The Effect of Light on Plastid Differentiation, Chlorophyll Biosynthesis, and Essential Oil Composition in Rosemary (Rosmarinus officinalis) Leaves and Cotyledons

Abstract

It is unclear whether light affects the structure and activity of exogenous secretory tissues like glandular hairs. Therefore, transmission electron microscopy was first used to study plastid differentiation in glandular hairs and leaves of light-grown rosemary (Rosmarinus officinalis "Arp") plants kept for 2 weeks under ambient light conditions. During our detailed analyses, among others, we found leucoplasts with tubuloreticular membrane structures resembling prolamellar bodies in stalk cell plastids of peltate glandular hairs. To study the effect of darkness on plastid differentiation, we then dark-forced adult, light-grown rosemary plants for 2 weeks and observed occasionally the development of new shoots with elongated internodes and pale leaves on them. Absorption and fluorescence spectroscopic analyses of the chlorophyllous pigment contents, the native arrangement of the pigment-protein complexes and photosynthetic activity confirmed that the first and second pairs of leaf primordia of darkforced shoots were partially etiolated (contained low amounts of protochlorophyll/ide and residual chlorophylls, had etio-chloroplasts with prolamellar bodies and low grana, and impaired photosynthesis). Darkness did not influence plastid structure in fifth leaves or secretory tissues (except for head cells of peltate glandular hairs in which rarely tubuloreticular membranes appeared). The mesophyll cells of cotyledons of 2week-old dark-germinated rosemary seedlings contained etioplasts with highly regular prolamellar bodies similar to those in mesophyll etio-chloroplasts of leaves and clearly differing from tubuloreticular membranes of secretory cells. Analyses of the essential oil composition obtained after solid phase microextraction and gas chromatography-mass spectroscopy showed that in addition to light, the age of the studied organ (i.e., first leaf primordia and leaf tip vs. fifth, fully developed green leaves) and the type of the organ

Protuberances are organized distinct regions of long-term callus: histological and transcriptomic analyses in kiwifruit

“…Some researchers have suggested the similarity of electron-dense materials inside plastids to ferritin protein clusters (Voith von Voithenberg et al 2019 ). Electron-dense inclusions were also detected in the mesophyll of Rosmarinus officinalis during etio-chloroplast differentiation (Böszörményi et al 2020 ). Altogether, the electron-dense inclusions in chloroplasts within PT and OC might indicate that the chloroplast development is still in progress.…”

The Role of Membranes and Lipid-Protein Interactions in the Mg-Branch of Tetrapyrrole Biosynthesis

“…In the former, cubic membrane formation was induced by starvation and/or autophagy processes of the amoeba cells, during which they were slowing the degradation of the organelle and thus contributed to the survival of the cell upon stress conditions (Chong et al, 2017 ). In case of plastids, they occurred either in etioplasts or etio-chloroplasts in the form of PLBs and were thus strongly associated with intensive Chl biosynthesis and accumulation of LPOR ( Figure 5 ) (Solymosi and Schoefs, 2008 , 2010 ; Solymosi and Aronsson, 2013 ) or in secretory plastids having active isoprenoid biosynthesis involving the plastid located MEP-pathway or biosynthesis of hydrophobic molecules such as cutin or suberin (Solymosi and Schoefs, 2010 ; Böszörményi et al, 2020 ). Rarely, such tubuloreticular membrane organizations could be interpreted as vesicle clusters (Lindquist et al, 2016 ) or as structures that appeared under various stress conditions [e.g., UV irradiation (Kovács and Keresztes, 2002 )].…”

“…Secretory plastids containing tubuloreticular membranes were observed in various taxa and secretory tissues including extrafloral nectaries of Passiflora (Schnepf, 1961 ), plastids of various glandular hairs [e.g., Cannabis (Hammond and Mahlberg, 1978 ; Kim and Mahlberg, 1997 ; Solymosi and Köfalvi, 2017 ), Artemisia (Ascensao and Pais, 1982 ), Chrysanthemum (Vermeer and Peterson, 1979 ), Centrolobium (Matos and Paiva, 2012 ), Platanthera (Stpiczyńska et al, 2005 )], Mentha piperita (Amelunxen, 1965 ; Turner et al, 2000 , 2012 ), Perilla ocymoides (Kashina and Danilova, 1993 ) and Rosmarinus officinalis (Böszörményi et al, 2020 ). Some authors suggested that light may play a role in the formation of these peculiar membrane structures in secretory cells (Kashina and Danilova, 1993 ), while others observed identical structures in the neck cells of the peltate glandular hairs of both light-grown and dark-forced shoots (Böszörményi et al, 2020 ). Detailed comparative analyses about these peculiar non-bilayer membranes of Rosmarinus officinalis plastids have clearly demonstrated important structural differences.…”

“…Detailed comparative analyses about these peculiar non-bilayer membranes of Rosmarinus officinalis plastids have clearly demonstrated important structural differences. The PLBs of etioplasts represented a highly ordered and symmetrical membrane organization when compared with the loose and irregular tubuloreticular membranes of the secretory plastids ( Figure 5 ) (Böszörményi et al, 2020 ).…”

“…Secretory plastids containing tubuloreticular membranes were observed in various taxa and secretory tissues including extrafloral nectaries of Passiflora (Schnepf, 1961), plastids of various glandular hairs [e.g., Cannabis (Hammond and Mahlberg, 1978;Kim and Mahlberg, 1997;Köfalvi, 2017), Artemisia (Ascensao andPais, 1982), Chrysanthemum (Vermeer and Peterson, 1979), Centrolobium (Matos and Paiva, 2012), Platanthera (Stpiczyńska et al, 2005)], Mentha piperita (Amelunxen, 1965;Turner et al, 2000Turner et al, , 2012, Perilla ocymoides (Kashina and Danilova, 1993) and Rosmarinus officinalis (Böszörményi et al, 2020). Some authors suggested that light may play a role in the formation of these peculiar membrane structures in secretory cells (Kashina and Danilova, 1993), while FIGURE 5 | Transmission electron micrographs of the prolamellar body (PLB) present in the etioplast of the cotyledon of a 2-week-old dark-germinated rosemary (Rosmarinus officinalis) seedling (A), and tubular complex (TC) of a leucoplast of the neck cell of a peltate glandular hair on the surface of a light-grown adult rosemary plant (B).…”