Genetius

The study identifies the extended NT‑C2 domain of Plastid Movement Impaired 1 (PMI1) as the main membrane‑binding module that interacts with PI4P and PI(4,5)P2, requiring basic residues for plasma‑membrane association. Calcium binding by the NT‑C2 domain modulates its phosphoinositide preference, and cytosolic Ca2+ depletion blocks blue‑light‑induced PMI1 redistribution, indicating that both the NT‑C2 domain and adjacent intrinsically disordered regions are essential for PMI1’s role in chloroplast movement.

The study reveals that the Arabidopsis O-GlcNAc transferase SEC is essential for timely ABA‑induced stomatal closure and drought tolerance, with sec-5 mutants showing delayed closure and increased water loss, while SEC overexpression enhances responsiveness. SEC influences guard‑cell microtubule remodeling, as loss of SEC impairs microtubule reorganization and SEC directly interacts with tubulin α‑4, suggesting tubulin as a target of O‑GlcNAcylation.

The study uses an optogenetic ChannelRhodopsin 2 variant (XXM2.0) to generate defined cytosolic Ca²⁺ transients in Arabidopsis root cells, revealing that these Ca²⁺ signatures suppress auxin‑induced membrane depolarization, Ca²⁺ spikes, and auxin‑responsive transcription, leading to reversible inhibition of cell division and elongation. This demonstrates that optogenetically imposed Ca²⁺ signals act as dynamic regulators of auxin sensitivity in roots.

The study used CRISPR/Cas9 to edit the downstream region of the Arabidopsis thaliana FLOWERING LOCUS T (FT) gene, identifying a 2.3‑kb segment containing the Block E enhancer as crucial for normal FT expression and flowering. Fine‑scale deletions pinpointed a 63‑bp core module with CCAAT‑ and G‑boxes, and revealed a cryptic CCAAT‑box that becomes active when repositioned, highlighting the importance of local chromatin context and motif arrangement for enhancer function.

The study demonstrates that jasmonate (JA) enhances Arabidopsis thaliana responses to extracellular ATP (eATP) by upregulating the eATP receptor P2K1 and amplifying eATP‑induced cytosolic Ca²⁺ spikes and transcriptional reprogramming in a COI1‑dependent manner, whereas salicylic acid pretreatment suppresses these responses. These findings reveal a JA‑mediated priming mechanism that potentiates eATP signaling during stress.

The study investigated the five Arabidopsis SCAMP proteins, focusing on SCAMP5, and identified conserved tyrosine and NPF motifs that mediate anterograde transport and endocytosis, respectively. SCAMPs were shown to dimerize at the plasma membrane and endosomes, interact with plasma‑membrane aquaporins, and their loss (triple and quintuple mutants) conferred mild developmental delay but increased drought tolerance, likely via altered PIP trafficking or stability.

The study identified a suppressor mutation (sune42) in the Golgi-localized Ca2+ transporter CCX4 that alleviates the dominant‑negative root hair phenotype caused by the extensin‑less LRX1ΔE14 protein in Arabidopsis. Detailed Ca2+ imaging showed that LRX1ΔE14 disrupts tip‑focused cytoplasmic Ca2+ oscillations, a defect rescued by the sune42 mutation, highlighting the role of Golgi‑mediated Ca2+ homeostasis in root hair growth.

The study introduces a CRISPR/Cas9‑based restoration system (CiRBS) that reactivates a disabled luciferase reporter (LUC40Ins26bp) in transgenic Arabidopsis, enabling long‑term single‑cell bioluminescence monitoring. Restoration occurs within 24 h after particle‑bombardment‑mediated CRISPR delivery, with ~7 % of cells regaining luminescence and most restored cells carrying a single correctly edited chromosome, facilitating reliable analysis of cellular gene‑expression heterogeneity.

The study demonstrates that constitutively active MLO (faNTA) can rescue the fer-4 root‑hair bursting and polarity defects, restoring tip‑focused cytosolic Ca2+ oscillations and ROS accumulation, highlighting a FERONIA‑MLO signaling module that governs Ca2+ influx and ROS production during root‑hair tip growth. Genetic analysis of mlo15-4 further confirms MLO15 as a key regulator of these Ca2+ and ROS dynamics. The findings suggest MLO proteins act downstream of FER to coordinate calcium and ROS signals essential for root‑hair integrity.

Loss‑of‑function mutations in the drought‑induced genes GASA3 and AFP1 confer enhanced drought tolerance in Arabidopsis thaliana, primarily through smaller stomatal apertures and increased ABA accumulation via hydrolysis of ABA‑GE. Constitutive overexpression of these genes heightens drought sensitivity, indicating that the AFP1/GASA3 module negatively regulates stomatal closure and ABA signaling.