Maize expressing the sunflower transcription factor HaHB11 has improved productivity in controlled and field conditions. (October 2019)

• Record Type: Journal Article
• Authors: Raineri, Jesica; Campi, Mabel; Chan, Raquel L.; Otegui, María E.
• Is Part Of: Plant science. Volume 287(2019)
• Publication Date: 2019-10
• Subjects: Homeodomain-leucine zipper -- Transgenic maize -- Transcription factors -- HaHB11 -- Plant biomass -- Leaf senescence -- Grain yield; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2019.110185
• Languages: English
• ISSNs: 0168-9452

Abstract

Highlights: The sunflower transcription factor HaHB11 expressed in maize delayed leaf senescence. HaHB11 improved maize biomass and yield in greenhouse and field trials. Such beneficial traits counterbalanced the negative effects of inbreeding. Several traits triggered by HaHB11 were conserved between Arabidopsis and maize. Abstract: HaHB11 is a sunflower transcription factor from the homeodomain-leucine zipper I family. Transgenic Arabidopsis plants expressing HaHB11 had larger rosettes and improved seed yield. In this work maize plants from hybrid HiII were transformed with 35S: HaHB11, ZmUBI:HaHB11 and ProHaHB11:HaHB11 and then backcrossed to B73 to obtain a more homozygous inbred phenotype. Transgene expression levels were stable at least during three generations. Greenhouse-grown HaHB11 transgenic lines had larger leaf area and delayed senescence than controls, together with increased total biomass (up to 25%) and seed yield (up to 28%). Field trials conducted with T2 and T4 generations indicated that enhanced leaf area (up to 18%), stem diameter (up to 28%) and total biomass (up to 40%) as well as delayed leaf senescence were maintained among transgenic individuals when upscaling from pots in the greenhouse to communal plants in the field. The T4 field-grown transgenic generation had increased light interception and radiation use efficiency as well as seed yield (43–47% for events driven by the 35S promoter). Results suggest that HaHB11 is a promising tool for crop improvement because differential traits observed in the Arabidopsis model plant were preserved in a crop like maize independently of growth conditions and backcross level.