作者：Jie Luo, Jing Zhou, Hong Li,
Wenguang Shi, Andrea Polle, Mengzhu Lu, Xiaomei Sun and Zhi-Bin Luo*
期刊：Tree Physiology
发表时间：2015年
卷.期.页码：00: 1–20. doi:10.1093/treephys/tpv091
摘要：Nitrogen (N) starvation and excess have distinct
effects on N uptake and metabolism in poplars, but the global transcriptomic
changes underlying morphological and physiological acclimation to altered N availability
are unknown. We found that N starvation stimulated the fine root length and
surface area by 54 and 49%, respectively, decreased the net photosynthetic rate
by 15% and reduced the concentrations of NH4+, NO3?
and total free amino acids in the roots and leaves of Populus simonii Carr. in comparison with normal N supply, whereas N
excess had the opposite effect in most cases. Global transcriptome analysis of
roots and leaves elucidated the specific molecular responses to N starvation
and excess. Under N starvation and excess, gene ontology (GO) terms related to
ion transport and response to auxin stimulus were enriched in roots, whereas
the GO term for response to abscisic acid stimulus was overrepresented in
leaves. Common GO terms for all N treatments in roots and leaves were related
to development, N metabolism, response to stress and hormone stimulus.
Approximately 30–40% of the differentially expressed genes formed a
transcriptomic regulatory network under each condition. These results suggest that
global transcriptomic reprogramming plays a key role in the morphological and
physiological acclimation of poplar roots and leaves to N starvation and
excess.