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 used comparative transcriptomics of dorsal and ventral petals across development, alongside expression profiling in floral symmetry mutants, to identify genes linked to dorsal (AmCYC-dependent) and ventral (AmDIV-dependent) identities in Antirrhinum majus. In situ hybridisation validated axis‑specific and boundary‑localized expression patterns, revealing that a conserved NGATHA‑LIKE1‑BRASSINAZOLE‑RESISTANT1‑miR164 module has been co‑opted to regulate AmDIV targets and shape the corolla. These findings delineate regulatory modules coordinating dorsoventral and proximal‑distal patterning in zygomorphic flowers.
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.
The study sequenced genomes of ericoid mycorrhiza‑forming liverworts and experimentally reconstituted the symbiosis, revealing a nutrient‑regulated state that supports intracellular colonization. Comparative transcriptomics identified an ancestral gene module governing intracellular symbiosis, and functional validation in Marchantia paleacea through genetic manipulation, phylogenetics, and transactivation assays confirmed its essential role. The findings suggest plants have retained and independently recruited this ancestral module for diverse intracellular symbioses.
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.
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 developed a high-throughput phenotyping platform to assess root infestation by Orobanche cumana in a diverse sunflower association mapping population and applied a dual GWAS using SNPs and k-mers to uncover resistance loci. It validated known QTLs with higher resolution, identified novel candidate genes such as leucine‑rich repeat receptor kinases, and highlighted introgressed segments from wild Helianthus species that contribute to broomrape resistance.