Abstract: In order to find a way to alleviate the stress of heavy metal cadmium in maize, this experiment used rare earth lanthanum to reduce the physiological and biochemical reactions of cadmium stress in maize, and combined with transcriptome analysis to study its mitigation mechanism. The experiment found that:Cd²⁺ treatment would inhibit the normal growth of the root length and aboveground part of maize seedlings, and this inhibitory effect would become more obvious with the increase of Cd²⁺ concentration. Low concentration of La³⁺ solution (10, 20 mg/L) would promote the growth of corn seedlings to a certain extent, while the higher concentration of La³⁺ solution (40 mg/L) would inhibit the growth of corn seedlings. Spraying lanthanum solution would improve the growth of corn seedlings under Cd²⁺ stress, and the activities of SOD, POD and CAT would significantly reduced compared with cadmium stress, but they were still slightly higher than the control. Transcriptome analysis of cadmium-stressed maize root samples was carried out using a second-generation sequencing technique. The cadmium treatment was used as a control to analyze the differentially expressed genes. It was found that the differential genes were mainly enriched in four pathways:Starch and sucrose metabolism,amino sugar and nucleotide sugar metabolism,plant hormone signal transduction,phenylpropanoid biosynthesis.Through experiments, it concluded that spraying lanthanum solution could alleviate the cadmium stress on corn seedlings, but it cannot restore it to its normal state.Through transcriptome sequencing,we hypothesize that the reason for the mitigation of heavy metal stress by rare earths may be related to the related genes of the above four pathways, and provide candidate molecular resources for the subsequent research on the response of rare earths to heavy metal stress.

Key words: Maize, Lanthanum, Cadmium, Transcriptome, Differentially expressed genes

CLC Number: 

• S513.01