Several grant numbers are incorrect in the funding information section. The correct funding information is: "This work was supported by grants from the National Key Basic Science "973" Program (2011CB016141), the National Natural Science Foundation (90817001 and 30671402), the National Special Projects for R&D of Transgenic Plants (2008ZX08009-004 and 2008ZX08010-001), and the State "863" High Technology R&D Program (2006AA06Z341) of the Chinese Government. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript."
Footnotes
Competing Interests: No competing interests declared.