A conserved role for CUP‐SHAPED COTYLEDON genes during ovule development. (23rd July 2015)

• Record Type: Journal Article
• Authors: Gonçalves, Beatriz; Hasson, Alice; Belcram, Katia; Cortizo, Millán; Morin, Halima; Nikovics, Krisztina; Vialette‐Guiraud, Aurélie; Takeda, Seiji; Aida, Mitsuhiro; Laufs, Patrick; Arnaud, Nicolas
• Is Part Of: Plant journal. Volume 83:Number 4(2015:Aug.)
• Page Start: 732
• Page End: 742
• Publication Date: 2015-07-23
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12923
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12923-abs-0001"> <title>Summary</title> <p>The evolution of plant reproductive strategies has led to a remarkable diversity of structures, especially within the flower, a structure characteristic of the angiosperms. In flowering plants, sexual reproduction depends notably on the development of the gynoecium that produces and protects the ovules. In <italic>Arabidopsis thaliana</italic>, ovule initiation is promoted by the concerted action of auxin with <italic>CUC1</italic> (<italic>CUP‐SHAPED COTYLEDON1</italic>) and <italic>CUC2</italic>, two genes that encode transcription factors of the NAC family (NAM/ATAF1, 2/CUC). Here we highlight an additional role for CUC2 and CUC3 in <italic>Arabidopsis thaliana</italic> ovule separation. While <italic>CUC1</italic> and <italic>CUC2</italic> are broadly expressed in the medial tissue of the gynoecium, <italic>CUC2</italic> and <italic>CUC3</italic> are expressed in the placental tissue between developing ovules. Consistent with the partial overlap between <italic>CUC1</italic>, <italic> CUC2</italic> and <italic>CUC3</italic> expression patterns, we show that CUC proteins can physically interact, both in yeast cells and <italic>in planta</italic>. We found that the <italic>cuc2;cuc3</italic> double mutant specifically harbours defects in ovule separation, producing fused seeds that share the seed coat, and suggesting that <italic>CUC2</italic> and <italic>CUC3</italic> promote ovule separation in a partially redundant manner. Functional analyses show that CUC transcription factors are also involved in ovule development in <italic>Cardamine hirsuta</italic>. Additionally we show a conserved expression pattern of <italic>CUC</italic> orthologues between ovule primordia in other phylogenetically distant species with different gynoecium architectures. Taken together these results suggest an ancient role for CUC transcription factors in ovule separation, and shed light on the conservation of mechanisms involved in the development of innovative structures.</p> </abstract>