Table 2.

The structure of phytochelatins identified in different plant species depending on the metal(loid) concentration in the medium and the duration of exposure.

Species	Plant Material	Metal(loid) Concentration	Duration of Exposure	PC Structure	Ref.
Amaranthaceae
Amaranthus hypochondriacus	Leaves	100 mg/kg Cd	3 months	PC2–4	[40]
Pfaffia glomerata	Roots	25, 50, 100 µM As	28 days	PC2–4	[41]
Spinacia oleraceae	Roots, leaves	1, 3, 5, 9 mg/L Cd	1, 3, 5, 7, 9, 14 days	PC2–4	[42]
Apiaceae
Datura innoxia	Cell culture	250 µM Cd	up to 2 h	PC2–5	[43]
Apocynaceae
Rauvolfia serpentina	Cell culture	200 µM Cd	1–9 h	PC2–5	[44]
Asteraceae
Dittrichia viscosa	Roots, shoots	5, 10, 15 mg/L Cd	10 days	PC2–4, iso-PC2–3(Cys), des-γGlu-iso-PC2–3(Gly), des-Gly-PC2–3	[45]
Eupatorium cannabinum	Roots	11 mg/L As	20 days	PC2–4, des-Gly-PC2–4, γGlu-iso-PC3(Gly)	[46]
	Leaves			PC3–4, des-Gly-PC2, des-γGlu-iso-PC2(Gly)
Helianthus annuus	Roots, stems, leaves	66 µmol/L As	1–96 h	PC2–3	[47]
Brassicaceae
Arabidopsis halleri	Roots	25 µM Cd 100 µM Cd	7 days	PC2–4 PC2–5	[48]
	Shoots	25 µM Cd 100 µM Cd		n.d. * PC2–4
Arabidopsis thaliana	Seedlings	30 µM Cd	1 day	PC2–4	[49]
		30, 90 µM Cd	3, 9 days	PC2–4	[50]
		20 µM Cd	3 days	PC2–4	[51]
		10 µM Cd	5 days	PC2–4	[52]
	Roots, leaves	5 µM Cd	1, 3, 7, 14, 21 days	PC2–5	[53]
	Roots, shoots	10, 25 µM Cd	7 days	PC2–5	[48]
	Leaves	7.5 mg/kg Cd 970 mg/kg Zn	24 days	PC2–3	[54]
	Roots, shoots	10 µM Cd 5 µM Cu 150 µM Zn	12 days	PC2–5	[55]
	Roots, shoots	20 µM Cd	72 h	PC2–4	[56]
	Roots, shoots	1 µM Hg, 0.1 µM phenylmercury	4 days	PC2	[57]
	Cell culture	200 µM Cd	1, 4, 8, 11, 24, 48 h	PC2–4(5), iso-PC3–4(Ser), iso- PC3(Glu), iso-PC3–4(βAla), iso-PC3–4(Gln)	[58]
		50 µM Cd	1 day	PC2–5, iso-PC3–4(βAla)
		400 µM Cd	1 day	PC2–5, iso-PC3–4(Ser), iso- PC3(Glu), iso-PC3–4(βAla), iso-PC3–4(Gln)
Armoracia rusticana	Roots	1000 µM Cd	3 days	PC3–4	[59]
Brassica chinensis	Roots	200 µM Hg	3 days	PC2–4	[60]
Brassica juncea	Roots, shoots	50, 200 µM Cd	7 days	PC2–4	[61]
	Roots, leaves	500, 1000, 2000 mg/kg Pb	45 days	PC2–3	[62]
Brassica oleracea	Seedlings	90 µM Cd	21 days	PC2–6	[44]
Noccaea caerulescens (Thlaspi caerulescens)	Roots, shoots	1–50 µM Cd	4 days	PC2–3	[63]
	Roots shoots	25, 100 µM Cd 25, 100 µM Cd	7 days 7 days	PC2–4 n.d.	[48]
	Roots, shoots	5–500 µM Cd	14 days	PC2–4	[64]
Sinapis alba	Leaves	0.5, 1 mg/L Pd	2 weeks	PC2–4	[65]
Thlaspi arvense	Roots, shoots	1–50 µM Cd	4 days	PC2–3	[63]
Caryophyllaceae
Silene vulgaris	Cell culture	20 µM Cd	3 days	PC2–4	[44]
	Roots	0.3, 1, 45, 135, 180 µM Cd	3 days	PC2–4	[66]
		40 mmol m−3 Cd	21 days	PC2–3	[67]
Crassulaceae
Sedum alfredii	Shoots	500 µM Cd	8 days	PC2–4	[68]
Cucurbitaceae
Cucumis sativus	Roots	10–250 µM Sb	28 days	PC2, 3	[69]
Fabaceae
Arachis hypogaea	Roots	10 µM Cd	30 days	PC2–4	[70]
Glycine max	Roots	20 µM Cd	4 days	iso-PC2–7(βAla)	[71]
Pisum sativum	Roots	20 µM Cd	3 days	PC2–3, iso-PC3(βAla)	[72]
		1–120 µM Cd	1–9 days	PC2–4, iso-PC2–4(βAla)	[73]
Lamiaceae
Clinopodium vulgare	Roots	20 mg/kg Cd 250 mg/kg Pb 400 mg/kg Cu 400 mg/kg Zn	95, 105 days	All metals: PC2–5, iso-PC2(Ala); Cu: iso-PC2(Glu), iso-PC2–4(Cys); Cu, Cd, Pb: des-γGlu-iso-PC2–3(Gly); Cu, Cd, Pb: des-Gly-PC2	[74]
	Shoots	20 mg/kg Cd 250 mg/kg Pb 400 mg/kg Cu 400 mg/kg Zn	95, 105 days	All metals: PC2–5Cu, Cd, Pb: des-γGlu-iso-PC2–3(Gly) Cu, Cd, Pb: des-Gly-PC2
Perilla frutescens	Roots, stems, leaves	2, 5, 10 mg/L Cd	14 days	PC2–4	[75]
			21 days	PC2–3
Marchantiaceae
Marchantia polymorpha	Gametophyte	10–36 µM Cd	6–120 h	PC2–4	[76]
		10, 20, 36 µM Cd	72 h	PC2–4	[77]
Poaceae
Agrostis tenuis	Cell culture	20 µM Cd	3 days	PC2–4	[44]
Avena sativa	Roots	10 µM Cd	4 days	PC2–3	[78]
Holcus lanatus	Roots	5, 15, 40, 800 µM As	7 days	PC2–4	[79]
Lolium perenne	Roots, shoots	20, 80 µM Cd	9 days	PC2–6	[80]
		20, 80 µM Cd	216 h	PC2–6	[81]
Oryza sativa	Roots	10 µM Cd 20 µM As	7 days	PC2–3, iso-PC2(Ser), iso-PC(Glu)	[82]
	Roots, stems, leaves	50, 100 µM Cd	7 days	PC2–4, iso-PC2–3(Gln), iso-PC2–3(Asn), iso-PC2(Cys), des-γGlu-iso-PC3(Ser), des-Cys-iso-PC2(Glu), des-Gly-PC2–4, iso-PC2–4(Ser), iso-PC2–4(Glu)	[83]
	Roots, shoots	100 µM As	10 days	PC2–4	[84]
	Roots, shoots	50 µM Cd	14 days	PC2–4	[85]
Panicum maximum	Roots	100 µM Cd	9 days	PC2–4, des-Gly-PC2–4, iso-PC2–3(βAla), des-γGlu-iso-PC2(Gly)	[86]
	Stems			PC3, 5, 6, iso-PC2–4(βAla), des-Gly-PC4, des-γGlu-iso-PC2–3(Gly)
	Leaves			PC6, iso-PC4(βAla)
Phragmites australis	Roots	100 µM Cd	21 days	PC2–4	[87]
Secale cereale	Roots	50, 250 µM Cd	3, 6, 12, 24 h, 3, 7, 14 days	PC2–3, iso-PC2–3(Ser), des-Gly-PC2–3	[88]
	Shoots	50 µM Cd 250 µM Cd	7,14 days 7 days	PC2–3, iso-PC2–3(Ser), des-Gly-PC2–3
Triticum aestivum	Roots	1 µM Cd	12 days	PC2–3, iso-PC2–3(Ser)	[89]
		30 µM Cd		PC2–4, iso-PC2–4(Ser)
	Roots	1 mM Cd	10, 20 days	PC2–4, des-Gly-PC2–3	[90]
	Shoots			PC2–4
Triticum turgidum var. durum	Roots	1 µM Cd	12 days	PC2–3, iso-PC2–3(Ser)	[89]
		30 µM Cd		PC2–4, iso-PC2–4(Ser)
Triticum vulgare	Roots	50, 250 µM Cd	3, 6, 12, 24 h, 3, 7, 14 days	PC2–3, iso-PC2–3(Ser), des-Gly-PC2–3	[88]
	Shoots		7,14 days
Zea mays	Roots	50 µM Cd	3, 6, 12, 24 h, 3, 7, 14 days	PC2–4, iso-PC2(Glu), des-Gly-PC2–3	[88]
		0.01 µM Cd 0.05, 0.1 µM Cd 0.5, 1, 10 µM Cd 3 µM Cd	1 day 1 day 1 day 2, 4, 6 h; 1, 2 days	PC2 PC2–3 PC2–4 PC2–4	[91]
		3 µM Cd	1–7 days	PC2–4, des-Gly-PC2–4, iso-PC2–4(Glu)	[92,93]
	Roots	38 µM Cd	5 days	PC2–5, iso-PC2–5(Ser)	[94]
	Shoots			PC2–3, iso-PC2–3(Ser)
	Roots	10, 15, 25 µM Cd	14 days	PC2–3, PC7, 8, PC10, PC4, 9 (10 and 15 µM Cd), PC5 (25 µM Cd), PC6 (10 and 25 µM Cd)	[95]
	Leaves			PC2,3,6,8,10 PC4 (25 µM Cd)
	Seedlings	20 µM Cd	3 days	PC2–4	[44]
Pontederiaceae
Pontederia crassipes (Eichhornia crassipes)	Seedlings	20 µM Cd	3 days	PC2–4	[44]
	Roots	1, 2.5, 3.5 ppm Cd	45 days	PC2–4	[96]
Proteaceae
Banksia seminuda	Roots	10–250 µM Sb	120 days	PC2, 3	[69]
Hakea prostrata	Roots	10–250 µM Sb	120 days	PC2, 3	[69]
Pteridaceae
Pteris cretica	Fronds	100 mg/kg As	1 year	PC2	[97]
Rubiaceae
Rubia tinctorum	Cell culture	100 µM Cd	3 days	PC2–4, des-Gly-PC2–4	[98]
Salicaceae
Salix atrocinerea	Roots	18 mg/L As	1, 3, 10, 30 days	PC2–3, des-Gly-PC3, des-γGlu-iso-PC2–3(Gly)	[99]
	Leaves			des-Gly-PC2–4
Solanaceae
Nicotiana rustica	Leaves	20 µM Cd	7 days	PC3–4	[100]
Nicotiana tabacum	Cell culture	250 µM Cd	3 days	PC4–5	[101]
	Seedlings	30, 90 µM Cd	3, 9 days	PC2–4	[50]
Solanum lycopersicum (Lycopersicon esculentum)	Cell culture	100 µM Cd	2 h	PC3–5	[102]
		100, 300 µM Cd	1–12 days	PC2	[103]
		600 µM Cd	36 h	PC3–4	[104]
		10, 50, 100 µM Cd	4 days	PC2–4	[105]
		100 µM Cd	7 days	PC2–4	[106]
	Roots	3 µM Cd	7 days	PC3	[107]
	Seedlings	90 µM Cd	21 days	PC2–6	[44]
	Roots, leaves	25, 100 µM Cd	14 days	PC2–4	[108]
Vitaceae
Vitis vinifera	Roots	100 mg/L Hg	3 days	PC2–4	[109]

* n.d.—not determined.