Ornamental glowing plants with FPs or nano-lanterns
Ornamental glowing plants would be available when the fluorescence or
bioluminescence was bright enough. The reported bioluminescent plants
are summaried and shown in Table 1 . The gene expression casstte
of FPs are easily to be integrated into genome and FPs can accumulated
enormously in plant cells, so it is feasible to generate fluorescent
plants. For example, CpYGFP, a yellowish-green FP from marine planktonChiridius poppei , can be excited at 509 nm laser line and
emission was collected at 517 nm which is a red-shifted visible light
(Masuda et al. 2006). Commercial plants were transformed withCpYGFP gene, and green fluorescence was observed from the flowers
when emission filter were used (Sasaki et al. 2014; Kishi-Kaboshi et al.
2017). Additionally, eYGFP and eYGFPuv, two derivatives of CpYGFP, were
expressed in the flowers of another flowering plant, Petunia
hybrida . Green fluorescence was macroscopically observed from the
flowers with naked eyes, when they were illuminated with visible and
ultraviolet LED, respectively. Among the various colors of flowers,
white flowers contain less petal pigments, indicating that less
exciation light and fluorescence would be absorbed. As a result, white
flowers were chosen in these trials (Chin et al., 2018). Many FPs
maintain fluorescent stability under acidic conditions, thus keeping
high activity in the acidic intracellular environment of higher plants
that pH approximately 4.5-7.2. To enhance fluorescence, nano-lanterns
were introduced into plant cells. Recently, green enhanced nano-lantern
gene was transferred into A. thaliana , which could be lightened
under the excitation of blue light. The luminescence became remarkably
brighter when the suitable substrate furimazine was added (Furuhata et
al., 2020). These results indicate it is possible to obtain commercial
ornamental fluorescent flowers. Characteristics of FPs provides the
fluorescent plants a specific proposed implementations, such as dried
fluorescent flowers and fluorescent plant specimens. It is reported that
embedding in fine grained silica gels, the desiccated fluorescent
flowers transferred with CpYGFP gene remained glowing for more
than a year, because some FPs are capable to generate fluorescence
without water (Sasaki et al., 2014). However, fluorescent plants
utilized as alternative light sources for street or reading lamp in
completely darkness is currently difficult, and these application might
be satisfied by glowing plants with luciferase-luciferin bioluminescent
systems.