title: A possible role for NDPK2 in the regulation of auxin-mediated responses for plant growth and development.
abstract: Auxin plays many crucial roles in the course of plant growth and development, such as hook opening, leaf expansion and inhibition of mesocotyl elongation. Although its mechanism of action has not been clarified at the molecular level, recent studies have indicated that auxin triggers the induction of a number of genes known as primary auxin-responsive genes. Hence, the identification of the regulatory components in auxin-mediated cellular responses would help to elucidate the mechanism of the action of this hormone in plant growth and development. NDPK2 encodes a nucleoside diphosphate kinase 2 (NDPK2) in Arabidopsis. We aim to elucidate the possible role of NDPK2 in auxin-related cellular processes, in view of the finding that a ndpk2 mutant displays developmental defects associated with auxin. Interestingly, the ndpk2 mutant exhibits defects in cotyledon development and increased sensitivity to an inhibitor of polar auxin transport (naphthylphthalamic acid; NPA). Consistent with this phenotype, the transcript levels of specific auxin-responsive genes were reduced in the ndpk2 mutant plants treated with auxin. The amount of auxin transported from the shoot apex to the shoot/root transition zone of ndpk2 mutant plants was increased, compared with that in the wild-type plants. These results collectively suggest that NDPK2 appears to participate in auxin-regulated processes, partly through the modulation of auxin transport.
authors.affiliation: Kumho Life and Environmental Science Laboratory (KLESL), 1 Oryoung-dong Buk-gu, Gwangju, 500-712 Korea.
authors.forename: Goh
authors.initials: G
authors.lastname: Choi
authors.forename: Jeong-Il
authors.initials: JI
authors.lastname: Kim
authors.forename: Suk-Whan
authors.initials: SW
authors.lastname: Hong
authors.forename: Byoungchul
authors.initials: B
authors.lastname: Shin
authors.forename: Giltsu
authors.initials: G
authors.lastname: Choi
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Blakeslee
authors.forename: Angus S
authors.initials: AS
authors.lastname: Murphy
authors.forename: Yong Weon
authors.initials: YW
authors.lastname: Seo
authors.forename: Kideok
authors.initials: K
authors.lastname: Kim
authors.forename: Eun-Ji
authors.initials: EJ
authors.lastname: Koh
authors.forename: Pill-Soon
authors.initials: PS
authors.lastname: Song
authors.forename: Hojoung
authors.initials: H
authors.lastname: Lee
mesh_terms: D015870:Gene Expression; D007210:Indoleacetic Acids / Q000502:physiology*; D008027:Light; D009701:Nucleoside-Diphosphate Kinase / Q000235:genetics / Q000502:physiology*; D010834:Phytochrome / Q000502:physiology; D063245:Plant Development; D010944:Plants / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction
chemical_list: D007210:Indoleacetic Acids; D012333:RNA, Messenger; D010834:Phytochrome; C121988:nucleoside diphosphate kinase 2; D009701:Nucleoside-Diphosphate Kinase