Dislocation Density Estimation and mosaic Model for GaN/SiC(0001) by High Resolution x-ray Diffraction

Yang, Quankui,Li, Aizhen The Korean Vacuum Society 1997 Applied Science and Convergence Technology Vol.6 No.1

High resolution x-ray diffraction and two dimensional triple axis mapping were used to characterize a group of GaN layers of about 1.1$\mu$m grown by direct current plasma molecular beam epitaxy technique on 6H-SiC(0001). A FWHM of 11.9 arcmins for an $\omega$ scan and 1.2 arcmins for an $\omega$/2$\theta$ scan were observed. A careful study of the rocking curves showed there were some large mosaics in the GaN layer and a tilt of $0.029^{\circ}$ between the GaN layer and the SIC substrate was detected. The two dimensional triple axis mapping showed that the GaN mosaica were disoriented in the (0001) plane but rather uniformed in direction perpendicular to the plane. A mosaics were disoriented in the (0001) plane but rather uniformed in direction perpendicular to the plane. A mosaic model was deduced to explain the phenomenon and the dislocation density was estimated to be about~$10^9\;\textrm{cm}^{-2}$ acc ding to the model.

Immunohistochemical Localization of Endogenous IAA in Peach (Prunus persica L.) Fruit during Development

Wei Zhang,Yang Li,Mengya Shi,Hao Hu,Baoguang Hua,Aizhen Yang,Yueping Liu 한국원예학회 2015 원예과학기술지 Vol.33 No.3

Peach (Prunus persica L.) is a model species for stone fruit studies within the Rosaceae family. Auxin plays an important role in the development of peach fruit. To reveal the distribution of auxin in the tissues of peach fruit, immunohistochemical localization of IAA was carried out in the seed, mesocarp, and endocarp in developing peach fruit using an anti-indole-3-acetic acid (anti-IAA) monoclonal antibody. A strong IAA signal was observed throughout the outer and inner integument during peach fruit development, and the distribution was zonal. The IAA signal was mainly focused in mucilage layers in the outer integument. The outer integument may function to produce or store IAA in the seed; a strong IAA signal was detected in the cells around the vascular tissue, whereas a weak IAA signal was located in the vascular tissues. In the mesocarp, the cells around the vascular bundle tissue gave rise to an IAA signal that increased in the late phase of fruit growth, which coincided with a significant increase in fruit growth. The distribution of IAA, however, was changed when fruit was treated with auxin transport inhibitors NPA (1-N-naphthylphthalamic acid) or TIBA (2, 3, 5-triiodobenzoic acid); in mesocarp tissues, an IAA signal was detected mainly in vessels of the t reated f ruit. During the c ritical period o f endocarp l ignification, the vessel lignification process was negatively correlated with IAA signal. The present results confirmed that the distribution of IAA was different in various tissues of peach fruit according to the developmental stage. This research provides cytological data for further study of the regulatory mechanism of auxin in peach fruit.

Hyperoside attenuates pyrrolizidine alkaloids-induced liver injury by ameliorating TFEB-mediated mitochondrial dysfunction

Jie Xu,Aizhen Xiong,Xunjiang Wang,Xing Yan,Yilin Chen,Xuanling Ye,Zhengtao Wang,Lili Ding,Li Yang 대한약학회 2023 Archives of Pharmacal Research Vol.46 No.8

Pyrrolizidine alkaloids (PAs) are potent hepatotoxins that can cause liver damage. Hyperoside (Hyp), a natural flavonoid, can be extracted from medicinal plants. Hyp displays hepatoprotective activity in various liver diseases. However, the potential effect and mechanism of action of Hyp in ameliorating PA-induced liver injury remain obscure. This study aimed to explore the protective effect of Hyp against PA-induced hepatotoxicity and its underlying mechanism. We established an in vitro model of PAs in mouse primary hepatocytes and developed a mouse model of acute PA toxicity to investigate the protective effect of Hyp. We found that Hyp notably attenuated PA-induced hepatotoxicity. RNA-sequencing showed that the beneficial effect of Hyp against PA-induced hepatotoxicity was associated with the transcription factor EB (TFEB)-peroxisome proliferator-activated receptor-γ coactivator-1-α (PGC1α) pathway. Our results confirmed that both the autophagy-lysosomal pathway and mitochondrial biogenesis were induced by Hyp through TFEB nuclear translocation in PA-induced liver injury. Furthermore, we demonstrated that activation of the mechanistic target of rapamycin complex 1 (mTORC1) by MHY 1485 decreased TFEB nuclear translocation and abrogated the protective effect of Hyp against PA-induced liver injury in mice. In contrast, inhibition of mTORC1 activity increased the level of TFEB and reduced hepatotoxicity induced by PAs in mouse livers. Likewise, Hyp-induced TFEB activation was validated in vitro. In conclusion, Hyp can activate the TFEB-mediated autophagy-lysosomal pathway and mitochondrial biogenesis through inhibition of mTORC1 activity, alleviating the liver injury induced by PAs, thus suggesting the potential value of Hyp in the treatment of PA-induced hepatotoxicity.

Immunohistochemical Localization of Endogenous IAA in Peach (Prunus persica L.) Fruit during Development

Zhang, Wei,Li, Yang,Shi, Mengya,Hu, Hao,Hua, Baoguang,Yang, Aizhen,Liu, Yueping Korean Society of Horticultural Science 2015 원예과학기술지 Vol.33 No.3

Peach (Prunus persica L.) is a model species for stone fruit studies within the Rosaceae family. Auxin plays an important role in the development of peach fruit. To reveal the distribution of auxin in the tissues of peach fruit, immunohistochemical localization of IAA was carried out in the seed, mesocarp, and endocarp in developing peach fruit using an anti-indole-3-acetic acid (anti-IAA) monoclonal antibody. A strong IAA signal was observed throughout the outer and inner integument during peach fruit development, and the distribution was zonal. The IAA signal was mainly focused in mucilage layers in the outer integument. The outer integument may function to produce or store IAA in the seed; a strong IAA signal was detected in the cells around the vascular tissue, whereas a weak IAA signal was located in the vascular tissues. In the mesocarp, the cells around the vascular bundle tissue gave rise to an IAA signal that increased in the late phase of fruit growth, which coincided with a significant increase in fruit growth. The distribution of IAA, however, was changed when fruit was treated with auxin transport inhibitors NPA (1-N-naphthylphthalamic acid) or TIBA (2, 3, 5-triiodobenzoic acid); in mesocarp tissues, an IAA signal was detected mainly in vessels of the treated fruit. During the critical period of endocarp lignification, the vessel lignification process was negatively correlated with IAA signal. The present results confirmed that the distribution of IAA was different in various tissues of peach fruit according to the developmental stage. This research provides cytological data for further study of the regulatory mechanism of auxin in peach fruit.

Altered Protein Expression in Peach (Prunus persica) Following Fruit Bagging

Zhang, Wei,Zhao, Xiaomeng,Shi, Mengya,Yang, Aizhen,Hua, Baoguang,Liu, Yueping Korean Society of Horticultural Science 2016 원예과학기술지 Vol.34 No.1

Fruit bagging has been widely practiced in peach cultivation to produce high quality and unblemished fruit. Moreover, fruit bagging has been utilized to study the effect of shading on the quality of fruit. We conducted a proteomic analysis on peach fruit to elucidate the biochemical and physiological events that characterize the effect of bagging treatment. Comparative analysis of 2D electrophoresis (2-DE) gels showed that relative protein levels differed significantly at 125 DAFB (days after full bloom), as well as at 133 DAFB in fruit that had been bagged until 125 DAFB, followed by exposure to sunlight. Most of the proteins with altered expression were identified by MALDI TOF/TOF. Twenty-one proteins with differential expression among the groups were identified at 125 DAFB, while thirty proteins with differential expression among the groups were identified at 133 DAFB. The analysis revealed that expression of proteins involved in photosynthesis, stress responses, and biochemical processes influencing metabolism were altered during bagging treatment, suggesting that regulation of the synthesis of carbohydrates, amino acids, and proteins influenced fruit size, solid/acid ratio, and peel color. This work provides the first characterization of proteomic changes in peach in response to fruit bagging treatment. Identifying and tracking protein changes may allow us to better understand the mechanisms underlying the effects of bagging treatment.

Caffeoyl Shikimate Esterase has a Role in Endocarp Lignification in Peach (Prunus persica L.) Fruit

Jinyi Liu,Xiao Hu,Jia Yu,Aizhen Yang,Yueping Liu 한국원예학회 2017 원예과학기술지 Vol.35 No.1

Caffeoyl shikimate esterase (CSE) is a key enzyme in lignin synthesis in Arabidopsis thaliana. To determine the role of CSE in lignification of the endocarp in peach (Prunus persica L.) fruit, we cloned and characterized the P. persica CSE homolog, which we designated PpCSE. The 954 - bp PpCSE gene encoded a 317 - amino acid polypeptide. PpCSE expression patterns in the mesocarp and endocarp changed during peach fruit development. There was no significant difference between the expression levels of PpCSE in the mesocarp and endocarp at 39 and 44 days after full bloom (DAFB), but the expression level of PpCSE in the endocarp at 50 and 55 DAFB was 80.73 and 72.75 times higher, respectively, than that in the mesocarp. During peach fruit development, PpCSE expression in the endocarp increased rapidly; the relative PpCSE expression level at 50 DAFB was 122.70 times higher than that at 39 DAFB. At the protein level, CSE was detected in the peach fruit endocarp at 50 and 55 DAFB. Our study suggests that PpCSE expression during peach fruit development is closely related to the degree of endocarp lignification.

Altered Protein Expression in Peach (Prunus persica) Following Fruit Bagging

Wei Zhang,Xiaomeng Zhao,Mengya Shi,Aizhen Yang,Baoguang Hua,Yueping Liu 한국원예학회 2016 원예과학기술지 Vol.34 No.1

Fruit bagging has been widely practiced in peach cultivation to produce high quality and unblemished fruit. Moreover, fruit bagging has been utilized to study the effect of shading on the quality of fruit. We conducted a proteomic analysis on peach fruit to elucidate the biochemical and physiological events that characterize the effect of bagging treatment. Comparative analysis of 2D electrophoresis (2-DE) gels showed that relative protein levels differed significantly at 125 DAFB (days after full bloom), as well as at 133 DAFB in fruit that had been bagged until 125 DAFB, followed by exposure to sunlight. Most of the proteins with altered expression were identified by MALDI TOF/TOF. Twenty-one proteins with differential expression among the groups were identified at 125 DAFB, while thirty proteins with differential expression among the groups were identified at 133 DAFB. The analysis revealed that expression of proteins involved in photosynthesis, stress responses, and biochemical processes influencing metabolism were altered during bagging treatment, suggesting that regulation of the synthesis of carbohydrates, amino acids, and proteins influenced fruit size, solid/acid ratio, and peel color. This work provides the first characterization of proteomic changes in peach in response to fruit bagging treatment. Identifying and tracking protein changes may allow us to better understand the mechanisms underlying the effects of bagging treatment.