ASHS 2015 Annual Conference

Light is a crucial regulator of plant growth and development. Knowledge on plant photoreceptors that sense discrete wavelengths has allowed increasing usage of light-emitting diodes (LEDs) as precise dictators of plant growth. Further, as growth and development are coordinated by light quality so is the metabolism and the accumulation of particular metabolites. The singularity of each individual crop (genotype and harvested tissue) requires building unique light treatments for any desired final product. We describe a successful approach on how to design a light treatment to enhance the yield and chemical content of sweet basil. This aromatic herb possesses a particular aroma highly appreciated by consumers; primarily composed of terpenes and terpenoids, phenylpropanoids, and fatty acid derived volatile compounds. These volatile compounds also display important antioxidant and antimicrobial molecular activities. Basil plants at multiple developmental time points were subjected to LED treatments of different spectral combinations, fluence rates, and durations. Basil was phenotyped for leaf area, height, mass, antioxidant capacity, and volatile emission. When subjected to varying treatments metabolite content of later developmental stages is not able to be modified to the extent as early. The GC-MS analyses revealed the possibility of creating basil microgreens with variable volatile profiles. Dependent on treatment, microgreens can be generated with reproducible, targeted alterations of specific volatile compounds. Particular treatments result in microgreens with increased volatile content when compared to standard greenhouse conditions. By targeting these modifications to consumer preferences, LEDs can be introduced in the near future at specific stages of production chains to allow producing novel crop products.