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 demonstrates that subfamily I ethylene receptors form the core ethylene‑sensing module and act epistatically over subfamily II receptors, uniquely possessing Ca2+‑permeable channel activity that drives ethylene‑induced cytosolic calcium influx. This reveals a mechanistic link whereby subfamily I receptors integrate hormone perception with calcium signaling in plants.
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 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.
The study examines how ectopic accumulation of methionine in Arabidopsis thaliana leaves, driven by a deregulated AtCGS transgene under a seed‑specific promoter, reshapes metabolism, gene expression, and DNA methylation. High‑methionine lines exhibit increased amino acids and sugars, activation of stress‑hormone pathways, and reduced expression of DNA methyltransferases, while low‑methionine lines show heightened non‑CG methylation without major transcriptional changes. Integrated transcriptomic and methylomic analyses reveal a feedback loop linking sulfur‑carbon metabolism, stress adaptation, and epigenetic regulation.
The study mapped the cis‑regulatory landscape of the winter rapeseed cultivar Express617, identifying thousands of novel regulatory elements and characterizing super‑enhancers that are asymmetrically enriched in the Cn subgenome of Brassica napus. An in‑silico pipeline combining population‑level expression data and machine‑learning models revealed that many SE‑associated genes are expressed above predicted levels, and structural variants disrupting SEs lead to reduced gene expression, highlighting their functional importance for gene regulation and breeding.
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 investigates the wheat Pm3 NLR allelic series, revealing that near-identical Pm3d and Pm3e alleles confer broad-spectrum resistance by recognizing multiple, structurally diverse powdery mildew effectors. Using chimeric NLR constructs, the authors pinpoint specificity-determining polymorphisms and demonstrate that engineered combinations of Pm3d and Pm3e further expand effector recognition, showcasing the potential for durable wheat protection through NLR engineering.
The study shows that inoculation with the non‑diazotrophic bacterium Enterobacter sp. SA187 significantly improves Arabidopsis thaliana growth under low nitrate conditions by increasing fresh weight, primary root length, and lateral root density, while enhancing nitrate accumulation and reducing shoot C:N ratios. Transcriptomic and mutant analyses reveal that these benefits depend on ethylene signaling and the activity of high‑affinity nitrate transporters NRT2.5 and NRT2.6, indicating an ethylene‑mediated, HATS‑dependent reprogramming of nitrogen uptake.