Key Peptide from Tomato Gene Affects Root Growth and Gene Activity

Jim Crocker
13th July, 2024

Key Peptide from Tomato Gene Affects Root Growth and Gene Activity

Image Source: Natural Science News, 2024

Key Findings

  • Researchers at Dalian University of Technology discovered that a small peptide, miPEP396a, is produced by the miRNA miR396a in tomatoes
  • miPEP396a is located in the nucleus and regulates the expression of its own pri-miR396a, miR396a, and their target genes
  • Applying miPEP396a in vitro significantly inhibited the elongation of tomato primary roots, showing its role in root development
MicroRNAs (miRNAs) are small, non-coding RNAs that play a crucial role in regulating gene expression by binding to target messenger RNAs (mRNAs) and inhibiting their translation or promoting their degradation. This regulatory mechanism has profound implications for various biological processes and diseases[2]. Recent research has uncovered a new layer of complexity in miRNA function, revealing that primary miRNAs (pri-miRNAs) can encode small peptides known as miPEPs, which also have significant biological roles. A recent study conducted by researchers at Dalian University of Technology has shed light on the function of a specific miPEP, miPEP396a, in tomatoes[1]. The study focused on tomato miR396a, a miRNA known to regulate various developmental processes. Using 5' RACE, a technique to map the start of RNA transcripts, the researchers characterized the primary sequence of miR396a and confirmed the presence of miPEP396a by verifying the translational activity of its start codon. This discovery is significant because it extends the understanding of miRNA functionality beyond gene silencing, suggesting that pri-miRNAs can also produce functional peptides. The researchers found that miPEP396a primarily resides in the nucleus, where it regulates the expression of its own pri-miR396a, miR396a, and the target genes of miR396a. This nuclear localization is crucial for its function, as it directly influences the transcription and processing of miR396a. This finding aligns with previous research showing that miRNAs are involved in intricate regulatory networks that control gene expression at multiple levels[3][4]. To understand the broader impact of miPEP396a, the researchers conducted transcriptomic and metabolomic analyses. These analyses revealed that in vitro synthesis of miPEP396a significantly increased the expression of genes related to phenylpropanoid biosynthesis and hormone pathways in tomatoes. Phenylpropanoids are important for plant defense and structural integrity, while hormones regulate various aspects of plant growth and development. This suggests that miPEP396a has a wide-ranging influence on tomato biology. One of the most striking findings of the study was the effect of miPEP396a on root growth. The in vitro application of miPEP396a significantly inhibited the elongation of tomato primary roots. This observation provides a functional insight into how miPEP396a regulates root development, likely through the modulation of miR396a expression and its downstream targets. This finding is particularly intriguing given that miRNAs are known to play critical roles in plant development[4]. The discovery of miPEP396a adds a new dimension to the understanding of miRNA function in plants. It suggests that pri-miRNAs can have dual roles: encoding functional peptides and producing miRNAs that regulate gene expression. This dual functionality could be a common feature among pri-miRNAs, offering new avenues for research and potential applications in agriculture and biotechnology. In summary, the study by Dalian University of Technology researchers provides compelling evidence that miPEP396a, encoded by pri-miR396a, regulates root growth in tomatoes by promoting the expression of miR396a. This expands the functional repertoire of miRNAs and highlights the complex regulatory networks in which they are involved. The findings also underscore the importance of investigating the molecular mechanisms of miRNAs to fully understand their diverse roles in biology[2][3][4][5].

GeneticsBiochemPlant Science

References

Main Study

1) Regulatory Peptide Encoded by the Primary Transcript of miR396a Influences Gene Expression and Root Development in Solanum lycopersicum.

Published 12th July, 2024

https://doi.org/10.1021/acs.jafc.4c03588

Related Studies

2) Reexamining assumptions about miRNA-guided gene silencing.

https://doi.org/10.1093/nar/gkab1256

3) HASTY modulates miRNA biogenesis by linking pri-miRNA transcription and processing.

https://doi.org/10.1016/j.molp.2020.12.019

4) microRNAs and Their Roles in Plant Development.

https://doi.org/10.3389/fpls.2022.824240

5) The Role of miRNAs in Metabolic Diseases.

https://doi.org/10.2174/0929867329666220801161536


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