Arabidopsis SNARE SYP132 impacts on PIP2;1 trafficking and function in salinity stress

Abstract

SUMMARYIn plants so‐called plasma membrane intrinsic proteins (PIPs) are major water channels governing plant water status. Membrane trafficking contributes to functional regulation of major PIPs and is crucial for abiotic stress resilience. Arabidopsis PIP2;1 is rapidly internalised from the plasma membrane in response to high salinity to regulate osmotic water transport, but knowledge of the underlying mechanisms is fragmentary. Here we show that PIP2;1 occurs in complex with SYNTAXIN OF PLANTS 132 (SYP132) together with the plasma membrane H+‐ATPase AHA1 as evidenced through in vivo and in vitro analysis. SYP132 is a multifaceted vesicle trafficking protein, known to interact with AHA1 and promote endocytosis to impact growth and pathogen defence. Tracking native proteins in immunoblot analysis, we found that salinity stress enhances SYP132 interactions with PIP2;1 and PIP2;2 isoforms to promote redistribution of the water channels away from the plasma membrane. Concurrently, AHA1 binding within the SYP132‐complex was significantly reduced under salinity stress and increased the density of AHA1 proteins at the plasma membrane in leaf tissue. Manipulating SYP132 function in Arabidopsis thaliana enhanced resilience to salinity stress and analysis in heterologous systems suggested that the SNARE influences PIP2;1 osmotic water permeability. We propose therefore that SYP132 coordinates AHA1 and PIP2;1 abundance at the plasma membrane and influences leaf hydraulics to regulate plant responses to abiotic stress signals.

Vesicle-Mediated Regulation of Pollen tube Growth inTorenia fournieri

“…For example, smaller vesicles are involved in membrane recycling and larger vesicles carry bulky cell wall materials and proteins 55 . Several regulators of vesicular trafficking have been identified in mutagenesis studies 7,22,27 . In pollen tubes, the specialized haploid cell responsible for tip growth relies on dynamic vesicular trafficking.…”

“…Mutant ykt61-3 does not interact with multiple SNARE proteins and shows substantially reduced membrane association and male infertility [19][20][21] . SYP121, a maize Q-SNARE protein localized to the plasma membrane, regulates K + channel trafficking and cellular osmotic homeostasis [22][23][24] . Rab GTPases such as RabA2 directly bind to SNARE proteins, coordinating vesicle budding and fusion in pollen tubes of A. thaliana and tobacco 8,[25][26][27] .…”

A novel semi-dominant mutation in brassinosteroid signaling kinase1 increases stomatal density

“…Moreover, photosynthesis-dependent phosphorylation and clade D type2C protein phosphatase-mediated dephosphorylation of PM H + -ATPase ( Ando and Kinoshita, 2018 ; Wong et al., 2021 ; Akiyama et al., 2022 ; Ando et al., 2022 ) raise a hypothesis that unidentified regulators are involved in the above processes in guard cells. Note that PM H + -ATPase trafficking in guard cells regulated by environmental stress greatly affects its activity and stomatal movement ( Xue et al., 2018 ; Xia et al., 2019 ; Baena et al., 2024 ).…”

Identification of Salt-Responsive Genes in Melatonin Regulated Alfalfa Salt Tolerance by Transcriptome Analysis

“…In recent years, with rising temperatures, changes in irrigation methods, and soil degradation, crop production worldwide has faced the challenge of increasing soil salinization [4]. The increase in soil salinity can cause osmotic stress on terrestrial plants, thereby affecting their growth, development, and adaptability [5]. Hence, the revelation of the molecular regulatory mechanisms of plant salt tolerance is crucial for the formulation of resistance breeding strategies and the creation of new crop germplasm, especially for the improvement of yield and quality of marginal land crops.…”