<i>BrDMC1</i>, a Recombinase Gene, Is Involved in Seed Germination in <i>Brassica rapa</i> under Salt Stress
Xulin Wang,
Zhengqing Xie,
Zhaoran Tian,
Shuaipeng Wang,
Gongyao Shi,
Weiwei Chen,
Gangqiang Cao,
Baoming Tian,
Xiaochun Wei,
Luyue Zhang,
Fang Wei
Affiliations
Xulin Wang
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Zhengqing Xie
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Zhaoran Tian
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Shuaipeng Wang
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Gongyao Shi
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Weiwei Chen
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Gangqiang Cao
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Baoming Tian
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Xiaochun Wei
Institute of Horticulture, Henan Academy of Agricultural Sciences, Graduate T and R Base of Zhengzhou University, Zhengzhou 450002, China
Luyue Zhang
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Fang Wei
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Recombinases are in part responsible for homologous recombination and genome integrity during DNA repair. DMC1 has a typical RecA domain, and belongs to the recombinase superfamily. The reactive oxygen species (ROS) as a potent DNA damage agent is produced during seed germination under stress conditions. DNA repair should be initiated immediately to allow for subsequent seedling development. In this study, we attempted to characterize the underlying mechanism of BrDMC1 responsiveness to salinity stress using the RNA interference approach in Brassica rapa (B. rapa). Bioinformatics and expression pattern analysis revealed that BrDMC1 only retained BrDMC1.A01 after the whole genome triplication (WGT) event and was primarily transcribed in flowers and seeds. BrDMC1 had high activity in the promoter region during germination, according to histochemical GUS staining. The data showed that salt treatment reduced the germination rate, weakened seed vigor and decreased antioxidant enzyme activity, but increased oxidative damage in BrDMC1-RNAi seeds. Furthermore, the expression of stress-responsive genes and damage repair genes was significantly different in transgenic lines exposed to salt stress. Therefore, BrDMC1 may respond to salt stress by controlling seed germination and the expression of stress-related and damage repair genes in B. rapa.
