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Organ boundary NAC‐domain transcription factors are implicated in the evolution of petal fusion
Author(s) -
Zhong J.,
Powell S.,
Preston J. C.
Publication year - 2016
Publication title -
plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 1435-8603
DOI - 10.1111/plb.12493
Subject(s) - biology , petal , microbiology and biotechnology , transcription factor , transcription (linguistics) , computational biology , domain (mathematical analysis) , evolutionary biology , genetics , botany , gene , mathematical analysis , linguistics , philosophy , mathematics
Abstract Research rationale: Evolution of fused petals (sympetaly) is considered to be an important innovation that has repeatedly led to increased pollination efficiency, resulting in accelerated rates of plant diversification. Although little is known about the underlying regulation of sympetaly, genetic pathways ancestrally involved in organ boundary establishment (e.g. CUP SHAPED COTYLEDON [ CUC ] 1–3 genes) are strong candidates. In sympetalous petunia, mutations in the CUC 1/2‐like orthologue NO APICAL MERISTEM ( NAM ) inhibit shoot apical meristem formation. Despite this, occasional ‘escape shoots’ develop flowers with extra petals and fused inter‐floral whorl organs. Central methods: To To determine if petunia CUC ‐like genes regulate additional floral patterning, we used virus‐induced silencing ( VIGS ) following establishment of healthy shoot apices to re‐examine the role of NAM in petunia petal development, and uniquely characterise the CUC 3 orthologue NH 16. Key results: Confirming previous results, we found that reduced floral NAM / NH 16 expression caused increased petal–stamen and stamen–carpel fusion, and often produced extra petals. However, further to previous results, all VIGS plants infected with NAM or NH 16 constructs exhibited reduced fusion in the petal whorl compared to control plants. Main conclusions: Together with previous data, our results demonstrate conservation of petunia CUC ‐like genes in establishing inter‐floral whorl organ boundaries, as well as functional evolution to affect the fusion of petunia petals.