Light quality affects the proliferation of in vitro cultured plantlets of Camellia oleifera Huajin

Abstract

Background Camellia oleifera is an important oil-yielding woody plant native to China. Tea oil extracted from the seeds is rich in health-beneficial compounds. Huajin is a high-yielding elite variety of C. oleifera, with large fruits and remarkable resilience, widely cultivated in southern China; however, its seedling quality tends to be uneven. At present, techniques such as grafting, and cuttings are primarily adopted to propagate C. oleifera. These approaches are susceptible to environmental constraints owing to the long growth period, resulting in the lack of C. oleifera seedlings. Methods to make the cultivation more economical are warranted; this can be facilitated by tissue culture technology to provide good-quality seedlings in a short time. Methods In vitro cultured plantlets of C. oleifera Huajin were exposed to red light (RL), blue light (BL), red:blue light at a 4:1 ratio (R4:B1), and red:blue light at a 1:4 ratio (R1:B4); white light (WL) was used as the control treatment. To investigate the influence of light spectral quality on the proliferation coefficient, photosynthetic pigments, soluble proteins, plant height, leaf shape, Rubisco enzyme activity, and stomata and leaf anatomical features. Results The highest proliferation coefficient was observed under combined red and blue (4:1) light. In addition, this treatment resulted in the second highest chlorophyll content, the thickest palisade and spongy tissues, and consequently, the thickest leaves. The same treatment resulted in the second highest stomatal density, albeit concomitantly with the smallest average stomatal length and width. Discussion These results indicate that high-quality propagation of Huajin shoots can be achieved by culturing the plants in vitro under a combination of red and blue (4:1) lights. Previous studies have shown that red and blue lights improve rooting and transplanting rates of tissue culture seedlings. Hence, future research should focus on the effect of light quality on rooting and transplanting of tissue culture plantlets of Huajin and its specific molecular mechanisms.

Photomorphogenesis and Photosynthetic Traits Changes in Rice Seedlings Responding to Red and Blue Light

“…When combining Rubisco activity and gene expression, the results of this study show that XZX24 (HZY261) presented the greatest Rubisco activity in B rather than R during all light-quality treatments (Figure 7A), and OsRBCS2, OsRBCS3, OsRBCS4, OsRBCS5, and OsRBCSL expressions under B-treatment conditions were higher than R treatment (Figure 7B-F), which may have been due to red light inhibiting the expression of these genes but activating the expression of other genes related to Rubisco activity. The Rubisco activity of XZX24 was not significantly different under combined-light-treatment conditions and was significantly higher than during single-light treatment [55,56]. Nevertheless, the Rubisco activity of HZY261 was not significantly different under combined-light-treatment conditions and was significantly higher than during white-and red-light treatments.…”

A comparative study on the leaf anatomical structure of Camellia oleifera in a low-hot valley area in Guizhou Province, China

“…At present, among the studies on the upper epidermis of C . oleifera leaves, the upper epidermis cells of different cultivars are uniformly composed of one layer of cells [ 22 , 44 , 45 ], while in the low-hot valley, a heterolayer phenomenon was observed in the upper epidermis cell layers. Calcium oxalate crystals were occasionally visible in the lower epidermis cells.…”

Morphological and Physiological Responses of Hybrid Aspen (Populus tremuloides Michx. × Populus tremula L.) Clones to Light In Vitro

“…compared to monochromatic and FL light [ 19 , 20 , 59 , 60 ]. The observed responses of the plantlets to light of composed spectrum ( Table 2 , Figure 2 ) indicated complexity of signaling pathways [ 26 , 61 ], suggesting the biasness of responses to monochromatic light [ 36 , 37 ].…”