Pepper stress-associated protein 14 is a substrate of CaSnRK2.6 that positively modulates abscisic acid-dependent osmotic stress responses.

The phytohormone abscisic acid (ABA) plays a prominent role in various abiotic stress responses of plants. In the ABA-dependent osmotic stress response, SnRK2.6, one of the subclass III SnRK2 kinases, has been identified as playing a key role by phosphorylating and activating downstream genes. Although several modulatory proteins have been reported to be phosphorylated by SnRK2.6, the identities of the full spectrum of downstream targets have yet to be sufficiently established. In this study, we identified CaSAP14, a stress-associated protein in pepper (Capsicum annuum), as a downstream target of CaSnRK2.6. We elucidated the physical interaction between SnRK2.6 and CaSAP14, both in vitro and in vivo, and accordingly identified a C-terminal C2H2-type zinc finger domain of CaSAP14 as being important for their interaction. CaSAP14-silenced pepper plants showed dehydration- and high salt-sensitive phenotypes, whereas overexpression of CaSAP14 in Arabidopsis conferred tolerance to dehydration, high salinity, and mannitol treatment, with plants showing ABA-hypersensitive phenotypes. Furthermore, an in-gel kinase assay revealed that CaSnRK2.6 phosphorylates CaSAP14 in response to exogenous ABA, dehydration, and high-salinity stress. Collectively, these findings suggest that CaSAP14 is a direct substrate of CaSnRK2.6 and positively modulates dehydration- and high salinity-induced osmotic stress responses.

Pepper SUMO protease CaDeSI2 positively modulates the drought responses via deSUMOylation of clade A PP2C CaAITP1.

Posttranslational modification of multiple ABA signaling components is an essential process for the adaptation and survival of plants under stress conditions. In our previous study, we established that the pepper group A PP2C protein CaAITP1, one of the core components of ABA signaling, undergoes ubiquitination mediated by the RING-type E3 ligase CaAIRE1. In this study, we discovered an additional form of regulation mediated via the SUMOylation of CaAITP1. Pepper plants subjected to drought stress were characterized by reductions in both the stability and SUMOylation of CaAITP1 protein. Moreover, we identified a SUMO protease, Capsicum annuum DeSUMOylating Isopeptidase 2 (CaDeSI2), as a new interacting partner of CaAITP1. In vitro and in vivo analyses revealed that CaAITP1 is deSUMOylated by CaDeSI2. Silencing of CaDeSI2 in pepper plants led to drought-hypersensitive and ABA-hyposensitive phenotypes, whereas overexpression of CaDeSI2 in transgenic Arabidopsis plants resulted in the opposite phenotypes. Importantly, we found that the CaAITP1 protein was stabilized in response to the silencing of CaDeSI2, and CaDeSI2 and CaAITP1 co-silenced pepper plants were characterized by drought-tolerant phenotypes similar to those observed in CaAITP1-silenced pepper. Collectively, our findings indicate that CaDeSI2 reduces the stability of CaAITP1 via deSUMOylation, thereby positively regulating drought tolerance.

A pepper RING-finger E3 ligase, CaFIRF1, negatively regulates the high-salt stress response by modulating the stability of CaFAF1.

Controlling protein stability or degradation via the ubiquitin-26S proteasome system is a crucial mechanism in plant cellular responses to stress conditions. Previous studies have revealed that the pepper FANTASTIC FOUR-like gene, CaFAF1, plays a positive role in salt tolerance and that, in this process, CaFAF1 protein degradation is delayed. Here, we sought to isolate the E3 ligases potentially responsible for modulating CaFAF1 protein stability in response to salt stress. The pepper RING-type E3 ligase CaFIRF1 (Capsicum  annuum  FAF1  Interacting  RING  Finger protein  1) was found to interact with and ubiquitinate CaFAF1, leading to the degradation of CaFAF1 proteins. In response to high-salt treatments, CaFIRF1-silenced pepper plants exhibited tolerant phenotypes. In contrast, co-silencing of CaFAF1 and CaFIRF1 led to increased sensitivity to high-salt treatments, revealing that CaFIRF1 functions upstream of CaFAF1. A cell-free degradation analysis showed that high-salt treatment suppressed CaFAF1 protein degradation via the 26S proteasome pathway, in which CaFIRF1 is functionally involved. In addition, an in vivo ubiquitination assay revealed that CaFIRF1-mediated ubiquitination of CaFAF1 proteins was reduced by high-salt treatment. Taken together, these findings suggest that the degradation of CaFAF1 mediated by CaFIRF1 has a critical role in pepper plant responses to high salinity.

Devosia rhodophyticola sp. nov. and Devosia algicola sp. nov., isolated from a marine red alga.

Two Gram-stain-negative, obligately aerobic, motile rod bacteria, designated as G2-5T and G20-9T, exhibiting catalase- and oxidase-positive activities, were isolated from the phycosphere of a Chondrus species, a marine red alga. Strain G2-5T exhibited optimal growth at 30 °C and pH 5.0-6.0 and in the presence of 0.5-1.0% NaCl. In contrast, strain G20-9T demonstrated optimal growth at 25 °C and pH 6.0 and in the presence of 0.5-1.5% NaCl. Both strains contained ubiquinone-10, summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C18 : 0 and 11-methyl-C18 : 1 ω7c, and diphosphatidylglycerol and phosphatidylglycerol as the major respiratory isoprenoid quinone, cellular fatty acids and polar lipids, respectively. The genomic DNA G+C contents were 57.2 mol% for strain G2-5T and 57.5 mol% for strain G20-9T. Strains G2-5T and G20-9T exhibited 98.2 % 16S rRNA gene sequence similarity, along with 82.3 % average nucleotide identity (ANI) and 25.0 % digital DNA-DNA hybridization (dDDH) values, indicating that they represent different species. Phylogenetic analyses based on both 16S rRNA gene and genome sequences revealed that strains G2-5T and G20-9T formed distinct phylogenic lineages within the genus Devosia. Strains G2-5T and G20-9T were most closely related to Devosia limi DSM 17137T and Devosia beringensis S02T with 97.7 and 96.9 % 16S rRNA gene sequence similarities, respectively. The ANI and dDDH values between strains G2-5T and G20-9T and other Devosia species were lower than 73.9 and 19.2 %, respectively, suggesting that they constitute novel species within the genus Devosia. Based on their distinct phenotypic, chemotaxonomic, and molecular characteristics, strains G2-5T and G20-9T represent two novel species of the genus Devosia, for which the names Devosia rhodophyticola sp. nov. (G2-5T=KACC 22601T=JCM 35404T) and Devosia algicola sp. nov. (G20-9T=KACC 22650T=JCM 35405T) are proposed, respectively.

Pepper U-Box E3 ubiquitin ligase 24, CaPUB24, negatively regulates drought stress response.

Under stress conditions, plants modulate their internal states and initiate various defence mechanisms to survive. The ubiquitin-proteasome system is one of the critical modules in these mechanisms, and Plant U-Box proteins play an important role in this process as E3 ubiquitin ligases. Here, we isolated the Plant U-box 24 gene CaPUB24 (Capsicum annuum Plant U-Box 24) from pepper and characterized its functions in response to drought stress. We found that, compared to the other CaPUBs in the same group, the expression of CaPUB24 was significantly induced by drought stress. We also found that CaPUB24 was localized to the nucleus and cytoplasm and had E3 ubiquitin ligase activity. To investigate the biological role of CaPUB24 in response to drought stress further, we generated CaPUB24-silenced pepper plants and CaPUB24-overexpressing Arabidopsis transgenic plants. CaPUB24-silenced pepper plants exhibited enhanced drought tolerance compared to the control plants due to reduced transpirational water loss and increased abscisic acid (ABA) sensitivity. In contrast, CaPUB24-overexpressing Arabidopsis transgenic plants exhibited reduced drought tolerance and ABA-insensitive phenotypes. Our findings suggest that CaPUB24 negatively modulates drought stress response in an ABA-dependent manner.

Pepper SnRK2.6-activated MEKK protein CaMEKK23 is directly and indirectly modulated by clade A PP2Cs in response to drought stress.

The phytohormone abscisic acid (ABA) is important for the plant growth and development, in which it plays a key role in the responses to drought stress. Among the core components of ABA signaling, SnRK2s interact with a range of proteins, including Raf-like MAP3Ks. In this study, we isolated the pepper MEKK subfamily member CaMEKK23 that interacts with CaSnRK2.6. CaMEKK23 has kinase activity and is specifically trans-phosphorylated by CaSnRK2.6. Compared with control plants, CaMEKK23-silenced pepper were found to be sensitive to drought stress and insensitive to ABA, whereas overexpression of CaMEKK23 in both pepper and Arabidopsis plants induced the opposite phenotypes. These altered phenotypes were established to be dependent on the kinase activity of CaMEKK23, which was also shown to interact with CaPP2Cs, functioning upstream of CaSnRK2.6. In addition to inhibiting the kinase activity of CaMEKK23, these CaPP2Cs were found to have inhibitory effects on CaSnRK2.6. Using CaMEKK23-, CaAITP1/CaMEKK23-, CaSnRK2.6-, and CaAITP1/CaSnRK2.6-silenced pepper, we revealed that CaMEKK23 and CaSnRK2.6 function downstream of CaAITP1. Collectively, our findings indicate that CaMEKK23 plays a positive regulatory role in the ABA-mediated drought stress responses in pepper plants, and that its phosphorylation status is modulated by CaSnRK2.6 and CaPP2Cs, functioning as core components of ABA signaling.

Roles of the pepper JAZ protein CaJAZ1-03 and its interacting partner RING-type E3 ligase CaASRF1 in regulating ABA signaling and drought responses.

Plants have developed various defense mechanisms against environmental stresses by regulating hormone signaling. Jasmonic acid (JA) is a major phytohormone associated with plant defense responses. JASMONATE ZIM-DOMAIN (JAZ) proteins play a regulatory role in repressing JA signaling, impacting plant responses to both biotic and abiotic stresses. Here, we isolated 7 JAZ genes in pepper and selected CA03g31030, a Capsicum annuum JAZ1-03 (CaJAZ1-03) gene, for further study based on its expression level in response to abiotic stresses. Through virus-induced gene silencing (VIGS) in pepper and overexpression in transgenic Arabidopsis plants, we established the functional role of CaJAZ1-03. Functional studies revealed that CaJAZ1-03 dampens abscisic acid (ABA) signaling and drought stress responses. The cell-free degradation assay showed faster degradation of CaJAZ1-03 in drought- or ABA-treated pepper leaves compared to healthy leaves. Conversely, CaJAZ1-03 was completely preserved under MG132 treatment, indicating that CaJAZ1-03 stability is modulated via the ubiquitin-26s proteasome pathway. We also found that the pepper RING-type E3 ligase CaASRF1 interacts with and ubiquitinates CaJAZ1-03. Additional cell-free degradation assays revealed a negative correlation between CaJAZ1-03 and CaASRF1 expression levels. Collectively, these findings suggest that CaJAZ1-03 negatively regulates ABA signaling and drought responses and that its protein stability is modulated by CaASRF1.

Pepper homeobox abscisic acid signalling-related transcription factor 1, CaHAT1, plays a positive role in drought response.

Abscisic acid (ABA) signalling triggers drought resistance mediated by SNF1-related kinase 2s (SnRK2s), which transmits stress signals through the phosphorylation of several downstream factors. However, these kinases and their downstream targets remain elusive in pepper plants. This study aimed to isolate interacting partners of CaSnRK2.6, a homologue of Arabidopsis SnRK2.6/OST1. Among the candidate proteins, we identified a homeodomain-leucine zipper (HD-Zip) class II protein and named it CaHAT1 (Capsicum annuum homeobox ABA signalling related- transcription factor 1). CaHAT1-silenced pepper and -overexpression (OE) transgenic Arabidopsis plants were generated to investigate the in vivo function of CaHAT1 in drought response. Following the application of drought stress, CaHAT1-silenced pepper plants exhibited drought-sensitive phenotypes with reduced ABA-mediated stomatal closure and lower expression of stress-responsive genes compared with control plants. In contrast, CaHAT1-OE transgenic Arabidopsis plants showed the opposite phenotypes, including increased drought resistance and ABA sensitivity. CaHAT1, particularly its N-terminal consensus sequences, was directly phosphorylated by CaSnRK2.6. Furthermore, CaSnRK2.6 kinase activity and CaSnRK2.6-mediated CaHAT1 phosphorylation levels were enhanced by treatment with ABA and drought stress. Taken together, our results indicated that CaHAT1, which is the target protein of CaSnRK2.6, is a positive regulator of drought stress response. This study advances our understanding of CaHAT1-CaSnRK2.6 mediated defence mechanisms in pepper plants against drought stress.

Pathogen-Associated Molecular Pattern-Triggered Immunity Involves Proteolytic Degradation of Core Nonsense-Mediated mRNA Decay Factors During the Early Defense Response.

Nonsense-mediated mRNA decay (NMD), an mRNA quality control process, is thought to function in plant immunity. A subset of fully spliced (FS) transcripts of Arabidopsis (Arabidopsis thaliana) resistance (R) genes are upregulated during bacterial infection. Here, we report that 81.2% and 65.1% of FS natural TIR-NBS-LRR (TNL) and CC-NBS-LRR transcripts, respectively, retain characteristics of NMD regulation, as their transcript levels could be controlled posttranscriptionally. Both bacterial infection and the perception of bacteria by pattern recognition receptors initiated the destruction of core NMD factors UP-FRAMESHIFT1 (UPF1), UPF2, and UPF3 in Arabidopsis within 30 min of inoculation via the independent ubiquitination of UPF1 and UPF3 and their degradation via the 26S proteasome pathway. The induction of UPF1 and UPF3 ubiquitination was delayed in mitogen-activated protein kinase3 (mpk3) and mpk6, but not in salicylic acid-signaling mutants, during the early immune response. Finally, previously uncharacterized TNL-type R transcripts accumulated in upf mutants and conferred disease resistance to infection with a virulent Pseudomonas strain in plants. Our findings demonstrate that NMD is one of the main regulatory processes through which PRRs fine-tune R transcript levels to reduce fitness costs and achieve effective immunity.

Psychroserpens ponticola sp. nov. and Marinomonas maritima sp. nov., isolated from seawater.

Two Gram-stain-negative, catalase- and oxidase-positive, aerobic non-motile and motile rod bacteria, strains MSW6T and RSW2T, were isolated from surface seawater. Strain MSW6T optimally grew at 20 °C, pH 7.0 and 3 % NaCl, while strain RSW2T optimally grew at 25 °C, pH 7.0-8.0 and 2 % NaCl. Strain MSW6T possessed menaquinone-6 as the major respiratory quinone, and its major fatty acids were iso-C15 : 1 G, iso-C15 : 0 and iso-C15 : 0 3-OH. The major polar lipid identified in strain MSW6T was phosphatidylethanolamine (PE). On the other hand, strain RSW2T had ubiquinone-8 as the predominant respiratory quinone, and its major fatty acids consisted of summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and C16 : 0. The major polar lipids identified in strain RSW2T were PE and phosphatidylglycerol. As the sole respiratory quinone, strain MSW6T possessed menaquinone-6, while strain RSW2T had ubiquinone-8. The DNA G+C contents of strains MSW6T and RSW2T were 31.9 and 43.4 mol%, respectively. Phylogenetic analyses based on 16S rRNA and core gene sequences showed that strain MSW6T formed a phylogenic lineage with Psychroserpens mesophilus KOPRI 13649T, while strain RSW2T formed a phylogenic lineage with Marinomonas primoryensis KMM 3633T. Strain MSW6T shared 97.9 % 16S rRNA gene sequence similarity and 80.7 % average nucleotide identity (ANI) ith P. mesophilus KOPRI 13649T, and strain RSW2T shared 99.1 % 16S rRNA gene sequence similarity and 93.1 % ANI with M. primoryensis KMM 3633T. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strains MSW6T and RSW2T represent novel species of the genera Psychroserpens and Marinomonas, respectively, for which the names Psychroserpens ponticola sp. nov. and Marinomonas maritima sp. nov. are proposed, respectively. The type strain of P. ponticola is MSW6T (=KACC 22338T=JCM 35022T) and the type strain of M. maritima is RSW2T (=KACC 22716T=JCM 35550T).

Tomato salt-responsive pseudo-response regulator 1, SlSRP1, negatively regulates the high-salt and dehydration stress responses.

Under severe environmental stress conditions, plants inhibit their growth and development and initiate various defense mechanisms to survive. The pseudo-response regulator (PRRs) genes have been known to be involved in fruit ripening and plant immunity in various plant species, but their role in responses to environmental stresses, especially high salinity and dehydration, remains unclear. Here, we focused on PRRs in tomato plants and identified two PRR2-like genes, SlSRP1 and SlSRP1H, from the leaves of salt-treated tomato plants. After exposure to dehydration and high-salt stresses, expression of SISRP1, but not SlSRP1H, was significantly induced in tomato leaves. Subcellular localization analysis showed that SlSRP1 was predominantly located in the nucleus, while SlSRP1H was equally distributed in the nucleus and cytoplasm. To further investigate the potential role of SlSRP1 in the osmotic stress response, we generated SISRP1-silenced tomato plants. Compared to control plants, SISRP1-silenced tomato plants exhibited enhanced tolerance to high salinity, as evidenced by a high accumulation of proline and reduced chlorosis, ion leakage, and lipid peroxidation. Moreover, SISRP1-silenced tomato plants showed dehydration-tolerant phenotypes with enhanced abscisic acid sensitivity and increased expression of stress-related genes, including SlRD29, SlAREB, and SlDREB2. Overall, our findings suggest that SlSRP1 negatively regulates the osmotic stress response.

Cytoreductive surgery and intraperitoneal chemotherapy for peritoneal metastasis of colorectal cancer: long-term follow-up results at a single institution in Korea.

PURPOSE: This study aimed to examine the 7-year follow-up results of cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC) for peritoneal metastasis (PM) of colorectal cancer. METHODS: We performed 54 cases of CRS and IPC in 53 patients with PM of colorectal cancer from December 2011 to December 2013. We prospectively collected data and analyzed peritoneal carcinomatosis grade, completeness of cytoreduction, and long-term follow-up (median, 10 [range, 2-92] months) results. RESULTS: The mean peritoneal cancer index was 15 (1 ~ 35), and complete cytoreduction was possible in 35 (64.8%) patients. Excluding the four patients who died, 11 (22.4%) out of the 49 patients were alive at the time of the last follow-up, and the overall median survival period was 10.3 months. The overall 2- and 5-year survival rates were 31% and 17%, respectively. Patients with complete cytoreduction had a median survival period of 22.6 months, which was significantly longer than that for patients without complete cytoreduction (3.5 months) (P < 0.001). The 5-year survival rate for patients with complete cytoreduction was 24%, and four patients were still alive without disease. CONCLUSIONS: CRS and IPC show a 5-year survival rate of 17% in patients with PM of colorectal cancer. A possibility of long-term survival is observed in a selected group. Multidisciplinary team evaluation for careful patient selection and CRS training program to achieve complete cytoreduction are significantly important factors in improving survival rate.

CHARACTERISTICS OF THE MACULAR MICROVASCULATURE IN IDIOPATHIC EPIRETINAL MEMBRANE PATIENTS WITH AN ECTOPIC INNER FOVEAL LAYER.

PURPOSE: To identify the characteristics of the retinal microvasculature in epiretinal membrane patients with ectopic inner foveal layer (EIFL). METHODS: Patients were classified into two groups: those without EIFL (Group 1) and those with EIFL (Group 2). The vessel density (VD), perfusion density (PD), and the foveal avascular zone (FAZ) parameters were compared using optical coherence tomography angiography. Linear regression analysis was performed to identify the optical coherence tomography angiography parameters associated with best-corrected visual acuity. RESULTS: The VD of the central area in Group 1 and Group 2 was 11.6 ± 3.3 and 17.2 ± 2.8 mm -1 , respectively ( P < 0.001), the PD of the central area was 21.7 ± 6.2 and 32.0 ± 5.5%, respectively ( P < 0.001), and the FAZ area was 0.24 ± 0.11 and 0.09 ± 0.08 mm 2 , respectively ( P < 0.001). Based on the linear regression analysis, the VD of the central area (B = 0.018, P = 0.003), the PD of the central area (B = 0.009, P = 0.004), and FAZ area (B = -0.489, P = 0.013) were significantly associated with best-corrected visual acuity in patients with epiretinal membrane. CONCLUSION: The VD and PD of the foveal area were significantly higher in patients with EIFL, and the FAZ area was lower in patients with EIFL than in those without EIFL. In addition, the VD and PD of the foveal area were negatively associated with best-corrected visual acuity, and the FAZ area was positively associated with best-corrected visual acuity in patients with epiretinal membrane.

PERIPHERAL EXUDATIVE HEMORRHAGIC CHORIORETINOPATHY IN ASIAN POPULATIONS.

PURPOSE: Peripheral exudative hemorrhagic chorioretinopathy (PEHCR) is a rare degenerative disease that affects the peripheral retina. Reports of PEHCR in Asian patients are rare. Thus, the aim of this study was to investigate the clinical characteristics and outcomes of PEHCR in Asian patients. METHODS: A retrospective chart review of 33 eyes of 29 Asian patients with PEHCR. RESULTS: The mean age of the patients was 70 years, and 75.9% of them were women. Vitreous hemorrhage occurred in 51.5% of eyes during a mean follow-up of 43.1 months. The occurrence of vitreous hemorrhage was associated with a thicker baseline subfoveal choroid ( P = 0.001) and the male sex ( P = 0.005). Final visual acuity was less than 20/200 in 29.2% of eyes. The predictive factors for a final visual acuity worse than 20/200 included poor initial visual acuity ( P = 0.002), initial lesion involvement of more than 180° of the peripheral retina ( P = 0.03), an extension of subretinal hemorrhage to the macula ( P = 0.040), and absence of complete tumor regression ( P = 0.02). CONCLUSION: Asian PEHCR patients seem to be more frequently associated with vitreous hemorrhages, especially in male patients with thicker choroids. Although PEHCR was largely self-limiting, approximately one-third of the eyes ended up with a visual acuity of less than 20/200 with extensive lesion involvement.

CHARACTERISTICS OF AGE-RELATED MACULAR DEGENERATION SHOWING A POOR RESPONSE TO THREE LOADING DOSES OF ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR.

PURPOSE: To analyze the clinical features of refractory age-related macular degeneration patients associated with the response to three consecutive loading doses of anti-vascular endothelial growth factor. METHODS: A retrospective chart review was performed on typical exudative age-related macular degeneration patients treated by three consecutive anti-vascular endothelial growth factor injections. The patients were divided into a group without residual fluid on optical coherence tomography images (Group 1) and a group with residual fluid (Group 2). We analyzed qualitative and quantitative morphologic features of optical coherence tomography and optical coherence tomography angiography. We performed univariate and multivariate logistic regression analyses to identify factors associated with the treatment response. RESULTS: We enrolled a total of 90 patients (Group 1: n = 60, Group 2: n = 30). Under optical coherence tomography, the choroidal thickness differed significantly between groups 1 and 2 (246.60 ± 67.67 vs. 286.90 ± 40.92 µ m, P = 0.001). Under optical coherence tomography angiography, the presence of branching (48.3% vs. 73.3%, P = 0.024), loops (31.7% vs. 66.7%, P = 0.002), and a peripheral arcade (40.0% vs. 76.7%, P = 0.001) differed significantly. Logistic regression analysis showed that the initial CT (B = 0.012; P = 0.007), presence of loops (B = 1.289; P = 0.015), and peripheral arcade (B = 1.483; P = 0.008) significantly affected the anti-vascular endothelial growth factor treatment response. CONCLUSION: A thicker choroid and the presence of loops and a peripheral arcade were significantly associated with a poorer response to three loading anti-vascular endothelial growth factor injections in typical exudative age-related macular degeneration patients.

Retinal microvasculature and choriocapillaris impairments according to the stage of dry age-related macular degeneration.

BACKGROUND: We aimed to analyse the retinal microvasculature and choriocapillaris according to the dry age-related macular degeneration (AMD) stage and to identify factors associated with their microvasculatures. METHODS: Patients were divided into four groups: normal controls, early, intermediate and advanced AMD groups. The vessel density (VD) of superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris was compared using optical coherence tomography angiography among the groups. Linear regression analysis was performed to identify factors associated with the VD. RESULTS: The VDs of the SCP were 22.1 ± 5.7, 19.1 ± 5.4, 18.0 ± 6.4 and 12.2 ± 6.4% (p < 0.001); the VDs of the DCP were 22.4 ± 4.5, 20.7 ± 4.3, 18.1 ± 5.3 and 14.6 ± 5.8% (p < 0.001); the VDs of the choriocapillaris were 29.4 ± 3.7, 26.4 ± 4.8, 24.5 ± 4.9 and 24.2 ± 3.7% (p < 0.001) in the control, early, intermediate, and advanced groups, respectively. AMD stage and age were significantly associated with the VDs of all layers, and the VDs of the SCP and DCP were associated with visual acuity (both p < 0.001). Additionally, hypertension was associated with the VDs of the DCP (p = 0.027) and choriocapillaris (p = 0.024). CONCLUSIONS: The retinal microvasculature and choriocapillaris tended to become more impaired as the AMD stage progressed. Age was significantly associated with the microvasculature impairments of all layers, and hypertension was significantly associated with impairments of the DCP microvasculature and choriocapillaris.

Pepper ubiquitin-specific protease, CaUBP12, positively modulates dehydration resistance by enhancing CaSnRK2.6 stability.

Abscisic acid (ABA) is a plant hormone that activates adaptive mechanisms to environmental stress conditions. Plant adaptive mechanisms are complex and highly modulated processes induced by stress-responsive proteins; however, the precise mechanisms by which these processes function under adverse conditions remain unclear. Here, we isolated CaUBP12 (Capsicum annuum ubiquitin-specific protease 12) from pepper (C. annuum) leaves. We show that CaUBP12 expression is significantly induced after exposure to abiotic stress treatments. We conducted loss-of-function and gain-of-function genetic studies to elucidate the biological functions of CaUBP12 in response to ABA and dehydration stress. CaUBP12-silenced pepper plants and CaUBP12-overexpressing Arabidopsis plants displayed dehydration-sensitive and dehydration-tolerant phenotypes, respectively; these phenotypes were characterized by regulation of transpirational water loss and stomatal aperture. Under dehydration stress conditions, CaUBP12-silenced pepper plants and CaUBP12-overexpressing Arabidopsis plants exhibited lower and higher expression levels of stress-related genes, respectively, than the control plants. We isolated a CaUBP12 interaction protein, CaSnRK2.6, which is a homolog of Arabidopsis OST1; degradation of this protein was partially inhibited by CaUBP12. Similar to CaUBP12-silenced pepper plants and CaUBP12-overexpressing Arabidopsis plants, CaSnRK2.6-silenced pepper plants and CaSnRK2.6-overexpressing Arabidopsis displayed dehydration-sensitive and dehydration-tolerant phenotypes, respectively. Our findings suggest that CaUBP12 positively modulates the dehydration stress response by suppressing CaSnRK2.6 protein degradation.

Pepper SUMO E3 ligase CaDSIZ1 enhances drought tolerance by stabilizing the transcription factor CaDRHB1.

Small ubiquitin-like modifier (SUMO) conjugation (SUMOylation) is a reversible post-translational modification associated with protein stability and activity, and modulates hormone signaling and stress responses in plants. Previously, we reported that the pepper dehydration-responsive homeobox domain transcription factor CaDRHB1 acts as a positive modulator of drought response. Here, we show that CaDRHB1 protein stability is enhanced by SUMO E3 ligase Capsicum annuum DRHB1-interacting SAP and Miz domain (SIZ1) (CaDSIZ1)-mediated SUMOylation in response to drought, thereby positively modulating abscisic acid (ABA) signaling and drought responses. Substituting lysine (K) 138 of CaDRHB1 with arginine reduced CaDSIZ1-mediated SUMOylation, indicating that K138 is the principal site for SUMO conjugation. Virus-induced silencing of CaDSIZ1 promoted CaDRHB1 degradation, suggesting that CaDSIZ1 is involved in drought-induced SUMOylation of CaDRHB1. CaDSIZ1 interacted with and facilitated SUMO conjugation of CaDRHB1. CaDRHB1, mainly localized in the nucleus, but also in the cytoplasm in the SUMOylation mimic state, suggesting that SUMOylation of CaDRHB1 promotes its nuclear export, leading to cytoplasmic accumulation. Moreover, CaDSIZ1-silenced pepper plants were less sensitive to ABA and considerably sensitive to drought stress, whereas CaDSIZ1-overexpressing plants displayed ABA-hypersensitive and drought-tolerant phenotypes. Collectively, our data indicate that CaDSIZ1-mediated SUMOylation of CaDRHB1 functions in ABA-mediated drought tolerance.

Rhodococcus oxybenzonivorans sp. nov., a benzophenone-3-degrading bacterium, isolated from stream sediment.

A Gram-stain-positive, facultative aerobic, oxidase-negative, catalase-positive, non-sporulating, and non-motile bacterium, which degraded benzophenone-3, was isolated from stream sediment collected in the Republic of Korea and designated as strain S2-17T. Cells of this strain were rod-shaped during the early growth phase but became coccoid after the late exponential growth phase. Bacterial growth was observed at 15-37 °C (optimum, 25-30 °C) and pH 6.0-9.5 (optimum, pH 7.5-8.5) and in the presence of 0-9.0 % (w/v) NaCl (optimum, 0-1.0 %). Menaquinone-8 (H2) was the sole isoprenoid quinone, and C16 : 0, C17 : 1 ω8c, summed feature 3 (comprising C16 : 1 ω7c/C16 : 1 ω6c) and C18 : 1 ω9c were the major fatty acids. The cell wall of strain S2-17T contained meso-diaminopimelic acid, and arabinose, galactose and mycolic acid were found in whole-cell hydrolysates, suggesting a chemotype IV cell wall. The G+C content of the genome was 65.6 mol%. Phylogenetic analyses revealed that strain S2-17T formed a phyletic lineage within the genus Rhodococcus and was most closely related to Rhodococcus jostii DSM 44719T (99.2 % 16S rRNA gene sequence similarity). Average nucleotide identity and digital DNA-DNA hybridization values between strain S2-17T and R. jostii DSM 44719T were 82.6 and 26.5 %, respectively, indicating differences between the species. Based on its phenotypic, chemotaxonomic and molecular features, strain S2-17T represents a novel species of the genus Rhodococcus, for which the name Rhodococcus oxybenzonivorans sp. nov. is proposed. The type strain is S2-17T (=KACC 19281T=JCM 32046T).

Massilia soli sp. nov., isolated from soil.

A Gram-stain-negative, catalase- and oxidase-positive and aerobic bacterium, designated strain R798T, was isolated from soil in South Korea. Cells were motile rods by means of a single polar flagellum. Growth of strain R798T was observed at 15-35 °C (optimum, 25-30 °C), pH 5.0-8.0 (optimum, 6.0) and 0-1.5 % NaCl (optimum, 0.3 %). Strain R798T contained ubiquinone-8 as the sole isoprenoid quinone, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 0 as the major fatty acids and phosphatidylglycerol and phosphatidylethanolamine as the major polar lipids. The DNA G+C content of strain R798T calculated from the whole genome sequence was 63.3 mol%. Phylogenetic analyses based on the 16S rRNA gene and whole genome sequences revealed that strain R798T formed a distinct phyletic lineage within the genus Massilia. Strain R798T was most closely related to Massilia eurypsychrophila B528-3T with a 98.0 % 16S rRNA gene sequence similarity. Average nucleotide identity and digital DNA-DNA hybridization values between strain R798T and the type strain of M. eurypsychrophila were 79.2 and 22.7 %, respectively. Based on the phenotypic, chemotaxonomic and molecular analyses, strain R798T represents a novel species of the genus Massilia, for which the name Massilia soli sp. nov. is proposed. The type strain is R798T (=KACC 22114T=JCM 34601T).