Effects of nitrogen deficiency on the transcriptome of the oleaginous alga Parachlorella kessleri TY

Figures & data

Table 1. The composition of TAP media and nitrogen deficient media

Composition of TAP	Working solution (g l^–1)	Nitrogen deficient
Tris-base	2.42	2.42
NH4Cl	0.375	NaCl/0.41
MgSO4–7H2O	0.1	0.1
CaCl2–2H2O	0.05	0.05
KH2PO4	0.005	0.005
K2HPO4	0.011	0.011
Glacial acetic acid	1 ml	1 ml
Trace	1 ml	1 ml

Figure 1. Comparison of physiological and biochemical indicators of P_KND (Parachlorella kessleri nitrogen deficient), and P_KC (P. kessleri control) over 7 days of cultivation. (a) Dry weight (bar graph) and neutral lipid content (line). (b) chlorophyll content (bar graph) and photochemical efficiency of photosystem II (Fv/Fm) (line). Data are shown as mean ± SE, n = 3

Table 2. Biochemical indicators of P_KND (nitrogen deficient) and P_KC (control) at day 0 and day 7 of cultivation

Sample	Total protein content (%)		Total carbohydrate content (%)		Total lipid content (%)
	0 days	7 days	0 days	7 days	0 days	7 days
P_KND	53.89 ± 2.93	19.4 ± 0.92	6.51 ± 0.29	28 ± 1.13	11.83 ± 1.56	45.5 ± 1.61
P_KC	53.91 ± 2.92	24.6 ± 1.83	6.5 ± 0.31	22.5 ± 1.24	11.07 ± 0.8	33.2 ± 1.25

Table 3. The fatty acid compositions of P_KND and P_KC on day 7

Fatty acids	P_KND (% DW)	P_KC (% DW)
C16:0	26.81 ± 0.6	22.26 ± 0.27
C16:1	4.15 ± 0.05	2.35 ± 0.06
C16:2	2.1 ± 0.03	7.27 ± 0.07
C16:3	3.7 ± 0.05	–
C18:0	6.32 ± 0.1	7.81 ± 0.06
C18:1	17.05 ± 0.21	4.75 ± 0.09
C18:2	22.1 ± 0.16	13.8 ± 0.19
C18:3	10.2 ± 0.11	29.75 ± 0.21
C16 + C18	92.43 ± 0.48	87.92 ± 0.33
others	7.57 ± 0.48	12.08 ± 0.33
SFA	35.84 ± 0.57	34.14 ± 0.12
MUFA	22.94 ± 0.39	8.07 ± 0.05
PUFA	41.22 ± 0.18	57.8 ± 0.11

Table 4. The output of transcriptome sequencing of Parachlorella kessleri TY

Sample	Raw reads	Clean reads	Clean bases	Error (%)	Q20 (%)	Q30 (%)	GC (%)
P_KND1	59 251 354	57 937 432	8.69 GB	0.03	97.87	94.03	59.61
P_KND2	58 341 128	56 773 714	8.52 GB	0.03	97.20	92.66	59.46
P_KND3	73 468 276	71 627 564	10.74 GB	0.03	97.08	92.39	59.34
P_KC1	52 455 540	51 236 876	7.69 GB	0.03	97.95	94.26	61.59
P_KC2	55 004 720	53 576 220	8.04 GB	0.03	96.70	91.61	61.35
P_KC3	61 581 554	59 893 130	8.98 GB	0.03	96.95	92.13	61.52

Table 5. Splicing length distribution of unigenes in Parachlorella kessleri TY

	Min length	Mean length	Median length	Max length	N50	N90	Total nucleotides
Unigenes	201	2 291	1 837	16 488	3 381	1 222	213 148 334

Figure 2. Differential gene expression patterns in P_KND and P_KC. (a) Density distribution of FPKM in P_KND and P_KC. (b) Volcano plot of differential gene expression in P_KND and P_KC. (c) Enrichment distribution point diagram of KEGG pathway in P_KND and P_KC

Figure 3. Quantification of the expression levels of lipid metabolism related genes in Parachlorella kessleri TY under P_KND and P_KC by RT-qPCR analysis. Data are shown as mean ± SD, n = 3, with superscript letters indicating significance (p < 0.05)