Showing papers on "Nigella damascena published in 2020"

Identification of the Key Regulatory Genes Involved in Elaborate Petal Development and Specialized Character Formation in Nigella damascena (Ranunculaceae)

Abstract: Petals can be simple or elaborate, depending on whether they have lobes, teeth, fringes, or appendages along their margins, or possess spurs, scales, or other types of modifications on their adaxial/abaxial side, or both. Elaborate petals have been recorded in 23 orders of angiosperms and are generally believed to have played key roles in the adaptive evolution of corresponding lineages. The mechanisms underlying the formation of elaborate petals, however, are largely unclear. Here, by performing extensive transcriptomic and functional studies on Nigella damascena (Ranunculaceae), we explore the mechanisms underlying elaborate petal development and specialized character formation. In addition to the identification of genes and programs that are specifically/preferentially expressed in petals, we found genes and programs that are required for elaborate rather than simple petal development. By correlating the changes in gene expression with those in petal development, we identified 30 genes that are responsible for the marginal/ventral elaboration of petals and the initiation of several highly specialized morphological characters (e.g., pseudonectaries, long hairs, and short trichomes). Expression and functional analyses further confirmed that a class I homeodomain-leucine zipper family transcription factor gene, Nigella damascena LATE MERISTEM IDENTITY1 (NidaLMI1), plays important roles in the development of short trichomes and bifurcation of the lower lip. Our results not only provide the first portrait of elaborate petal development but also pave the way to understanding the mechanisms underlying lateral organ diversification in plants.

The morphology, molecular development and ecological function of pseudonectaries on Nigella damascena (Ranunculaceae) petals

Abstract: Pseudonectaries, or false nectaries, the glistening structures that resemble nectaries or nectar droplets but do not secrete nectar, show considerable diversity and play important roles in plant-animal interactions. The morphological nature, optical features, molecular underpinnings and ecological functions of pseudonectaries, however, remain largely unclear. Here, we show that pseudonectaries of Nigella damascena (Ranunculaceae) are tiny, regional protrusions covered by tightly arranged, non-secretory polygonal epidermal cells with flat, smooth and reflective surface, and are clearly visible even under ultraviolet light and bee vision. We also show that genes associated with cell division, chloroplast development and wax formation are preferably expressed in pseudonectaries. Specifically, NidaYABBY5, an abaxial gene with ectopic expression in pseudonectaries, is indispensable for pseudonectary development: knockdown of it led to complete losses of pseudonectaries. Notably, when flowers without pseudonectaries were arrayed beside those with pseudonectaries, clear differences were observed in the visiting frequency, probing time and visiting behavior of pollinators (i.e., honey bees), suggesting that pseudonectaries serve as both visual attractants and nectar guides.

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

Abstract: In this study we report the development of effective in vitro systems for a medicinal plant Nigella damascena L. comprising: (1) callus induction, (2) somatic embryogenesis in callus cultures with subsequent plant regeneration, and (3) isolation and regeneration of callus-derived protoplasts. Callus development was achieved on 83–100% of hypocotyl and cotyledon explants, whereby Murashige and Skoog medium (MS) supplemented with 3 mg L−1 6-benzylaminopurine and 0.5 mg L−1 α-naphthaleneacetic acid (NAA; BN medium) was more advantageous than MS with kinetin and NAA (KN medium). Histological observations of calli revealed the presence of embryogenic zones from which somatic embryos developed on the hormone-free medium. Plant regeneration was observed on 76–95% of calli. A high capacity to form somatic embryos and regeneration was maintained in long-lasting cultures, i.e. even in 2 year old callus. The obtained callus was also a good source tissue for protoplast isolation. By applying a mixture of cellulase and pectolyase, the acceptable yield of viable protoplasts was achieved, especially from hypocotyl-derived callus maintained on BN medium. Protoplasts embedded in an alginate matrix and cultured in modified Kao and Michayluk media re-constructed their cell wall and re-entered mitotic divisions. About 30% of small cell aggregates formed microcalli, which, after the release from alginate, proliferated continuously on KN and BN media, irrespective of the tissue variant used as the protoplast source. Somatic embryo formation and plant regeneration were successful on hormone-free media. An effective plant regeneration system of N. damascena protoplast cultures has been developed and is being reported for the first time. The main objective of this study was to develop in vitro systems utilizing N. damascena seedlings, as an easily accessible explant source, for efficient callus induction and proliferation, and plant regeneration via somatic embryogenesis. Moreover, we attempted to validate the usefulness of the obtained callus as a source of protoplasts and their capability to develop into plants.

Comparative performance assessment seedling method for the introduction of Nigella damascena L. in the Middle Urals

Abstract: Abstract. Introduction allows not only to expand the range of medicinal plants, but also to reduce the severity of the problem of their import substitution. In 2019, a study was conducted at the “Uralets” agricultural farm, on the collection spot of the Ural state agrarian University, to assess the effectiveness of the seedling method for the introduction of Nigella damascena. The purpose of the research: to study the formation of productivity of Nigella damascena in the Middle Urals. The research objectives were to study the most important aspects of the growth and development of Nigella damascena: phenological phases and their onset dates; dynamics of height and average daily growth, productivity. Method of research. During the experiment all observations and records were made according to generally accepted methods. The scheme of the experiment includes 3 options that differ in the timing of sowing seeds of Nigella damascena for seedlings: I – seeding on March 20th (control); II – seeding on March 30th; III – seeding on April 10th. Results. During the first two to three weeks, after planting seedlings in the open ground, the growth of plants was minimal, its value varied in variants from 0.14 (III variant) to 0.31 (I variant) mm per day. The earliest transition of plants to the generative stage of development was noted in I variant, where the budding phase occurred 9 days earlier than in 2 and 22 days earlier than in III variant. The period of mass flowering lasted until mid-August, single flowering – until the end of September. The largest seeds (weight of 100 seeds – 0.31–0.36 g) were obtained in I var. – 66.48 g/m2, significantly lower than in III variant – 11.16 g/m2. The maximum seed productivity is formed in I variant – 100.57 g/m2, the minimum in III variant – 38.93 g/m2. Scientific novelty. For the first time, the effectiveness of the seedling method of cultivation of Nigella damascena – a valuable medicinal plant in the Middle Urals has been studied. The optimal variant allowing to obtain high seed productivity is established.

Cardioprotective botanical herbal formulation for preventing and alleviating coronary disease

Abstract: Provided is a natural plant formulation, comprising extracts of the following plant parts: Salvia miltiorrhiza, walnut grass, Aesculus hippocastanum, ginger root, bark of Chinese cinnamon, sesame seeds, papaya, Nigella damascena, pomegranate seeds, cornflower leaves, Pistacia Lentiscus resin, drupe of coconut tree, cacao beans, dried pulp and kernels of Phoenix dactylifera, olive, ficus carica, walnut, blueberry dried pulp, garlic cloves and rose petals. Also provided is a method for preparing said botanical formulation, comprising treating said plant parts by means of ethanol.