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.
The study identified lineage-specific long non‑coding RNAs (lncRNAs) from the aphid‑specific Ya gene family in Rhopalosiphum maidis and R. padi, demonstrating that these Ya lncRNAs are secreted into maize, remain stable, and move systemically. RNA interference of Ya genes reduced aphid fecundity, while ectopic expression of Ya lncRNAs in maize enhanced aphid colonization, indicating that Ya lncRNAs act as cross‑kingdom effectors that influence aphid virulence.
The researchers created tomato lines overexpressing the autophagy gene SlATG8f and evaluated their performance under high-temperature stress. qRT‑PCR and physiological measurements revealed that SlATG8f overexpression enhances expression of autophagy‑related and heat‑shock protein genes, accelerates fruit ripening, and improves fruit quality under heat stress.
The study used a computer‑vision phenotyping pipeline (EarVision.v2) based on Faster R-CNN to map Ds‑GFP mutant kernels on maize ears and a statistical framework (EarScape) to assess spatial patterns of allele transmission from the apex to the base. They found that alleles causing pollen‑specific transmission defects often show significant spatial biases, whereas Mendelian alleles do not, indicating that reduced pollen fitness can shape the spatial distribution of progeny genotypes in Zea mays.
Clathrin-coated vesicles are targeted for selective autophagy during osmotic stress.
Authors: dragwidge, j., Buridan, M., Kraus, J., Kosuth, T., Chambaud, C., Brocard, L., Yperman, K., Mylle, E., Vandorpe, M., Eeckhout, D., De Jaeger, G., Pleskot, R., Bernard, A., Van Damme, D.
The study identifies an autophagy pathway that degrades plasma membrane-derived clathrin-coated vesicles (CCVs) during hyperosmotic stress, helping maintain membrane tension as cell volume decreases. Using live imaging and correlative microscopy, the authors show that the TPLATE complex subunits AtEH1/Pan1 and AtEH2/Pan1 act as selective autophagy receptors by directly binding ATG8, thereby removing excess membrane under drought or salt conditions.
The study investigates autophagy’s protective role against cadmium stress in Arabidopsis thaliana by comparing wild-type, atg5 and atg7 autophagy-deficient mutants, and ATG5/ATG7 overexpression lines. Cadmium exposure triggered autophagy, shown by ATG8a-PE accumulation, GFP-ATG8a fluorescence and ATG gene up-regulation, with atg5 mutants displaying heightened Cd sensitivity and disrupted metal ion homeostasis, whereas overexpression had limited impact. Genotype-specific differences between Col-0 and Ws backgrounds were also observed.
The study introduces a native‑condition method combining cell fractionation and immuno‑isolation to purify autophagic compartments from Arabidopsis, followed by proteomic and lipidomic characterisation of the isolated phagophore membranes. Proteomic profiling identified candidate proteins linked to autophagy, membrane remodeling, vesicular trafficking and lipid metabolism, while lipidomics revealed a predominance of glycerophospholipids, especially phosphatidylcholine and phosphatidylglycerol, defining the unique composition of plant phagophores.
The study investigates how the pleiotropic maize genes GRASSY TILLERS1 (GT1) and RAMOSA3 (RA3) are differentially regulated to suppress axillary meristems and floral organs, using a newly developed high-throughput quantitative phenotyping method for grass flowers. Distinct environmental mechanisms were found to control each suppression process, and upstream regulatory pathways of GT1 and RA3 have diverged, illustrating how ancient developmental genes can be redeployed to increase genetic pleiotropy during evolution.
Non-catalytic and catalytic TREHALOSE-6-PHOSPHATE SYNTHASES interact with RAMOSA3 to control maize development.
Authors: Tran, T., Claeys, H., Abraham Juarez, M. J., Vi, L. S., Xu, X., Michalski, K., Chou, T. H., Iohannes, S. D., Boumpas, P., Williams, Z., Sheppard, S., Griffiths, C., Paul, M., Furukawa, H., Jackson, D.
The study reveals that the maize catalytic trehalose-6-phosphate phosphatase RA3 interacts with the non‑catalytic TPS ZmTPS1, and together with the catalytic TPS ZmTPS14 they form a protein complex that enhances enzymatic activity. Genetic analyses show that mutations in ZmTPS1 and its paralog ZmTPS12 exacerbate ra3 branching phenotypes, while loss of the catalytic TPSs ZmTPS11 and ZmTPS14 causes embryonic lethality, indicating essential and regulatory roles for both catalytic and non‑catalytic TPS/TPP proteins in plant development.
Using CRISPR‑Cas9‑generated Zmcry mutants, the study shows that maize cryptochromes redundantly mediate blue‑light signaling, suppress mesocotyl elongation, and enhance UV‑B stress tolerance by upregulating genes for phenylpropanoid, flavonoid, and fatty‑acid pathways. Blue light also promotes epidermal wax accumulation, and ZmCRY1 directly interacts with GLOSSY2 in a light‑dependent manner to drive C32 aldehyde synthesis, linking cryptochrome activity to wax biosynthesis and UV‑B resistance.