Infrared light-emitting diode radiation causes gravitropic and morphological effects in dark-grown oat seedlings

Involvement of Anthocyanin Biosynthesis of Cabernet Sauvignon Grape Skins in Response to Field Screening and In Vitro Culture Irradiating Infrared Radiation

To study the role of infrared (IR) radiation in the color change of the grape berry, field screening (IR-) and in vitro culture irradiation (IR+) were used. Acylated anthocyanin biosyntheses, including the biosynthesis of malvidin 3-O-glucoside, peonidin 3-O-glucoside, and their derivatives (acetylation and p-coumaroylation), were inhibited by IR-. IR+ promoted the biosynthesis of malvidin 3-O-glucoside and its derivatives, and IR+ inhibited the biosynthesis of peonidin 3-O-glucoside and its derivatives. WGCNA analysis revealed that the red module positively correlated with the flavonoid pathway. The hub genes were related to the anthocyanin pathway, including VvF3'5'H, VvANS, VvOMT1, VIT_18s0001g09400, and VvGST4. Further, the results revealed that transcription factors like RLK-Pelle, MYB, and C2H2 families were involved in response to IR radiation. Therefore, these results provide a complete understanding of IR radiation in grape skin color formation and the prospect of using supplemental light to improve the overall color of berries.

Non-mammalian Hosts and Photobiomodulation: Do All Life-forms Respond to Light?

Photobiomodulation (PBM), also known as low-level laser (light) therapy, was discovered over 50 years ago, but only recently has it been making progress toward wide acceptance. PBM originally used red and near-infrared (NIR) lasers, but now other wavelengths and non-coherent light-emitting diodes (LEDs) are being explored. The almost complete lack of side effects makes the conduction of controlled clinical trials relatively easy. Laboratory research has mainly concentrated on mammalian cells (normal or cancer) in culture, and small rodents (mice and rats) as models of different diseases. A sizeable body of work was carried out in the 1970s and 1980s in Russia looking at various bacterial and fungal cells. The present review covers some of these studies and a recent number of papers that have applied PBM to so-called "model organisms." These models include flies (Drosophila), worms (Caenorhabditis elegans), fish (zebrafish) and caterpillars (Galleria). Much knowledge about the genomics and proteomics, and many reagents for these organisms already exist. They are inexpensive to work with and have lower regulatory barriers compared to vertebrate animals. Other researchers have studied different models (snails, sea urchins, Paramecium, toads, frogs and chickens). Plants may respond to NIR light differently from visible light (photosynthesis and photomorphogenesis) but PBM in plants has not been much studied. Veterinarians routinely use PBM to treat non-mammalian patients. The conclusion is that red or NIR light does indeed have significant biologic effects conserved over many different kingdoms, and perhaps it is true that "all life-forms respond to light."

The Effect of Macroalgal Extracts and Near Infrared Radiation on Germination of Soybean Seedlings: Preliminary Research Results

In the present study, synergistic effects between the application of near-infrared radiation (NIR) and macroalgal extracts on the germination of soybean seeds were searched for. NIR is captured by special photoreceptors (i.e. phytochromes, cryptochromes and phototropins) and next plants generate a wide range of specific physiological responses through these receptors. For the study, a special system of NIR was applied to irradiate soybean seeds. To our knowledge, this is the first time this kind of radiation was used for the biostimulation of soybean seeds. Previously, the effect of other ranges of light (e.g. green, red, blue) was analysed in terms of photosynthetic activity, growth and yield of different plants, except seeds. NIR for 3 and 5 minutes was also combined with the application of macroalgal extracts used for seeds soaking. They are known as a rich source of biologically active compounds that can stimulate plant growth. These preliminary studies show that the examined factors can stimulate plant’s growth and their quality.

Design and fabrication of adjustable red-green-blue LED light arrays for plant research

BACKGROUND

Although specific light attributes, such as color and fluence rate, influence plant growth and development, researchers generally cannot control the fine spectral conditions of artificial plant-growth environments. Plant growth chambers are typically outfitted with fluorescent and/or incandescent fixtures that provide a general spectrum that is accommodating to the human eye and not necessarily supportive to plant development. Many studies over the last several decades, primarily in Arabidopsis thaliana, have clearly shown that variation in light quantity, quality and photoperiod can be manipulated to affect growth and control developmental transitions. Light emitting diodes (LEDs) has been used for decades to test plant responses to narrow-bandwidth light. LEDs are particularly well suited for plant growth chambers, as they have an extraordinary life (about 100,000 hours), require little maintenance, and use negligible energy. These factors render LED-based light strategies particularly appropriate for space-biology as well as terrestrial applications. However, there is a need for a versatile and inexpensive LED array platform where individual wavebands can be specifically tuned to produce a series of light combinations consisting of various quantities and qualities of individual wavelengths. Two plans are presented in this report.

RESULTS

In this technical report we describe the practical construction of tunable red-green-blue LED arrays to support research in plant growth and development. Two light fixture designs and corresponding circuitry are presented. The first is well suited for a laboratory environment for use in a finite area with small plants, such as Arabidopsis. The second is expandable and appropriate for growth chambers. The application of these arrays to early plant developmental studies has been validated with assays of hypocotyl growth inhibition/promotion and phototropic curvature in Arabidopsis seedlings.

CONCLUSION

The presentation of these proven plans for LED array construction allows the teacher, researcher or electronics aficionado a means to inexpensively build efficient, adjustable lighting modules for plant research. These simple and effective designs permit the construction of useful tools by programs short on electronics expertise. These arrays represent a means to modulate precise quality and quantity in experimental settings to test the effect of specific light combinations in regulating plant growth, development and plant-product yield.