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 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 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.
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 complete chloroplast genome of the endemic fruit species Dillenia philippinensis was sequenced, assembled, and annotated, revealing a 161,591‑bp quadripartite structure with 113 unique genes. Comparative analyses identified simple sequence repeats, codon usage patterns, and phylogenetic placement close to D. suffroticosa, providing a genomic resource for future breeding and conservation efforts.
The authors compiled and standardized published data on Rubisco dark inhibition for 157 flowering plant species, categorizing them into four inhibition levels and analyzing phylogenetic trends. Their meta‑analysis reveals a complex, uneven distribution of inhibition across taxa, suggesting underlying chloroplast microenvironment drivers and providing a new resource for future photosynthesis improvement efforts.
Six new Viola species and two reinstated species from China were identified using field surveys, detailed morphological comparison, and phylogenetic analysis of ITS and GPI gene sequences, placing them in section Plagiostigma subsect. Diffusae. The GPI data offered higher resolution, indicating complex relationships possibly due to ancient hybridization or incomplete lineage sorting, thereby clarifying species boundaries and evolutionary patterns in Chinese Viola.
The study provides a comprehensive genome-wide catalog and single‑cell expression atlas of the carbonic anhydrase (CA) gene family in maize, identifying 18 CA genes across α, β, and γ subfamilies and detailing their structural and regulatory features. Phylogenetic, synteny, promoter motif, bulk tissue RNA‑seq, and single‑cell RNA‑seq analyses reveal distinct tissue and cell‑type specific expression patterns, highlighting β‑CAs as key players in C4 photosynthesis and γ‑CAs in ion/pH buffering, and propose cell‑type‑specific CA genes as targets for improving stress resilience.
The study presents a plant‑focused phylogenetic analysis of class B flavin‑dependent monooxygenases, identifying eight distinct families and revealing lineage‑specific diversification, especially in the NADPH‑binding domain. Using known FMOs as baits, they assembled flavin‑related proteins from key Viridiplantae lineages, performed domain architecture and motif analyses, and reclassified several families, providing a framework for future functional studies.
Evolutionary origin and functional mechanism of Lhcx in the diatom photoprotection
Authors: Kumazawa, M., Akimoto, S., Takabayashi, A., Imaizumi, K., Tsuji, S., Hasegawa, H., Sakurai, A., Imamura, S., Ishikawa, N., Inoue-Kashino, N., Kashino, Y., Ifuku, K.
Molecular phylogenetic analysis indicated that diatom Lhcx proteins share a common ancestor with green algal Lhcsrs, suggesting acquisition via horizontal gene transfer. Knockout of the Lhcx1 gene in the diatom Chaetoceros gracilis almost eliminated non‑photochemical quenching and revealed that Lhcx1 mediates quenching in detached antenna complexes, while also influencing PSII quantum yield and carbon fixation under high‑light conditions. These findings elucidate the evolutionary origin and mechanistic role of Lhcx‑mediated photoprotection in diatoms.