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This study evaluated the effects of different light spectra (white light; WL, blue light; BL and red light; RL) on the root morphological traits and metabolites accumulation and biosynthesis in Sarcandra glabra . We performed transcriptomic and metabolomic profiling by RNA-seq and ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS), respectively. When morphological features were compared to WL, BL substantially increased under-ground fresh weight, root length, root surface area, and root volume, while RL inhibited these indices. A total of 433 metabolites were identified, of which 40, 18, and 68 compounds differentially accumulated in roots under WL (WG) vs. roots under BL (BG), WG vs. roots under RL (RG), and RG vs. BG, respectively. In addition, the contents of sinapyl alcohol, sinapic acid, fraxetin, and 6-methylcoumarin decreased significantly in BG and RG. In contrast, chlorogenic acid, rosmarinyl glucoside, quercitrin and quercetin were increased considerably in BG. Furthermore, the contents of eight terpenoids compounds significantly reduced in BG. Following transcriptomic profiling, several key genes related to biosynthesis of phenylpropanoid-derived and terpenoids metabolites were differentially expressed, such as caffeic acid 3- O -methyltransferase) ( COMT ), hydroxycinnamoyl-CoA shikimate hydroxycinnamoyl transferase ( HCT ), O-methyltransferase ( OMT ), and 1-deoxy-D-xylulose-5-phosphate synthetase ( DXS ). In summary, our findings showed that BL was suitable for growth and accumulation of bioactive metabolites in root tissue of S. glabra . Exposure to a higher ratio of BL might have the potential to improve the production and quality of S. glabra seedlings, but this needs to be confirmed further.

Background: Sarcandra glabra is an evergreen and traditional Chinese herb with anti-oxidant, anti-bacterial, anti-inflammatory, and anti-tumor effects. Light is one of the most influential factor affecting the growth and quality of herbs. In recent times, the introduction of Light Emission Diode (LED) technology has been widely used for plants in greenhouse. However, the impact of such lights on plant growth and the regulatory mechanism of phenylpropanoid-derived compounds in S. glabra remain unclear., Results: The red LED light (RL) substantially increased the plant height and decreased the stem diameter and leaf area relative to the white LED light (WL), while the blue LED light (BL) significantly reduced the height and leaf area of S. glabra. According to transcriptomic profiling, 861, 378, 47, 10,033, 7917, and 6379 differentially expressed genes (DEGs) were identified among the groups of leaf tissue under BL (BY) vs. leaf tissue under RL (RY), BY vs. leaf tissue under WL (WY), RY vs. WY, root tissue under WL (WG) vs. WY, stem tissue under WL (WJ) vs. WG, and WJ vs. WY, respectively. We identified 46 genes encoding for almost all known enzymes involved in phenylpropanoid biosynthesis, e.g., phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), and flavonol synthase (FLS). We found 53 genes encoding R2R3-MYB proteins and bHLH proteins, respectively, where several were related to flavonoids biosynthesis. A total of 454 metabolites were identified based on metabolomic profiling, of which 44, 87, and 296 compounds were differentially produced in WY vs. RY, WY vs. BY, and WY vs. WG. In BY there was a substantial reduction in the production of esculetin, caffeic acid, isofraxidin, and fraxidin, while the yields of quercitrin and kaempferol were significantly up-regulated. In RY, the contents of cryptochlorogenic acid, cinnamic acid, and kaempferol decreased significantly. Besides, in WG, the production of metabolites (e.g. chlorogenic acid, cryptochlorogenic acid, and scopolin) declined, while their yields increased significantly (e.g. esculetin, fraxetin, isofraxidin, and fraxidin)., Conclusion: These results provide further insight into the regulatory mechanism of accumulation patterns of phenylpropanoid-derived compounds in S. glabra under various light conditions, allowing optimum breeding conditions to be developed for this plant.

Fokienia hodginsii is characterized by shallow and developed lateral roots with no obvious taproot. It can be used as a pioneer tree species for opening up barren land and as a mixed species for creating plantation forests. During the growth process of F. hodginsii seedlings, they are often exposed to heterogeneous nutrient environments and competition for nutrients, water, and space from neighboring plants, which have significant impacts on the growth of F. hodginsii. These impacts are most directly reflected in the root vitality of F. hodginsii, whose physiological changes embody the plant's adaptability to different heterogeneous nutrient environments and neighbor competition. Herein, high-quality one-year-old F. hodginsii seedlings were subjected to three planting patterns to simulate different competition patterns. The three planting patterns were also exposed to three heterogeneous nutrient environments and a homogeneous nutrient environment (control) to determine the differences in the F. hodginsii seedling growth and root vitality under different heterogeneous nutrient environments and planting patterns. The F. hodginsii seedling height, ground diameter (root neck diameter), and root biomass under the heterospecific neighbor condition were significantly higher than under the single-plant condition. Across heterogeneous nutrient environments, the average seedling height in the N heterogeneous environments was higher than in the P and K heterogeneous environments. The root biomass in the P heterogeneous environment was slightly higher than in the N heterogeneous environment and significantly higher than in the homogeneous and the K heterogeneous environments. Moreover, the average F. hodginsii seedling root vitality under the heterospecific neighbor was the highest, and the root vitality in the N heterogeneous environment was the highest under each planting pattern. The F. hodginsii root catalase (CAT) and peroxidase (POD) activities under the competition patterns were significantly higher than under the single-plant condition. Additionally, the superoxide dismutase (SOD) activity under single-plant was higher than under the competition patterns. At the same time, the F. hodginsii root malondialdehyde (MDA) content was the highest under the conspecific neighbor. Relative to the homogeneous environment, the root CAT, SOD, and POD activities were increased in the N and P heterogeneous environments. The CAT, SOD, and POD activities were highest in the P heterogeneous environment, while the K heterogeneous environment had the highest average MDA content. From the results of principal component analysis, when F. hodginsii seedlings were in N and P heterogeneous nutrient environments and heterospecific neighbor, their growth, root biomass accumulation, and root activity indexes reached better levels. [ABSTRACT FROM AUTHOR]