Plant nuclear factor Y (NF-Y) B subunits confer drought tolerance and lead to improved corn yields on water-limited acres

TLDR

Improving crop performance under drought is difficult because the trait is complex and influenced by many factors. A functional genomics screen identified the NF‑YB transcription factor AtNF‑YB1 and its maize ortholog ZmNF‑YB2, and overexpressing ZmNF‑YB2 in maize enhances drought tolerance through improved stress responses and raises grain yield on water‑limited acres, offering a promising technology for drought‑prone production systems.

Abstract

Commercially improved crop performance under drought conditions has been challenging because of the complexity of the trait and the multitude of factors that influence yield. Here we report the results of a functional genomics approach that identified a transcription factor from the nuclear factor Y (NF-Y) family, AtNF-YB1 , which acts through a previously undescribed mechanism to confer improved performance in Arabidopsis under drought conditions. An orthologous maize transcription factor, ZmNF-YB2, is shown to have an equivalent activity. Under water-limited conditions, transgenic maize plants with increased ZmNF-YB2 expression show tolerance to drought based on the responses of a number of stress-related parameters, including chlorophyll content, stomatal conductance, leaf temperature, reduced wilting, and maintenance of photosynthesis. These stress adaptations contribute to a grain yield advantage to maize under water-limited environments. The application of this technology has the potential to significantly impact maize production systems that experience drought.