Effects of growth under different light spectra on the subsequent high light tolerance in rose plants.

Leyla Bayat,Tao Li,Mehdi Seif,Oksana Lastochkina,Mostafa Arab,Sasan Aliniaeifard

doi:10.1093/aobpla/ply052

Abstract

Photosynthesis is defined as a light-dependent process; however, it is negatively influenced by high light (HL) intensities. To investigate whether the memory of growth under monochromatic or combinational lights can influence plant responses to HL, rose plants were grown under different light spectra [including red (R), blue (B), 70:30 % red:blue (RB) and white (W)] and were exposed to HL (1500 μmol m-2 s-1) for 12 h. Polyphasic chlorophyll a fluorescence (OJIP) transients revealed that although monochromatic R- and B-grown plants performed well under control conditions, the functionality of their electron transport system was more sensitive to HL than that of the RB- and W-grown plants. Before exposure to HL, the highest anthocyanin concentration was observed in R- and B-grown plants, while exposure to HL reduced anthocyanin concentration in both R- and B-grown plants. Ascorbate peroxidase and catalase activities decreased, while superoxide dismutase activity was increased after exposure to HL. This caused an increase in H2O2 concentration and malondialdehyde content following HL exposure. Soluble carbohydrates were decreased by exposure to HL, and this decrease was more emphasized in R- and B-grown plants. In conclusion, growing plants under monochromatic light reduced the plants ability to cope with HL stress.

Highlights

Light is the original source of energy for plant photosynthesis and growth
The calculated parameters for specific energy fluxes per reaction centre such as ABS/ RC, TR0/RC and DI0/RC were increased following exposure to high light (HL) for all plants grown under different light spectra, except for the RB-grown plants (Fig. 5A, B and D)
ET0/RC was similar in the C and HL treatments for R- and B-grown plants, while it was increased in W- and RB-grown plants after exposure to HL (Fig. 5C)

Summary

Introduction

Light is the original source of energy for plant photosynthesis and growth. Different characteristics of light such as spectral composition (wavelengths), intensity, duration and direction can influence plant growth and development. The photosynthesis process is sensitive to all aspects of lighting environments. The rapid development of lighting technologies using light-emitting diodes (LEDs) has caused an increase in the application of this technology for lighting in closed horticultural systems (Kozai et al 2015). Light-emitting diodes are attractive because of their high radiant efficiency, long lifetimes, small size, low temperature, narrow spectrum and physical robustness (Tennessen et al 1994; Kim et al 2004; Breive et al 2005; Morrow 2008). The application of LEDs in horticulture makes it possible to use certain wavelengths to study particular

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