Table I.

Concentrations of defensive phytochemical compounds in roots and shoots from studies that simultaneously investigated both plant parts

Although not comprehensive, we attempted to broadly survey plant families and classes of chemical compounds. Data are mostly from mature leaf and root tissues.

Family	Plant Species	Compound	Root	Shoot	Unit	R/Sa	Citation
Apiaceae	Wild parsnip	Furanocoumarin	0.02	0.52	μg/mg dry wt	0.04	Zangerl and Rutledge (1996)
Apocynaceae	Asclepias nivea	Cardenolide	0.26	0.48	μg/mg dry wt	0.53	S. Rasmann and A.A. Agrawal (unpublished data)
Asteraceae	S. jacobaea	Pyrrolizidine alkaloid	0.88	1.68	mg/g dry wt	0.53	Hol et al. (2004)
	Taraxacum officinale	Triterpene	0.29	0.59	% of mg dry wt	0.50	Akashi et al. (1994)
Betulaceae	Betula papyrifera	Phenolic	1.08	1.21	mg/g dry wt	0.89	Mattson et al. (2005)
Brassicaceae	Arabidopsis	Glucosinolate	22.52	19.40	μmol/g dry wt	1.16	Petersen et al. (2002)
	Barbarea vulgaris	Glucosinolate	33.17	33.33	% mol dry wt	1.00	Agerbirk et al. (2003)
	B. oleracea	Glucosinolate	14.63	4.88	μmol/g dry wt	3.00	van Dam et al. (2004)
	Radish	Glucosinolate	0.48	0.26	μmol/g fresh wt	1.86	Hara et al. (2000)
Chenopodiaceae	Spinach	Phytoecdysteroid	38.79	124.94	μg/g dry wt	0.31	Schmelz et al. (1999)
Euphorbiaceae	Cassava	Cyanogenic glucoside	77.63	0.77	μmol/g fresh wt	101.02	Jorgensen et al. (2005)
Fabaceae	Lupinus argenteus	Alkaloid	0.47	3.26	mg/g dry wt	0.14	Adler and Wink (2001)
Malvaceae	Gossypium herbaceum	Terpenoid aldeheyde	8,460.10	149.44	μg/g dry wt	56.61	Bezemer et al. (2004)
Orchidaceae	Phalaenopsis hybrids	Pyrrolizidine alkaloid	28.00	10.50	mg/g fresh wt	2.67	Frolich et al. (2006)
Pinaceae	Picea sitchensis	Polyphenol	5.20	4.00	% g dry wt	1.30	Wainhouse et al. (1998)
	P. sitchensis	Resin	2.10	3.70	% g dry wt	0.57
	P. sitchensis	Tannin	10.49	4.87	% g dry wt	2.15
Plantaginaceae	Plantago laceolata	Iridoid glycoside	1.50	1.39	% dry wt	1.08	Marak et al. (2002)
Poaceae	Secale cereale	Hydroxamic acid	3.93	19.31	mmol/kg fresh wt	0.20	Collantes et al. (1999)
	Maize	Hydroxamic acid	18.70	80.80	% g fresh wt	0.23	Collantes et al. (1998)
Polygonaceae	Rumex acetosa	Phenolic	0.31	0.07	μmol/g fresh wt	4.52	Tolra et al. (2005)
Solanaceae	Nicotiana sylvestris	Alkaloid	20.24	3.57	% μg fresh wt	5.67	Ohnmeiss and Baldwin (2000)
	Solanum carolinense	Polyphenol	0.17	0.03	mg/g dry wt	5.89	Walls et al. (2005)
	S. carolinense	Glycoalkaloid	3.50	0.03	μmol/g fresh wt	114.21

^aR/S indicates a comparison of root and shoot chemistry, where 1 indicates equivalent concentrations, and values above or below 1 represent higher or lower concentrations of phytochemicals in the roots compared with the shoots, respectively.