Cloning of 9-cis-epoxycarotenoid dioxygenase gene (TaNCED1) from wheat and its heterologous expression in tobacco

Abstract

Abscisic acid (ABA) regulates plant responses to various environmental stresses. Oxidative cleavage of cis-epoxycarotenoids catalyzed by 9-cis-epoxycarotenoid dioxygenase (NCED) is the critical step in the biosynthesis of ABA in higher plants. Using a homologous cloning approach, a NCED-like gene (designated as TaNCED1) was isolated from wheat (Triticum aestivum). It contained an open reading frame of 1 848 bp and encodes a peptide of 615 amino acids. Multiple sequence alignments showed that TaNCED1 shared high identity with NCEDs from other plants. Phylogenetic analysis revealed that TaNCED1 was most closely related to a barley HvNCED1 gene. The predicted 3D structure of TaNCED1 showed high similarity with other homologues. Southern blot analysis indicated that TaNCED1 was a single copy in the genome of wheat. TaNCED1 was differentially expressed in various organs and the expression was up-regulated by low temperature, drought, NaCl, and ABA. Heterologous expression of TaNCED1 in tobacco (Nicotiana tabacum) significantly improved its drought tolerance. Under drought treatment, TaNCED1overexpressing transgenic tobacco plants exhibited higher germination rate, higher relative water content, content of soluble sugars and of ABA when compared with the wild type plants.

Spatiotemporal modulation of abscisic acid and gibberellin metabolism and signalling mediates the effects of suboptimal and supraoptimal temperatures on seed germination in wheat (Triticum aestivum L.)

“…Nucleotide sequences of TaNCED1 (GenBank ID: JQ772528, Zhang et al ), TaCYP707A2 (GenBank ID: AB849504–06, Iehisa et al ), TaGA20ox1 (Pearce et al ), TaGA20ox2 (GenBank ID: LN828667), TaGA20ox3 (GenBank ID: LN828668), TaGA20ox4 (GenBank ID: LN828665/LN828666/LN828669), TaPYL5 (GeneBank ID: AK335719, Gordon et al ), TaPP2C (GeneBank ID: AB238930, Gordon et al ), TaSnRK2 ( PKABA1 ) (GeneBank ID: M94726, Anderberg & Walker‐Simmons ), TaABI3 (GeneBank ID: AB047554, Nakamura & Toyama ) and TaABI5 (GeneBank ID: AB238932, Nakamura et al ) were used for designing primers with Primer3 software (http://bioinfo.ut.ee/primer3-0.4.0/) (Table ). Primers were designed from conserved regions in cases where nucleotide sequences for the three homeologues of a target gene are available.…”

“…The NCED genes have also been implicated in controlling ABA level and germination in seeds of cereal crops such as maize, Brachypodium and barley (Tan et al ; Leymarie et al ; Barrero et al ). Two NCED genes of wheat, TaNCED1 and TaNCED2 , have been identified to date (Zhang et al ; Son et al ), and the expression patterns of these genes is associated with dormancy (Kashiwakura et al ; Son et al ). ABA level and germination in Arabidopsis seeds have also been shown to be associated with the expression of specific CYP707A gene, CYP707A2 , in both embryo and endosperm tissues (Okamoto et al ).…”

Genetic Dissection of the Seminal Root System Architecture in Mediterranean Durum Wheat Landraces by Genome-Wide Association Study

“…Li et al [48] overexpressed the F-box TaFBA1 in transgenic tobacco to improve heat tolerance, and one of the results was increased root length in the transgenic plants. 9-cis-epoxycarotenoid dioxygenase (NCED) is a key enzyme in the biosynthesis of ABA in higher plants, which regulates the response to various environmental stresses [49]. This enzyme is located within mtaq-2A.3.…”

Mutation in Rice Abscisic Acid2 Results in Cell Death, Enhanced Disease-Resistance, Altered Seed Dormancy and Development

“…Second, zeaxanthin is converted into 9- cis -violaxanthin and 9- cis -neoxanthin by neoxanthin synthase that is encoded by ATABA4 ( North et al, 2007 ). They are dissociated to xanthoxin (Xan) by 9-cis-epoxycarotenoid dioxygenase ( NCED ) ( Iuchi et al, 2001 ; Riahi et al, 2013 ; Zhang et al, 2014 ). Third, Xan is transferred to the cytosol and converted to abscisyl aldehyde (ABAld) by xanthoxin dehydrogenase ( XanDH ) ( Miguel et al, 2002 ; Endo et al, 2014 ).…”