Premium
A systems biology approach identifies new regulators of poplar root development under low nitrogen
Author(s) -
Dash Madhumita,
Yordanov Yordan S.,
Georgieva Tatyana,
Kumari Sapna,
Wei Hairong,
Busov Victor
Publication year - 2015
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13002
Subject(s) - transcriptome , biology , gene , transgene , gene expression , proteasome , transcription (linguistics) , transcription factor , microbiology and biotechnology , shoot , genetics , botany , linguistics , philosophy
Summary In Populus , low nitrogen ( LN ) elicits rapid and vigorous lateral root ( LR ) proliferation, which is closely mirrored by corresponding transcriptomic changes. Using transcriptomic data, we built a genetic network encompassing a large proportion of the differentially regulated transcriptome. The network is organized in a hierarchical fashion, centered on 11 genes. Transgenic manipulations of only three of the 11 genes had a strong impact on root development under LN . These three genes encoded an F‐box protein similar to Hawaiian Skirt ( Pta HWS ) and two transcription factors ( Pta RAP 2.11 and Pta NAC 1 ). Up‐ and downregulation of the three genes caused increased and decreased root proliferation under LN conditions, respectively. The transgenic manipulations had a strong positive effect on growth under greenhouse conditions including increased shoot and root biomass. The three genes appeared to encompass a putative yet‐unknown mechanism that underlies root development under LN . Specifically, the genes are predominantly expressed in roots and have a similar temporal response to LN . More importantly, transgenic manipulation for each of the three genes had a highly significant impact on the expression of the other two. The transgenic manipulations appear to also affect the expression of the regulatory mi RNA ( Ptami RNA 164e ) of one of the transcription factors ( Pta NAC 1 ), albeit in an opposite fashion. Consistent with a putative function of Pta HWS in proteasome degradation, treatment with proteasome inhibitor reversed the expression changes in the transgenic plants. The insights from this study will allow genetic modifications of root architecture for more efficient and dynamic nitrogen foraging in biofuel crops like poplar.