Mechanism of foliar application of boron to alleviate cadmium toxicity in winter wheat (Triticum aestivum L.).

Our previous work shown that boron (B) can inhibit cadmium (Cd) absorption in winter wheat, while the mechanism is not well understood. In this study, the mechanism of foliage spray B on Cd uptake in Cd-contaminated farmland was characterized with three treatments: spraying distilled water (CK), spraying 0.3% B fertilizer (F0.3%), and spraying 0.6% B fertilizer (F0.6%). The spraying treatment was conducted during the jointing stage and booting stage, respectively. The objective was to investigate the impact of different concentrations of B fertilizer application on Cd content, yield, physiological biochemical response, Cd transporter in wheat. Results showed that the yield increased with increasing B spray concentration compared with CK treatment. The wheat yield increased by 1.29%∼12.50% under foliar B application. The Cd concentration in both shoot and root of wheat seedlings were significantly decreased with foliar application of B at jointing stage and booting stage. The Cd concentrations in root and seed were also decreased with B treatment at maturity stage, especially after treatment with F0.6%, the Cd absorption in wheat grains exhibited a significant reduction of 31.20%. In addition, foliar application of B significantly increased antioxidant enzyme activities, include APX, SOD, CAT, and POD. Compared with CK, the MDA content in leaves showed a significant decrease with 30.48%-50.14%, while the GSH content showed an increase with 76.32%-1.05%. The down-regulation of the uptake and transport genes (TaNramp5, TaLCT1 and TaHMA2) and the up-regulation of compartmentalization transport genes (TaTM20 and TaHMA3) may contribute to the reduction of Cd accumulation in shoot. Overall, our results suggest that foliar spraying of B could increase B accumulation and yield, and alleviate Cd toxicity by reducing Cd uptake, enhancing the antioxidant capacity, regulating the expression of Cd genes in wheat.

Xie M ，Feng Y ，Zhao P ，Nie Z ，Liu H ，Gao W ，Li C ，Sui F ，Wang L ，Qin S ... -  《-》

(1)Selenium supply alters the subcellular distribution and chemical forms of cadmium and the expression of transporter genes involved in cadmium uptake and translocation in winter wheat (Triticum aestivum).

Zhu J ，Zhao P ，Nie Z ，Shi H ，Li C ，Wang Y ，Qin S ，Qin X ，Liu H ... -  《-》

[Effect and Mechanism of Chlamydomonas reinhartii Living Cell Agents in Alleviating Cd Stress on Wheat Seedlings].

Lei CY ，Li YN ，Liang MJ ，Yang Z ，Sun Y ，Ji CL ，Zhang CH ，Li RZ ，Sun XP ，Cui HL ... -  《-》

Foliar application of selenium and zinc to alleviate wheat (Triticum aestivum L.) cadmium toxicity and uptake from cadmium-contaminated soil.

Due to the large area of agricultural soils contaminated by Cd worldwide, cost-effective and practical method for safety food production are necessary. The roles of micronutrient on reducing Cd accumulation in crops are recently introduced. In the current study, a pot-culture experiment in the greenhouse was conducted to study the foliar spraying of Se (Na2SeO4) and Zn (ZnSO4) on physiological and growth parameters, as well as Cd concentrations in wheat plants grown in Cd-contaminated soil. The foliar was sprayed with four concentration of Se and Zn (0, 10, 20, and 40 mg L-1) at different growth stage (tillering, elongating and heading) and whole wheat plants were collected after maturity. Both foliar spraying with Se and Zn significantly enhanced the photosynthesis, tissue biomass and antioxidant enzyme activity. Additionally, Se and Zn application can also increase Se and Zn concentrations in different plant tissues. Selenium and Zn decreased malondialdehyde (MDA) and Cd concentrations in wheat grains, hulks, leaves, stalks and root in a dose-additive manner. Overall, Se and Zn both efficiently enhanced the wheat growth and Se and Zn concentrations, and simultaneously decreased the Cd concentration in wheat plant. Compared with Zn, Se more efficiently improved wheat growth and reduced Cd concentration in the wheat in a Cd-contaminated soil. Present results suggest that use of foliar spraying, especially Se, could be a cost-effective strategy and could be recommended for remediation of light-or moderate-polluted soils contaminated by Cd.

Wu C ，Dun Y ，Zhang Z ，Li M ，Wu G ... -  《-》

[Effect of Exogenous Chitosan on Physiological Properties, Antioxidant Activity, and Cadmium Uptake of Wheat (Triticum aestivum L.) Seedlings Under Cadmium Stress].

Zhang JJ ，Jiao QJ ，Xu ZY ，Fan LN ，Jiang Y ，Song J ，Hua DL ，Li GZ ，Lin D ，Liu HT ... -  《-》