Table 4.

Summary of protein changes in each strain during salt stress

Protein accession ID	Protein name	Pathway/role	Salt stress treatment comparisons with relative protein changes (values indicate fold change)
			C. reinhardtii				C. nivalis
			0–11 h salt	11–18 h salt	0–18 h salt	18 h control–18 h salt	0–80 h salt	80–168 h salt	0–168 h salt	168 h control–168 h salt
Stress proteins
A8HYV3/ Q39603	Heat shock protein 70B	Chloroplast localised heat shock protein protecting against photoinhibition [84]	↑ 1.073	→	↑ 1.077	→	↓ -1.340	→	↓ -1.363	↓ -1.708
A8J3P5	Heat shock protein 70E	Cytosolic heat shock protein [84]	→	→	→	↓ -1.172	→	→	→	→
A8JEU4	Heat shock protein 70A	Cytosolic heat shock protein [84]	→	→	→	→	↓ -1.358	→	↓ -1.334	↓ -1.880
A8IZU0	Heat shock protein 70C	Mitochondrial heat shock protein [84]	→	→	→	→	↓ -1.336	→	↓ -1.386	↓ -1.731
A8J1U1	Heat shock protein 90A	Cytosolic heat shock protein [85]	→	→	→	→	→	→	↓ -1.189	↓ -1.848
Q66T67	Heat shock protein 90C	Chloroplastic heat shock protein [85]	→	→	→	→	→	→	↓ -1.543	↓ -1.868
A8I7T1	Heat shock protein 90B (Fragment)	ER localised heat shock protein [86]	→	→	→	→	→	→	→	↓ -1.771
Q1RS84	Aldehyde-alcohol dehydrogenase	Aldehyde scavenging (during lipid peroxidation) [42]	↑ 1.134	→	↑ 1.106	→	→	→	→	→
A8JHR9/ A8JHS0/ P49644	Glyceraldehyde-3-phosphate dehydrogenase	Glycolysis (and carbohydrate metabolism)	→	↑ 1.155	↑ 1.284	→	↑ 2.166	→	↑ 2.200	→
A8HXA6	Glutathione reductase	Reduction of glutathione disulphide [45]	↓ -1.195	↑ 1.201	→	→	→	↑ 1.277	→	→
A8JG06	Programmed cell death protein 6-interacting protein	Protein self-association and ubiquitin binding	→	→	→	→	→	↑ 1.208	→	→
A8J1C1	Ubiquitin-activating enzyme E1	Ubiquitin conjugation cascade	↓ -1.088	↑ 1.169	→	→	→	↑ 1.254	↑ 1.198	↑ 1.097
A8J5Z8	Aldehyde dehydrogenase	Aldehyde detoxification, ROS scavenging, inhibits lipid peroxidation	→	↑ 1.180	↑ 1.274	↑ 1.271	→	→	↑ 1.306	→
A8JB85	Autophagy-related protein	Autophagy	↑ 1.385	→	↑ 1.274	→	→	→	↑ 1.352	→
A8J431	Stress-related chlorophyll a/b binding protein 2	Non-photochemical quenching, protect photosynthetic apparatus from photo-oxidative damage	→	→	→	↑ 1.776	→	→	↑ 1.572	→
Photosynthesis proteins
Q39588	Carbonic anhydrase, alpha type	Carbon dioxide fixation [87]	→	→	↓ -1.202	↓ -1.135	→	→	→	→
Q8S567	Chlorophyll a/b-binding protein	Photosynthesis and light harvesting	↓ -1.190	→	↓ -1.191	→	→	→	→	→
A8J270	Chlorophyll a-b binding protein of LHCII	Light harvesting in photosystem I	→	→	→	↑ 1.144	→	→	→	→
Q8S3T9	Chlorophyll a-b binding protein of LHCII	Light harvesting in photosystem I	→	→	→	↑ 1.171	→	→	→	→
A8HP84/ P50362	Glyceraldehyde-3-phosphate dehydrogenase	Photosynthesis, Calvin cycle	→	→	→	→	↓ -1.529	→	↓ -1.682	↓ -2.147
Q75VY7	Light-harvesting chlorophyll-a/b protein of photosystem I	Chlorophyll binding, light harvesting in photosystem I	↓ -1.240	→	→	↓ -1.347	→	→	→	→
A8ITV3	Light-harvesting protein of photosystem I	Chlorophyll binding, light harvesting in photosystem I	↓ -1.190	→	↓ -1.191	→	→	→	→	→
Q93VE0	Light-harvesting chlorophyll-a/b binding protein LhcII-4	Chlorophyll binding, light harvesting in photosystem I	→	→	→	↑ 1.147	→	→	→	→
A8J0B1	Low-CO2-inducible protein	Inorganic carbon uptake [52]	↓ -1.161	→	→	→	→	→	→	→
A8J225	Low-CO2-inducible protein (Fragment)	Inorganic carbon uptake [52]	↑ 1.285	→	↑ 1.240	↑ 1.385	→	→	→	→
Q75NZ1	Low-CO2 inducible protein	Inorganic carbon uptake [52]	→	↑ 1.067	→	→	→	→	→	→
A8IT08	Low-CO2-inducible chloroplast envelope protein	L-orthinine transmembrane transport activity	→	→	↑ 1.268	↑ 1.390	→	→	→	→
A8JEV1	Oxygen evolving enhancer protein 3	Photosynthetic electron transfer chain, calcium ion binding	→	↓ -1.150	↓ -1.141	↓ -1.226	↓ -1.495	→	↓ -1.674	→
A8J0E4	Oxygen-evolving enhancer protein 1 of photosystem II	Photosystem II assembly and stability, oxygen evolving activity	→	↓ -1.094	↓ -1.145	↓ -1.290	↓ -1.864	→	↓ -2.186	↓ -2.300
A8IYH9	Oxygen-evolving enhancer protein 2 of photosystem II	Photosynthesis, calcium ion binding	→	→	↓ -1.136	↓ -1.108	↓ -1.520	→	↓ -1.626	↓ -2.072
P12852	Oxygen-evolving enhancer protein 3, chloroplastic	Photosynthesis, calcium ion binding	→	↓ -1.150	↓ -1.141	↓ -1.226	↓ -1.495	→	↓ -1.674	→
Q00914	Photosystem I iron-sulphur centre	Photosynthetic electron transport in photosystem I	→	→	→	→	↓ -1.672	→	↓ -1.932	→
P13352	Photosystem I reaction centre subunit VI, chloroplastic	Photosynthesis	→	→	→	→	→	→	→	↓ -2.285
Q5NKW4	Photosystem I reaction centre subunit II, 20 kDa	Photosynthesis	→	↓ -1.177	→	→	→	→	→	→
Q39615	Photosystem I reaction centre subunit II, chloroplastic	Photosynthesis	→	↓ -1.177	→	→	→	→	→	→
P12154	Photosystem I P700 chlorophyll a apoprotein A1	Photosynthesis, electron transfer, chlorophyll binding	→	→	↓ -1.261	→	↓ -1.823	→	↓ -1.864	→
P09144	Photosystem I P700 chlorophyll a apoprotein A2	Photosynthesis, electron transfer, chlorophyll binding	→	→	↓ -1.200	→	↓ -1.643	→	↓ -1.614	→
P10898	Photosystem II CP43 reaction centre protein	Photosynthetic electron transport in photosystem II, chlorophyll binding	→	→	→	→	↓ -1.623	→	↓ -1.824	↓ -1.469
P37255	Photosystem II CP47 reaction centre protein	Photosynthetic electron transport in photosystem II, chlorophyll binding	→	→	→	→	↓ -1.583	→	↓ -1.693	→
P06007	Photosystem II D2 protein	Photosynthetic electron transport in photosystem II, chlorophyll binding	→	→	→	→	↓ -1.611	→	↓ -1.634	→
P07753	Photosystem II protein D1	Photosynthetic electron transport in photosystem II, chlorophyll binding	→	→	→	→	↓ -1.840	→	↓ -1.727	↓ -1.445
A8J4S1	Photosystem I reaction centre subunit III	Photosynthesis, protein domain specific binding	→	↓ -1.255	↓ -1.289	↓ -1.461	→	→	→	→
P12356	Photosystem I reaction centre subunit III, chloroplastic	Photosynthesis, protein domain specific binding	→	↓ -1.255	↓ -1.289	↓ -1.461	→	→	→	→
A8HVJ9	Photosystem II stability/assembly factor HCF136 fragment	Photosystem II biogenesis	→	→	→	↓ -1.190	→	→	→	→
A8JGP9	Ribulose bisphosphate carboxylase small chain	Carbon fixation, photorespiration, photosynthesis	↓ -1.213	→	↓ -1.356	→	→	→	→	→
P00873	Ribulose bisphosphate carboxylase small chain 1, chloroplastic	Carbon fixation, photorespiration, photosynthesis	↓ -1.213	→	↓ -1.356	→	→	→	→	→
P08475	Ribulose bisphosphate carboxylase small chain 2, chloroplastic	Carbon fixation, photorespiration, photosynthesis	↓ -1.219	→	↓ -1.357	→	→	→	→	→
P00877	Ribulose bisphosphate carboxylase large chain	Photorespiration, reductive pentose-phosphate cycle	→	↓ -1.078	↓ -1.154	↓ -1.110	↓ -1.810	→	↓ -1.991	↓ -2.751
P23489	Ribulose bisphosphate carboxylase/oxygenase activase, chloroplastic	Photosynthesis regulation	→	↓ -1.107	↓ -1.108	↓ -1.186	→	→	↓ -1.555	↓ -2.809
Q6SA05	Rubisco activase	Photosynthesis regulation	→	↓ -1.107	↓ -1.108	→	→	→	↓ -1.555	↓ -2.809
Carbohydrate proteins
Q2VA40	Alpha-1,4 glucan phosphorylase	Starch degradation [88]	↑ 1.123	↑ 1.105	↑ 1.240	↑ 1.122	↑ 1.237	↑ 1.158	↑ 1.433	↓ -1.688
Q2VA41/ A8IYK1	Alpha-1,4 glucan phosphorylase	Starch degradation [88]	↑ 1.096	→	↑ 1.147	→	→	→	→	→
A2PZC2	UDP-glucose:protein transglucosylase	Polysaccharide biosynthesis	→	→	→	→	↓ -1.535	→	↓ -1.713	↓ -2.510
A8HW52	Starch branching enzyme	Starch biosynthesis	→	→	→	→	→	→	→	↓ -2.318
A8IHX1	Starch branching enzyme	Starch biosynthesis	→	→	↑ 1.207	→	→	→	→	→
A8J914	UDP-glucose 6-dehydrogenase	Starch catabolism for glycolysis [58]	↑ 1.263	↑ 1.239	↑ 1.562	↑ 1.478	→	→	→	→
A2PZC3	UDP-glucose 6-dehydrogenase	Starch catabolism for glycolysis [58]	↑ 1.298	↑ 1.231	↑ 1.595	↑ 1.461	→	→	→	↑ 2.008
Lipid proteins
A8HNN4/ A0A0B5KTL4	Glycerol-3-phosphate dehydrogenase	Glycerol metabolism, link between carbohydrate and lipid metabolism	↑ 1.675	↑ 1.169	↑ 1.959	↑ 1.959	↑ 2.135	↑ 1.192	↑ 2.544	↑ 2.648
A0A0B5KYA7	Glycerol-3-phosphate dehydrogenase	Glycerol metabolism, link between carbohydrate and lipid metabolism	↑ 1.719	↑ 1.179	↑ 2.027	↑ 2.064	→	→	→	→
A8HNN6	Glycerol-3-phosphate dehydrogenase (fragment)	Glycerol metabolism, link between carbohydrate and lipid metabolism	↑ 1.744	↑ 1.189	↑ 2.073	↑ 2.109	→	→	→	→
A8J6J6	Acetyl-CoA acyltransferase	Catabolic beta-oxidation of fatty acids [63]	↑ 1.162	→	↑ 1.181	↑ 1.209	→	→	↑ 1.250	↑ 1.375
A8J2S0	Citrate synthase	Tricarboxylic acid cycle	→	→	→	→	→	→	→	↓ -2.725
Q6DN05	Betaine lipid synthase	Betaine lipid synthesis, including DGTS synthesis	→	↓ -1.093	→	→	→	→	→	→
A8HXT4	Pyruvate carboxylase	Pyruvate metabolism, gluconeogenesis, links carbohydrate and lipid metabolism	→	↓ -1.047	↓ -1.100	→	→	→	→	→
A8JGF4	Biotin carboxylase, acetyl-CoA carboxylase component	Malonyl-CoA biosynthesis, lipid metabolism	→	→	→	↓ -1.113	↓ -1.479	→	↓ -1.482	↓ -1.860
Q763T6	UDP-sulfoquinovose synthase	Glycerolipid metabolism, sulfoquinovosyl diacylglycerol (SQDG) metabolism	→	→	→	→	↓ -1.275	→	↓ -1.289	↓ -1.770
A8J1T4	Dihydrolipoyl dehydrogenase	Acetyl CoA production, cell redox homeostasis	→	→	→	→	↑ 1.110	→	→	↑ 1.149

Changes in stress-related proteins, photosynthesis-related proteins, carbohydrate-related proteins and lipid-related proteins are shown for C. reinhardtii and C. nivalis subjected to salt stress. Arrows indicate up-regulation (↑), down-regulation (↓) and not significantly changed ( →). Values indicate fold changes