Abstract
Cadmium (Cd) contamination has been recognized as a major threat to the agricultural system and crop production which posing serious threat to human health. Salicylic acid (SA) serves as an important signaling molecule and plays an important role in against Cd toxicity. In the previous field experiments, we found SA spraying could reduce the Cd accumulation of rice grain grown in Cd-contaminated soil. This study investigated the effects and mechanisms of SA spraying on leaves of rice seedlings under Cd stress. Results showed that SA treatment could alleviate the Cd toxicity of rice not by changing the physical and chemical properties of the soil, but by increasing the activities of antioxidant enzymes to reduce the H 2 O 2 accumulation in rice. And the key factor of SA treatment reducing Cd accumulation in rice grain was the decreasing of Cd contents in rice leaves at the flowering stage. This indicated that SA could modulate the Cd accumulation of shoots to reduce the Cd translocation to rice grain. Furthermore, SA could increase the H 2 O 2 contents in a short-term to activate the SA-signaling pathway, and modulate the expression levels of Cd transporters ( OsLCT1 and OsLCD ) in rice leaves toraise Cd tolerance and reduce Cd accumulation in rice grain. Thus, SA spraying can be used as an effective measure to cope with Cd contamination in paddy soils.
Salicylic acid application alleviates cadmium accumulation in brown rice by modulating its shoot to grain translocation in rice
