Background: In order to reveal the mechanism of drought resistance of maize, establish the molecular identification system of drought resistance and solve the problem of difficult identification of drought resistance of maize. Taking Nongdan 476, a drought-tolerant maize hybrid cultivar, and Zhongxin 978, a drought-sensitive maize hybrid cultivar, as materials, drought stress and normal watering treatment were carried out at seedling stage, flare stage, tasseling stage and filling stage, and leaf tissue were collected for transcriptomes.
Results: P-vaule < 0.05 was selected as the screening standard. There were 6281, 17191, 21790 and 15475 differentially expressed genes of each stage, respectively. At the same time, only DnaJ gene was significantly differentially expressed at the four stages. The preliminary results of qRT-PCR showed that the up regulation of DnaJ gene expression was consistent with the results of transcriptome analysis. DnaJ gene expression was further detected by using control samples with specific drought resistance index of yield. The results showed that DnaJ gene expression drought resistance index (DIE) was highly correlated with yield drought resistance index (DIP), and the 5-level criteria for DnaJ gene expression drought resistance index (DIE) were defined by their linear equations.
Conclusion: Drought resistance of maize is a character controlled by multiple genes. There is a significant difference between the expression of DnaJ gene in drought resistant and non drought resistant maize, which has the potential to be used as molecular identification of drought resistance of maize, and can provide a more comprehensive and accurate technical means for drought resistance cultivation and breeding of maize.