Molecular and phenotypic characterization of transgenic wheat and sorghum events expressing the barley alanine aminotransferase

Authors

Pamela A. Peña, University of Nebraska-LincolnFollow
Truyen Quach, University of Nebraska-LincolnFollow
Shirley Sato, University of Nebraska-LincolnFollow
Zhengxiang Ge, University of Nebraska-LincolnFollow
Natalya Nersesian, University of Nebraska-LincolnFollow
Ismail M. Dweikat, University of Nebraska-LincolnFollow
Madhavan Soundararajan, University of Nebraska-LincolnFollow
Tom Clemente, University of Nebraska-LincolnFollow

Date of this Version

2017

Citation

Published in Planta 246 (2017), pp. 1097–1107. doi 10.1007/s00425-017-2753-1

Comments

Copyright © 2017 Springer-Verlag GmbH Germany. Used by permission.

Abstract

Main conclusion — The expression of a barley alanine aminotransferase gene impacts agronomic outcomes in a C3 crop, wheat.

The use of nitrogen-based fertilizers has become one of the major agronomic inputs in crop production systems. Strategies to enhance nitrogen assimilation and flux in planta are being pursued through the introduction of novel genetic alleles. Here an Agrobacterium-mediated approach was employed to introduce the alanine aminotransferase from barley (Hordeum vulgare), HvAlaAT, into wheat (Triticum aestivum) and sorghum (Sorghum bicolor), regulated by either constitutive or root preferred promoter elements. Plants harboring the transgenic HvAlaAT alleles displayed increased alanine aminotransferase (alt) activity. The enhanced alt activity impacted height, tillering and significantly boosted vegetative biomass relative to controls in wheat evaluated under hydroponic conditions, where the phenotypic outcome across these parameters varied relative to time of year study was conducted. Constitutive expression of HvAlaAT translated to elevation in wheat grain yield under field conditions. In sorghum, expression of HvAlaAT enhanced enzymatic activity, but no changes in phenotypic outcomes were observed. Taken together these results suggest that positive agronomic outcomes can be achieved through enhanced alt activity in a C3 crop, wheat. However, the variability observed across experiments under greenhouse conditions implies the phenotypic outcomes imparted by the HvAlaAT allele in wheat may be impacted by environment.