Biology subjects

Reig-Valiente, J. L.

Publications and source records attributed to Reig-Valiente, J. L..

3 recordsLinked to original sources

bioRxiv2025

Developmentally-controlled generation of tRNA halves facilitates translational repression during sexual reproduction

The role of transfer RNAs (tRNAs) as mediators between the genetic code and protein synthesis is well established. In parallel, tRNAs can generate different types of functional small RNAs (sRNAs) that accumulate during stress and certain developmental processes across diverse organisms. Interestingly, this class of sRNAs (termed tRNA-derived sRNAs, tsRNAs) accumulate in the male gamete of mammals, insects, and plants but their role in these reproductive cells is unclear. Here, we determine the molecular pathway of tsRNA biogenesis in the plant male gamete-containing structure (the pollen grain) and identify their role in mediating the characteristic translational repression taking place in this tissue. Our data demonstrates that male-accumulating tsRNAs are generated by a cell-controlled pathway to aid in mediating reproductive translational repression and that their accumulation is key to ensuring the proper function of the pollen grain.

plant biology↗

bioRxiv2023

Heterochromatin re-organization associated with the transcriptional reprogramming under viral infection in Arabidopsis

Epigenetic mechanisms are key regulators of genomic integrity and genic expression. Emerging evidence shows that epigenetic regulation is an important component of the transcriptional reprogramming during stress. Despite this, the overall stress-induced reprogramming of the different epigenetic marks and their targets are unknown. Here, we uncovered multiple epigenetic changes taking place during viral infection in Arabidopsis thaliana and their connection with gene expression. We find that cucumber mosaic virus (CMV) infection induces an overall reorganization of the repressive epigenetic marks H3K9me2, H3K27me3, and DNA methylation, which interact between them and are dynamic during infection. Overall, these epigenetic changes are involved in the reprogramming of the transcriptional program to adapt to the biotic stress, and might ensure genome stability through the transcriptional control of transposable elements (TEs). Mechanistically, we demonstrate that the catalytic component of the Polycomb Repressive Complex 2 (PRC2) CURLY LEAF (CLF) mediates the transcriptional repression of genes gaining H3K27me3 during viral infection and that mutants on that component induce resistance against CMV. Altogether, our results provide a complete picture of the epigenetic changes that occur during biotic stress and exemplify the overall dynamism of epigenetic regulation in eukaryotic organisms.

plant biology↗

bioRxiv2020

Aphid feeding induces the relaxation of epigenetic control and the associated regulation of the defense response in Arabidopsis

Environmentally induced changes in the epigenome help individuals to quickly adapt to fluctuations in the conditions of their habitats. Here we explored those changes in Arabidopsis thaliana plants subjected to multiple biotic and abiotic stresses, and identified transposable element (TE) activation in plants infested with the green peach aphid, Myzus persicae. We performed a genome-wide analysis of DNA methylation, mRNA expression, mRNA degradation and small RNA accumulation. Our results demonstrate that aphid feeding induces loss of methylation of hundreds of loci, mainly TEs. This loss of methylation has the potential to regulate gene expression and we found evidence that it is involved in the control of key plant immunity genes. Accordingly, we find that mutant plants deficient in epigenetic silencing show increased resistance to M.persicae infestation. Collectively, our results show that changes in DNA methylation play a significant role in the regulation of the plant transcriptional response and induction of defense response against aphid feeding.

plant biology↗