Multi-omics analysis reveals bHLHs acting as master transcription factor (MTF) regulators in the reproductive development-hormone signaling network in Pospiviroid infection in tomato

Authors: AVINA-PADILLA, KATIA - Langebio Cinvestav; Abrahamian, Peter; MORENO, OCTAVIO ZAMBADA - Autonomous University Of Sinaloa; HERRERA-OROPEZA, GABRIEL EMILIO - King'S College; MARIBEL, HERNANDEZ-ROSAL - Langebio Cinvestav; Hammond, Rosemarie

Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 4/16/2021
Publication Date: 10/20/2021
Citation: Avina-Padilla, K., Abrahamian, P., Moreno, O., Herrera-Oropeza, G., Maribel, H.E., Hammond, R. 2021. Multi-omics analysis reveals bHLHs acting as master transcription factor (MTF) regulators in the reproductive development-hormone signaling network in Pospiviroid infection in tomato. American Phytopathological Society Abstracts. 111/S2.20. https://doi.org/10.1094/PHYTO-111-10-S2.1.
DOI: https://doi.org/10.1094/PHYTO-111-10-S2.1

Interpretive Summary:

Technical Abstract: Viroids are minimal pathogens of angiosperms, consisting of non-coding RNAs that cause severe diseases in agronomic crops. In tomato, symptoms of infection by Pospiviroid species include dwarfism, reduction in vigor, abortion of flowers, and reduced size and number in fruits. The transition from vegetative growth to reproductive development requires gene network coordination, where transcription factors (TFs) act as essential organ morphogenesis components. Symptoms associated with viroid infection are linked to reproductive development related to hormone signaling pathways, affecting the expression levels of involved TFs, including the possibility that vd-siRNAs or host factors may be involved in genetic regulation. A network of gene associations of the 161 BHLH TF in tomato genome and their targets was proposed to infer a mechanism of interaction during viroid infection. Hormone signaling pathways are primarily implicit within this network. Our study aims to determine an interaction mechanism among the FT-bHLH master regulators and the vd-siRNAs/targets as effectors of the disease that could be key in the expression of genes involved in biological processes linked to viroid symptoms in susceptible hosts. Our results highlighted that the tomato SolBigPetal1:SIBHLH036 gene ortholog of Arabidopsis BIGPETAL-1 (petal size-morphology) contains 20 of 21 nts of exon sequence corresponding to the region within the pathogenicity domain of the viroid genome, and it is highly induced during infection. Another striking finding was that two PIF-TFs (SlBHLH06, SlBHLH052) are potentially linked with microproteins (miPs) regulation in brassinosteroid pathways. Furthermore, key interactor genes in jasmonic acid (Omega 3 fatty acid desaturase/Fad7), gibberellin (Gibberellin B hydroxylase/ 3OH-1), and auxin (indoleacetic acid 3/ IAA3) hormone pathways, were identified as being negatively regulated via predicted Pospiviroid derived siRNAs. Overall, our study suggests the participation of vd-siRNAs as modulators of target genes in hormone pathways and represents the first approach to study the role of bHLH-miPs in the genetic regulation of reproductive developmental processes during viroid infection.