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The protein Pal (peptidoglycan-associated lipoprotein) is anchored in the outer membrane (OM) of Gram-negative bacteria and interacts with Tol proteins. Tol-Pal proteins form two complexes: the first is composed of three inner membrane Tol proteins (TolA, TolQ and TolR); the second consists of the TolB and Pal proteins linked to the cell's OM. These complexes interact with one another forming a multiprotein membrane-spanning system. It has recently been demonstrated that Pal is essential for bacterial survival and pathogenesis, although its role in virulence has not been clearly defined. This review summarizes the available data concerning the structure and function of Pal and its role in pathogenesis.

The construction of Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL), a 0.1-nm hard X-ray free-electron laser (FEL) facility based on a 10-GeV S-band linear accelerator (LINAC), is achieved in Pohang, Korea by the end of 2016. The construction of the 1.11 km-long building was completed by the end of 2014, and the installation of the 10-GeV LINAC and undulators started in January 2015. The installation of the 10-GeV LINAC, together with the undulators and beamlines, was completed by the end of 2015. The commissioning began in April 2016, and the first lasing of the hard X-ray FEL line was achieved on 14 June 2016. The progress of the PAL-XFEL construction and its commission are reported here.

A Nanobeam X‐ray Experiments (NXE) instrument was developed and installed at the hard X‐ray beamline of the Pohang Accelerator Laboratory X‐ray Free Electron Laser. This instrument consists of a diagnostic system, focusing optics, an X‐ray diffraction endstation and a femtosecond laser delivery system. The NXE instrument enables sophisticated X‐ray experiments using nanofocused X‐rays. At a 9.5 keV X‐ray energy, the beam was successfully focused to 390 nm × 230 nm at the focal plane using Kirkpatrick–Baez mirrors. Following the successful commissioning experiments in December 2021 and April 2022, the instrument became available for regular user experiments in January 2023. The first user experiment was conducted in January 2024. This article provides detailed information on the beamline optics, the NXE instrument, and its performance and capabilities. The Nanobeam X‐ray Experiments (NXE) instrument at the Pohang Accelerator Laboratory X‐ray Free Electron Laser (PAL‐XFEL) is introduced. The NXE instrument enables users to conduct X‐ray experiments with nanofocused X‐rays.

Background The phenylalanine ammonia-lyase ( PAL ) gene, a well-studied plant defense gene, is crucial for growth, development, and stress resistance. The PAL gene family has been studied in many plants. Citrus is among the most vital cash crops worldwide. However, the PAL gene family has not been comprehensively studied in most Citrus species, and the biological functions and specific underlying mechanisms are unclear. Results We identified 41 PAL genes from nine Citrus species and revealed different patterns of evolution among the PAL genes in different Citrus species. Gene duplication was found to be a vital mechanism for the expansion of the PAL gene family in citrus. In addition, there was a strong correlation between the ability of PAL genes to respond to stress and their evolutionary duration in citrus. PAL genes with shorter evolutionary times were involved in more multiple stress responses, and these PAL genes with broad-spectrum resistance were all single-copy genes. By further integrating the lignin and flavonoid synthesis pathways in citrus, we observed that PAL genes contribute to the synthesis of lignin and flavonoids, which enhance the physical defense and ROS scavenging ability of citrus plants, thereby helping them withstand stress. Conclusions This study provides a comprehensive framework of the PAL gene family in citrus, and we propose a hypothetical model for the stress resistance mechanism in citrus. This study provides a foundation for further investigations into the biological functions of PAL genes in the growth, development, and response to various stresses in citrus.

Phenylalanine ammonia-lyase is one of the most widely studied enzymes in the plant kingdom. It is a crucial pathway from primary metabolism to significant secondary phenylpropanoid metabolism in plants, and plays an essential role in plant growth, development, and stress defense. Although PAL has been studied in many actual plants, only one report has been reported on potato, one of the five primary staple foods in the world. In this study, 14 StPAL genes were identified in potato for the first time using a genome-wide bioinformatics analysis, and the expression patterns of these genes were further investigated using qRT-PCR. The results showed that the expressions of StPAL1, StPAL6, StPAL8, StPAL12, and StPAL13 were significantly up-regulated under drought and high temperature stress, indicating that they may be involved in the stress defense of potato against high temperature and drought. The expressions of StPAL1, StPAL2, and StPAL6 were significantly up-regulated after MeJa hormone treatment, indicating that these genes are involved in potato chemical defense mechanisms. These three stresses significantly inhibited the expression of StPAL7, StPAL10, and StPAL11, again proving that PAL is a multifunctional gene family, which may give plants resistance to multiple and different stresses. In the future, people may improve critical agronomic traits of crops by introducing other PAL genes. This study aims to deepen the understanding of the versatility of the PAL gene family and provide a valuable reference for further genetic improvement of the potato.

Heavy metal stress can lead to many adverse effects that inhibit cellular processes at various levels of metabolism, causing a decrease in plant productivity. In response to environmental stressors, phenolic compounds fulfill significant molecular and biochemical functions in plants. Increasing the biosynthesis of phenolic compounds in plants subjected to heavy metal stress helps protect plants from oxidative stress. A pot experiment was carried out to determine the effect of the accumulation of copper (Cu) and lead (Pb) salts at concentrations of 200, 500, and 1000 ppm on seed germination, the activity of enzymes in the phenylalanine ammonia-lyase pathway (PAL) and tyrosine ammonia-lyase (TAL), along with the total phenol and flavonoid contents in seedlings of hybrid Triticum aestivum L. (winter wheat) cultivars. The accumulation of heavy metals, especially Cu, had a negative impact on the seed germination process. The cultivar “Hyacinth” reacted most strongly to heavy metal stress, which was confirmed by obtaining the lowest values of the germination parameters. Heavy metal stress caused an increase in the activity of PAL and TAL enzymes and an increase in the accumulation of phenolic compounds. Under the influence of Cu, the highest activity was shown in cv. “Hyvento” (especially at 200 ppm) and, due to the accumulation of Pb, in cv. “Hyacinth” (1000 ppm) and cv. “Hyking” (200 ppm). The cultivar “Hyking” had the highest content of phenolic compounds, which did not increase with the application of higher concentrations of metals. In other cultivars, the highest content of total phenols and flavonoids was usually observed at the lowest concentration (200 ppm) of the tested heavy metals, Cu and Pb.

Phenylalanine ammonia lyase (PAL) is a pivotal enzyme bridging primary and secondary phenylpropanoid metabolism, influencing plant growth, development, and stress responses. Despite extensive studies on PAL genes across various plant species, their investigation in barley, a critical staple food globally, has been relatively scarce. In this study, we have successfully identified 10 HvPAL genes, designated as HvPAL genes, in Hordeum vulgare (barley). These HvPAL genes were categorized based on their conserved sequences, which revealed patterns through MEME analysis and multiple sequence alignment. Interestingly, we found cis elements related to stress in the promoter regions of HvPAL genes, indicating their involvement in the response to pathogens. Furthermore, these gene promoters contained components associated with light, development, and hormone responsiveness. This suggests that they may play a role in hormonal developmental processes. MicroRNAs were also identified as regulators of the HvPAL genes we identified highlighting their significance in barley. To further investigate these gene expression patterns, we analyzed the RNA-seq data revealed the upregulating of HvPAL 2, HvPAL3, and HvPAL8, and downregulating HvPAL 5, HvPAL 6, and HvPAL9 genes in this study. This study focused on the regulation of PAL genes in response to 23 different races of Puccinia graminis f. sp. tritici in barley. These results suggest ways to improve traits and develop barley varieties that are resistant to pathogens by selectively increasing the expression of certain HvPAL genes that were not previously regulated. This thorough investigation aims to expand our knowledge of the versatility of the PAL gene family, providing insights for advancements in host -pathogen genetics.

This study aimed to investigate and evaluate the efficiency of intercropping garlic plants with tomato and their root secretions in controlling the cause of Fusarium wilt disease by using alternative methods to the use of chemical pesticides, and the experiment was carried out in the College of Agricultural Engineering Sciences/University of Baghdad. Garlic root secretions were extracted and their effectiveness in inhibiting radial growth was studied at several concentrations. The concentration of 30 µl.ml-1 showed the highest rate of inhibition, reaching 96.3%, compared to the control treatment, which amounted to 0%, and this result confirmed the ability of garlic root secretions to inhibit pathogenic fungi. The effect of planting garlic with tomatoes on plant growth-promoting rhizobacteria (PGPR) populations was also studied, and an increase was found in the numbers of these beneficial bacteria. Intercropping significantly, in contrast to monocropping, which increased by a small percentage in the fruit-setting stage and then continued to decrease in the late fruit stage. In the pot experiment, the results of using two treatments of intercropping garlic with tomato plants and watering with garlic root secretions showed a significant reduction in the percentage of infection and disease index, reaching 58.3% and 25%, respectively. The results showed the effectiveness of the treatments used in increasing the concentrations of defensive compounds such as the enzymes Peroxidase, PAL, and the content of phenols, as the FGR treatment recorded an increase in the induction and accumulation of these compounds when detected in tomato leaves, which amounted to 39 Δ absorbance.min-1.g-1, 31 nM.mi-1.g-1, and 5.47 mg of catechol.g-1, respectively. هدفت الدراسة إلى التحقيق في تقويم كفاءة الزراعة البينيَّة لنباتات الثوم مع الطماطة وافرازات جذورها في السيطرة على مُسبب مَرَّض الذُبول الفيوزارمي باتباع طرق بديلة عن استعمال المبيدات الكيمائية، وتم تنفيذ التجربة في كلية علوم الهندسة الزراعية / جامعة بغداد. إذ تم استخلاص افرازات جذور نبات الثوم ودراسة فعاليتها في تثبيط النمو الشعاعي بعدة تراكيز، اذ اظهر التركيز 30 مايكرولتر.مل-1 اعلى نسبة تثبيط بلغت 96.3% مقارنة بمعاملة السيطرة التي بلغت 0%، وهذه النتيجة اكدت قدرة الثوم على تثبيط الفطر الممرض. كذلك تم دراسة تأثير زراعة الثوم مع الطماطة على التجمعات البكتيرية المحفزة لنمو النبات PGPR ووجد تزايد في اعداد هذه البكتريا النافعة في الزراعة البينية بشكل كبير على العكس من الزراعة المنفردة التي زادت بنسبة ضئيلة في مرحلة عقد الثمار وبعدها استمرت بالانخفاض في مرحلة الثمار المتأخرة. في تجربة الاصص، اظهرت نتائج استعمال معاملتي زراعة الثوم بينيًا مع نبات الطماطة والسقي بإفرازات جذور الثوم الى خفض نسبة الاصابة ومؤشر المرض بشكل كبير إذ بلغت 58.3% و 25% على التتابع.  أوضحت النتائج فعالية المعاملات المستعملة في زيادة تراكيز المركبات الدفاعية مثل انزيمي Peroxidase، PAL ومحتوى الفينولات إذ سجلت معاملة FGR زيادة في استحثاث وتراكم هذه المركبات في عند الكشف عنها في اوراق نبات الطماطة إذ بلغت 39 Δabsorbance.min-1.g-1، 31 nM.mi-1.g-1 و 5.47 mg of catechol.g-1 على التتابع.