Figure 4. Phenotypic and biochemical characterizations of plants grown under laser light.

(a) 30-days old Arabidopsis thaliana grown under white fluorescent (W) and single-wavelength red and blue (RB) laser light respectively. (b) Leaf development (leaf count) of plants that are fully-grown under the laser light regime. (c) Measurement of fresh and dry weights and biochemical analysis (total chlorophyll and carotenoid quantification) of Arabidopsis plants exposed to a continuous (RB) laser light for seven days. (d) Diameter and (e) surface area of rosette leaf pair of plants fully-grown under (RB) laser light. (f) Bolting and flowering time of plants grown under laser. All data collected with the exception for (c), were obtained from plants that were grown from the first day of sowing to the completion of growth cycle under (RB) laser light only (9:1 ratio of red (671 nm) and blue (473 nm) lasers) at an average photon flux density of 90–100 μmol m⁻² s⁻¹ for 16/8-hour photoperiod at 22 °C with a relative humidity of 50–60%. For (c), Arabidopsis plants were germinated and grown under cool-white fluorescent light at similar light intensity and growth condition for three to four weeks prior to exposure to a continuous (RB) laser regime for seven days. Both the leaf diameter and surface area were analyzed and measured using ImageJ software⁵⁸. Error bars represent standard error of the mean calculated from n > 10 for (b, d and e), where n represents the number of leaves from seven independent plant replicates (n = 7 (c) and n = 3 (f)) where n represents the number of independent biological replicates. One asterisk (*) signifies P < 0.05 and two asterisks (**) signify P < 0.005.