Global poplar root and leaf transcriptomes reveal links between growth and stress responses under nitrogen starvation and excess

作   者：罗杰，周婧，李红，石文广， Andrea Polle, 卢孟柱, 苏晓华，罗志斌
期刊名称：Tree Physiology
影响因子：3.653
卷 期 号：00
页     码：1-20
关键词：nutrient physiology, phytohormone, Populus, RNA sequencing, woody plants.
论文摘要：
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 NH
4
+
, 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.