Reduced phototropism in pks mutants may be due to altered auxin-regulated gene expression or reduced lateral auxin transport.

Détails

Ressource 1Télécharger: BIB_782E9B5128BA.P001.pdf (8265.59 [Ko])
Etat: Serval
Version: Author's accepted manuscript
ID Serval
serval:BIB_782E9B5128BA
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Reduced phototropism in pks mutants may be due to altered auxin-regulated gene expression or reduced lateral auxin transport.
Périodique
Plant Journal
Auteur(s)
Kami C., Allenbach L., Zourelidou M., Ljung K., Schütz F., Isono E., Watahiki M.K., Yamamoto K.T., Schwechheimer C., Fankhauser C.
ISSN
1365-313X (Electronic)
ISSN-L
0960-7412
Statut éditorial
Publié
Date de publication
2014
Peer-reviewed
Oui
Volume
77
Numéro
3
Pages
393-403
Langue
anglais
Résumé
Phototropism allows plants to orient their photosynthetic organs towards the light. In Arabidopsis, phototropins 1 and 2 sense directional blue light such that phot1 triggers phototropism in response to low fluence rates, while both phot1 and phot2 mediate this response under higher light conditions. Phototropism results from asymmetric growth in the hypocotyl elongation zone that depends on an auxin gradient across the embryonic stem. How phototropin activation leads to this growth response is still poorly understood. Members of the phytochrome kinase substrate (PKS) family may act early in this pathway, because PKS1, PKS2 and PKS4 are needed for a normal phototropic response and they associate with phot1 in vivo. Here we show that PKS proteins are needed both for phot1- and phot2-mediated phototropism. The phototropic response is conditioned by the developmental asymmetry of dicotyledonous seedlings, such that there is a faster growth reorientation when cotyledons face away from the light compared with seedlings whose cotyledons face the light. The molecular basis for this developmental effect on phototropism is unknown; here we show that PKS proteins play a role at the interface between development and phototropism. Moreover, we present evidence for a role of PKS genes in hypocotyl gravi-reorientation that is independent of photoreceptors. pks mutants have normal levels of auxin and normal polar auxin transport, however they show altered expression patterns of auxin marker genes. This situation suggests that PKS proteins are involved in auxin signaling and/or lateral auxin redistribution.
Mots-clé
phototropism, phytochrome kinase substrate, phototropin 1, auxin, Arabidopsis thaliana
Pubmed
Web of science
Création de la notice
06/02/2014 14:20
Dernière modification de la notice
03/03/2018 18:29
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