Genetius

The study demonstrates that CRISPR‑mediated knockout of cassava eIF4E family members, particularly the nCBP-1 and nCBP-2 genes, significantly reduces Cassava brown streak disease (CBSD) symptoms and viral load, though redundancy remains. Double mutants in the nCBP clade showed the strongest phenotype, and a yeast two‑hybrid screen identified the L51F substitution in nCBP-2 as a key loss‑of‑affinity mutation, suggesting that analogous edits across the eIF4E family could enhance resistance without pleiotropic effects.

The study applied four linear mixed‑model frameworks to dissect fresh root yield variation among 42 provitamin A cassava genotypes across two contrasting rainfall seasons, identifying months after planting as the primary source of variance. While genotypic effects were modest, specific accessions showed broad adaptability or drought responsiveness, highlighting the value of incorporating environmental sensitivity into cassava breeding.

The study sequenced 387 Colombian cassava landraces alongside existing genotypes to assess genomic diversity and the distribution of loss‑of‑function alleles. It found that landraces retain high diversity, with deleterious LoF alleles largely purged except in genes linked to coumarin biosynthesis and immunity, and identified climate‑associated loci as candidates for gene‑editing to improve resilience.

Expressing the Arabidopsis thaliana non‑rectifying K⁺ channel AKT2var in cassava vascular tissue enhanced electron transport, CO₂ assimilation, and bulk flow, leading to improved source‑sink carbohydrate transport. These physiological gains translated into significantly higher storage‑root yields and greater drought tolerance in both greenhouse and multi‑year field trials. The results suggest targeted K⁺ transport manipulation as a viable strategy to boost cassava productivity under limited inputs and climate stress.

The study used time-course RNA‑Seq to compare gene expression in a susceptible cassava line (TMS 96/0304) with two resistant lines that either restrict virus to roots or are immune to Cassava brown streak disease. Early transcriptional responses, especially in stems at 1 day post‑inoculation, revealed many differentially expressed genes linked to hormonal regulation, defense, and signaling, suggesting that rapid activation of these pathways underlies resistance.

The authors used a dCas9-DMRcd‑SunTag system to target DNA methylation to the promoters of two cassava eIF4E susceptibility genes (nCBP‑1 and nCBP‑2) to combat cassava brown streak disease. While methylation was successfully introduced, control experiments showed that CRISPR interference alone reduced gene expression, suggesting that transcriptional repression, not the added methylation, was responsible for the observed disease resistance. Future work will separate the epigenetic tools by genetic crossing to determine if heritable methylation alone can confer resistance.

The study generated bi‑parental cassava populations from a whitefly‑tolerant and a susceptible line, screened F1 and F2 progeny for enhanced resistance, and used untargeted metabolomics to identify metabolic markers associated with tolerance. Principal component analysis distinguished resistant from susceptible groups, highlighting a key metabolite (m/z 316.0924) and perturbed pathways including cyanogenic glycosides, apocarotenoids, and phenylpropanoid derivatives, providing potential low‑cost markers for breeding.

Using cryo-sectioning to obtain high‑resolution transcriptomes of cassava (Manihot esculenta) stems and storage roots, the study reveals that storage parenchyma formation is linked to repression of the NAC/MYB‑controlled secondary cell‑wall program and reduced GA signaling, while auxin, ABA, and extended MeKNOX1 activity are maintained. The findings identify key transcription factors (MeWOX14, MeKNOX1, LSH genes) and propose a regulatory model for parenchyma differentiation in cassava storage roots.