Title of the dataset:
Data underlying the article Chilling Tolerance of Basil Is Not Affected by UVB/C: A ¹H NMR Study 

Creators:
Ying Liu
Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University & Research, PO Box 16, 6700 AA, Wageningen, The Netherlands
https://orcid.org/0000-0002-5340-0812

Contributors:
Sumin Seo, Young Hae Choi
Natural Products Laboratory, Institute of Biology, Leiden University, 2333 BE, Leiden, The Netherlands
https://orcid.org/0000-0003-1484-1700

Yongran Ji, Miaomiao Yao
Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University & Research, PO Box 16, 6700 AA, Wageningen, The Netherlands
https://orcid.org/0000-0002-7747-8702
https://orcid.org/0009-0002-8597-2222

Related publication:
Chilling Tolerance of Basil Is Not Affected by UVB/C: A ¹H NMR Study 


Description:
Research data

Basil (Ocimum basilicum L.) is susceptible to chilling injury (CI), leading to significant postharvest quality loss. This research aimed to improve basil’s chilling tolerance during cold storage through the application of supplemental UVB and UVC light at the end-of-production (EoP). Plant growth parameters (fresh weight and dry weight) were measured at harvest. The overall visual quality (OVQ) of basil leaves were scored and the maximum quantum yield of photosystem II (Fv/Fm) were measured to represent chilling damage at- and postharvest. Metabolite profiles of basil (cv. Dolly) leaves stored at 4 °C for up to 12 days were quantified by 1H NMR.

Light treatment: Control (red-white LED with no supplemental UV light), EoP-UVB (red-white LED with supplemental UVB light), EoP-UVC (red-white LED with supplemental UVC light)
Postharvest storage time: 0, 3, 6, 9, and 12 days
 
-Experimental details
 --Plant Growth
Basil plants (Ocimum basilicum L.) cv. Dolly (Enza Zaden, Enkhuizen, The Netherlands) were cultivated in a climate room at Wageningen University, The Netherlands, using a vertical farming system set-up consisting of two layers with three separate growing compartments (experimental units) at each layer. Seeds were sown on two separate dates (November 9th and December 15th 2022) for two independent replicated experiments. In each independent experiment, after transplanting, basil plants were randomly placed in six compartments.
 --Supplemental EoP-UV light treatments
All basil plants were continuously grown under a background of red-white LED light for 30 days and supplemental UVB or UVC treatments were applied during the last five days of cultivation as an EoP treatment. The three light treatments are red-white light (control), red-white light with supplemental UVB light (EoP-UVB), and red-white light with supplemental UVC light (EoP-UVC). The peak wavelength of UVB is at 311 nm and UVC at 250 nm. For EoP-UVB, plants were irradiated by fluorescent lamps at 0.62 ± 0.08 W m-2 for 30 min (total dose 5.5 ± 0.1 kJ m-2 , TL 20W/01 RS Narrowband UV-B, Philips, Eindhoven, The Netherlands), and for EoP-UVC, for 15 min at 0.65 ± 0.09 W m-2 (total dose 2.9 ± 0.1 kJ m-2, TUV T8 F17 UV-C 12W, Philips), both in the middle of the photoperiod. The three treatments were applied in both the top and bottom layers, with their positions randomly assigned within each layer.  
 --Measurements of growth parameters
At harvest, leaves and stems were separated and weighed for fresh mass and dry mass determination. 
 --Postharvest sampling and measurements
Uniform non-border plants were harvested after five-day UV illumination: 80 plants from control, 160 plants from EoP-UVB, and 160 plants from EoP-UVC treatments. At harvest, top two mature leaf pairs were taken per plant. Harvested leaves from two basil plants were stored in one plastic box at 4 °C. Samplings were performed on 0 (at harvest), 3, 6, 9, and 12 days of storage. At each sampling day, Fv/Fm of dark-adapted leaves was measured and a OVQ was given to leaves based on the abundance of CI symptoms. Afterwards, leaves from two boxes, (derived from four plants), were pooled as one sample, frozen in liquid nitrogen, ground into powder and stored at -80 °C for metabolomics analysis. In total, there were 100 samples collected.
 --Data processing and statistical analysis
The complete experiment was conducted as two independent experiments, each using one climate room with six growing compartments allocated to three light treatments. The experiment was analysed as a completely randomized block design. Each layer in the climate room was considered as one block, resulting in four blocks (n = 4) for statistical analysis. The growth parameters at harvest were calculated for each block based on two plants for the control (no UV) treatment, four for EoP-UVB, and four for EoP-UVC. For postharvest parameters, each block on each sampling day consisted of one pooled sample (four plants from two boxes) for the control, two pooled samples for EoP-UVB, and two pooled samples EoP-UVC. Values were averaged for each experimental unit except for metabolite analysis where the values of pooled samples were used. 


Keywords:
Chilling injury, Ocimum basilicum, end-of-production (EoP), UVB radiation, UVC radiation, 1H NMR, metabolomics


This dataset contains the following files: Chilling Tolerance of Basil Is Not Affected by UVBC A ¹H NMR Study_Research data deposit.xlsx
This file has the following tabs:
1) ORCID: Available ORCIDs of authors
2) Materials and Methods: partly extracted from Material and Method section of the related publication
3) Growth: Measurements of leaf fresh weight, stem fresh weight, leaf dry weight, stem dry weight, leaf dry matter content, and stem dry matter content. Table 1 contains the measured data of individual plant, and Table 2 contains the averaged data per block for statistical analysis. 
4) FvFm & OVQ: Fv/Fm measurements and OVQ scores. Table 1 contains the measured data of individual plant, and Table 2 contains the averaged data per block for statistical analysis. 
5) NMR bucket: bucket data of NMR measurement


Explanation of variables:
FW: fresh weight
DW: dry weight
DMC: dry matter content; DMC (%) = DW / FW *100
Fv/Fm: Maximum quantum yield of PSII - is employed as a sensitive indicator of plant photosynthetic performance, particularly with lower values indicating stresses. Fv/Fm is used in this study to quantify CI. 
OVQ: Overall visual quality - scored from 8 (high quality, no defects) to 1 (fully decayed leaves, wilted, black), with a score of 5 (clear brown or black coloration, or first signs of senescence) designating as the customer acceptance limit, representing the end of shelf life.

-Growth Tab
Plant: contains individual plant numbers
Treatment: contains three light treatments that applied at the end of production (EoP), namely control (white-red LED), EoP-UVB (supplemental UVB + white-red LED), and EoP-UVC (supplemental UVC + white-red LED)
Block: contains block information. Four blocks in total. 
Leaf FW (g), Stem FW (g), Leaf DW (g) & Stem DW (g): measured value in Table 1 and block-averaged value in table 2
Leaf DMC (%) & Stem DMC (%): calculated value based on FW and DW. Individual plant value in Table 1 and block-average value in Table 2

-FvFm & OVQ Tab
Treatment: contains three light treatments that applied at the end of production (EoP), namely control (white-red LED), EoP-UVB (supplemental UVB + white-red LED), and EoP-UVC (supplemental UVC + white-red LED)
Day: indicates on which day the samples were measured (0, 3, 6, 9, and 12 days). Day 0 indicates the day at harvest.
Block: contains block information. Four blocks in total. 
Plant: contains individual plant number per block
OVQ: estimated score in Table 1 and block-averaged value in table 2
Fv/Fm: measured value in Table 1 and block-averaged value in table 2
Pooled Sample: four plants from the same block were pooled as one sample

-NMR bucket Tab
Code: contains numbering of pooled samples
Pooled Samples: contains the name of pooled samples
Treatment: contains three light treatments that applied at the end of production (EoP), namely control (white-red LED), EoP-UVB (supplemental UVB + white-red LED), and EoP-UVC (supplemental UVC + white-red LED)
Day: indicates on which day the samples were measured (0, 3, 6, 9, and 12 days). Day 0 indicates the day at harvest.
Block: contains block information. Four blocks in total.
Row 1 (from column F to RW): NMR signal
Row 2 (from column F to RW): chemical shifts (ppm)


Methods, materials and software:
-The assessment of OVQ employed a scoring system, on visual symptoms.
-The Fv/Fm of leaves was measured using chlorophyll fluorescence imaging (Fluorcam 800-C, PSI, Czech Republic).
-For NMR analysis, 30 mg of freeze-dried ground material was placed into 2 mL microtubes and extracted with either 1 mL of CH3OH-d4 containing 0.418 mM hexamethyldisiloxane (HMDSO) as an internal standard or 1 mL of CH3OH-d4 – KH2PO4 buffer in D2O (90 mM, pH 6.0, 1:1, v/v) containing 0.29 mL trimethysilylpropionic acid sodium salt (TMSP) as an internal standard. The tubes underwent vortex for 1 min and ultrasonication for 20 min at room temperature (22 °C). The extracts were centrifuged (12000 x g, 10 min, 22 °C) to obtain a clear supernatant, from which 300 µL aliquots were transferred into 3 mm NMR tubes for 1H NMR analysis. The 1H NMR measurements were conducted using an Avance-III 600 MHz standard bore liquid-state NMR spectrometer (Bruker, Billerica, Massachusetts, USA) equipped with a TCI cryoprobe optimized for 1H detection with Z-gradient capability, with CH3OH-d4 for internal locking. Measurements were conducted at a constant temperature of 298 K (25 °C), employing a 30-degree pulse with a duration of 2.64 ms, relaxation delay of 1.5 s, and an acquisition time of 2.7 s. The time-domain data were transformed into the frequency domain via Fourier transformation, utilizing an exponential window function with a line broadening factor of 0.3 Hz to achieve smoothing. The resulting spectra were manually phased, baseline corrected, and calibrated to reference standards: TMSP-d4 at δ 0.0 ppm or HMDSO at δ 0.06 ppm using TOPSPIN V. 3.0 (Bruker). 


This dataset is published under the CC BY (Attribution) license.
This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator.

