Practical Design of an Artificial Light-Used Plant Factory for Common Ice Plant (Mesembryanthemum crystallinum L.)

The common ice plant, Mesembryanthemum crystallinum L., is a eu-halophytic model species with an environmental stress-initiated switch from C3 photosynthesis to crassulacean acid metabolism (CAM). Phosphoenolpyruvate carboxylase activity in 6-week-old plants exposed to salt stress for 5 days was ~15-fold higher than before stress, indicating the salinity-dependent induction of the C3 to CAM transition. Five plant protein phosphatase type 2C (PP2C) genes were cloned, representative of five of the 10 plant PP2C sub-families. We measured mRNA levels of these PP2Cs and of myo-inositol 1-phosphate synthase (Inps1) in 6-week-old plants before (C3) and after (CAM) salt stress. Remarkably, four PP2C genes and Inps1 were expressed with a diurnal fluctuation in plants in C3 mode. After salt-induced CAM induction, the six genes were expressed with more prominent fluctuations than before stress, suggesting that these PP2C genes may be involved in the diurnal regulation of protein phosphorylation in CAM. Under continuous light treatment the expression of two PP2C genes continued to fluctuate, indicating that their expression is controlled by circadian rhythm.

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End-Of-Day LED Lightings Influence the Leaf Color, Growth and Phytochemicals in Two Cultivars of Lettuce

Agronomy ◽

10.3390/agronomy10101475 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1475 ◽

Cited By ~ 1

Author(s):

Yamin Li ◽

Rui Shi ◽

Haozhao Jiang ◽

Linyuan Wu ◽

Yiting Zhang ◽

...

Keyword(s):

Lactuca Sativa ◽

White Light ◽

Growth Stage ◽

Dark Period ◽

Red Light ◽

Shoot Biomass ◽

Artificial Light ◽

Ultraviolet A ◽

Leaf Color ◽

Plant Factory

Four light treatments (W: white light; EOD-B: end-of-day enhanced blue light; EOD-FR: end-of-day supplementary far-red light; EOD-UV: end-of-day supplementary ultraviolet-A light) were designed to explore the effects of end-of-day (EOD) lightings (30 min before dark period) on leaf color, biomass and phytochemicals accumulation in two lettuce cultivars (Lactuca sativa cv. ‘Red butter’ and ‘Green butter’) in artificial light plant factory. EOD-FR stimulated the plant and shoot biomass of two cultivars, and EOD-B suppressed the growth of ‘Red butter’ but induced higher biomass in ‘Green butter’. EOD lightings generated brighter, greener and yellower leaf in ‘Red butter’ at harvest, but the highest lightness and the deepest redness of ‘Green butter’ leaf were observed in the middle growth stage. ‘Red butter’ had prominent higher contents of chlorophylls and carotenoids, while these pigments showed less sensitivity to the interaction of cultivars and EOD lightings. EOD lightings impeded the accumulation of anthocyanin in two cultivars, except EOD-UV slightly increased the anthocyanin contents in ‘Green butter’. EOD-UV strengthened the antioxidant capability of ‘Green butter’, but EOD lightings had different effects on the antioxidant and nutritional compound contents in two lettuce cultivars.

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