Syntaxin of plants71 plays essential roles in plant development and stress response via regulating pH homeostasis

Abstract

SYP71, a plant-specific Qc-SNARE with multiple subcellular localization, is essential for symbiotic nitrogen fixation in nodules in Lotus, and is implicated in plant resistance to pathogenesis in rice, wheat and soybean. Arabidopsis SYP71 is proposed to participate in multiple membrane fusion steps during secretion. To date, the molecular mechanism underlying SYP71 regulation on plant development remains elusive. In this study, we clarified that AtSYP71 is essential for plant development and stress response, using techniques of cell biology, molecular biology, biochemistry, genetics, and transcriptomics. AtSYP71-knockout mutant atsyp71-1 was lethal at early development stage due to the failure of root elongation and albinism of the leaves. AtSYP71-knockdown mutants, atsyp71-2 and atsyp71-3, had short roots, delayed early development, and altered stress response. The cell wall structure and components changed significantly in atsyp71-2 due to disrupted cell wall biosynthesis and dynamics. Reactive oxygen species homeostasis and pH homeostasis were also collapsed in atsyp71-2. All these defects were likely resulted from blocked secretion pathway in the mutants. Strikingly, change of pH value significantly affected ROS homeostasis in atsyp71-2, suggesting interconnection between ROS and pH homeostasis. Furthermore, we identified AtSYP71 partners and propose that AtSYP71 forms distinct SNARE complexes to mediate multiple membrane fusion steps in secretory pathway. Our findings suggest that AtSYP71 plays an essential role in plant development and stress response via regulating pH homeostasis through secretory pathway.

A Physiological and Molecular Docking Insight on Quercetin Mediated Salinity Stress Tolerance in Chinese Flowering Cabbage and Increase in Glucosinolate Contents

“…Three proteins, namely dehydration-responsive element-binding protein, salt overly sensitive 3 protein, and syntaxin binding protein 1, were selected as receptors in molecular docking studies. Dehydration-responsive element-binding protein (DREB) and syntaxin binding protein 1 (STXBP1) are essential for normal plant growth and play a key role in abiotic stress management in plants [ 34 ]. Similarly, salt overly sensitive 3 (SOS3) maintains the integrity of the cytoskeleton under stress [ 35 ].…”

Bacillus altitudinis AD13−4 Enhances Saline–Alkali Stress Tolerance of Alfalfa and Affects Composition of Rhizosphere Soil Microbial Community

“…A quantity of 0.2 g roots of one−month−old alfalfa plants were collected for physiological measurement. Briefly, guaiacol colorimetry was used for the determination of the POD activity, nitro blue tetrazolium photoreduction for SOD activity, and the hydrogen peroxide method for CAT activity, while APX activity was determined according to the reduction in the AsA content [ 75 ]. The MDA content was determined using the thiobarbituric acid method, and the proline content using the acidic ninhydrin colorimetry method [ 1 , 75 ].…”

“…The root material was the same as that used for physiological determination in 4.3. The procedures for the determination of total flavonoids and total phenolics referred to [ 75 , 78 ]. For determination of total terpenoids, 10 mL of methanol was added to 0.1 g of powder of the tissues, ultrasonicated (80 kW) for 30 min, and left stewing overnight at 4 °C; then, the supernatant was used as a test solution.…”

Plant Growth Regulation in Cell and Tissue Culture In Vitro

“…In natural conditions, plants must create an acid (local) environment to facilitate nutrient uptake. A recent investigation pointed out the key role of pH homeostasis in the plant morphogenetic process [ 157 ]. In plant tissue culture, for the maintenance of a pH balance, in most cases, researchers use a chemical buffer to keep the pH of media in the physiological range.…”