Open AccessAgronomic nitrogen‐use efficiency of rice can be increased by driving Os NRT 2.1 expression with the Os NAR 2.1 promoter
Author(s) -
Chen Jingguang,
Zhang Yong,
Tan Yawen,
Zhang Min,
Zhu Longlong,
Xu Guohua,
Fan Xiaorong
Publication year - 2016
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.12531
Subject(s) - nitrogen , biology , promoter , oryza sativa , genetically modified rice , transgene , gene expression , gene , horticulture , microbiology and biotechnology , genetically modified crops , chemistry , genetics , organic chemistry
Summary The importance of the nitrate ( NO 3 − ) transporter for yield and nitrogen‐use efficiency ( NUE ) in rice was previously demonstrated using map‐based cloning. In this study, we enhanced the expression of the Os NRT 2.1 gene, which encodes a high‐affinity NO 3 − transporter, using a ubiquitin ( Ubi ) promoter and the NO 3 − ‐inducible promoter of the Os NAR 2.1 gene to drive Os NRT 2.1 expression in transgenic rice plants. Transgenic lines expressing pU bi:Os NRT 2.1 or pOsNAR 2.1:Os NRT 2.1 constructs exhibited the increased total biomass including yields of approximately 21% and 38% compared with wild‐type ( WT ) plants. The agricultural NUE ( ANUE ) of the pU bi:Os NRT 2.1 lines decreased to 83% of that of the WT plants, while the ANUE of the pOsNAR 2.1:Os NRT 2.1 lines increased to 128% of that of the WT plants. The dry matter transfer into grain decreased by 68% in the pU bi:Os NRT 2.1 lines and increased by 46% in the pOsNAR 2.1:Os NRT 2.1 lines relative to the WT . The expression of Os NRT 2.1 in shoot and grain showed that Ubi enhanced Os NRT 2.1 expression by 7.5‐fold averagely and Os NAR 2.1 promoters increased by about 80% higher than the WT . Interestingly, we found that the Os NAR 2.1 was expressed higher in all the organs of pU bi:Os NRT 2.1 lines; however, for pOsNAR 2.1:Os NRT 2.1 lines, Os NAR 2.1 expression was only increased in root, leaf sheaths and internodes. We show that increased expression of Os NRT 2.1 , especially driven by Os NAR 2.1 promoter, can improve the yield and NUE in rice.