Overexpression of the Maize ZmNLP6 and ZmNLP8 Can Complement the Arabidopsis Nitrate Regulatory Mutant nlp7 by Restoring Nitrate Signaling and Assimilation

• Published in: Frontiers in plant science Vol. 8; p. 1703
• Main Authors: Cao, Huairong, Qi, Shengdong, Sun, Mengwei, Li, Zehui, Yang, Yi, Crawford, Nigel M, Wang, Yong
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 05-10-2017
• Subjects: Maize; nitrate assimilation; nitrate regulatory gene; nitrate signaling; Plant Science; ZmNLP6 and ZmNLP8; Maize; ZmNLP6 and ZmNLP8; nitrate signaling; nitrate assimilation; nitrate regulatory gene
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2017.01703

Nitrate is a key nutrient that affects maize growth and yield, and much has yet to be learned about nitrate regulatory genes and mechanisms in maize. Here, we identified nine
genes in maize and analyzed the functions of two
members in nitrate signaling. qPCR results revealed a broad pattern of expression for
genes in different stages and organs with the highest levels of transcript expression of
and
. When
and
were overexpressed in the
nitrate regulatory gene mutant
, nitrate assimilation and induction of nitrate-responsive genes in the transgenic plants were recovered to WT levels, indicating that
and
can replace the essential roles of the master nitrate regulatory gene
in nitrate signaling and metabolism. ZmNLP6 and ZmNLP8 are localized in the nucleus and can bind candidate nitrate-responsive
-elements
. The biomass and yield of transgenic
lines overexpressing
and
showed significant increase compared with WT and
mutant line in low nitrate conditions. Thus,
and
regulate nitrate signaling in transgenic
plants and may be potential candidates for improving nitrogen use efficiency of maize.