This work was supported, in part, by Grants from the National Key R&D Program of China (2016YFD0501210), Natural Science Foundation of Hubei Province (2016CFA070), Hubei Provincial Technology and Innovation Program (2016ABA121), the Program of National Agricultural Research Outstanding Talents of China (2015), Hubei Hundred Talent program, Agriculture and Food Research Initiative Competitive Grants (2014-67015-21770 and 2015-67015-23276) from the USDA National Institute of Food and Agriculture, and Texas A&M AgriLife Research (H-8200). The authors declare that they have no conflict of interest.