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.
The study examined DNA methylation dynamics in Arabidopsis thaliana shoots and roots under heat, phosphate deficiency, and combined stress using whole-genome bisulfite sequencing, small RNA‑seq, and RNA‑seq. Distinct stress‑specific methylation patterns were identified, with heat and combined stress causing CHH hypomethylation, phosphate deficiency causing hyper‑ and hypomethylation in shoots and roots respectively, and the combined stress exhibiting a unique signature independent of additive effects. Methylation changes were concentrated in transposable elements and regulatory regions, implicating RdDM and CMT2 pathways and suggesting a role in chromatin accessibility rather than direct transcriptional control.
The study engineered Tobacco rattle virus vectors incorporating distinct RNA secondary structures as mobility factors to improve guide RNA delivery to plant meristems. Using Nicotiana benthamiana plants expressing Cas9, optimal virus constructs were identified that generated both somatic and heritable edits, and these constructs were successfully applied to edit the emerging oilseed crop pennycress (Thlaspi arvense).
The study reveals that heat tolerance of meiotic division in Arabidopsis thaliana depends on sustained translation of cell‑cycle genes mediated by the protein TAM, which forms specialized condensates under high temperature. Natural variation was used to identify heat‑sensitive and heat‑tolerant TAM alleles, and boosting TAM translation with complementary peptides rescued heat‑induced meiotic defects, highlighting a potential mechanism driving polyploidisation under climate stress.
Integrating physiological, transcriptomic, and cellular analyses, the study shows that olive fruit abscission zones undergo lignification, alkalization, and extensive cell‑wall remodeling during natural maturation and after ethephon treatment. A set of 733 FAZ‑specific genes, including β‑1,3‑glucanases, pectate lyases, and pH‑regulating transporters, were identified, and increased glucanase activity together with reduced plasmodesmata callose suggest enhanced intercellular communication facilitates organ detachment in this non‑climacteric fruit.
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 authors introduce the ENABLE(R) Gene Editing in planta toolkit, a streamlined two‑step cloning system for creating CRISPR/Cas9 knockout vectors suitable for transient or stable transformation. Validation was performed in Oryza sativa protoplasts and Arabidopsis thaliana plants, and the toolkit includes low‑cost protocols aimed at facilitating adoption in the Global South.
Daily Heat Stress Induces Accumulation of Non-functional PSII-LHCII and Donor-side Limitation of PSI via Downregulation of the Cyt bf Complex in Arabidopsis thaliana
The study examined the impact of daily moderate heat stress (38 °C for 4 h) on Arabidopsis thaliana, revealing altered thylakoid ultrastructure and structurally intact but functionally impaired PSII‑LHCII complexes. A pronounced reduction in cytochrome b6f content limited PSI on the donor side, suggesting that Cyt b6f down‑regulation serves as an acclimation mechanism that protects PSI at the expense of overall photosynthetic efficiency.
The authors created a fast‑cycling, isogenic barley line (GP‑rapid) by introgressing the wild‑type Ppd‑H1 allele from Igri into the Golden Promise cultivar and performing two backcrosses to limit the donor genome, achieving a 25% reduction in generation time under speed‑breeding conditions while retaining high transformation efficiency. CRISPR/Cas9‑mediated editing of Ppd‑H1 showed regeneration and transformation rates comparable to the original Golden Promise, establishing GP‑rapid as a rapid platform for transgenic and gene‑edited barley research.
The study applied CRISPR/Cas9 gene editing to Physalis peruviana to modify plant‑architecture genes and create a compact growth ideotype. This compact phenotype is intended to increase per‑plot yield and support future breeding efforts for this nutritionally valuable minor crop.