The circadian clock gates lateral root development
Authors: Nomoto, S., Mamerto, A., Ueno, S., Maeda, A. E., Kimura, S., Mase, K., Kato, A., Suzuki, T., Inagaki, S., Sakaoka, S., Nakamichi, N., Michael, T. P., Tsukagoshi, H.
The study identifies the circadian clock component ELF3 as a temporal gatekeeper that limits hormone‑induced pericycle proliferation and lateral root development in Arabidopsis thaliana. Time‑resolved transcriptomics, imaging, and genetic analyses show that ELF3 maintains rhythmic expression of key regulators via LNK1 and MADS‑box genes, and that loss of ELF3 disrupts this rhythm, enhancing callus growth and accelerating root organogenesis.
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 reveals that the microtubule-associated protein MAP70-2 integrates mechanical and biochemical signals to guide division plane orientation during early lateral root primordium formation in Arabidopsis thaliana. Dynamic MAP70-2 localization to cell corners and the cortical division zone precedes cytokinesis, and loss of MAP70-2 results in misoriented divisions and malformed lateral roots, highlighting its role in three‑dimensional differential growth under mechanical constraints.
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 shows that maize plants carrying autophagy-defective atg10 mutations exhibit delayed flowering and significant reductions in kernel size, weight, and number, culminating in lower grain yield. Reciprocal crossing experiments reveal that the maternal genotype, rather than the seed genotype, primarily drives the observed kernel defects, suggesting impaired nutrient remobilization from maternal tissues during seed development.
The interplay between autophagy and the carbon/nitrogen ratio as key modulator of the auxin-dependent chloronema-caulonema developmental transition in Physcomitrium patens.
Authors: Pettinari, G., Liberatore, F., Mary, V., Theumer, M., Lascano, R., Saavedra, L. L.
Using the bryophyte Physcomitrium patens, the study shows that loss of autophagy enhances auxin‑driven caulonemata differentiation and colony expansion under low nitrogen or imbalanced carbon/nitrogen conditions, accompanied by higher internal IAA, reduced PpPINA expression, and up‑regulated RSL transcription factors. Autophagy appears to suppress auxin‑induced differentiation during nutrient stress, acting as a hub that balances metabolic cues with hormonal signaling.
Thermopriming enhances heat stress tolerance by orchestrating protein maintenance pathways: it activates the heat shock response (HSR) via HSFA1 and the unfolded protein response (UPR) while modulating autophagy to clear damaged proteins. Unprimed seedlings cannot mount these responses, leading to proteostasis collapse, protein aggregation, and death, highlighting the primacy of HSR and protein maintenance over clearance mechanisms.
The study reveals that REMORIN protein evolution is primarily driven by diversification of their conserved C-terminal domain, defining four major clades. Structural bioinformatics predicts a common membrane‑binding interface with diverse curvatures and lengths, and suggests that some REMs can form C‑terminal‑mediated oligomers, adding complexity to membrane organization.
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.