1. State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Shaanxi Key Laboratory of Apple, Northwest A&F University , Yangling 712100 , China
2. State Key Laboratory of Hydraulics and Mountain River Engineering & College of Water Resource and Hydropower, Sichuan University , Chengdu 610065 , China
3. Division of Plant Sciences, Research School of Biology, The Australian National University , Canberra, ACT 2601 , Australia