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Margaritopoulou, T.

Publications and source records attributed to Margaritopoulou, T..

2 recordsLinked to original sources

Halophytic endophytes provide transferable immune functions for crop resilience

Halophytic microbiomes represent an untapped reservoir of stress-adapted microbial functions, yet whether these functions can be transferred across ecological boundaries to enhance crop immune resilience remains unknown. Here we show that Kushneria, a halophyte-associated genus with broad environmental resilience, confers robust disease protection in tomato and cucumber plants against fungal and oomycete pathogens despite lacking direct antagonistic activity. Comparative genomics across 26 genomes revealed extensive biosynthetic novelty and conserved catabolic clusters associated with rhizosphere competence, providing a genomic framework for persistence of Kushneria in saline environments. Multi-omics profiling associated protection with a distinct host immune regulatory response, characterized by strong induction of core NLR receptors, including a ZAR1 paralogue. This response was further linked to a previously uncharacterized long noncoding RNA, Solyc10r048010.1, connected to the induced NLR network. Our findings establish halophytic endophytes as field-validated and transferable modulators of crop immunity and identify a candidate regulatory RNA-NLR axis associated with Kushneria-induced disease resistance.

microbiology↗

Environment and HSP90 modulate MAPK stomatal developmental pathway

Stomatal ontogenesis is a key element of plant adaptation aiming to control photosynthetic efficiency and water management under fluctuating environments 1,2,3. Development of stomata is guided by endogenous and environmental cues and is tightly coupled to overall plant growth 1,2,3. YODA signaling pathway is essential to stomatal lineage specification4,5,6 since it regulates the activities of transcription factors such as SPEECHLESS (SPCH)7,8,9,10. Heat-shock proteins 90 (HSP90s) are evolutionarily conserved molecular chaperones implicated in a broad range of signalling pathways being integrated in interaction networks with client proteins11,12,13,14. Herein, based on genetic, molecular, biochemical, and cell biological evidence we report that heat-stress conditions affect phosphorylation and deactivation of SPCH and modulate stomatal density. We show that genetic and physical interactions between HSP90s and YODA control stomatal patterning, distribution and morphology. We provide solid evidence that HSP90s play a major role in transducing the heat-stress response since they act upstream and downstream of YODA signalling, regulate the activity and nucleocytoplasmic distribution of MAPKs, and the activation of SPCH. Thus, HSPs control the stomatal development both under normal temperature and acute heat-stress conditions. Our results demonstrate that HSP90s couple stomatal formation and patterning to environmental cues providing an adaptive mechanism of heat-stress tolerance response and stomatal formation in Arabidopsis.

plant biology↗