Transcriptomic Changes in Internode Explants of Stinging Nettle during Callogenesis

Abstract

Callogenesis, the process during which explants derived from differentiated plant tissues are subjected to a trans-differentiation step characterized by the proliferation of a mass of cells, is fundamental to indirect organogenesis and the establishment of cell suspension cultures. Therefore, understanding how callogenesis takes place is helpful to plant tissue culture, as well as to plant biotechnology and bioprocess engineering. The common herbaceous plant stinging nettle (Urtica dioica L.) is a species producing cellulosic fibres (the bast fibres) and a whole array of phytochemicals for pharmacological, nutraceutical and cosmeceutical use. Thus, it is of interest as a potential multi-purpose plant. In this study, callogenesis in internode explants of a nettle fibre clone (clone 13) was studied using RNA-Seq to understand which gene ontologies predominate at different time points. Callogenesis was induced with the plant growth regulators α-napthaleneacetic acid (NAA) and 6-benzyl aminopurine (BAP) after having determined their optimal concentrations. The process was studied over a period of 34 days, a time point at which a well-visible callus mass developed on the explants. The bioinformatic analysis of the transcriptomic dataset revealed specific gene ontologies characterizing each of the four time points investigated (0, 1, 10 and 34 days). The results show that, while the advanced stage of callogenesis is characterized by the iron deficiency response triggered by the high levels of reactive oxygen species accumulated by the proliferating cell mass, the intermediate and early phases are dominated by ontologies related to the immune response and cell wall loosening, respectively.

Development of a Transformation System and Locus Identification Pipeline for T-DNA in Chrysanthemum seticuspe, A Model Species for Hexaploid Cultivated Chrysanthemum

“…In plant tissue culture and development, plant growth regulators have a great influence on the formation of adventitious buds in plant explants [ 22 , 23 , 24 ]. Therefore, the type and concentration of plant growth regulators are often key to optimizing transformation systems [ 25 , 26 , 27 ].…”

Production of Polyphenolic Natural Products by Bract-Derived Tissue Cultures of Three Medicinal Tilia spp.: A Comparative Untargeted Metabolomics Study

“…Plants 2024, 13, 1288 2 of 19 Calli can be initiated from a wide variety of young tissues, although bracts, which are modified leaves associated with reproductive organs, have been infrequently used as explants in previous studies [3][4][5]. Since the hormones required for sustaining stable growth interfere with the biosynthesis and accumulation of specialized metabolites [6,7], comparative studies on tissue cultures and organs of whole plants can yield interesting results. In particular, the chemical pattern of calli can be markedly different from that of the organs of wild plants [8][9][10].…”