Table 4.

Si concentrations in shoots and roots and net accumulation (total uptake of element per g of root DW) of various plant species untreated and treated with K₂SiO₃ during 5–7 days or three weeks. n = 4 (three-week-treatment), n = 5 (maize and lettuce) and 10 (wheat) ± SE. * indicates significant difference from the control. p-value indicates if concentration of element increase/decrease with increased Si-treatment.

Species		5–7 Days Treatment			3-Week Treatment
Si (μM)		Shoot	Root	Net Accumulation	Shoot	Root	Net Accumulation
		μg gDW−1		(mg gDWroot−1)	μg gDW−1		(mg gDWroot−1)
Maize
	0	120 ± 18	115 ± 17	—	—	—	—
	5000	10294 ± 1544 *	14702 ± 2205 *	30.23 ± 3.15 *	—	—	—
Lettuce
	0	26 ± 6	31 ± 4	—	26 ± 1	31 ± 0	—
	100	—	—	—	96 ± 7 *	762 ± 9 *	1.07 ± 0.09 *
	500	—	—	—	512 ± 16 *	1528 ± 57 *	3.88 ± 0.35 *
	1000	882 ± 132 *	1776 ± 266 *	5.78 ± 0.75 *	887 ± 60 *	1844 ± 165 *	6.21 ± 0.38 *
	p	—	—	—	<0.001 *	<0.001 *	<0.001 *
Wheat
	0	24 ± 1	26 ± 5	—	21 ± 2	36 ± 4	—
	100	—	—	—	2486 ± 244 *	3870 ± 152 *	14.05 ± 0.96 *
	500	—	—	—	3711 ± 160 *	7045 ± 451 *	22.66 ± 1.34 *
	1000	3535 ± 157 *	7798 ± 528 *	23.30 ± 1.41 *	4008 ± 44 *	8439 ± 721 *	25.21 ± 1.44 *
	p	—	—	—	<0.001 *	<0.001 *	<0.001 *
Carrot
	0	—	—	—	22 ± 2	27 ± 1	—
	100	—	—	—	158 ± 4 *	415 ± 35 *	0.61 ± 0.07 *
	500	—	—	—	344 ± 17 *	977 ± 5 *	1.42 ± 0.14 *
	1000	—	—	—	586 ± 9 *	1364 ± 46 *	2.13+0.24 *
	p	—	—	—	<0.001 *	<0.001 *	<0.001 *
Pea
	0	—	—	—	19 ± 2	21 ± 1	—
	100	—	—	—	108 ± 3 *	549 ± 48 *	0.72 ± 0.06 *
	500	—	—	—	355 ± 18 *	1070 ± 71 *	1.73 ± 0.16 *
	1000	—	—	—	641 ± 16 *	1477 ± 48 *	2.69 ± 0.22 *
	p	—	—	—	<0.001 *	<0.001 *	<0.001 *