Vacuolar invertase knockout enhances drought tolerance in potato plants
Authors: Roitman, M., Teper-Bamnolker, P., Doron-Faigenboim, A., Sikron, N., Fait, A., Vrobel, O., Tarkowski, P., Moshelion, M., Bocobza, S., Eshel, D.
CRISPR/Cas9 knockout of the vacuolar invertase gene (StVInv) in potato enhanced drought resilience, with mutants maintaining higher stomatal conductance, transpiration, and photosynthetic efficiency, leading to improved agronomic water-use efficiency and biomass under water limitation. Metabolomic profiling showed accumulation of galactinol and raffinose, while ABA levels were reduced, indicating altered osmoprotective and hormonal responses that support sustained growth during drought.
Four barley genotypes were examined under simultaneous Fusarium culmorum infection and drought, revealing genotype-dependent Fusarium Head Blight severity and largely additive transcriptomic responses dominated by drought. Co‑expression and hormone profiling linked ABA and auxin to stress‑specific gene modules, and a multiple linear regression model accurately predicted combined‑stress gene expression from single‑stress data, suggesting modular regulation.
The mRNA covalent modification dihydrouridine regulates transcript turnover and photosynthetic capacity during plant abiotic stress
Authors: Yu, L., Melandri, G., Dittrich, A. C., Calleja, S., Rozzi, B., Ganguly, D. R., Palos, K., Srinivasan, A., Brewer, E. K., Fischer, H., Obata, T., Elgawad, H. A., Beemster, G. T. S., Henderson, R., Garcia, C. D., Zhang, X., Stern, D., Eveland, A., Schroeder, S. J., Skirycz, A., Lyons, E., Arnold, E. A., Gregory, B. D., Nelson, A. D. L., Pauli, D.
The study integrates multi-omics data from six Sorghum bicolor accessions under field drought to link RNA covalent modifications (RCMs) with photosynthetic performance, identifying the enzyme SbDUS2 that produces dihydrouridine (DHU) on transcripts. Loss‑of‑function dus2 mutants in Arabidopsis thaliana reveal that DHU deficiency leads to hyperstability of photosynthesis‑related mRNAs, impairing germination, development, and stress‑induced CO2 assimilation. The authors propose DHU as a post‑transcriptional mark that promotes rapid mRNA turnover during abiotic stress, enhancing plant resilience.
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 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 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.
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.