N-1-naphthylphthalamic acid (NPA) inhibits polar auxin transport (PAT). Though used for over six decades, the precise mechanism by which it inhibits PAT is still unclear. A new study by Abas and colleagues now suggests that NPA directly associates with and inhibits the activity of PIN-FORMED (PIN) transporters. The authors used oocytes from Xenopus laevis as […]
Photosynthesis, in addition to generating ‘food’ for plants, is also known to control root growth, although the mechanism has been unknown. Duan and co-workers identified CYCLOPHILIN38 (CYP38) as necessary for photosynthesis-mediated lateral root (LR) emergence. The chloroplast-localized CYP38 is necessary for assembly of photosystem II, and its mutants show defects in LR emergence, linking it […]
Inceptins are degraded fragments of host chloroplast ATP synthase subunit (cATPC) that are an important class of herbivore-associated molecular patterns (HAMPs). These peptides are abundant in herbivore oral secretions (OS). Using Vu-In, a conserved inceptin from cowpea, Steinbrenner and colleagues have identified a receptor-like kinase (RLK) that specifically senses inceptins in a subtribe of legumes. […]
While ammonium ions (NH4+) serve as important sources of nitrogen nutrition, higher concentrations are toxic and inhibit plant growth and development. In an attempt to understand how roots of rice plant adapt to high concentrations of NH4+, Jia and colleagues found the roots coil and adopt a helical growth pattern at their tips. Experiments indicated […]
CLE40 induces localized root Ca2+ transients through CNGC9 Growth and differentiation of cells in the meristematic region are tightly regulated by different signaling pathways. In the root meristem, the small peptide CLE40 acts as a ligand that binds to cell surface receptors and regulates cellular differentiation. In a new study, Breiden and colleagues have shown […]
Auxin transport during development or wound regeneration is known to require auxin-induced channel or ‘canal’ formation that includes polar localization of PIN auxin transport proteins. Hajný and colleagues have characterized a receptor-like kinase (RLK) complex involved in auxin-induced pattern formation as well as PIN localization. The authors identified CAMEL, a membrane-localized RLK, and its interactor, […]
Calcium-dependent protein kinases (CPKs) form an important class of sensor-responder proteins that bind Ca2+ to ‘sense’ intracellular Ca2+ levels, and ‘respond’ by phosphorylating target proteins. CPK28 has distinct roles in growth and defense. To analyze the importance of Ca2+ in fine-tuning CPK28 function, Bredow and colleagues identified a single phosphorylation site, serine (Ser) 318, as […]
Ethylene is synthesized from 1-Aminocyclopropane carboxylic acid (ACC), and ACC has long been used as a substitute to induce ethylene responses. In a new study, Li and colleagues show that ACC functions as a stand-alone signaling molecule in the liverwort Marchantia. While treatment with ethylene gas increased overall vegetative growth by increasing cell division and […]
Polar cell growth is a key feature in plant organs like root hairs, trichomes and pollen tubes. Kulich and co-workers have identified novel regulatory elements governing the polar growth of root hairs and trichomes in Arabidopsis thaliana. Studying a group of proteins named ARMADILLO REPEAT ONLY (ARO), the authors found them to specifically localize to […]