作者：Lingyu Zheng, Yu Meng, Jing
Ma, Xiulian Zhao, Tielong Cheng, JingJi, Ermei Chang, ChenMeng, NanDeng,
LanzhenChen, ShengqingShi* and Zeping Jiang*.
期刊：Frontiers in Plant Science
发表时间：2015年
卷.期.页码：6: 678
摘要：Populus
tomentosa (Chinese white poplar) is well adapted to various extreme
environments, and is considered an important species to study the effects of
salinity stress on poplar trees. To decipher the mechanism of poplar’s rapid
response to short-term salinity stress, we firstly detected the changes in H2O2
and hormone, and then profiled the gene expression pattern of ten-week-old
seedling roots treated with 200mM NaCl for 0, 6, 12 and 24hours (h) by RNA-seq
on the Illumina-Solexa platform. Physiological determination showed that the
significant increase in H2O2 began at 6h, while that in
hormone ABA was at 24h, under salt stress. Compared with controls (0h), 3991, 4603
and 4903 genes were up regulated, and 1408, 2206 and 3461 genes were down
regulated (adjusted P-value ≤ 0.05 and |log2Ratio|≥1) at 6, 12, and 24h time
points, respectively. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes
and Genomes (KEGG) pathway annotation revealed that the differentially
expressed genes (DEGs) were highly enriched in hormone- and reactive oxygen
species-related biological processes, including ‘response to oxidative stress
or abiotic stimulus’, ‘peroxidase activity’, ‘regulation of transcription’,
‘hormone synthetic and metabolic process’, ‘hormone signal transduction’,
‘antioxidant activity’ and ‘transcription factor activity’. Moreover, K-means
clustering demonstrated that DEGs (total RPKM value>12 from four time
points) could be categorized into four kinds of expression trends: quick
up/down over 6h or 12h, and slow up/down over 24h. Of these, DEGs involved in H2O2-
and hormone- producing and signal-related genes were further enriched in this
analysis, which indicated that the two kinds of small molecules, hormones and H2O2,
play pivotal roles in the short-term salt stress response in poplar. This study
provides a basis for future studies of the molecular adaptation of poplar and
other tree species to salinity stress.