Phosphite (Phi) and phosphate (Pi) share the same root uptake system, but Phi acts as a biostimulant that modulates plant growth and disease resistance in a species‑ and Pi‑dependent manner. In Arabidopsis, Phi induces hypersensitive‑like cell death and enhances resistance to Plectosphaerella cucumerina, while in rice it counteracts Pi‑induced susceptibility to Magnaporthe oryzae and Fusarium fujikuroi, accompanied by extensive transcriptional reprogramming.
The review examines the genetic networks governing spikelet number per spike (SNS) in wheat, highlighting how the balance between inflorescence meristem activity and the timing of terminal spikelet transition determines yield potential. It discusses how mutations affecting meristem identity can create supernumerary spikelets, the trade-offs of such traits, and recent advances using spatial transcriptomics, single‑cell analyses, and multi‑omics to identify new SNS genes for breeding.
The study examined how elevated atmospheric CO₂ (550 ppm) affects immunity in the C₄ cereal maize (Zea mays L.) by exposing plants grown under ambient and elevated CO₂ to a range of pathogens. Elevated CO₂ increased susceptibility to sugarcane mosaic virus, decreased susceptibility to several bacterial and fungal pathogens, and left susceptibility to others unchanged, with reduced bacterial disease linked to heightened basal immune responses. These findings provide a baseline for future investigations into CO₂‑responsive defense mechanisms in C₄ crops.
In vivo binding by Arabidopsis SPLICING FACTOR 1 shifts 3' splice site choice, regulating circadian rhythms and immunity in plants
Authors: Agrofoglio, Y. C., Iglesias, M. J., de Leone, M. J., Hernando, C. E., Lewinski, M., Torres, S. B., Contino, G., Yanovsky, M. J., Staiger, D., Mateos, J. L.
The study characterizes the plant spliceosomal protein AtSF1 in Arabidopsis thaliana, using iCLIP and RNA‑seq to map its in vivo branch point binding sites and demonstrate that loss of AtSF1 causes widespread 3' splice‑site mis‑selection. Structural comparison reveals a plant‑specific domain architecture, and the identified AtSF1 targets are enriched for circadian and defense genes, linking splicing regulation to timing and immunity.
Spatiotemporal regulation of arbuscular mycorrhizal symbiosis at cellular resolution
Authors: Chancellor, T., Ferreras-Garrucho, G., Akmakjian, G. Z., Montero, H., Bowden, S. L., Hope, M., Wallington, E., Bhattacharya, S., Korfhage, C., Bailey-Serres, J., Paszkowski, U.
The study applied dual-species spatial transcriptomics at single-cell resolution to map plant and fungal gene activity in rice roots colonized by Rhizophagus irregularis, revealing transcriptional heterogeneity among morphologically similar arbuscules. By pioneering an AM-inducible TRAP-seq using stage‑specific promoters, the authors uncovered stage‑specific reprogramming of nutrient transporters and defence genes, indicating dynamic regulation of nutrient exchange and arbuscule lifecycle.
A genome-wide survey identified 217 EXO70 genes across five kiwifruit (Actinidia spp.) species, classifying them into three subfamilies and nine clades and revealing lineage‑specific expansions, especially in EXO70C, EXO70E, and EXO70H. Functional assays demonstrated that kiwifruit EXO70B1 interacts with the immune hub protein RIN4_1, suggesting a conserved EXO70‑RIN4 module in plant immunity. The study provides a foundational resource for exploring EXO70‑mediated disease resistance in kiwifruit.
The study reveals that the energy sensor SnRK1 modulates Arabidopsis defense by repressing SA‑dependent gene expression and bacterial resistance, with its activity enhanced under high humidity. SnRK1 interacts with TGA transcription factors to attenuate PR1 expression, linking cellular energy status to immune regulation.
The study characterizes the single-copy S-nitrosoglutathione reductase 1 (MpGSNOR1) in the liverwort Marchantia polymorpha, showing that loss-of-function mutants generated via CRISPR/Cas9 exhibit marked morphological defects and compromised SNO homeostasis and immune responses. These findings indicate that GSNOR-mediated regulation of S‑nitrosylation is an ancient mechanism linking development and immunity in early land plants.
The study applied spatial transcriptomics to map the transcriptional landscape of wheat (Triticum aestivum) inflorescences during spikelet development, revealing two distinct regions—a RAMOSA2‑active primordium and an ALOG1‑expressing boundary. Developmental assays showed that spikelets arise from meristematic zones accompanied by vascular rachis formation, identifying key regulators that could be targeted to improve spikelet number and yield.
NUDIX Hydrolases Target Specific Inositol Pyrophosphates and Regulate Phosphate Homeostasis and Bacterial Pathogen Susceptibility in Arabidopsis
Authors: Schneider, R., Lami, K., Prucker, I., Stolze, S. C., Strauss, A., Schmidt, J. M., Bartsch, S. M., Langenbach, K., Lange, E., Ritter, K., Furkert, D., Faiss, N., Kumar, S., Hasan, M. S., Makris, A., Krusenbaum, L., Wege, S., Belay, Y. Z., Kriescher, S., The, J., Harings, M., Grundler, F., Ried-Lasi, M. K., Schoof, H., Gaugler, P., Kamleitner, M., Fiedler, D., Nakagami, H., Giehl, R. F., Lahaye, T., Bhattacharjee, S., Jessen, H. J., Gaugler, V., Schaaf, G.
The study identified two subclades of Arabidopsis NUDIX hydrolases that selectively hydrolyze distinct inositol pyrophosphate isomers, with subclade I targeting 4-InsP7 and subclade II targeting 3-InsP7 in a Mg2+-dependent manner. Loss-of-function mutants of subclade II NUDTs displayed disrupted phosphate and iron homeostasis, elevated 1/3-InsP7 levels, and increased resistance to Pseudomonas syringae, revealing roles in nutrient signaling and plant immunity, while cross-kingdom analyses showed conserved PP-InsP‑metabolizing activities.