Flower development schedule andAGAMOUS-like gene expression patterns in two morphs ofNigella damascena(Ranunculaceae) differing in floral architecture

Abstract

Love-in-a-mist (Nigella damascena) is an annual species of Ranunculaceae native to the Mediterranean Basin, characterized by delicate flowers lying on long lacy bracts. Two floral morphs of N. damascena, designated [P] and [T], differ in the identity and number of perianth organs and in the position of the perianth-androecium boundary on the meristem. They both occur in the wild. Here we describe a precise comparative schedule of floral development in the two morphs. We divided the sequence of developmental events affecting the floral meristem into six stages and related them to the height of the elongating stem and to the time elapsed after the beginning of stem elongation. In addition, we characterized the expression pattern of C-class genes in floral organs of both morphs in an attempt to better characterize the differences between the two floral groundplans. In the [T] morph an expansion of the expression domain of AGAMOUS (AG) paralogues outside the fertile organs was observed, correlating with the change in identity of the inner perianth organs. Expression of AG-like genes in the sepal-like organs suggests these are not identical to true sepals at the molecular level. The morpho-temporal framework we have defined will allow us to compare various gene expression profiles at targeted developmental stages in both morphs, providing further insight into the molecular control of the floral dimorphism in N. damascena and into the processes underlying the transition from a differentiated (bipartite) to an undifferentiated (unipartite) perianth.

Effective callus induction and plant regeneration in callus and protoplast cultures of Nigella damascena L.

“…Another sesquiterpene, β-elemene, also has great therapeutic potential, which, in turn, undergoes intensive biosynthesis in N. damascena, an annual herbaceous plant (D'Antuono et al 2002;Edris et al 2009). N. damascena, commonly known as love-in-a-mist or devil-in-the-bush, is native to the Mediterranean region and West Asia, but today is grown as an ornamental plant in temperate regions of Europe (Fico et al 2000;Jabbour et al 2015). The entomophilous flowers consist of usually blue petaloid sepals lying on lacy bracts and long-stalked petals located at the base of the stamens (Zhao et al 2011;Liao et al 2020).…”

Floral Organogenesis and Morphogenesis ofStaphisagria(Ranunculaceae): Implications for the Evolution of Synorganized Floral Structures in Delphinieae

“…To investigate the evolution and development of the Delphinieae hyperorgan in a phylogenetic framework, we chose the well-studied genus Nigella as a representative of Nigelleae, the sister group of Delphinieae (Zhai et al 2019). Nigella, and especially Nigella damascena, has been intensively studied regarding the development and evolution of its perianth (Zhao et al 2011;Gonçalves et al 2013;Zhang et al 2013;Deroin et al 2015;Jabbour et al 2015;Wang et al 2015;Damerval and Becker 2017;Damerval et al 2018;Yao et al 2019;Liao et al 2020;F. Jabbour et al unpublished manuscript).…”

Micro- and Macroscale Patterns of Petal Morphogenesis in Nigella damascena (Ranunculaceae) Revealed by Geometric Morphometrics and Cellular Analyses

“…As in other Nigella species, the mature petal of Nigella damascena is composed of several differentiated domains (Figure 1). These domains differentiate progressively during development from a simple lamina (Jabbour et al, 2015). Their respective contribution to the overall petal shape and size during development is still to be described.…”

“…In the early-diverging eudicot family Ranunculaceae, a large diversity of petal forms is found, from simple laminas with a tiny nectariferous scale, as in Ranunculus, to highly elaborate nectariferous spurred organs, as in Aquilegia. Floral development and, to a lesser extent, petal development have already been described qualitatively using the classical microscopy techniques (Erbar et al, 1999;Tucker and Hodges, 2005;Jabbour et al, 2009Jabbour et al, , 2015Ren et al, 2009;Zhao et al, 2011). A detailed investigation of the development of the elaborate petal has been conducted in the genus Nigella using histology and micro-CT (Yao et al, 2019).…”