Thermotolerant pollen tube growth is controlled by RALF signaling.
Authors: Althiab Almasaud, R., Ouonkap Yimga, S. V., Ingram, J., Oseguera, Y., Alkassem Alosman, M., Travis, C., Henry, A., Medina, M., Oulhen, N., Wessel, G. M., Delong, A., Pease, J., DaSilva, N., Johnson, M.
The study investigates the molecular basis of heat‑tolerant pollen tube growth in tomato (Solanum lycopersicum) by comparing thermotolerant and sensitive cultivars. Using live imaging, transcriptomics, proteomics, and genetics, the authors identified the Rapid Alkalinization Factor (RALF) signaling pathway as a key regulator of pollen tube integrity under high temperature, with loss of a specific RALF peptide enhancing tube integrity in a thermotolerant cultivar.
The study combined high-throughput image-based phenotyping with genome-wide association studies to uncover the genetic architecture of tolerance to the spittlebug Aeneolamia varia in 339 interspecific Urochloa hybrids. Six robust QTL were identified for plant damage traits, explaining up to 21.5% of variance, and candidate genes linked to hormone signaling, oxidative stress, and cell‑wall modification were highlighted, providing markers for breeding.
The study investigates how the timing of the vegetative phase change (VPC) in Arabidopsis thaliana influences drought adaptation, revealing strong genotype-by-environment interactions that create stage-specific fitness tradeoffs. Genotypes from warmer, drier Iberian climates transition earlier, and genome-wide association mapping identifies loci linked to VPC timing and drought response, with several candidates validated using T‑DNA insertion lines.
Discovery of tomato UDP-glucosyltransferases involved in bioactive jasmonate homeostasis using limited proteolysis-coupled mass spectrometry
Authors: Venegas-Molina, J., Mohnike, L., Selma Garcia, S., Janssens, H., Colembie, R., Kimpe, I., Jaramillo-Madrid, A. C., Lacchini, E., Winne, J. M., Van Damme, P., Feussner, I., Goossens, A., Sola, K.
The study applied limited proteolysis‑coupled mass spectrometry (LiP‑MS) to map JA‑protein interactions, validating known JA binders and uncovering novel candidates, including several UDP‑glucuronosyltransferases (UGTs). Functional omics, biochemical, enzymatic, and structural analyses demonstrated that two tomato UGTs glucosylate jasmonic acid, revealing a previously missing step in JA catabolism.
RNA sequencing of the halophyte Salicornia europaea revealed that combined hypoxia‑salt stress triggers a unique transcriptional response, with 16% of genes specifically altered and distinct synergistic, antagonistic, and additive effects across functional pathways. Metabolic analyses indicated enhanced sucrose and trehalose metabolism, a shift toward lactate fermentation, and increased proline synthesis, highlighting complex regulatory strategies for coping with concurrent stresses.
In a controlled dry-down experiment, Arabis sagittata showed significantly higher recovery from drought than the endangered Arabis nemorensis, a difference that could not be traced to a single major QTL, indicating a polygenic basis. Transcriptome and small‑RNA sequencing revealed that A. sagittata mounts a stronger transcriptional response, including species‑specific regulation of the conserved drought miRNA miR408, and machine‑learning identified distinct cis‑regulatory motif patterns underlying these divergent stress‑response networks.
The study assessed the impact of adding mammalian growth factors and cytokines to transformation media on CRISPR‑Cas9–mediated genome editing in six tomato (Solanum lycopersicum) accessions with varying regeneration capacities. Over three years, supplementation with these factors significantly increased regeneration rates and the production of stable secondary transgenic lines, especially in recalcitrant genotypes.
The researchers created tomato lines overexpressing the autophagy gene SlATG8f and evaluated their performance under high-temperature stress. qRT‑PCR and physiological measurements revealed that SlATG8f overexpression enhances expression of autophagy‑related and heat‑shock protein genes, accelerates fruit ripening, and improves fruit quality under heat stress.
Proteomic comparison of mock‑ and potato spindle tuber viroid‑infected tomato revealed a broad down‑regulation of nucleoporins and nuclear transport receptors, leading to impaired nuclear import of the immune regulator NPR1. Overexpression of NPR1 or treatment with a salicylic‑acid analog restored defense and reduced PSTVd infection, highlighting nuclear transport repression as a key vulnerability in plant immunity against viroids.
The study examined whether colonisation by the arbuscular mycorrhizal fungus Rhizophagus irregularis primes immune responses in barley against the leaf rust pathogen Puccinia hordei. While AMF did not affect disease severity or plant growth, co‑infected leaves showed heightened expression of defence genes and transcriptome reprogramming, including altered protein ubiquitination, indicating a priming mechanism. These results highlight transcriptional and post‑translational pathways through which AMF can enhance barley disease resistance for sustainable crop protection.