Recently, Professor Hongwei Guo of SUSTech biology department got published an invited review paper in Current Opinion in Plant Biology. The academic paper, “mRNA decay in plants: both quantity and quality matter”(http://www.sciencedirect.com/science/article/pii/S136952 6616302217), systematically summarized the advance in the field of mRNA metabolism and mRNA quality control, and further prospected the central roles of mRNA decay pathways in plant development.
Figure 1. Disruption of bidirectional RNA decay exhibits RDR6-dependent developmental defects and transcriptomic alterations. (A) Rosette morphology of 3-week-old plants of indicated genotypes. Scale bar, 1 cm
Research interests in Professor Hongwei Guo’s lab is mainly focus on the plant hormone signaling transduction and post-transcriptional gene silencing regulation. Prof. Guo’s group has been engaged in studying the mechanism that mRNA decay pathway suppresses post-transcriptional gene silencing for many years, and they published the milestone work in Science 2015, which is a breakthrough in this field (http://science.sciencemag.org/content/348/6230/120.long).
Figure 2. Accumulation of cellular aberrant mRNAs from invading genes but not coding genes are channeled to RDR6-mediated posttranscriptional gene silencing. In plant cells, aberrant mRNAs are normally substrates of the 5’-3’ and 3’-5’ mRNA decay pathways in the cytoplasm. High loading of aberrant transcripts from invading genes such as transgenes and viral genes overrides the mRNA surveillance and decay mechanisms and are subjected to posttranscriptional gene silencing that involves RDR6, SGS3, DCL2/DCL4, AGO1. Meanwhile, the majority of endogenous coding genes do not undergo gene silencing because of the efficient elimination of aberrant transcripts produced during mRNA biogenesis or after their exit from translation.
In eukaryote, mRNA decay is of great importance in mRNA quantity and quality control. The mature mRNAs are the templates for protein translation, while the quantity of mRNA used for translation is precisely regulated, which not only includes transcriptional regulation, but also requires mRNA degradation. Three sets of enzymes—depolyadenylase, decapping enzymes, and ribonuclease, are involved in this process. Recent study revealed that mRNA degradation can occur co-translational and plants use this translation-dependent mRNA surveillance to distinguish and degrade the defective mRNA in case of any aberrant proteins. Those mRNA surveillance machines are also play key roles in regulating plant development and environmental adaptation. Defective mRNA can trigger small RNA dependent PTGS if they can’t be properly degraded thus mRNA decay pathways in cells serve as safeguards for the normal endogenous gene expression. Meanwhile, PTGS is also an efficient way to clear the spurious aberrant mRNA especially the exogenous mRNA. So in this review, authors summarized the mechanisms that RNA decay regulates plant development and prospected the important questions about dynamic mRNA decay and mRNA quantity and mRNA quality control.
The paper’s first author is Dr. Xinyan Zhang, who is now the postdoc at Purdue University. Its corresponding author is Professor Hongwei Guo. SUSTech is the first author affiliation, and this work is supported by the National Natural Science Foundation of China, Peking-Tsinghua Center of life science, and SUSTech Scientific Research Foundation.
Contributed by Wu Huihui
