Data of ecoenzyme activities in throughfall and rainfall samples taken at five subtropical forests in southern China

The data presented in this article are referred to the research article “A potential source of soil ecoenzymes: From the phylllosphere to soil via throughfall” (Mori et al., 2019). The data included the activities of β-1,4-glucosidase (BG, EC 3.2.1.21), β-d-cellobiosidase (CBH, EC 3.2.1.91), β-1,4-N-acetyl-glucosaminidase (NAG, EC 3.2.1.52), leucine amino peptidase (LAP, EC 3.4.11.1), polyphenol oxidase (PPO, EC 1.10.3.2), and phosphomonoesterase (PME, EC 3.1.3.2). The informatin of study sites and sampling method are shown in Fig. 1 and 2.


Data
The six types of ecoenzymes, i.e., b-1,4-glucosidase ( Table 1. Supplementary csv file provides the raw data of the enzyme activities. The activities of BG, CBH, NAG, LAP, and PME were measured by fluorescence enzyme assays. The activity of PPO was determined by spectrophotometric assay.

Study site
This study was conducted in five subtropical forests in two research stations, i.e., Dinghushan Biosphere Reserve (DHS) (112 10 0 E, 23 10 0 N) [2] and Heshan National Field Research Station (HS) Specifications Table   Subject area Ecology More specific subject area

Ecosystem Ecology
Type of data Table and csv file  How data was acquired Fluorescence enzyme assay and spectrophotometric assay.

Data format
Raw, analyzed

Experimental factors
Throughfall and rainfall samples were taken in five types of subtropical forests located in southern China. The samples were taken after rainfall events as soon as possible.

Experimental features
A portion of the collected samples was incubated with artificial substrates. After the incubation, we determined the changes in the substrates, which represent the enzyme activity of the collected samples.

Data source location
The studied area is situated within Dinghushan Biosphere Reserve (DHS) (112 10 0 E, 23 10 0 N), and Value of the data This data, for the first time, provide information of ecoenzymes transferred from forest canopy into soils via throughfall. This data will be available for future works comparing the amount of ecoenzymes in throughfall among different types of forests in different climate zone. The present data can be reused in future works looking for the contribution of ecoenzyme in throughfall to soil enzyme activity. Table 1 The enzyme activity of throghfall and rainfall in five subtropical forests in southern China.

TF/ RF
site Forest type (112 50 0 E, 22 34 0 N) (Fig. 1) [3]. Three types of forests, i.e., a primary monsoon evergreen broadleaf forest (BF), a secondary mixed pine/broadleaf forest (MF), a planted Pinus massoniana forest (PM) are located in DHS. According to earlier studies, the BF has been protected for more than 400 years [2]. Dominant species of the BF are Castanopsis chinensis Hance, Schima superba Gardn. & Champ., Cryptocarya chinensis (Hance) Hemsl., Machilus chinensis (Champ. ex Benth.) Hemsl. and Syzygium rehderianum Merr. & Perry in the canopy and subcanopy layer [2,4]. The other two forests in DHS (MF and PF) were clear-cut in the 1930s, and P. massoniana plantations were established thereafter. The pine plantation was naturally colonized by broadleaf species to become a mixed forest in MF. Meanwhile, the understory vegetation and litter in PM were harvested constantly until the late 1990s, which resulted in a dominance of P. massoniana (more than 90% of the total basal area) in PM. In MF, Pinus massoniana and Schima superba are the dominant tree species. The soils in the DHS are lateritic red earths (Oxisols) formed from sandstone [2,4]. In HS site, the other two forests, i.e., a planted Acacia auriculiformis forest (AA), and a planted Eucalyptus urophylla forest, are located. Both AA and EU are 34 years old at the time of sampling. Previous studies reported that the soils in the two plantations are classified as Acrisols [5]. The annual precipitation and mean annual temperature are 1927 mm and 21.0 C, respectively, in DHS [6], and 1580 mm and 22.5 C, respectively, in HS [7].

Sampling
In August 2017, throughfall samples were collected in the five subtropical forests. We placed plastic boxes both inside and outside of the five forests (Fig. 2). We prepared 7, 5, 7, 6, and 6 replications of the boxes in BF, MF, PM, AA, and EU, respectively. We also collected rainfall samples in order to determine the background enzyme activity of rainfall. The boxes were placed at the outside of the forests, where there was no vegetation above the boxes. Rainfall samples were collected in triplicate in each research station. In total, 31 throughfall samples and 6 rainfall samples were collected. Those samples were collected as soon as possible after a rainfall event and kept cool/frozen in the research station near the forests.

Enzyme assay
We measured six types of ecoenzymes in the throughfall and rainfall samples. The activities of b-1,4-glucosidase (BG, EC 3.2.1.21), b-D-cellobiosidase (CBH, EC 3.2.1.91), b-1,4-N-acetyl-glucosaminidase , and phosphomonoesterase (PME, EC 3.1.3.2) were determined. Fluorescence enzyme assays were used for determining hydrolytic enzyme activities [8,9]. A portion of the collected samples (100 m) was dispensed into 96-deep-well plates. For analyzing BG, CBH, NAG, and PME activities, substrates labeled with 4-methylumbelliferone (MUB) were added. For the analysis of LAP activity, 7-amino-4methylcoumarin (MUC) were added. The final substrate concentration was 150 mM for BG, CBH, NAG, and PME, and 100 mM for LAP. The solution volume was 1000 mL. After mixed well, the deep plates were incubated for 4 hours at 20 C in the dark. After the incubation, 250 mL of the incubated solution was transferred into black 96-well plates. We measured fluorescence (365 nm excitation, 450 nm emission) with a microplate spectrophotometer. Standard lines were prepared for all samples by determining the fluorescence of known concentrations of the MUB or MUC solutions with 100-mL aliquots of the collected samples. PPO activity was measured by spectrophotometric assay [9]. A portion of the collected samples (100 m) was dispensed into 96-deep-well plates with 700 mL of pure water and 200 mL of dihydroxyphenylalanine (DOPA, 25 mM). The deep-well plates were incubated for 65 hours at 20 C in the dark. Absorbance at 450 nm was measured using a microplate spectrophotometer. We prepared negative and blank controls for all enzyme assays. For minimizing "well to well variation" (Bell et al., 2013), three assay replicates in each plate were prepared. The activities of each types of ecoenzymes are represented in units of mg substrates (MUB for BG, CBH, NAG, and PME; MUC for LAP; and DOPA for PPO) h À1 L À1 .