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SUMMARY: Apple leaf spot, a disease caused by Alternaria alternata f. sp. mali and other fungal species, leads to severe defoliation and results in tremendous losses to the apple (Malus × domestica) industry in China. We previously identified three RPW8, nucleotide‐binding, and leucine‐rich repeat domain CCR‐NB‐LRR proteins (RNLs), named MdRNL1, MdRNL2, and MdRNL3, that contribute to Alternaria leaf spot (ALT1) resistance in apple. However, the role of NB‐LRR proteins in resistance to fungal diseases in apple remains poorly understood. We therefore used MdRNL1/2/3 as baits to screen ALT1‐inoculated leaves for interacting proteins and identified only MdRNL6 (another RNL) as an interactor of MdRNL2. Protein interaction assays demonstrated that MdRNL2 and MdRNL6 interact through their NB‐ARC domains. Transient expression assays in apple indicated that complexes containing both MdRNL2 and MdRNL6 are necessary for resistance to Alternaria leaf spot. Intriguingly, the same complexes were also required to confer resistance to Glomerella leaf spot and Marssonina leaf spot in transient expression assays. Furthermore, stable transgenic apple plants with suppressed expression of MdRNL6 showed hypersensitivity to Alternaria leaf spot, Glomerella leaf spot, and Marssonina leaf spot; these effects were similar to the effects of suppressing MdRNL2 expression in transgenic apple plantlets. The identification of these novel broad‐spectrum fungal resistance genes will facilitate breeding for fungal disease resistance in apple. Significance Statement: Apple leaf spot includes three major fungal diseases affecting the apple industry: Alternaria leaf spot, caused by Alternaria alternata f. sp. mali, Glomerella leaf spot, caused by Glomerella cingulata, and Marssonina leaf spot, caused by Marssonina coronaria. These three devastating diseases of apple (Malus × domestica) cause early severe defoliation, weaken tree vigor, and reduce apple production. In the present study we identified the mode of action of two CCR‐NB‐LRR R proteins, MdRNL2 and MdRNL6, to enhance resistance to Alternaria leaf spot, Glomerella leaf spot, and Marssonina leaf spot infection in the resistant apple cultivar HF. The identification and cloning of these novel broad‐spectrum fungal resistance genes will facilitate breeding for fungal disease resistance in apple. Also, we generated genetically transformed HF plantlets to prove that suppression of MdRNL2 expression results in susceptibility to three apple leaf spot pathogens, similar to the effect of suppressing MdRNL6 in transgenic apple plantlets. Taken together, our data provide detailed evidence for a previously unknown regulatory mechanism in which three apple leaf spot pathogens induce the production of MdRNL2 and MdRNL6, which form a heterocomplex at the NB‐ARC domain and contribute to Alternaria leaf spot, Glomerella leaf spot, and Marssonina leaf spot resistance. Our results provide a basis for deciphering the R‐protein‐based defense mechanism against three apple leaf spot pathogens. [ABSTRACT FROM AUTHOR]

We aim to deal with the Hub-genes and signalling pathways connected with Sepsis-associated encephalopathy (SAE). The raw datasets were acquired from the Gene Expression Omnibus (GEO) database (GSE198861 and GSE167610). R software filtered the differentially expressed genes (DEGs) for hub genes exploited for Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Hub genes were identified from the intersection of DEGs via protein–protein interaction (PPI) network. And the single-cell dataset (GSE101901) was used to authenticate where the hub genes express in hippocampus cells. Cell–cell interaction analysis and Gene Set Variation Analysis (GSVA) analysis of the whole transcriptome validated the interactions between hippocampal cells. A total of 161 DEGs were revealed in GSE198861 and GSE167610 datasets. Biological function analysis showed that the DEGs were primarily involved in the phagosome pathway and significantly enriched. The PPI network extracted 10 Hub genes. The M2 Macrophage cell decreased significantly during the acute period, and the hub gene may play a role in this biological process. The hippocampal variation pathway was associated with the MAPK signaling pathway. Hub genes (Pecam1 , Cdh5 , Fcgr , C1qa , Vwf , Vegfa , C1qb , C1qc , Fcgr4 and Fcgr2b) may paticipate in the biological process of SAE. [ABSTRACT FROM AUTHOR]

The issue of missing teeth caused by dental microcracks has become a central topic in dental clinical medicine. Near-infrared technology combined with advanced image segmentation algorithms has become one of the leading technical routes for dental clinical medicine diagnosis. In this study, the NIR image segmentation method of dental microcracks was studied in depth to further utilize the advantages of near-infrared imaging technology in the detection technology of dental microcracks. The main contributions and research contents of this paper include (1) we designed a near-infrared imaging system for dental imaging, which provides solid data support for the study of advanced segmentation algorithms; (2) we designed a self-equilibrium segmentation algorithm for occult fracture of teeth based on U-Net++. The core module of this algorithm includes a multi-resolution residual encoder and a self-equilibrium composite loss function. The multi-scale residual encoder significantly improves the feature extraction capability of U-Net++. The self-equilibrium combined loss function ensures the consistency of the model's attention to positive and negative samples, which enhances the robustness of U-Net++. (3) We have demonstrated through extensive experiments that our algorithm performs better than other dental occultation segmentation methods. This study is valuable for improving the diagnostic accuracy of dental occult fractures and promptly detecting the potential danger of the dental. • A near-infrared system designed for dental enamel imaging. • A algorithm based U-Net++ designed for segmentation of dental microcracks. • A multi-resolution residual encoder as the backbone of the segmentation framework. • A loss function that equalizes positive and negative samples is proposed. [ABSTRACT FROM AUTHOR]

Apple leaf spot caused by the Alternaria alternata f. sp mali (ALT1) fungus is one of the most devastating diseases of apple (Malus × domestica). We identified a hairpin RNA (hpRNA) named MdhpRNA277 that produces small RNAs and is induced by ALT1 infection in 'NGR196' apple. MdhpRNA277 produces mdm-siR277-1 and mdm-siR277-2, which target five resistance (R) genes that are expressed at high levels in the resistant apple variety 'Hanfu' and at low levels in the susceptible variety 'NGR196' following ALT1 infection. MdhpRNA277 was strongly induced in 'NGR196' but not 'Hanfu' following ALT1 inoculation. MdhpRNA277 promoter activity was much stronger in inoculated 'NGR196' versus 'Hanfu'. We identified a single-nucleotide polymorphism (SNP) in the MdhpRNA277 promoter region between 'NGR196' (pMdhpRNA277-NGR196) and 'Hanfu' (pMdhpRNA277-HF). The transcription factor MdWHy binds to pMdhpRNA277-NGR196 , but not to pMdhpRNA277-HF. Transgenic 'GL-3' apple expressing pMdhpRNA277-NGR196:MdhpRNA277 was more susceptible to ALT1 infection than plants expressing pMdhpRNA277-HF:MdhpRNA277 due to induced mdm-siR277 accumulation and reduced expression of the five target R genes. We confirmed that the SNP in pMdhpRNA277 is associated with A. alternata leaf spot resistance by crossing. This SNP could be used as a marker to distinguish between apple varieties that are resistant or susceptible to A. alternata leaf spot. [ABSTRACT FROM AUTHOR]

Background: Recent evidence suggests that colonic macrophages and microRNAs play important roles in motor activity in the gastrointestinal tract. However, there are almost no data concerning colonic macrophages and microRNAs in slow transit constipation. Aim: The purpose of this study was to investigate colonic macrophages and microRNA-128 expression in the pathogenesis of slow transit constipation in colon tissues. Methods: Full-thickness colonic specimens from patients undergoing surgery for slow transit constipation, due to refractoriness to other therapeutic interventions ( n = 25), were compared to controls ( n = 25), and the number of colonic macrophages (as evaluated by specific monoclonal antibodies) was counted. Gene expression analysis of microRNA-128 was performed by microRNA microarray and qRT-PCR. Lastly, bioinformatics analysis, coupled with luciferase reporter assays, was used to investigate the mRNA transcript(s) targeted by microRNA-128. Results: Compared to controls, 20 of 25 slow transit constipation patients (80 %) had significantly higher numbers of macrophages in colonic specimens, coupled with down-regulation of microRNA-128. Linear regression analyses showed a significant negative correlation between macrophage number and microRNA-128 expression level. Among 83 bioinformatically predicated candidates, mitogen-activated protein kinase 14 (p38α) was validated to be a direct target of microRNA-128 in human intestinal epithelial cells. Conclusions: This study presents evidence for the negative correlation of macrophage number and microRNA-128 expression, in slow transit constipation patients, representing a possible mechanism of impaired gastrointestinal motility. [ABSTRACT FROM AUTHOR]

[Display omitted] • Soluble solids content (SSC) is a critical quality attribute of pear fruit. • Si-RF-PLS was a powerful tool to select the most effective variables. • The device showed potential to predict the SSC of pears in the lab and the field. • The analytical performance of the DLP system is compared with that of the LVF system. • The critical factor limiting the performance of handheld NIR is the scanning range. The soluble solids content (SSC) is a key parameter to affect the quality of Korla fragrant pears. Having reliable and rapid measurement of the SSC is crucial for producers and technicians. However, the equipment necessary to meet these requirements is frequently complex and expensive. This paper developed a portable nondestructive SSC detector, primarily composed of a handheld near-infrared (NIR) spectrometer in the wavelength of 900–1700 nm, a display, a lithium battery, and a Raspberry Pi board. In addition, the whole detector was only about 425 g in total. To test the performance of the prototype, we chose 100 Korla fragrant pears as our fruit samples. Different spectral pre-processing methods were combined with principal component regression (PCR) and partial least squares regression (PLSR) to obtain accurate models. To further simplify the model, the synergy interval (Si), genetic algorithm (GA), and random frog (RF) were used to choose characteristic wavelengths. Laboratory tests show that compared with PLSR and PCR based on the full-spectrum, the prediction models obtained after conducting RF selection have yielded satisfactory results. The number of wavelength features was reduced from 228 to 10, and the R2 of the model was improved from 0.942 to 0.966. The mean relative error rate in the field test was 1.41%, indicating that the developed SSC detector was also effective in the field. It can be verified that the NIR diffuse reflectance spectroscopy is a reliable tool for the nondestructive measurement of SSC in Korla fragrant pears. The appropriate pretreatment methods and selection of characteristic wavelengths can increase NIR spectroscopy accuracy in actual measurement. [ABSTRACT FROM AUTHOR]

Tumor-associated macrophages (TAMs) are closely related to poor prognosis in triple-negative breast cancer (TNBC). Thus, gaining insight into how TAMs support cancer progression could contribute to effective therapies. We utilized the 4 T1 murine TNBC cell line and murine bone marrow-derived macrophages to assess TAM-mediated pro-proliferative effects in vivo and in vitro. Further, Transcriptional analysis was performed to identify pathways activated in TAM-stimulated 4 T1 cells. We also explored the therapeutic efficacy of combining a mitogen-activated protein kinase kinase (MEK) inhibitor with TAM-targeted therapy using a TNBC mouse model. We found that the presence of TAMs was significantly associated with proliferating cancer cells in a TNBC mouse model. Moreover, RNA sequencing analysis showed that TAMs could enhance mitogen-activated protein kinase (MAPK) pathway activation in 4 T1 cells compared to that in control cells. Further, the depletion of TAMs by clodronate liposomes significantly reduced MAPK pathway activation in vivo. In addition, the blockade of MAPK signaling by a MEK inhibitor repressed TAM-mediated cancer cell proliferation. Most importantly, MEK inhibition combined with macrophage depletion significantly suppressed tumor growth and increased T lymphocyte infiltration in a TNBC model. Our study suggests the possibility that TAM-induced MAPK pathway activation promotes cancer cell proliferation. Thus, MEK inhibition combined with macrophage depletion might represent an effective treatment for TNBC. • TAMs are significantly associated with proliferating cancer cells. • TAMs could enhance MAPK pathway activation in 4 T1 cells. • MEK inhibition combined with macrophage depletion shows therapeutic effects in a TNBC model. [ABSTRACT FROM AUTHOR]

Plants are frequently attacked by a variety of pathogens and thus have evolved a series of defense mechanisms, one important mechanism is resistance gene (R gene)-mediated disease resistance, but its expression is tightly regulated. NBS-LRR genes are the largest gene family of R genes. microRNAs (miRNAs) target to a number of NBS-LRR genes and trigger the production of phased small interfering RNAs (phasiRNAs) from these transcripts. phasiRNAs cis or trans regulate NBS-LRR genes, which can result in the repression of R gene expression. In this study, we screened for upregulated miR482 in the susceptible apple cultivar 'Golden Delicious' (GD) after inoculation with the fungal pathogen Alternaria alternata f. sp. mali (ALT1). Additionally, through combined degradome sequencing, we identified a gene targeted by miR482, named MdTNL1 , a gene encoding a TIR-NBS-LRR (Toll/interleukin1 receptor-nucleotide binding site-leucine-rich repeat) protein. This gene exhibited a significant down-regulation post ALT1 inoculation, suggesting an impact on gene expression mediated by miRNA regulation. miR482 could cleave MdTNL1 and generate phasiRNAs at the cleavage site. We found that overexpression of miR482 inhibited the expression of MdTNL1 and thus reduced the disease resistance of GD, while silencing of miR482 increased the expression of MdTNL1 and thus improved the disease resistance of GD. This work elucidates key mechanisms underlying the immune response to Alternaria infection in apple. Identification of the resistance genes involved will enable molecular breeding for prevention and control of Alternaria leaf spot disease in this important fruit crop. • MdTNL1 belonging to the TIR type significantly down-regulated after infection with ALT1. • miR482 generates phasi RNAs after cleavage of MdTNL1. • miR482- MdTNL1 pathway involved in apple resistance to apple Alternaria leaf spot disease. • Overexpression of MdTNL1 or silencing of miR482 improves apple resistance to Alternaria leaf spot disease. [ABSTRACT FROM AUTHOR]

Using reverse transcription (RT) PCR and quantitative RT‐PCR, we showed the presence of apple stem grooving virus (ASGV), apple stem pitting virus (ASPV), apple chlorotic leaf spot virus (ACLSV), and apple scar skin viroid (ASSVd) in all tested parts of pear plants from China. Relative RNA accumulation of ASGV, ASPV, and ASSVd in the annual branch phloem of different pear cultivars displayed different seasonal variations, but all showed relatively high RNA accumulation in October. Based on these results, 821 samples (annual branches) in October 2018 and 2019 were collected from major pear‐growing areas to evaluate the phytosanitary status of pear orchards in China by RT‐PCR‐based testing and sequencing. ASGV was found in 91.2% of the samples, followed by ASPV (74.8%) and ASSVd (46.9%); in contrast, ACLSV, pear blister canker viroid, and apple mosaic virus were rarely detected, if at all. About 79.5% of the samples showed mixed infections, the most common being of ASGV+ASPV+ASSVd. Two batches of Pyrus betulifolia seedlings were tested for the presence of the above viruses and viroids; one batch displayed 97.9% infection rate of ASSVd, including 14.1% of seedlings coinfected with ASGV; the other batch showed 0.9%, 1.3%, and 0.9% infection rates with ASGV, ASPV, and ACLSV, respectively. This is the first extensive report on the incidence of major pome fruit tree viruses and viroids in pear orchards in China, and also provides information on the occurrence of viruses and viroids in pear rootstock seedlings. [ABSTRACT FROM AUTHOR]

Breast cancer is the most frequently diagnosed malignancy among women, and triple-negative breast cancer (TNBC) is a highly aggressive subtype. Increasing evidence has shown that lncRNAs are involved in tumor growth, cell-cycle, and apoptosis through interactions with miRNAs or mRNAs. However, there is still limited data on ceRNAs involved in the molecular mechanisms underlying TNBC. In this study, we applied the weighted gene co-expression network analysis to the existing microarray mRNA and lncRNA expression data obtained from the breast tissues of TNBC patients to find the hub genes and lncRNAs involved in TNBC. Functional enrichment was performed on the module that correlated with Ki-67 status the most (Turquoise module). The hub genes in the Turquoise module were found to be associated with DNA repair, cell proliferation, and the p53 signaling pathway. We performed co-expression analysis of the protein-coding and lncRNA hub genes in the Turquoise module. Analysis of the RNA-seq data obtained from The Cancer Genome Atlas database revealed that the protein-coding genes and lncRNAs that were co-expressed were also differentially expressed in the TNBC tissues compared with the normal mammary tissues. On the basis of establishing the ceRNA network, two mRNAs (RAD51AP1 and TYMS) were found to be correlated with overall survival in TNBC. These results suggest that TNBC-specific mRNA and lncRNAs may participate in a complex ceRNA network, which represents a potential therapeutic target for the treatment of TNBC. [ABSTRACT FROM AUTHOR]

Abstract The application of Natural Ventilation (NV) as a measure to improve comfort conditions in transition and summer periods has been a topic of research on the spotlight for years. However, there is a lack of knowledge about how the combined effect of a dense urban layout with high pollutant concentrations may affect its potential. This paper addresses this gap by running detailed thermal simulations for a typical apartment flat located in the Yuzhong district of Chongqing city (China) using a holistic approach that makes use of: i) wind pressure coefficients on building facades from urban-scale CFD simulations, ii) hourly measured values of PM2.5 concentrations and weather variables and iii) indoor environment measurements for validation purposes. Scenario analysis revealed the average amount of air change rates achievable in a year varies from 8 to 15 ACH according to the windows orientation. These figures drop down to around 2 ACH when taking into account reduced windows opening time when outdoor PM2.5 concentrations are too high. The resulting natural ventilation potential of the case study decreases from 4234 h when outdoor pollution is neglected to 2707 and 529 h when considering the exposure thresholds set by the Chinese government and the WHO respectively. Highlights • Dense and polluted urban environments reduce Natural Ventilation (NV) potential. • A holistic approach to appraise these reductions is demonstrated for Chongqing city. • Scenario analysis is run to appraise thermal conditions considering PM2.5 pollutant. • Dense urban layouts can reduce pressure coefficients at facades up to 4 times. • NV potential is reduced of 36% and 88% if considering different thresholds for PM2.5 [ABSTRACT FROM AUTHOR]

Highlights • Developed a high-resolution building model using the state-space method. • One-hour time interval overestimates building heating and cooling loads in part-time patterns. • Explored the impact of thermal mass on residential buildings with different compositions and insulation placements. Abstract A high-resolution time interval numerical model is more accurate to analyze the building dynamic thermophysical processes in the intermittent occupancy, while relevant professional software, such as EnergyPlus, is not compatible with different time intervals. The present study aims to investigate the thermal mass effectiveness of external walls on the part-time part-space operation of heating and cooling of a typical residence. A high-resolution model of a typical 3-occupant residential apartment has been developed using the state-space method and validated by the simulation results from EnergyPlus. The model is then amended to calculate building energy demands with fixed heat and cold supply powers from the perspective of system control, in order to interpret the effectiveness of thermal mass with identical recommended U -value in the HSCW (Hot Summer and Cold Winter) zone in terms of room operative temperatures. It is found that high thermal mass does not help to reduce ideal building loads in the residential buildings in the HSCW zone, but it will improve indoor thermal comfort control in real engineering compared to low thermal mass. Regarding thermal insulation placements of heavy weight external walls under the same thermal mass, it is evidenced that the adoption of internal insulation weakens the thermal mass impact of the heavy weight wall composition compared to that of external insulation. It is inferred that the high thermal mass in the composition of external walls should be exposed to the indoor air to avoid overheating in the cooling conditions. [ABSTRACT FROM AUTHOR]

Highlights • PbPTB3, a polypyrimidine tract-binding protein, was used as bait to screen a library of phloem cDNA from 'Du Li'(Pyrus betulaefolia). PbTTG1 was identified as a new protein to interact with PbPTB3. • PbTTG1 enhanced the stability of PbPTB3-based RNP complex resulted in an increase of RNA-binding affinity. • PbTTG1 binding to PbPTB3 facilitated the transmission of the PbPTB3-based RNP complex. Abstract The grafting of horticultural crops enables breeders to induce phenotypic changes in rootstocks and scions. A number of signaling molecules, including RNAs and proteins, were recently shown to underlie these changes; however, little is known about the composition of ribonucleoprotein (RNP) complexes or how these macromolecules are transported. Here, we used a polypyrimidine tract-binding protein, PbPTB3, as a bait to screen a library of phloem cDNA from a pear variety 'Du Li' (Pyrus betulaefolia). We identified a new protein constituent of the RNP complex, TRANSPARENT TESTA GLABRA1 (PbTTG1), a WD40 protein that interacts with PbPTB3 to facilitate its transport with PbWoxT1 mRNA through the phloem. Overexpression experiments indicated that PbTTG1 binds to PbPTB3, facilitating its transmission from the leaf through the petiole, while silencing of PbTTG1 expression prevented their translocation. Heterografting experiments also showed that silencing of PbTTG1 prevented the transport of PbPTB3 from the rootstock to the scion. Collectively, these findings established that PbTTG1 binds to PbPTB3 and PbWoxT1 to form an RNP complex, which facilitates their long-distance movement. [ABSTRACT FROM AUTHOR]

Highlights • New climate zoning method to help improve building energy designs. • Method applicable to diverse climates and will enhance natural resource utilisation. • Method demonstrated in the HSCW zone of China. • Hierarchical Agglomerative Clustering using 166 weather stations (10 years). • New HSCW sub-zones allow improved spatial resolution of heating/cooling loads. Abstract The climate-responsive strategies for energy efficient building design and management require a detailed understanding of the local climatic conditions, while climate zones are fundamental to building regulations and the application of technologies. Smaller and more homogeneous climate zones could help policy-makers and building designers to improve building energy efficiency while improving the indoor thermal environment. A new climate zoning method, with two-tier classification designed for passive building design, is proposed, using climate data (degree-days, relative humidity, solar radiation and wind speed) with Hierarchical Agglomerative Clustering (HAC) following the Ward's method. The method is applied to the Hot Summer and Cold Winter (HSCW) zone of China as a showcase, where there are no fine climate zones for energy efficient building design with diverse climate characteristics. Seven sub-zones that consider both cooling and heating demands are generated in Tier 1. In the second tier, the HSCW zone is further sub-divided into three humidity groups, three solar radiation clusters, and four wind speed clusters. To assess the impact of climate zoning on building heating and cooling, EnergyPlus simulations are conducted with the output of heating and cooling load. The cooling loads decrease from sub-zone A to B to C (mean = 82.8, 65.3, 43.8 kWh m−2, respectively) with sub-zone mean heating A1 larger than A2 and A3, B1 larger than B2, and C1 larger than C2, which is in accordance with the assumption made in the first-tier division. The higher wind speeds can raise the possibility of natural ventilation, and further increase the free-running period (FRP) when heating and cooling are not needed. The proposed zones are mapped and provide a useful reference for the policy/building code makers for heating and cooling strategies in this region. The method to create the climate zones could be applied in any region with local climate data. [ABSTRACT FROM AUTHOR]

Little is known about the mechanisms by which mRNAs are transported over long distances in the phloem between the rootstock and the scion in grafted woody plants., We identified an mRNA in the pear variety 'Du Li' ( Pyrus betulaefolia) that was shown to be transportable in the phloem. It contains a WUSCHEL- RELATED HOMEOBOX ( WOX) domain and was therefore named Wox Transport 1 ( PbWoxT1)., A 548-bp fragment of PbWoxT1 is critical in long-distance transport. PbWoxT1 is rich in CUCU polypyrimidine domains and its mRNAs interact with a polypyrimidine tract binding protein, Pb PTB3. Furthermore, the expression of PbWoxT1 significantly increased in the stems of wild-type (WT) tobacco grafted onto the rootstocks of PbWoxT1 or Pb PTB3 co-overexpressing lines, but this was not the case in WT plants grafted onto PbWoxT1 overexpressing rootstocks, suggesting that Pb PTB3 mediates PbWoxT1 mRNA long-distance transport., We provide novel information that adds a new mechanism with which to explain the noncell-autonomous manner of WOX gene function, which enriches our understanding of how WOX genes work in fruit trees and other species. [ABSTRACT FROM AUTHOR]

• S-RNase triggers substantial increase of ROS content in pollen tubes. • Expression of MdOXI1 is specifically induced by outburst of ROS in self S-RNase treated pollen tubes. • MdOXI1 physically interacts and phosphorylates MdPTI1L. • Silencing of either MdOXI1 or MdPTI1L weakens the toxic effect of S-RNase on pollen tubes. Apple (Malus domestica) exhibits classic S-RNase-mediated gametophytic self-incompatibility. Previous studies have shown that the S-RNase secreted from style cells could trigger signal transduction and defense responses mediated by Ca2+ and reactive oxygen species (ROS) after entering into the pollen tube. In this study, we investigated the downstream genes activated by ROS during S-RNase-mediated gametophytic self-incompatibility in pollen tubes. A substantial increase in ROS, as well as up-regulated expression of a serine-threonine protein kinase gene, OXIDATIVE SIGNAL-INDUCIBLE1 (MdOXI1), was detected in apple pollen tubes treated with self-S-RNase. A kinase assay-linked phosphoproteomics (KALIP) analysis suggested that MdOXI1 could bind and phosphorylate the downstream protein kinase Pto-interacting protein 1-like (MdPTI1L). The phosphorylation level of MdPTI1L was significantly reduced after silencing MdOXI1 with antisense oligonucleotides in the pollen tube. Silencing of either MdOXI1 or MdPTI1L alleviated the inhibitory effect of self-S-RNase on pollen tube growth. Our results thus indicate that MdPTI1L is phosphorylated by MdOXI1 in the pollen tube and participates in the ROS signaling pathway triggered by S-RNase. [ABSTRACT FROM AUTHOR]