Open AccessDevelopment and field performance of nitrogen use efficient rice lines for Africa
Author(s) -
Selvaraj Michael Gomez,
Valencia Milton Orlando,
Ogawa Satoshi,
Lu Yingzhi,
Wu Liying,
Downs Christopher,
Skinner Wayne,
Lu Zhongjin,
Kridl Jean C.,
Ishitani Manabu,
Boxtel Jos
Publication year - 2017
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12675
Subject(s) - biology , field (mathematics) , nitrogen , microbiology and biotechnology , computational biology , agronomy , physics , quantum mechanics , mathematics , pure mathematics
Summary Nitrogen (N) fertilizers are a major input cost in rice production, and its excess application leads to major environmental pollution. Development of rice varieties with improved nitrogen use efficiency ( NUE ) is essential for sustainable agriculture. Here, we report the results of field evaluations of marker‐free transgenic NERICA 4 (New Rice for Africa 4) rice lines overexpressing barley alanine amino transferase ( HvAla AT ) under the control of a rice stress‐inducible promoter ( pOsA nt1). Field evaluations over three growing seasons and two rice growing ecologies (lowland and upland) revealed that grain yield of pOsA nt1: HvAla AT transgenic events was significantly higher than sibling nulls and wild‐type controls under different N application rates. Our field results clearly demonstrated that this genetic modification can significantly increase the dry biomass and grain yield compared to controls under limited N supply. Increased yield in transgenic events was correlated with increased tiller and panicle number in the field, and evidence of early establishment of a vigorous root system in hydroponic growth. Our results suggest that expression of the HvAla AT gene can improve NUE in rice without causing undesirable growth phenotypes. The NUE technology described in this article has the potential to significantly reduce the need for N fertilizer and simultaneously improve food security, augment farm economics and mitigate greenhouse gas emissions from the rice ecosystem.