Plant Cell Growth Research Articles

Protocol for Generating Arabidopsis thaliana Cell Suspension Cultures Under Different Light Conditions.

Plant cell suspension cultures (PCSCs) are in vitro-cultured cells that can divide indefinitely in a sterile growth medium. These PCSCs can be derived from various plant tissues, such as the root, stem, leaves, or seeds, and are maintained in a suitable culture medium containing nutrients, vitamins, hormones, and other essential components necessary for their growth. PCSCs have extensive applications in biotechnology, particularly in producing pharmaceutical and chemical compounds. This chapter presents a protocol for generating cell lines from Arabidopsis thaliana root callus under different light conditions, which can be used to investigate the effects of light on plant cell growth and development. The protocol described in this chapter is a valuable tool for researchers interested in utilizing PCSCs in their studies.

Tailoring Plant Cell Growth with Collagen-Starch Biomatrices with Calcium bioMOFs

Biomatrices designed to stimulate the growth of tomato cells were prepared in this study. These biomatrices were composed of collagen-starch (CA) through a system of semi-interpenetrating polymer networks, allowing the inclusion of calcium metal-organic frameworks (MOFs) to facilitate plant metabolic stimulation. BioCaMOFs were prepared under hydrothermal conditions (100°C, 48 h) using Ca(NO3)2 and the essential amino acids L-phenylalanine, L-histidine, and L-tryptophan. A 1 mg of each bioCaMOF was dispersed in the collagen-starch matrix, generating the biomatrices CA-MOFCaF, CA-MOFCaH, and CA-MOFCaT, respectively. Infrared spectroscopy was employed to identify the chemical bonds present in each component of the biomatrices. The results indicated that the CA-MOFCaT biomatrix exhibited increased water swelling capacity (2900 ± 180 %) and the highest crosslinking index (74 ± 4 %). Tomato cells derived from sterile seeds (50,000 cells per biomatrix), both red and green varieties, migrated within the biomatrices, enhancing their metabolic activity. The biomatrices containing bioactive calcium MOFs actively stimulated the metabolism of plant cells for up to 48 hours upon contact. Determining that the biomatrix CA-MOFCaF promotes greater stimulation in green tomato cells, while CA-MOFCaT does so with red tomato cells. Such biomatrices hold promise as effective 3D cultures that promote the metabolism of plant cells and could lead to innovative formulations of biofertilizers.

Genome-wide identification of poplar GSTU gene family and its PtrGSTU23 and PtrGSTU40 to improve salt tolerance in poplar

Glutathione S-transferases (GSTs) are abundant proteins encoded by a highly differentiated family of ancient genes. GSTs play an important role in plant cell detoxification and growth and development. However, their precise function in growth and response to abiotic stresses in poplar remains unclear. We have identified 81 GST genes from Populus trichocarpa, which have been categorized into 8 subfamilies. Among these subfamilies, the Tau subfamily stands out as the largest, consisting of 58 members. We isolated two Tau-like Glutathione S-transferases encoding genes, PtrGSTU23 and PtrGSTU40, and investigated the biological functions of these two genes in transgenic poplar to regulate salt tolerance in poplar. Under salt stress, reactive oxygen species (ROS) accumulate in plants, and overexpression of PtrGSTU23/40 in 84 K poplar (Populus alba × Populus glandulosa) could play a crucial role in regulating ROS scavenging by controlling the activity of plant GST enzyme. This regulation of GST enzyme activity enhanced the tolerance of poplar to salt stress. Ultimately, our findings contribute to the availability of genetic resources that can be utilized in the breeding of salt tolerance traits within fast-growing tree species.

Functional validation of Lobularia maritima thioredoxin-h2 protein for its ability to combat bacterial and fungal infections

Thioredoxins (Trxs) belong to a family of multifunctional redox proteins that is critical for maintaining and regulating the cellular redox environment during plant cell growth. Also, they are important for the development of plant's response to biotic and abiotic stress; however, the specific biological functions of h-type thioredoxins (Trxhs) in plants have not been fully elucidated. Herein, we investigated the role of LmTrxh2, a specific member of the Trxh family, in response to various biotic stress simulants, including mechanical wounding, exposure to jasmonic acid (JA), picolinic acid (PA), salicylic acid (SA), ethephon (ETP), and hydrogen peroxide (H2O2). We observed that LmTrxh2 transcripts were significantly upregulated upon exposure to these stress simulants. The characterization of enzymatic activity revealed that the recombinant LmTrxh2 protein functions as a disulfide reductase. While the role of Trx proteins in redox regulation is well known, their involvement in antimicrobial activity is still unexplored. Therefore, we assessed the antimicrobial effect of LmTrxh2 towards various microorganisms and observed a concentration-dependent inhibition of microbial growth. The minimum inhibitory and minimum bactericidal concentrations and the diameters of the inhibition zones were 40–1250 μg/mL, 40–1250 μg/mL, and 12.5–32.5 mm, respectively. In addition, we used previously developed LmTrxh2-transgenic tobacco lines and found that they showed enhanced resistance to fungal infections triggered by Fusarium graminearum and Aspergillus niger. This resistance was associated with an upregulation of known defense-related genes. Overall, our findings suggest that LmTrxh2 is responsive to multiple biotic stress simulants and plays a critical role in the basal resistance of plants to pathogen infections. These results highlight the potential of LmTrxh2 in the development of strategies to protect crops from various stress factors and emphasize its importance in the adaptation of plants to different stress conditions.

Two subtypes of GTPase-activating proteins coordinate tip growth and cell size regulation in Physcomitrium patens

The establishment of cell polarity is a prerequisite for many developmental processes. However, how it is achieved during tip growth in plants remains elusive. Here, we show that the RHO OF PLANTs (ROPs), ROP GUANINE NUCLEOTIDE EXCHANGE FACTORs (RopGEFs), and ROP GTPASE-ACTIVATING PROTEINs (RopGAPs) assemble into membrane domains in tip-growing cells of the moss Physcomitrium patens. The confinement of membrane domains requires redundant global inactivation of ROPs by PpRopGAPs and the PLECKSTRIN HOMOLOGY (PH) domain-containing RenGAP PpREN. Unexpectedly, PpRopGAPs and PpREN exert opposing effects on domain size and cell width upon overexpression. Biochemical and functional analyses indicate that PpRopGAPs are recruited to the membrane by active ROPs to restrict domain size through clustering, whereas PpREN rapidly inactivates ROPs and inhibits PpRopGAP-induced clustering. We propose that the activity- and clustering-based domain organization by RopGAPs and RenGAPs is a general mechanism for coordinating polarized cell growth and cell size regulation in plants.

Arabidopsis reticulons inhibit ROOT HAIR DEFECTIVE3 to form a stable tubular endoplasmic reticulum network.

The endoplasmic reticulum (ER) is a network of interconnected tubules and sheets stretching throughout the cytoplasm of plant cells. In Arabidopsis (Arabidopsis thaliana), ROOT HAIR DEFECTIVE3 (RHD3) mediates ER tubule fusion, while reticulon proteins induce ER membrane curvature to produce ER tubules. However, it is unclear if and how RHD3-reticulon interplay during the formation of the interconnected tubular ER network. We discovered that RHD3 physically interacts with Arabidopsis reticulon proteins, including reticulon-like protein subfamily B3 (RTNLB3), on ER tubules and at 3-way junctions of the ER. The RTNLB3 protein is widely expressed in Arabidopsis seedlings and localizes to ER tubules. Although the growth of knockout rtnlb3 mutant plants was relatively normal, root hairs of rtnlb3 were shorter than those of wild type. The ER in mature mutant cells was also more sheeted than that in wild type. rhd3 is known to have short roots and root hairs and less branched ER tubules in cells. Interestingly, rtnlb3 genetically antagonizes rhd3 in plant root development and in ER interconnectivity. We show that reticulons including RTNLB3 inhibit the ER fusion activity of RHD3, partly by interfering with RHD3 dimerization. We conclude that reticulon proteins negatively regulate RHD3 to balance its ER fusion activity for the formation of a stable tubular ER network in plant cell growth.

РЕГУЛЯТОРЫ РОСТА ПОВЫШАЮЩИЕ ПРОДУКТИВНОСТЬ СОИ

Plant growth regulators have a wide spectrum of physiological activity. Thanks to their action, resistance of soybean plants to adverse environmental factors, diseases, growth, development and quality is observed. Soy is the most widely used oilseed in the world. The world annual production of soybeans exceeds 260 million tons. It is the main edible plant and the main source of vegetable protein worldwide.The global demand for soybeans is constantly growing as its seeds provide essential proteins, oils and nutraceuticals. In an effort to meet the increased demand for this crop, it has become necessary to introduce cultural practices that promote adaptation to difficult environmental conditions, can improve soybean tolerance to abiotic stress and increase yields. Plant growth regulators are mainly used for this purpose due to their critical role in plant growth and development. One of the main growth regulators are such phytohormones as: auxins, gibberellins, cytokinins, brassinolides, ethylene, abscisic and jasmonic acid. Each of the groups of phytohormones produces its own characteristic action, which is similar in plants of different species. Cell division and elongation, which underlie all processes of growth and morphogenesis, are under the control of auxins and cytokines in plants, so their complete absence can lead to death. These compounds generally have a positive effect on the morphology, physiology and quality of the soybean crop. They are also able to regulate and control to a large extent the processes of growth and differentiation of plant cells. It should be noted that these phytohormones are required in small amounts for the activation and regulation of morphogenetic processes in soybean and other agricultural plants.

GhSMO2-2 is regulated by brassinosteroid signal and involved in cotton fiber elongation via influencing phytosterol and sphingolipid biosynthesis

Cotton fiber cell is an extremely elongated single cell and is regarded as an ideal material to study the growth and development of plant cell. Phytohormone brassinosteroids (BRs) play crucial roles in fiber cell development. However, its action mechanism in fiber growth is largely unknown. In this study, we identified a homologue of Arabidopsis SMO2–2 (Sterol C-4α Methyl Oxidase), GhSMO2–2, in upland cotton (Gossypium hirsutum L.), which predominantly expressed in fiber cell and peaked at the rapid elongation stage, and responded to BR signal. The GhBES1, a transcription factor in BR signaling could directly bind to the promoter of GhSMO2–2 and promoted its expression. Overexpression of GhSMO2–2 significantly promoted fiber cell elongation and phytosterol synthesis in cotton, and elevated some sphingolipid species that was important for fiber elongation. On the contrary, down-regulating GhSMO2–2 suppressed fiber elongation and blocked these chemicals accumulation. These results indicated that GhSMO2–2 is an important gene involved in fiber cell elongation, and is valuable for genetic engineering to improve fiber quality and yield. Taken together, our study revealed that BR regulated fiber cell elongation by influencing phytosterol and sphingolipid biosynthesis, the key components of membrane lipid raft and provided a new clue for further revealing the function and mechanism of phytosterols, sphingolipids, and BRs in plant cell development.

Tissue Culture: Aeon of Micro Propagation in Vegetable Crops

Tissue culture in vegetable crops is a technique that has revolutionized the way we produce and propagate plants. It involves the growth of plant cells, tissues or organs in an artificial nutrient medium under sterile conditions. This method offers numerous advantages, including the production of disease-free plants, rapid multiplication and the ability to grow plants year-round. One of the key benefits of tissue culture in vegetable crops is the production of disease-free plants. By starting with a small piece of healthy tissue such as a leaf or stem, it is possible to grow an entire plant that is free from any pathogens. This is particularly important in vegetable crops, as diseases can significantly reduce yields and quality. By using tissue culture, farmers can ensure that the plants they grow are healthy and resistant to common diseases. Another advantage of tissue culture is the rapid multiplication of plants. Through a process called micropropagation, a single piece of tissue can be used to produce hundreds or even thousands of identical plants within a short period. This is particularly useful for vegetable crops that have a high demand or are difficult to propagate through traditional methods. By using tissue culture, farmers can quickly and efficiently produce large quantities of plants to meet market demands. Furthermore, tissue culture allows for year-round plant production. Unlike traditional methods that are limited by seasonal variations, tissue culture can be done in controlled environments such as laboratories or greenhouses. This means that farmers can grow vegetable crops regardless of the weather conditions outside. This is particularly advantageous for regions with harsh climates or limited growing seasons.

Every end is a new beginning: Histological features of galls induced on Macairea radula (Melastomataceae) allow a post-senescence colonization

Galls are a kind of plant-organism interaction defined as a manifestation of the reprogramming of plant cell growth induced by organisms with ecological impacts on host plants. The galling insect taxa and the targeted plant organ for oviposition determine the gall morphology and its histological features. Galls induced at budding sites can develop morphologically more complex structures due to the greater meristematic potential of their tissues. In addition, as buds can develop into shoots, bud galls should have a modified stem-like structure, which may remain attached to the plant for long periods after the galling insects emerge. Herein, we conducted histological analyzes in galls induced by Palaeomystella oligophaga on Macairea radula to investigate (i) if the galls induced on buds develop as stem-branches-like connections, with histological characteristics that favor their affixation to the host plants after senescence. Also, we inspected senescent galls to investigate (ii) if the microhabitats within these galls are occupied by opportunistic arthropods. The structural features of M. radula galls allowed us to diagnose them as stem-like galls, which develop as stems with shortened internodes with leaf-like projections. The stem-branch vascular connection allows these galls to remain fixed on the host plants for long periods and work as shelters for different taxa of arthropods in all sampled ecosystems. The interactions here go beyond the impacts on both galling insect and host plant populations, with trophic and non-trophic interactions allowing us to understand the insect P. oligophaga as a shelter-builder and an ecosystem engineer.

HECT-type ubiquitin ligase KAKTUS mediates the proteasome-dependent degradation of cyclin-dependent kinase inhibitor KRP2 during trichome morphogenesis in Arabidopsis.

SUMMARYTrichome development is a fascinating model to elaborate the plant cell differentiation and growth processes. A wealth of information has pointed to the contributions of the components associated with cell cycle control and ubiquitin/26S proteasome system (UPS) to trichome morphogenesis, but how these two pathways are connected remains obscure. Here, we report that HECT‐type ubiquitin ligase KAKTUS (KAK) targets the cyclin‐dependent kinase (CDK) inhibitor KRP2 (for kip‐related protein 2) for proteasome‐dependent degradation during trichome branching in Arabidopsis. We show that over‐expression of KRP2 promotes trichome branching and endoreduplication which is similar to kak loss of function mutants. KAK directly interacts with KRP2 and mediates KRP2 degradation. Mutation of KAK results in the accumulation of steady‐state KRP2. Consistently, in kak pKRP2:KRP2‐GFP plants, the trichome branching is further induced compared with the single mutant. Taken together, our studies bridge the cell cycle control and UPS pathways during trichome development and underscore the importance of post‐translational control in epidermal differentiation.

Use of Doubling Number as an Arithmetic Measure of Plant Cell Growth and Metal-Induced Cell Growth Inhibition

Cell growth inhibition is generally handled as a measure of toxicity. Shortly, more toxicity implies more growth inhibition. Then, the question arises; How to calculate & evaluate cell growth inhibition in a universal manner? Actually, the method for calculating growth inhibition is not considered to be a central issue, in general. There are various approaches (subtractive, divisionary, and logarithmic) for calculating cell growth. Among these approaches, two of them are highly easy and popular, subtraction-based and division-based calculations. However, these two methods for the calculation of cell growth do not strongly reflect the nature of cell growth. Alternatively, the use of a doubling number-based formulation can provide a better approach and performance in the evaluation of cell growth and cell growth inhibition unless the culture attains the confluent status. Here, we discussed different methods of growth calculation which we applied to the study of “growth inhibition of BY-2 cells under Cd exposure”.

LfiTCP15;2 regulates plant height of Lagerstroemia indica by influencing the growth of stem cells

Plant height is one of the key traits affecting plant architecture, which affects the appearance and application of Lagerstroemia indica (crape myrtle) in gardens. TCP transcription factors are specific to plants and widely involved in the biological process of plant growth and development related to cell proliferation and growth, including plant height. However, the molecular mechanism by which TCP transcription factors regulate plant height development remains unclear and requires further analysis. In this study, LfiTCP15;2 was isolated from dwarf and non-dwarf progenies of crape myrtle, and the function was analyzed. Silencing of LfiTCP15;2 in non-dwarf crape myrtle inhibited internode elongation and stem cell growth, while overexpression of LfiTCP15;2 in tobacco promoted plant height, internode elongation and cell growth. To screen proteins interacting with LfiTCP15;2 and further elucidate the molecular mechanism by which LfiTCP15;2 regulates the plant height development of crape myrtle, we constructed a cDNA library of the yeast two-hybrid system using stem tips of dwarf and non-dwarf crape myrtle. The library was identified as 8.0 × 107cells/ml, with an average insert >1,000 bp in size and a 100% positive rate, providing a database for the subsequent study of the molecular regulation mechanism of the plant architecture in crape myrtle. Total of 70 proteins interacting with LfiTCP15;2 were screened in the library. LfiCHI1 and LfiCHI2 interacting with LfiTCP15;2 was proved by yeast two-hybrid assay. In conclusion, LfiTCP15;2 regulates the plant height of crape myrtle by promoting stem cell growth and internode elongation, and LfiCHI1 and LfiCHI2, which interact with LfiTCP15;2, may also be involved in this process.

Simulation of microtubule-cytoplasm interaction revealed the importance of fluid dynamics in determining the organization of microtubules.

Although microtubules in plant cells have been extensively studied, the mechanisms that regulate the spatial organization of microtubules are poorly understood. We hypothesize that the interaction between microtubules and cytoplasmic flow plays an important role in the assembly and orientation of microtubules. To test this hypothesis, we developed a new computational modeling framework for microtubules based on theory and methods from the fluid-structure interaction. We employed the immersed boundary method to track the movement of microtubules in cytoplasmic flow. We also incorporated details of the encounter dynamics when two microtubules collide with each other. We verified our computational model through several numerical tests before applying it to the simulation of the microtubule-cytoplasm interaction in a growing plant cell. Our computational investigation demonstrated that microtubules are primarily oriented in the direction orthogonal to the axis of cell elongation. We validated the simulation results through a comparison with the measurement from laboratory experiments. We found that our computational model, with further calibration, was capable of generating microtubule orientation patterns that were qualitatively and quantitatively consistent with the experimental results. The computational model proposed in this study can be naturally extended to many other cellular systems that involve the interaction between microstructures and the intracellular fluid.

Probing stress-regulated ordering of the plant cortical microtubule array via a computational approach

BackgroundMorphological properties of tissues and organs rely on cell growth. The growth of plant cells is determined by properties of a tough outer cell wall that deforms anisotropically in response to high turgor pressure. Cortical microtubules bias the mechanical anisotropy of a cell wall by affecting the trajectories of cellulose synthases in the wall that polymerize cellulose microfibrils. The microtubule cytoskeleton is often oriented in one direction at cellular length-scales to regulate growth direction, but the means by which cellular-scale microtubule patterns emerge has not been well understood. Correlations between the microtubule orientation and tensile forces in the cell wall have often been observed. However, the plausibility of stress as a determining factor for microtubule patterning has not been directly evaluated to date.ResultsHere, we simulated how different attributes of tensile forces in the cell wall can orient and pattern the microtubule array in the cortex. We implemented a discrete model with transient microtubule behaviors influenced by local mechanical stress in order to probe the mechanisms of stress-dependent patterning. Specifically, we varied the sensitivity of four types of dynamic behaviors observed on the plus end of microtubules – growth, shrinkage, catastrophe, and rescue – to local stress. Then, we evaluated the extent and rate of microtubule alignments in a two-dimensional computational domain that reflects the structural organization of the cortical array in plant cells.ConclusionOur modeling approaches reproduced microtubule patterns observed in simple cell types and demonstrated that a spatial variation in the magnitude and anisotropy of stress can mediate mechanical feedback between the wall and of the cortical microtubule array.

Raman spectroscopic signals of carotenoid distribution during stages of cell growth of unicellular organisms and plant cells

AbstractUnderstanding life at the molecular level is inherently difficult, as no precise method can very specifically determine “The activities of life.” The feasibility to observe the activation of life in an organism using molecular information through Raman spectroscopy in various biological systems is investigated in this work. The idea of determining the “dormant” state to the “growing state” state in complex organisms using specific Raman spectral bands is explained in this study. We found the Raman spectral evidence of carotenoids molecule that shows its appearance from freshwater worms to germinated and non‐germinated seeds. This study investigates the molecular functions of carotenoids in different biosystems. Given the complexity of biological systems, observations from Raman spectroscopic measurements indicate that carotenoids show strong molecular activity when life is growing as compared with a dormant state. We conclude that carotenoid's Raman bands can be considered as the biomarker of growing states in living organisms.

The Arabidopsis xylosyltransferases, XXT3, XXT4, and XXT5, are essential to complete the fully xylosylated glucan backbone XXXG-type structure of xyloglucans.

Although most xyloglucans (XyGs) biosynthesis enzymes have been identified, the molecular mechanism that defines XyG branching patterns is unclear. Four out of five XyG xylosyltransferases (XXT1, XXT2, XXT4, and XXT5) are known to add the xylosyl residue from UDP-xylose onto a glucan backbone chain; however, the function of XXT3 has yet to be demonstrated. Single xxt3 and triple xxt3xxt4xxt5 mutant Arabidopsis (Arabidopsis thaliana) plants were generated using CRISPR-Cas9 technology to determine the specific function of XXT3. Combined biochemical, bioinformatic, and morphological data conclusively established for the first time that XXT3, together with XXT4 and XXT5, adds xylosyl residue specifically at the third glucose in the glucan chain to synthesize XXXG-type XyGs. We propose that the specificity of XXT3, XXT4, and XXT5 is directed toward the prior synthesis of the acceptor substrate by the other two enzymes, XXT1 and XXT2. We also conclude that XXT5 plays a dominant role in the synthesis of XXXG-type XyGs, while XXT3 and XXT4 complementarily contribute their activities in a tissue-specific manner. The newly generated xxt3xxt4xxt5 mutant produces only XXGG-type XyGs, which further helps to understand the impact of structurally deficient polysaccharides on plant cell wall organization, growth, and development.

Effects of Light Intensity on in Vitro Regeneration Of Stevia Rebaudiana Bertoni, Bacopa Monnieri L. And Solanum Tuberosum L.

Light is the most essential factor controlling plant growth, morphogenesis, metabolism and chlorophyll content of plant cells, tissues and organ culture. The present investigations were carried out to find out effects of different light intensities (210, 500, 1000, 1500, 2000, 2500 and 3000 lx) on the regeneration of three plants, namely Stevia rebaudiana Bertoni., Solanum tuberosum L. and Bacopa monnieri L. Results showed that light intensity has a direct effect on plant growth in vitro. There was less time for shoot initiation and the highest mean number of shoots/explants (9.75 ± 3.862) of S. rebaudiana was observed from the nodal explants when the culture was maintained at 1000 lx light conditions. At maximum light intensity (3000 lx) best result was recorded for S. tuberosum. A distinct intensity of light, 1500 lx showed the best outcome both for the number and length of shoots of B. monnieri (p = 0.00). The present study also demonstrated the relationship between root growth and light condition. Bangladesh J. Bot. 52(1): 53-60, 2023 (March)

Multifractal Analysis of the Influence of Indole-3-Acetic Acid on Fast-Activating Vacuolar (FV) Channels of Beta vulgaris L. Taproot Cells.

In this paper, the multifractal properties of the ion current time series in the fast-activating vacuolar (FV) channels of Beta vulgaris L. taproot cells were investigated. These channels are permeable for only monovalent cations and mediate K+ at very low concentrations of cytosolic Ca2+ and large voltages of either polarity. Using the patch clamp technique, the currents of the FV channels in red beet taproot vacuoles were recorded and analysed by using the multifractal detrended fluctuation analysis (MFDFA) method. The activity of the FV channels depended on the external potential and was sensitive to the auxin. It was also shown that the singularity spectrum of the ion current in the FV channels is non-singular, and the multifractal parameters, i.e., the generalised Hurst exponent and the singularity spectrum, were modified in the presence of IAA. Taking into account the obtained results, it can be suggested that the multifractal properties of fast-activating vacuolar (FV) K+ channels, indicating the existence of long-term memory, should be taken into account in the molecular mechanism of the auxin-induced growth of plant cells.

Phosphoproteomics analysis of the effect of target of rapamycin kinase inhibition on Cucumis sativus in response to Podosphaera xanthii

Target of rapamycin (TOR) kinase is a conserved sensor of cell growth in yeasts, plants, and mammals. Despite the extensive research on the TOR complex in various biological processes, large-scale phosphoproteomics analysis of TOR phosphorylation events upon environmental stress are scarce. Powdery mildew caused by Podosphaera xanthii poses a major threat to the quality and yield of cucumber (Cucumis sativus L.). Previous studies concluded that TOR participated in abiotic and biotic stress responses. Hence, studying the underlying mechanism of TOR-P. xanthii infection is particularly important. In this study, we performed a quantitative phosphoproteomics studies of Cucumis against P. xanthii attack under AZD-8055 (TOR inhibitor) pretreatment. A total of 3384 phosphopeptides were identified from the 1699 phosphoproteins. The Motif-X analysis showed high sensitivity and specificity of serine sites under AZD-8055-treatment or P. xanthii stress, and TOR exhibited a unique preference for proline at +1 position and glycine at −1 position to enhance the phosphorylation response to P. xanthii. The functional analysis suggested that the unique responses were attributed to proteins related to plant hormone signaling, mitogen-activated protein kinase cascade signaling, phosphatidylinositol signaling system, and circadian rhythm; and calcium signaling– and defense response–related proteins. Our results provided rich resources for understanding the molecular mechanism of how the TOR kinase controlled plant growth and stress adaptation.