TABLE 3.

Research progress on the effects of Se on accumulation of heavy metals in higher plants.

Added Se form	Amounts	Heavy metal species	Crop species	Test results	Heavy metal availability	References
Se(IV)	0, 0.5, 1 mg kg–1	As	Rice	The addition of Se (IV) reduced total As content in soil solution, but increased As content in rice grain by 43.7–74.6%.	Decrease	Wan et al., 2018
Se(IV)	0, 1, 5, 10 mg kg–1	As	Rice	Se (IV) application significantly reduced rice grain As content by 8.6, 31.4, and 33.7% with the Se content of 1, 5, and 10 mg kg–1, respectively.	–	Zhou et al., 2017b
Se(IV)	0, 1, 5 mg kg–1	As	Rice	Se (IV) application reduced As availability in rhizosphere soil. Se (IV) application significantly reduced the grain As content.	Decrease	Lv et al., 2020
Se(IV)	0, 0.5, 3, 6 mg kg–1	Hg	Rice	Se(IV) addition forms IHg-Se complexes, resulting reduction of effectiveness of Hg in soil. As content in rice grain reduced with the increase of Se (IV) concentration.	Decrease	Tang et al., 2017
Se(IV)	0, 20, 40, 60, 100, 300, 500 mg kg–1	Hg	Rice	Se (IV) application decreased inorganic Hg and MeHg concentration in grain and root.	Decrease	Xu et al., 2019
Se(IV)	0, 3 mg kg–1	Hg	Rice	Se(IV) application reduced MeHg content in soil and in rice root, straw and grain.	Decrease	Wang et al., 2016
Se(IV)	1 mg kg–1	Cd	Rice	Se(IV) reduced exchangeable Cd content but increased the Cd content combined with carbonate and iron-manganese oxides. Se(IV) addition reduced rice Cd content by 36.5%	Decrease	Huang et al., 2018
Se(IV)	0, 0.5, 1, 2, 4, 8 mg kg–1	Cd	Wheat	Se(IV) reduced Cd content in wheat shoot from 25 to 35%.	–	Atarodi et al., 2018
Se(IV)	0, 1, 5, 10, 15, 20 mg kg–1	Cd	Rape	Se(IV) markedly reduced Cd concentration in both root and shoot.	–	Wu et al., 2016b
Se(IV)	0, 1, 5 mg kg–1	Cd	Rice	Se (IV) application reduced Cd availability in rhizosphere soil. Se (IV) application significantly reduced the grain Cd content.	Decrease	Lv et al., 2020
Se(VI)	0, 0.1, 1, 5 mg kg–1	As	Rice	Se(VI) addition reduced As content in rice root, shoot and grain.	–	Liao et al., 2016
Se(VI)	0, 0.5, 3, 6 mg kg–1	Hg	Rice	Se(VI) addition forms IHg-Se complexes, resulting reduction of effectiveness of Hg in soil. Hg content in rice grain reduced with the increase of Se (VI) concentration.	Decrease	Tang et al., 2017
Se(VI)	0, 0.1, 1, 5 mg kg–1	Cd	Rice	Se(VI) addition reduced Cd content in rice root, shoot and grain.	–	Liao et al., 2016
Se(VI)	0, 3 mg kg–1	Hg	Rice	Se(VI) application reduced MeHg content in soil and in rice root, straw and grain.	Decrease	Wang et al., 2016
Undefined	0, 0.003, 0.03, 0.15, 0.3, 1.5 mg kg–1	Hg	Rice	Low Se concentration reduced Hg and MeHg content in rice grains, but high Se concentration increased it.	–	Li et al., 2019a