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 genetic architecture of leaf vein density traits and its importance for photosynthesis in maize
Authors: Coyac-Rodriguez, J. L., Perez-Limon, S., Hernandez-Jaimes, E., Hernandez-Coronado, M., Camo-Escobar, D., Alonso-Nieves, A. L., Ortega-Estrada, M. d. J., Gomez-Capetillo, N., Sawers, R. J., Ortiz-Ramirez, C. H.
Using diverse Mexican maize varieties and a MAGIC population, the study demonstrated that leaf vein density is both variable and plastic, correlating positively with photosynthetic rates for small intermediate veins and increasing under heat in drought-adapted lines. Twelve QTLs linked to vein patterning were identified, highlighting candidate genes for intermediate vein development and shedding light on the evolution of high-efficiency C4 leaf architecture.
The study assessed 17 morphological, biochemical, and salt‑stress tolerance traits in 19 maize (Zea mays) landrace accessions from northern Argentina, revealing substantial variation both within and among accessions. Redundancy analysis linked phenotypic variation to the altitude of the collection sites, underscoring the potential of these landraces as sources of diverse biochemical and stress‑related traits for breeding.
The study tests whether heavy‑metal stress contributed to maize domestication by exposing teosinte (Zea mays ssp. parviglumis) and the Palomero toluqueno landrace to sublethal copper and cadmium, then analysing genetic diversity, selection signatures, and transcriptomic responses of three chromosome‑5 heavy‑metal response genes (ZmHMA1, ZmHMA7, ZmSKUs5). Results reveal strong positive selection on these genes, heavy‑metal‑induced phenotypes resembling modern maize, and up‑regulation of Tb1, supporting a role for volcanic‑derived metal stress in early maize evolution.
Authors: Baer, M., Zhong, Y., Yu, B., Tian, T., He, X., Gu, L., Huang, X., Gallina, E., Metzen, I. E., Bucher, M., Song, R., Gutjahr, C., SU, Z., Moya, Y., von Wiren, N., Zhang, L., Yuan, L., Shi, Y., Wang, S., Qi, W., Baer, M., Zhao, Z., Li, C., Li, X., Hochholdinger, F., Yu, P.
The study uncovers how arbuscular mycorrhizal (AM) fungi induce lateral root formation in maize by activating ethylene‑responsive transcription factors (ERFs) that regulate pericycle cell division and reshape flavonoid metabolism, lowering inhibitory flavonols. It also shows that the rhizobacterium Massilia collaborates with AM fungi, degrading flavonoids and supplying auxin, thereby creating an integrated ethylene‑flavonoid‑microbe signaling network that can be harnessed to improve nutrient uptake and crop sustainability.
The mRNA covalent modification dihydrouridine regulates transcript turnover and photosynthetic capacity during plant abiotic stress
Authors: Yu, L., Melandri, G., Dittrich, A. C., Calleja, S., Rozzi, B., Ganguly, D. R., Palos, K., Srinivasan, A., Brewer, E. K., Fischer, H., Obata, T., Elgawad, H. A., Beemster, G. T. S., Henderson, R., Garcia, C. D., Zhang, X., Stern, D., Eveland, A., Schroeder, S. J., Skirycz, A., Lyons, E., Arnold, E. A., Gregory, B. D., Nelson, A. D. L., Pauli, D.
The study integrates multi-omics data from six Sorghum bicolor accessions under field drought to link RNA covalent modifications (RCMs) with photosynthetic performance, identifying the enzyme SbDUS2 that produces dihydrouridine (DHU) on transcripts. Loss‑of‑function dus2 mutants in Arabidopsis thaliana reveal that DHU deficiency leads to hyperstability of photosynthesis‑related mRNAs, impairing germination, development, and stress‑induced CO2 assimilation. The authors propose DHU as a post‑transcriptional mark that promotes rapid mRNA turnover during abiotic stress, enhancing plant resilience.
A meta‑analysis of 73 studies on cucumber (Cucumis sativus) under elevated CO₂ (eCO₂) revealed that eCO₂ significantly increased net photosynthetic rate (+56.31%), biomass (+27.75%) and yield (+21.98%), while reducing stomatal conductance (‑36.07%) and transpiration (‑30.42%). The authors recommend maintaining eCO₂ levels between 800–1200 ppm together with higher light, temperature, optimal humidity, and adequate fertilization to optimise greenhouse cucumber production under climate‑change scenarios.
The study investigated the evolution of the rubisco large subunit (RbcL) across four plant clades using rbcL gene sequences, codon models, and protein structure predictions, finding widespread positive selection and convergent amino‑acid changes affecting side‑chain polarity. Phylogenetic comparative analyses linked higher protein stability to warmer growing‑season temperatures, though this relationship weakened after accounting for phylogeny.
The study introduces an enhanced crosslinking mass spectrometry workflow that preserves native protein interactions within functional thylakoid membranes of Arabidopsis and spinach, while electron transport remains active. Mapping the obtained crosslinks to known structures validates complex integrity and reveals novel assemblies, facilitating in situ exploration of photosynthetic membrane protein networks.
KATANIN promotes cell elongation and division to generate proper cell numbers in maize organs
Authors: Martinez, S. E., Lau, K. H., Allsman, L. A., Irahola, C., Habib, C., Diaz, I. Y., Ceballos, I., Panteris, E., Bommert, P., Wright, A. J., Weil, C., Rasmussen, C.
The study identifies two maize genes, Discordia3a and Discordia3b, that encode the microtubule‑severing protein KATANIN. Loss‑of‑function allele combinations reduce microtubule severing, impair cell elongation, delay mitotic entry, and disrupt preprophase band and nuclear positioning, leading to dwarfed, misshapen plants.