1. State Key Laboratory of Crop Stress Biology for Arid Areas, Center of Bioinformatics, College of Life Sciences, Northwest A&F University , Yangling, Shaanxi 712100 , China
2. College of Chemistry & Pharmacy, Northwest A&F University , Yangling, Shaanxi 712100 , China
3. Key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, Northwest A&F University , Yangling, Shaanxi 712100 , China