Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture / Hubei Provincial Engineering Laboratory for New Fertilizers / Research Center of Trace Elements, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
Key Laboratory of Testing and Evaluation for Agro-product Safety and Quality, Ministry of Agriculture, Guangzhou, 510640, China.
Environ Pollut. 2019 Jun;249:716-727. doi: 10.1016/j.envpol.2019.03.079. Epub 2019 Mar 24.
Understanding the chemical response and characteristics of bacterial communities in soil is critical to evaluate the effects of selenium (Se) supplement on plant growth and chromium (Cr)/Se uptake in Cr contaminated soil. The rhizosphere soil characteristics of pak choi (Brassica campestris L. ssp. Chinensis Makino) were investigated in soil contaminated with different levels and forms of Cr when supplemented with Se. Although inhibition of plant growth caused by Cr stress was not completely alleviated by Se, Cr content in plant tissues decreased in Cr(VI)120Se5 treatment (Cr(VI): 120 mg kg soil; Se: 5 mg kg soil) and its bioavailability in soil decreased in Cr(III)200Se5 (Cr(III): 200 mg kg soil; Se: 5 mg kg soil) treatment. Moreover, antagonism of Cr and Se on soil enzyme activities and bacterial communities were revealed. Notably, results of Cr(VI) reduction and Se metabolism functional profiles confirmed that bacterial communities play a critical role in regulating Cr/Se bioavailability. Additionally, the increases of Se bioavailability in Cr contaminated soil were ascribed to oxidation of Cr(VI) and reduction of Se reductases proportions, as well as the enhancing of pH in soil. These findings reveal that Se has the potential capacity to sustain the stability of microdomain in Cr contaminated soil.
了解土壤中细菌群落的化学响应和特征对于评估硒（Se）补充对植物生长和铬（Cr）/Se 吸收的影响至关重要。在添加 Se 的情况下，研究了受不同水平和形态 Cr 污染的土壤中白菜（ Brassica campestris L. ssp. Chinensis Makino）根际土壤的特征。尽管 Se 不能完全缓解 Cr 胁迫对植物生长的抑制作用，但 Cr(VI)120Se5 处理（Cr(VI)：120 mg kg 土壤；Se：5 mg kg 土壤）中植物组织中的 Cr 含量降低，Cr(III)200Se5 处理（Cr(III)：200 mg kg 土壤；Se：5 mg kg 土壤）中 Cr 的生物有效性降低。此外，揭示了 Cr 和 Se 对土壤酶活性和细菌群落的拮抗作用。值得注意的是，Cr(VI)还原和 Se 代谢功能谱的结果证实了细菌群落在调节 Cr/Se 生物有效性方面起着关键作用。此外，Cr 污染土壤中 Se 生物有效性的增加归因于 Cr(VI)的氧化和 Se 还原酶比例的降低，以及土壤 pH 值的升高。这些发现表明 Se 具有维持 Cr 污染土壤微区稳定性的潜力。
