accession: JX887153) isolated from a salt-resistant lotus root using cDNA-AFLP approach with RT-PCR and RACE-PCR method. Full-length cDNA which consisted of a single open reading frame encoded a putative polypeptide of 488 amino acids. On the basis of 78, 76, and 75 % sequence similarity with the bZIPs from Medicago truncatula (XP_003596814.1), Carica papaya (ABS01351.1) and Arabidopsis thaliana (NP_563810.2), we designed it as LrbZIP. Semi quantitative RT-PCR results, performed on the total RNA extracted from tips of lotus root, showed that LrbZIP expression was increased with 250 mM NaCl treatment for 18 h. Effects of low temperature on the expression of LrbZIP was also studied, and its expression was significantly enhanced with a 4 °C treatment for 12 h. In addition, LrbZIP expression was strongly induced by treatment with exogenous 100 μM ABA. To evaluate its function across the species, tobacco (Nicotiana tabacum L.) was transformed with LrbZIP in a binary vector construct. Transgenic plants exhibited higher resistance as compared with the control according to the results of the root growth, chlorophyll content and electrolyte leakage when exposed to NaCl treatment. In addition, LrCDPK2, LrLEA, and TPP also showed enhanced expression in the transgenic plants. Overall, expression of LrbZIP was probably very important for salt-resistant lotus root to survive through salt stress.
authors.affiliation: School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China.
authors.forename: Libao
authors.initials: L
authors.lastname: Cheng
authors.forename: Shuyan
authors.initials: S
authors.lastname: Li
authors.forename: Javeed
authors.initials: J
authors.lastname: Hussain
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Xu
authors.forename: Jingjing
authors.initials: J
authors.lastname: Yin
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xuehao
authors.initials: X
authors.lastname: Chen
authors.forename: Liangjun
authors.initials: L
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D031653:Nelumbo / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010802:Phylogeny; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D014026:Nicotiana / Q000187:drug effects / Q000378:metabolism
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D002734:Chlorophyll; D012965:Sodium Chloride