A KNOX-Cytokinin Regulatory Module Predates the Origin of Indeterminate Vascular Plants - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Current Biology - CB Année : 2019

A KNOX-Cytokinin Regulatory Module Predates the Origin of Indeterminate Vascular Plants

Yoan Coudert
Ondřej Novák
  • Fonction : Auteur

Résumé

The diverse forms of today's dominant vascular plant flora are generated by the sustained proliferative activity of sporophyte meristems at plants' shoot and root tips, a trait known as indeterminacy [1]. Bryophyte sister lineages to the vascular plants lack such indeterminate meristems and have an overall sporophyte form comprising a single small axis that ceases growth in the formation of a reproductive sporangium [1]. Genetic mechanisms regulating indeterminacy are well characterized in flowering plants, involving a feedback loop between class I KNOX genes and cytokinin [2, 3], and class I KNOX expression is a conserved feature of vascular plant meristems [4]. The transition from determinate growth to indeterminacy during evolution was a pre-requisite to vascular plant diversification, but mechanisms enabling the innovation of indeterminacy are unknown [5]. Here, we show that class I KNOX gene activity is necessary and sufficient for axis extension from an intercalary region of determinate moss shoots. As in Arabidopsis, class I KNOX activity can promote cytokinin biosynthesis by an ISOPENTENYL TRANSFERASE gene, PpIPT3. PpIPT3 promotes axis extension, and PpIPT3 and exogenously applied cytokinin can partially compensate for loss of class I KNOX function. By outgroup comparison, the results suggest that a pre-existing KNOX-cytokinin regulatory module was recruited into vascular plant shoot meristems during evolution to promote indeterminacy, thereby enabling the radiation of vascular plant shoot forms.

Dates et versions

hal-02352215 , version 1 (06-11-2019)

Identifiants

Citer

Yoan Coudert, Ondřej Novák, C. Jill Harrison. A KNOX-Cytokinin Regulatory Module Predates the Origin of Indeterminate Vascular Plants. Current Biology - CB, 2019, 29 (16), pp.2743-2750.e5. ⟨10.1016/j.cub.2019.06.083⟩. ⟨hal-02352215⟩
23 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Mastodon Facebook X LinkedIn More