Huimin Liu1, Wanwen Yu2, Jiangting Wu3, Zhuorong Li3, Hui Li4, Jing Zhou3, Jingjing Hu5, Yan Lu6. 1. State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Non-Timber Forest Germplasm Enhancement and Utilization of State Forestry and Grassland Administration, Non-Timber Forest Research and Development Center, Chinese Academy of Forestry, Zhengzhou, 450003, China. 2. Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China. 3. State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Silviculture of the National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China. 4. State Key Laboratory of Tree Genetics and Breeding, Research Institution of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, 510000, China. 5. Inertia Shanghai Biotechnology Co., Ltd., Shanghai, 200335, China. 6. State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Silviculture of the National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China. 18260093866@163.com.
Abstract
MAIN CONCLUSION: Circular RNA (circRNA) identification and expression profiles, and construction of circRNAs-miRNAs-mRNAs networks indicates that circRNAs are involved in wood formation of poplars in acclimation to low nitrogen availability. Circular RNAs (circRNAs) are covalently closed non-coding RNAs that play pivotal roles in various biological processes. However, circRNAs' roles in wood formation of poplars in acclimation to low nitrogen (N) availability are currently unknown. Here, we undertook a systematic identification and characterization of circRNAs in the wood of Populus × canescens exposed to either 50 (low N) or 500 (normal N) µM NH4NO3 using rRNA-depleted RNA-sequencing. A total of 2,509 unique circRNAs were identified, and 163 (ca. 6.5%) circRNAs were significantly differentially expressed (DE) under low N condition. We observed a positive correlation between the expression patterns of DE circRNAs and their hosting protein-coding genes. Moreover, circRNAs-miRNAs-mRNAs' networks were identified in the wood of poplars under low N availability. For instance, upregulated several circRNAs, such as circRNA1226, circRNA 1732, and circRNA392 induced increases in nuclear factor Y, subunit A1-A (NFYA1-A), NFYA1-B, and NFYA10 transcript levels via the mediation of miR169b members, which is in line with reduced xylem width and cell layers of the xylem in the wood of low N-supplied poplars. Upregulation of circRNA1006, circRNA1344, circRNA1941, circRNA901, and circRNA146 caused increased transcript level of MYB61 via the mediation of a miR5021 member, corresponding well to the higher lignin concentration in the wood of low N-treated poplars. Overall, these results indicated that DE circRNAs play an essential role in regulating gene expression via circRNAs-miRNAs-mRNAs' networks to modulate wood anatomical and chemical properties of poplars in acclimation to low N availability.
MAIN CONCLUSION: Circular RNA (circRNA) identification and expression profiles, and construction of circRNAs-miRNAs-mRNAs networks indicates that circRNAs are involved in wood formation of poplars in acclimation to low nitrogen availability. Circular RNAs (circRNAs) are covalently closed non-coding RNAs that play pivotal roles in various biological processes. However, circRNAs' roles in wood formation of poplars in acclimation to low nitrogen (N) availability are currently unknown. Here, we undertook a systematic identification and characterization of circRNAs in the wood of Populus × canescens exposed to either 50 (low N) or 500 (normal N) µM NH4NO3 using rRNA-depleted RNA-sequencing. A total of 2,509 unique circRNAs were identified, and 163 (ca. 6.5%) circRNAs were significantly differentially expressed (DE) under low N condition. We observed a positive correlation between the expression patterns of DE circRNAs and their hosting protein-coding genes. Moreover, circRNAs-miRNAs-mRNAs' networks were identified in the wood of poplars under low N availability. For instance, upregulated several circRNAs, such as circRNA1226, circRNA 1732, and circRNA392 induced increases in nuclear factor Y, subunit A1-A (NFYA1-A), NFYA1-B, and NFYA10 transcript levels via the mediation of miR169b members, which is in line with reduced xylem width and cell layers of the xylem in the wood of low N-supplied poplars. Upregulation of circRNA1006, circRNA1344, circRNA1941, circRNA901, and circRNA146 caused increased transcript level of MYB61 via the mediation of a miR5021 member, corresponding well to the higher lignin concentration in the wood of low N-treated poplars. Overall, these results indicated that DE circRNAs play an essential role in regulating gene expression via circRNAs-miRNAs-mRNAs' networks to modulate wood anatomical and chemical properties of poplars in acclimation to low N availability.
Authors: Xuan Jun Feng; Jing Rui Li; Shi Lian Qi; Qing Fang Lin; Jing Bo Jin; Xue Jun Hua Journal: Proc Natl Acad Sci U S A Date: 2016-12-07 Impact factor: 11.205
Authors: Céline Sorin; Marie Declerck; Aurélie Christ; Thomas Blein; Linnan Ma; Christine Lelandais-Brière; Maria Fransiska Njo; Tom Beeckman; Martin Crespi; Caroline Hartmann Journal: New Phytol Date: 2014-02-17 Impact factor: 10.151