Arabidopsis lines with modified ascorbate concentrations reveal a link between ascorbate and auxin biosynthesis
Authors: Fenech, M., Zulian, V., Moya-Cuevas, J., Arnaud, D., Morilla, I., Smirnoff, N., Botella, M. A., Stepanova, A. N., Alonso, J. M., Martin-Pizarro, C., Amorim-Silva, V.
The study used Arabidopsis thaliana mutants with low (vtc2, vtc4) and high (vtc2/OE-VTC2) ascorbate levels to examine how ascorbate concentration affects gene expression and cellular homeostasis. Transcriptomic analysis revealed that altered ascorbate levels modulate defense and stress pathways, and that TAA1/TAR2‑mediated auxin biosynthesis is required for coping with elevated ascorbate in a light‑dependent manner.
Comparative multi-omics profiling of Gossypium hirsutum and Gossypium barbadense fibers at high temporal resolution reveals key differences in polysaccharide composition and associated glycosyltransferases
Authors: Swaminathan, S., Lee, Y., Grover, C. E., DeTemple, M. F., Mugisha, A. S., Sichterman, L. E., Yang, P., Xie, J., Wendel, J. F., Szymanski, D. B., Zabotina, O. A.
The study performed daily large-scale glycome, transcriptome, and proteome profiling of developing fibers from the two cultivated cotton species, Gossypium barbadense and G. hirsutum, across primary and secondary cell wall stages. It identified delayed cellulose accumulation and distinct compositions of xyloglucans, homogalacturonans, rhamnogalacturonan‑I, and heteroxylans in G. barbadense, along with higher expression of specific glycosyltransferases and expansins, suggesting these molecular differences underlie the superior fiber length and strength of G. barbadense.
The study evaluated how acute heat stress affects early-stage rice seedlings, identifying a critical temperature threshold that impairs growth. Transcriptomic profiling of shoots and roots revealed ethylene‑responsive factors (ERFs) as central regulators, with ethylene and jasmonic acid acting upstream, and pre‑treatment with these hormones mitigated heat damage. These findings highlight ERF‑hormone interaction networks as targets for improving rice heat resilience.
Using the Euphorbia peplus genome, the authors performed organ‑specific transcriptomic profiling of the cyathium and combined it with gene phylogenies and dN/dS analysis to investigate floral‑development gene families. They found distinct SEP1 paralog expression, lack of E‑class gene duplications typical of other pseudanthia, and divergent expression patterns for CRC, UFO, LFY, AP3, and PI, suggesting unique developmental pathways in Euphorbia.
The study shows that heatwaves impair the ability of apple (Malus domestica) to mount ASM‑induced immunity against fire blight and apple scab, leading to a loss of protective gene expression. Transcriptomic analysis revealed a broad suppression of ASM‑regulated defense and other biological processes under high temperature, identifying thermo‑sensitive resistance and susceptibility marker genes. The findings highlight that elevated temperature both weakens plant defenses and creates a more favorable environment for pathogens.
Extensive photophysiological variation in wild barley is linked to environmental origin
Authors: Breil-Aubert, M., Shaw, K., Royles, J., Rodrigues Gabriel Sales, C., Walter, J., Taylor, G., Vath, R., Bdolach, E., Dev Tiwari, L., Mathan, J., Lawson, T., Fridman, E., Kromdijk, J., Ferguson, J. N.
A common garden experiment with 320 wild barley (Hordeum vulgare) accessions across two seasons quantified over 30 photophysiological traits, revealing heritable variation and strong genotype-by-environment interactions. Genome-wide association studies and population genetics identified signals of local adaptation, particularly involving stomatal conductance under water limitation, highlighting its role in maintaining photosynthesis and biomass.
The study identified a major QTL (qDTH3) on chromosome 3 responsible for a 7‑10‑day earlier heading phenotype in the rice line SM93, using QTL‑seq, KASP genotyping, association mapping, and transcriptomic analysis to fine‑map the locus to a 2.53 Mb region and pinpoint candidate genes. SNP markers linked to these genes were proposed as tools for breeding early‑maturing, climate‑resilient rice varieties.
The study compares transcriptional, proteomic, and metabolomic responses of wild‑type Arabidopsis and a cyp71A27 mutant to a plant‑growth‑promoting Pseudomonas fluorescens strain and a pathogenic Burkholderia glumeae strain, revealing distinct reprogramming and an unexpected signaling role for the non‑canonical P450 CYP71A27. Mutant analysis showed that loss of CYP71A27 alters gene and protein regulation, especially during interaction with the PGP bacterium, while having limited impact on root metabolites and exudates.
The genome of the vining fern Lygodium microphyllum highlights genomic and functional differences between life phases of an invasive plant
Authors: Pelosi, J., Davenport, R., Kuo, L.-Y., Gray, L. N., Dant, A. J., Kim, E. H., Li, F.-W., Dlugosch, K. M., Krabbenhoft, T. J., Barbazuk, W. B., Sessa, E. B.
The study presents a chromosome-level reference genome for the invasive fern Lygodium microphyllum and compares the transcriptomic and epigenomic profiles of its haploid gametophyte and diploid sporophyte phases, revealing differential regulation of developmental genes and similar methylation patterns across tissues. Base‑pair resolution methylome data and freezing‑stress experiments show that each life phase employs distinct molecular pathways for stress response, emphasizing the importance of considering both phases in invasive‑species management.
A forward genetic screen in the negative photoblastic plant Aethionema arabicum identified a phytochrome A null mutant (koy2) that fails to inhibit seed germination under various light qualities, demonstrating that phytochrome A mediates light‑inhibited germination. The study links natural variation in phytochrome A signaling to local adaptation across the Irano‑Turanian region.