Light is the source of energy for plants. Light wavelengths, densities and
irradiation periods act as signals directing morphological and physiological
characteristics during plant growth and development. To evaluate the effects
of light wavelengths on tomato growth and development, Solanum lycopersicum
(cv. micro-Tom) seedlings were exposed to different light-quality
environments, including white light and red light supplemented with blue
light (at ratios of 3:1 and 8;1, respectively). Tomatoes grown under red
light supplemented with blue light displayed significantly shorter stem
length, a higher number of flower buds and rate of fruit set, but an
extremely late flowering compared to white-light-grown plants. To illustrate
the mechanism underlying the inhibition of stem growth and floral transition
mediated by red/blue light, 10 trehalose-6-phosphate synthase (TPS) genes
were identified in tomato, and bioinformatics analysis was performed. qRT-PCR
analysis showed that SlTPSs were expressed widely throughout plant
development and SlTPS1 was expressed at extremely high levels in stems and
buds. Further analysis of several flowering-associated genes and microRNAs
showed that the expressions of SlTPS1, SlFT and miR172 were significantly
downregulated in tomato grown under red and blue light compared with those
grown under white light, whereas miR156 transcript levels were increased. A
regulatory model underlying vegetative growth and floral transition regulated
by light qualities is presented. Our data provide evidence that light quality
strongly affects plant growth and phase transition, most likely via the
TPS1-T6P signaling pathway.
Biodegradable Polylactide/Rare Earth Complexes in Light Conversion Agricultural Films
