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 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.
A cryptic START domain regulates deeply conserved transcription factors
Authors: Dresden, C. E., Andrianova, E. P., Smith, B. J., Callery, N. I., Kolonay, D., Holub, A. S., Urquidi Camacho, R. A., Choudury, S. G., Higgins, I. J., Jouline, I., Husbands, A. Y.
The study uncovers a hidden, evolutionarily conserved disorder-containing START (dSTART) domain within plant HD-ZIPIII and HD-ZIPIV transcription factors, demonstrating that dSTART is essential for proper subcellular localization, DNA-binding specificity, and developmental function. It also identifies phosphatidylglycerol and phosphatidic acid species as candidate ligands, linking lipid binding to transcription factor regulation.
The study identifies a novel C-terminal FR motif in Lotus japonicus NODULE INCEPTION (NIN) that expands DNA‑binding specificity by stabilizing the RWP‑RK dimer, and shows that loss of this motif impairs nodulation and nitrogen fixation. Comparative analysis reveals that Arabidopsis NLP2 also possesses a NIN‑type FR, and phylogenetic data suggest the motif originated in early gymnosperms, indicating it predates the evolution of root nodule symbiosis.
The study examines how the SnRK1 catalytic subunit KIN10 integrates carbon availability with root growth regulation in Arabidopsis thaliana. Loss of KIN10 reduces glucose‑induced inhibition of root elongation and triggers widespread transcriptional reprogramming of metabolic and hormonal pathways, notably affecting auxin and jasmonate signaling under sucrose supplementation. These findings highlight KIN10 as a central hub linking energy status to developmental and environmental cues in roots.