@article{aaaae57cafa94a23b76b9abf23f54382,
title = "Identification and characterization of a novel stay-green QTL that increases yield in maize",
abstract = "Functional stay-green is a valuable trait that extends the photosynthetic period, increases source capacity and biomass and ultimately translates to higher grain yield. Selection for higher yields has increased stay-green in modern maize hybrids. Here, we report a novel QTL controlling functional stay-green that was discovered in a mapping population derived from the Illinois High Protein 1 (IHP1) and Illinois Low Protein 1 (ILP1) lines, which show very different rates of leaf senescence. This QTL was mapped to a single gene containing a NAC-domain transcription factor that we named nac7. Transgenic maize lines where nac7 was down-regulated by RNAi showed delayed senescence and increased both biomass and nitrogen accumulation in vegetative tissues, demonstrating NAC7 functions as a negative regulator of the stay-green trait. More importantly, crosses between nac7 RNAi parents and two different elite inbred testers produced hybrids with prolonged stay-green and increased grain yield by an average 0.29 megagram/hectare (4.6 bushel/acre), in 2 years of multi-environment field trials. Subsequent RNAseq experiments, one employing nac7 RNAi leaves and the other using leaf protoplasts overexpressing Nac7, revealed an important role for NAC7 in regulating genes in photosynthesis, chlorophyll degradation and protein turnover pathways that each contribute to the functional stay-green phenotype. We further determined the putative target of NAC7 and provided a logical extension for the role of NAC7 in regulating resource allocation from vegetative source to reproductive sink tissues. Collectively, our findings make a compelling case for NAC7 as a target for improving functional stay-green and yields in maize and other crops.",
keywords = "yield, QTL, stay-green, nitrogen remobilization, photosynthesis, proteolysis",
author = "Jun Zhang and Fengler, {Kevin A.} and {Van Hemert}, {John L.} and Rajeev Gupta and Nick Mongar and Jindong Sun and Allen, {William B.} and Yang Wang and Benjamin Weers and Hua Mo and Renee Lafitte and Zhenglin Hou and Angela Bryant and Farag Ibraheem and Jennifer Arp and Kankshita Swaminathan and Moose, {Stephen P.} and Bailin Li and Bo Shen",
note = "Funding Information: This work was funded by DuPont Pioneer, a for‐profit agricultural technology company, as part of its research and development programme. J.Z., K.F., J.L.V.H., R.G., N.M., J.S., W.A., B.W., R.L., H.M., Z.H., A.B., B.L. and B.S. were DuPont Pioneer employees when contributing to this work. Funding Information: We acknowledge Gina Zastrow-Hayes for supervising the RNAseq experiments and Wangnan Hu for qPCR analysis. We thank Charlie Messina for helpful input on the physiological experiments, John Everard and Jeff Habben for critical review of the manuscript, and Dale Loussaert for initiating the IHP/ILP collaboration project. The authors acknowledge Eddie Ross, Stephen Jinga and Brian Rhodes for their assistance with sequencing nac7 alleles of IHP and ILP. Farag Ibraheem and Jennifer Arp were supported by NSF grants IOS-0501700 and 1339362. We also recognize our colleagues who conducted excellent field trials at our research stations. We thank the many Dupont Pioneer staff members for their contribution to vector construction, transformation, RNAseq and greenhouse support. We also thank Tom Greene for his organizational leadership support for this project. Funding Information: We acknowledge Gina Zastrow‐Hayes for supervising the RNAseq experiments and Wangnan Hu for qPCR analysis. We thank Charlie Messina for helpful input on the physiological experiments, John Everard and Jeff Habben for critical review of the manuscript, and Dale Loussaert for initiating the IHP/ILP collaboration project. The authors acknowledge Eddie Ross, Stephen Jinga and Brian Rhodes for their assistance with sequencing nac7 alleles of IHP and ILP. Farag Ibraheem and Jennifer Arp were supported by NSF grants IOS‐0501700 and 1339362. We also recognize our colleagues who conducted excellent field trials at our research stations. We thank the many Dupont Pioneer staff members for their contribution to vector construction, transformation, RNAseq and greenhouse support. We also thank Tom Greene for his organizational leadership support for this project. Publisher Copyright: {\textcopyright} 2019 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.",
year = "2019",
month = dec,
day = "1",
doi = "10.1111/pbi.13139",
language = "English (US)",
volume = "17",
pages = "2272--2285",
journal = "Plant Biotechnology Journal",
issn = "1467-7644",
publisher = "Wiley-Blackwell",
number = "12",
}