Nanopriming with selenium doped carbon dots improved rapeseed germination and seedling salt tolerance
Mohammad Nauman Khan,
Chengcheng Fu,
Xiaohui Liu,
Yanhui Li,
Jiasen Yan,
Lin Yue,
Jiaqi Li,
Zaid Khan,
Lixiao Nie,
Honghong Wu
Affiliations
Mohammad Nauman Khan
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan 430070, Hubei, China; School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572000, Hainan, China
Chengcheng Fu
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan 430070, Hubei, China; Hubei Hongshan Laboratory, Wuhan 430070, Hubei, China
Xiaohui Liu
College of Food and Pharmaceutical Engineering, Guizhou Institute of Technology, Guiyang 550003, Guizhou, China
Yanhui Li
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
Jiasen Yan
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
Lin Yue
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan 430070, Hubei, China; Hubei Hongshan Laboratory, Wuhan 430070, Hubei, China
Jiaqi Li
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
Zaid Khan
College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong, China
Lixiao Nie
School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572000, Hainan, China; Corresponding authors.
Honghong Wu
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan 430070, Hubei, China; Hubei Hongshan Laboratory, Wuhan 430070, Hubei, China; Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Shenzhen 511464, Guangdong, China; Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 511464, Guangdong, China; Corresponding authors.
Soil salinity is a big environmental issue affecting crop production. Although seed nanopriming has been widely used to improve seed germination and seedling growth under salinity, our knowledge about the underlying mechanisms is still insufficient. Herein, we newly synthesized selenium-doped carbon dots nanoparticles coated with poly acrylic acid (poly acrylic acid coated selenium doped carbon dots, PAA@Se-CDs) and used it to prime seeds of rapeseeds. The TEM (transmission electron microscope) size and zeta potential of PAA@Se-CDs are 3.8 ± 0.2 nm and −30 mV, respectively. After 8 h priming, the PAA@Se-CDs nanoparticles were detected in the seed compartments (seed coat, cotyledon, and radicle), while no such signals were detected in the NNP (no nanoparticle control) group (SeO2 was used as the NNP). Nanopriming with PAA@Se-CDs nanoparticles increased rapeseeds germination (20%) and seedling fresh weight (161%) under saline conditions compared to NNP control. PAA@Se-CDs nanopriming significantly enhanced endo-β-mannanase activities (255% increase, 21.55 µmol h−1 g−1 vs. 6.06 µmol h−1 g−1, at DAS 1 (DAS, days after sowing)), total soluble sugar (33.63 mg g−1 FW (fresh weight) vs. 20.23 mg g−1 FW) and protein contents (1.96 µg g−1 FW vs. 1.0 µg g−1 FW) to support the growth of germinating seedlings of rapeseeds under salt stress, in comparison with NNP control. The respiration rate and ATP content were increased by 76% and 607%, respectively. The oxidative damage of salinity due to the over-accumulation of reactive oxygen species (ROS) was alleviated by PAA@Se-CDs nanopriming by increasing the antioxidant enzyme activities (SOD (superoxide dismutase), POD (peroxidase), and CAT (catalase)). Another mechanism behind PAA@Se-CDs nanopriming improving rapeseeds salt tolerance at seedling stage was reducing sodium (Na+) accumulation and improving potassium (K+) retention, hence increasing the K+/Na+ ratio under saline conditions. Overall, our results not only showed that seed nanopriming with PAA@Se-CDs could be a good approach to improve salt tolerance, but also add more knowledge to the mechanism behind nanopriming-improved plant salt tolerance at germination and early seedling growth stage.
