The roles of endomembrane trafficking in plant abiotic stress responses

Abstract

Endomembrane trafficking is a fundamental cellular process in all eukaryotic cells and its regulatory mechanisms have been extensively studied. In plants, the endomembrane trafficking system needs to be constantly adjusted to adapt to the ever-changing environment. Evidence has accumulated supporting the idea that endomembrane trafficking is tightly linked to stress signaling pathways to meet the demands of rapid changes in cellular processes and to ensure the correct delivery of stress-related cargo molecules. However, the underlying mechanisms remain unknown. In this review, we summarize the recent findings on the functional roles of both secretory trafficking and endocytic trafficking in different types of abiotic stresses. We also highlight and discuss the unique properties of specific regulatory molecules beyond their conventional functions in endosomal trafficking during plant growth under stress conditions.

Strigolactones inhibit auxin feedback on PIN-dependent auxin transport canalization

“…Modeling of auxin-mediated polarization 14 has linked auxin feedback on PIN polarity to the auxin effect on PIN subcellular trafficking 15 – 17 . PM-associated PINs are internalized in clathrin-coated vesicles in a process called endocytosis 18 – 20 that might precede PIN relocation to different (plasma) membrane domains 21 , 22 . Numerous pharmacological and genetic determinants that impact on specific cellular events in the control of auxin transport have shaped our current picture of cellular mechanisms and crosstalk therein 1 .…”

“…For example, treatment with the fungal toxin Brefeldin A (BFA) revealed the constitutive endocytic recycling of PIN proteins. This requires BFA-mediated interference of GNOM ARF-GEF activity, causing PM proteins, including PINs, to aggregate in cells 18,20 . Notably, auxin itself appears to inhibit the process of endocytosis and antagonize the BFA effect on PIN recycling 15 .…”

SINAT E3 ligases regulate the stability of the ESCRT component FREE1 in response to iron deficiency in plants

“…Plants possess most canonical ESCRT components, which function in MVB biogenesis and MVB-mediated endosomal sorting (Valencia et al 2016;Gao et al 2017). However, emerging evidence indicates that unique ESCRT components have evolved in plants and these perform both conserved ESCRT-dependent cellular activities and plant-specific functions (Gao et al 2017;Wang et al 2019). For example, our and other studies have identified a plant-specific ESCRT component, FYVE DOMAIN PROTEIN REQUIRED FOR ENDO-SOMAL SORTING1 (FREE1), which localizes to MVBs by binding to MVB-enriched phosphatidylinositol-3-phosphate and interacts with several ESCRT subunits, including Vps23, BRO1-LIKE DOMAIN-CONTAINING PRO-TEIN/APOPTOSIS-LINKED GENE-2 INTERACTING PROTEIN X (AtBRO1/ALIX), and Snf7.…”

Halotropism: Phytohormonal Aspects and Potential Applications

“…Salt can induce remodeling of spatially restricted clathrin-independent endocytic pathways in Arabidopsis root ( Baral et al., 2015 ). Endomembrane trafficking has a significant role in plant abiotic stresses ( Wang et al., 2020 ). For example, Golgi-localized cation/proton exchangers regulate ionic homeostasis and skotomorphogenesis in Arabidopsis ( Wang et al., 2018 ).…”