Table 1.

Estimation of tetrapyrroles in aerial tissue of Arabidopsis WT and gun5 seedlings determined by LC/MS

Treatment	pmol·g−1 FW
	Proto IX	Mg-proto	Mg-proto ME	DV-Pchilde	MV-Pchlide	DV-Chlide	MV-Childe
1 + ALA Dk
WT	165 ± 74	47 ± 22	280 ± 181	2450 ± 1394	2116 ± 1362	200 ± 35	287 ± 124
gun5	313 ± 115	21 ± 5	97 ± 45	1996 ± 1272	1170 ± 845	318 ± 82	294 ± 141
2 Dk
WT	32 ± 9	ND	ND	510 ± 218	1172 ± 600	79 ± 14	172 ± 45
gun5	39 ± 11	ND	ND	354 ± 121	151 ± 72	109 ± 15	99 ± 12
3 24 h WL
WT	ND	ND	ND	137 ± 49	358 ± 175	2098 ± 1155	3421 ± 878
gun5	Present	ND	ND	51 ± 16	201 ± 114	1436 ± 812	654 ± 105
4 + ALA + NF Dk
WT	101 ± 53	47 ± 22	108 ± 54	2355 ± 1318	1390 ± 889	58 ± 25	243 ± 131
gun5	410	Present	71	2614	1565	136	401
5 + NF Dk
WT	Present	ND	ND	481 ± 217	689 ± 357	219 ± 56	250 ± 73
gun5	Present	ND	ND	536 ± 335	226 ± 144	79 ± 10	184 ± 110
6 + NF 24 h WL
WT	ND	ND	ND	7 ± 1	5 ± 1	13 ± 5	73 ± 36
gun5	ND	ND	ND	14 ± 8	5 ± 1	25 ± 9	11 ± 5

Seedlings were grown for 4 d in the dark (Dk) or 3 d in the dark then 24 h in light (WL). For treatments 4–6, seedlings were grown with 5 μM NF. ALA (1 mM) was applied to the seedlings 16 h before harvest for treatments 1 and 4. Values are the mean of at least four independent experiments ± standard deviation, except for gun5 under treatment 4. The limit of sensitivity for accurate quantification is equivalent to 20 pmol·g⁻¹ FW. Present, compound identified unambiguously by the mass of the major ion and its fragmentation pattern but below the quantification threshold; ND, correct mass/fragmentation pattern not detected.