The effects of red and blue light on growth and steady-state photosynthesis have been widely studied, but there are few studies focusing on dynamic photosynthesis and the effects of LED pre-treatment on cucumber seedlings’ growth, so in this study, cucumber (Cucumis sativus L. cv. Jinyou 365) was chosen as the test material. White light (W), monochromatic red light (R), monochromatic blue light (B), and mixed red and blue lights with different red-to-blue ratios (9:1, 7:3, 5:5, 3:7, and 1:9) were set to explore the effects of red and blue light on cucumber seedlings’ growth, steady-state photosynthesis, dynamic photosynthesis, and subsequent growth under fluctuating light. The results showed that compared with R and B, mixed red and blue light was more suitable for cucumber seedlings’ growth, and the increased blue light ratios would decrease the biomass of cucumber seedlings under mixed red and blue light; cucumber seedlings under 90% red and 10% blue mixed light (9R1B) grew better than other treatments. For steady-state photosynthesis, blue light decreased the actual net photosynthetic rate but increased the maximum photosynthetic capacity by promoting stomatal development and opening; 9R1B exhibited higher actual net photosynthetic rate, but the maximum photosynthetic capacity was low. For dynamic photosynthesis, the induction rate of photosynthetic rate and stomatal conductance were also accelerated by blue light. For subsequent growth under fluctuating light, higher maximum photosynthetic capacity and photoinduction rate could not promote the growth of cucumber seedlings under subsequent fluctuating light, while seedlings pre-treated with 9R1B and B grew better under subsequent fluctuating light due to the high plant height and leaf area. Overall, cucumber seedlings treated with 9R1B exhibited the highest biomass and it grew better under subsequent fluctuating light due to the higher actual net photosynthetic rate, plant height, and leaf area.

A plant factory with artificial light (PFAL) is defined as an advanced agricultural production system with a precisely controlled environment, playing an important role in vertical farming and urban food supply. Artificial light is one of the core technologies in PFALs and accounts for a large part of energy consumption; elevating the light utilization efficiency of plants is vital for the sustainable development of PFALs. Meanwhile, the enclosed structure of the plant factory resulted in the independence of its light environment, indicating that the light environment in PFALs can be custom-made. Lighting strategy is an attempt to reprogram the light environmental parameters in unconventional ways, resulting in innovative lighting modes for energy-saving, high-yield, and high-quality production in PFALs. This article reviewed the recent endeavors aiming to increase light conversion efficiency and nutritive properties of crops by different lighting strategies, providing economic irradiation patterns or modes for various PFALs production goals.