Necrotic upper tips1 mimics heat and drought stress and encodes a protoxylem-specific transcription factor in maize

Significance When water deficits coincide with flowering in maize they result in severe developmental consequences such as leaf wilting, tassel browning, and sterility, a condition known as “tassel blasting.” Due to global warming, tassel blasting is becoming a major problem that can greatly reduce yields. Necrotic upper tips1 ( nut1 ) is a transcription factor that mimics tassel blasting when mutated. We show that NUT1 protein localizes to the developing protoxylem where it activates genes necessary for reinforcing the secondary cell wall, and thus enables these cells to withstand the high negative pressures required for long-distance water movement. Thus, nut1 or its targets may be promising breeding targets to help maize resist the effects of rising temperatures in the future.