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 employed immunofluorescence labeling and fluorescence intensity quantification to examine tissue-specific cellular modifications in plants under drought stress, revealing targeted alterations in proteoglycans, polysaccharides, and AGPs in leaves and roots. These findings highlight the importance of in planta analyses for accurately capturing stress-induced structural changes.
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.
The study discovers that drought stress triggers proteolytic activation of chloroplast‑localized polyphenol oxidase (PPO) in Camellia sinensis, converting catechins into theaflavins that act as signaling molecules to induce an unfolded protein response and IRE1‑bZIP60‑dependent programmed cell death. Germplasm comparison, transcriptomic profiling, virus‑induced silencing, PPO overexpression, and pharmacological feeding experiments demonstrate that this PPO‑theaflavin pathway is a conserved stress sensor across species such as tomato and wheat.
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.
The study applied single-nucleus RNA sequencing to mature Sorghum bicolor leaves under well‑watered and drought conditions, identifying major leaf cell types and their transcriptional responses. Drought induced transcriptomic changes that surpassed cell‑type differences, indicating a common response across mesophyll, bundle sheath, epidermal, vascular, and stomatal cells, and enabling the identification of candidate drought‑responsive regulators for improving water‑use efficiency.
Drought drives reversible disengagement of root-mycorrhizal symbiosis
Authors: Akmakjian, G. Z., Nozue, K., Nakayama, H., Borowsky, A. T., Morris, A. M., Baker, K., Canto-Pastor, A., Paszkowski, U., Sinha, N., Brady, S., Bailey-Serres, J.
The study shows that during drought, rice (Oryza sativa) downregulates nutrient acquisition and arbuscular mycorrhizal (AM) symbiosis genes, causing the fungal partner to enter metabolic quiescence and retract hyphae, but upon re-watering the symbiosis is rapidly reactivated. This reversible dynamic suggests that plant‑fungus mutualisms are fragile under fluctuating water availability.
The study isolated an endophytic Pseudomonas aeruginosa strain (SPT08) from tomato cotyledon seedlings that suppressed the wilt pathogen Ralstonia pseudosolanacearum and promoted plant growth, increasing height by 20% and root biomass by 60%. GFP labeling confirmed endophytic colonization, and genomic analysis revealed multiple secretion systems and secondary‑metabolite gene clusters associated with biocontrol and growth‑promoting traits.