Growth and development of Arabidopsis thaliana under single-wavelength red and blue laser light

Abstract

Indoor horticulture offers a sensible solution for sustainable food production and is becoming increasingly widespread. However, it incurs high energy and cost due to the use of artificial lighting such as high-pressure sodium lamps, fluorescent light or increasingly, the light-emitting diodes (LEDs). The energy efficiency and light quality of currently available horticultural lighting is suboptimal, and therefore less than ideal for sustainable and cost-effective large-scale plant production. Here, we demonstrate the use of high-powered single-wavelength lasers for indoor horticulture. They are highly energy-efficient and can be remotely guided to the site of plant growth, thus reducing on-site heat accumulation. Furthermore, laser beams can be tailored to match the absorption profiles of different plant species. We have developed a prototype laser growth chamber and demonstrate that plants grown under laser illumination can complete a full growth cycle from seed to seed with phenotypes resembling those of plants grown under LEDs reported previously. Importantly, the plants have lower expression of proteins diagnostic for light and radiation stress. The phenotypical, biochemical and proteome data show that the single-wavelength laser light is suitable for plant growth and therefore, potentially able to unlock the advantages of this next generation lighting technology for highly energy-efficient horticulture.

Plant Growth and Photosynthetic Characteristics of Mesembryanthemum crystallinum Grown Aeroponically under Different Blue- and Red-LEDs

“…Recently, Ooi et al (2016) has also demonstrated the use of high-powered single-wavelength red and blue laser lights for indoor horticulture using Arabidopsis . However, the potential application of laser light for sustainable food production needs further research with more crops.…”

“…They reported that shoot DW increased with increasing red/blue light ratio, which was mainly due to increased leaf number and leaf area under the higher red/blue light ratio. It was also reported that the optimal red/blue light ratios for FW and DW accumulation were 7/3 in strawberry plantlet (Nhut et al, 2003) and 1/3 in rapeseed plantlets in vitro (Li et al, 2013), respectively, but 9 in cucumber seedlings (Hernández and Kubota, 2016), spinach (Yorio et al, 2001), lettuce (Bula et al, 1991; Yorio et al, 2001; Stutte et al, 2009), and Arabidopsis (Ooi et al, 2016). Based on the above discussion, blue light promote growth by stimulating morphological response.…”

“…Similar results were found in strawberry plantlet (Nhut et al, 2003), rapeseed ( Brassica napus L.) plantlets in vitro (Li et al, 2013), rapeseed rosette leaves (Shengxin et al, 2016), and cucumber seedlings (Hernández and Kubota, 2016; Trouwborst et al, 2016). In a recent developed highly energy-efficient laser-illuminated growth chamber, Ooi et al (2016) also showed that the application of diffused single-wavelength red and blue laser light is adequate for the growth and development of Arabidopsis thaliana .…”

Breeding crops to feed 10 billion

“…One feature of existing speed breeding systems is the use of LEDs to improve light quality and reduce operational costs 12,15 . Instead, laser light could be used to reduce costs further because it has a higher electrical conversion efficiency, with 40-60% of energy being converted into light, depending on the light color 72 (Fig. 5e).…”

“…As well as boosting growth and increasing returns on energy input, laser light can be generated outside a growth cabinet or greenhouse,   beamed inside and then scattered over plants, eradicating much of the cooling costs that make crop research in controlled environments expensive. Arabidopsis thaliana plants grown under these conditions exhibit reduced expression of certain proteins that are associated with light and radiation stress in comparison to those grown under cool-white fluorescent light 72 ; higher photon irradiance intensities could therefore be applied using this approach with less damage to the plant (Fig. 5g).…”