Ginkgo biloba L. is one of the most extensively planted and productive commercial species in temperate areas around the world, but slow-growth is the most limiting factor for its utilization. Fertilization is one of the key technologies for high quality and high forest yield. To better understand the impacts of fertilization on Ginkgo productivity, the effects of fertilization treatments (single fertilizer and combined fertilizer) on growth, nutrient content in Ginkgo leaves, and photosynthesis characteristics were studied in a 10-year-old Ginkgo plantation over two years. The single factor experiments suggested that DBH (diameter at breast height), H (height), NSL (length of new shoots), and V (trunk volume) showed significant differences between the different levels of single nitrogen (N) or phosphate (P) fertilizer application. Orthogonal test results showed that the nine treatments all promoted the growth of Ginkgo, and the formula (N: 400 g·tree⁻¹, P: 200 g·tree⁻¹, potassium (K): 90 g·tree⁻¹) was the most effective. G_s (stomatal conductance) and P_n (net photosynthesis rate) showed significant differences between the different amounts of single N or P fertilizer application, while single K fertilizer only affected P_n. Combined N, P, and K fertilizer had significant promoting effects on C_i (intercellular CO₂ concentration), G_s and P_n. N and P contents in Ginkgo leaves showed significant differences between the different amounts of a single N fertilizer application. A single P fertilizer only improved foliar P contents in Ginkgo leaves. A single K fertilizer application improved N and K content in Ginkgo leaves. The effects of different N, P, and K fertilizer treatments on the nutrient content of Ginkgo leaves were different.

To elucidate the transcriptomic regulation mechanisms that underlie the response of Ginkgo biloba to dehydration and rehydration, we used ginkgo saplings exposed to osmotically driven water stress and subsequent rewatering. When compared with a control group, 137, 1453, 1148, and 679 genes were differentially expressed in ginkgo leaves responding to 2, 6, 12, and 24 h of water deficit, and 796 and 1530 genes were differentially expressed responding to 24 and 48 h of rewatering. Upregulated genes participated in the biosynthesis of abscisic acid, eliminating reactive oxygen species (ROS), and biosynthesis of flavonoids and bilobalide, and downregulated genes were involved in water transport and cell wall enlargement in water stress-treated ginkgo leaves. Under rehydration conditions, the genes associated with water transport and cell wall enlargement were upregulated, and the genes that participated in eliminating ROS and the biosynthesis of flavonoids and bilobalide were downregulated in the leaves of G. biloba. Furthermore, the weighted gene coexpression networks were established and correlated with distinct water stress and rewatering time-point samples. Hub genes that act as key players in the networks were identified. Overall, these results indicate that the gene coexpression networks play essential roles in the transcriptional reconfiguration of ginkgo leaves in response to water stress and rewatering.

To understand the characteristics of net NH₄⁺ and NO₃⁻ fluxes and their relation with net H⁺ fluxes in Taxodium, net fluxes of NH₄⁺, NO₃⁻ and H⁺ were detected by a scanning ion-selective electrode technique under different forms of fixed nitrogen (N) and experimental conditions. The results showed that higher net NH₄⁺ and NO₃⁻ fluxes occurred at 2.1–3.0 mm from the root apex in T. ascendens and T. distichum. Compared to NH₄⁺ or NO₃⁻ alone, more stable net NH₄⁺ and NO₃⁻ fluxes were found under NH₄NO₃ supply conditions, of which net NH₄⁺ flux was promoted at least 1.71 times by NO₃⁻, whereas net NO₃⁻ flux was reduced more than 81.66% by NH₄⁺ in all plants, which indicated that NH₄⁺ is preferred by Taxodium plants. T. ascendens and T. mucronatum had the largest net NH₄⁺ and total N influxes when NH₄⁺:NO₃⁻ was 3:1. ¹⁵N Atom% and activities of N assimilation enzymes were improved by single N fertilization in the roots of T. distichum. In most cases, net H⁺ fluxes were tightly correlated with net NH₄⁺ and NO₃⁻ fluxes. Thus, both N forms and proportions could affect N uptake of Taxodium. These findings could provide useful guidance for N management for better productivity of Taxodium plants.