Transgenic maize plants expressing HaHB11: a promising proof of concept

JESICA RAINERI; MARÍA OTEGUI ; RAQUEL L. CHAN

Congreso; LII Reunión de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2016

HaHB11 is a sunflower transcription factor belonging to the HD-Zip I family. It was previously shown that Arabidopsis plants transformed with this gene had improved biomass and yield as well as an increased tolerance to a variety of abiotic stress factors like drought, waterlogging and submergence. Two genetic constructs in which either the 35S CaMV or the maize ubiquitin promoter direct the expression of HaHB11 (Mora and Giacomelli, unpublished) were carried out. Transgenic maize plants were obtained on the HiII AxB genotype and crossed with B73 (Campi and Gómez, IAL transformation platform*). Here we show a phenotypic analysis of HaHB11 T1 maize transgenic plants compared with their controls. Plants bearing the UBI promoter had higher transcript levels than those with the 35S CaMV and the differential phenotypes observed were related with these expression levels. HaHB11 plants had higher stems, more leaves and larger total leaf area than controls. Moreover, they were delayed in the onset of the reproductive organs, achieving in some cases, larger ears. The combination of these traits could be contributing to an increased yield.Altogether the results indicate that HaHB11 could be displaying conserved physiological mechanisms between Arabidopsis and maize which supports HaHB11 as a biotechnological tool to improve crops.