A pervasive phosphorylation cascade modulation of plant transcription factors in response to abiotic stress.

MAIN CONCLUSION: Transcriptional regulation of stress-responsive genes is a crucial step in establishing the mechanisms behind plant abiotic stress tolerance. A sensitive method of regulating transcription factors activity, stability, protein interaction, and subcellular localization is through phosphorylation. This review highlights a widespread regulation mechanism that involves phosphorylation of plant TFs in response to abiotic stress. Abiotic stress is one of the main components limiting crop yield and sustainability on a global scale. It greatly reduces the land area that is planted and lowers crop production globally. In all living organisms, transcription factors (TFs) play a crucial role in regulating gene expression. They participate in cell signaling, cell cycle, development, and plant stress response. Plant resilience to diverse abiotic stressors is largely influenced by TFs. Transcription factors modulate gene expression by binding to their target gene's cis-elements, which are impacted by genomic characteristics, DNA structure, and TF interconnections. In this review, we focus on the six major TFs implicated in abiotic stress tolerance, namely, DREB, bZIP, WRKY, ABF, MYB, and NAC, and the cruciality of phosphorylation of these transcription factors in abiotic stress signaling, as protein phosphorylation has emerged as one of the key post-translational modifications, playing a critical role in cell signaling, DNA amplification, gene expression and differentiation, and modification of other biological configurations. These TFs have been discovered after extensive study as stress-responsive transcription factors which may be major targets for crop development and important contributors to stress tolerance and crop production.

A Novel mechanisms of the signaling cascade associated with the SAPK10-bZIP20-NHX1 synergistic interaction to enhance tolerance of plant to abiotic stress in rice (Oryza sativa L.).

The bzip transcription factors can modulate the transcriptional expressions of target genes by binding specifically to cis-regulatory elements in the promoter region of stress-related genes, hence regulating plant stress resistance. Here, we investigated a stress-responsive transcription factor Osbzip20 under abiotic stresses. The OsbZIP20-GFP fusion protein predominantly aggregated in the nucleus, in accordance with our subcellular localization. OsbZIP20 transcript was observed in all vegetative tissues with highest levels being detected in the seed. Transcription of Osbzip20 was induced by salinity, exsiccation, and abscisic acid. Overexpression of OsbZIP20 in transgenic rice considerably improved tolerance to salt and drought stresses, as well as increased sensitivity to ABA. Furthermore, abiotic stress responsive genes transcript were found to be remarkably elevated in transgenic rice overexpressing OsbZIP20 than in wild-type plants. SAPK10 was discovered to directly interact with and phosphorylate OsbZIP20. Yeast one-hybrid and luciferase assay revealed that OsbZIP20 acted as a transcriptional stimulator. Interestingly, gel shift assay showed that phosphorylated bZIP20 augmented its DNA-binding affinity to the ABRE element of the NHX1 promoter and induced its transcription. In sum, our findings establish a novel signaling pathway associated with the SAPK10-bZIP20-NHX1 synergistic interaction, as well as a new strategy for enhancing rice drought and salt tolerance.

A novel SAPK10-WRKY87-ABF1 biological pathway synergistically enhance abiotic stress tolerance in transgenic rice (Oryza sativa).

WRKY transcription factors play a role in a variety of biological processes. Several studies have revealed that abiotic stress regulates the transcription of a large number of WRKY genes. In this study, we report the identification of a novel 'SAPK10-WRKY87-ABF1' biological pathway, through which they harmoniously enhance drought and salinity tolerance. We generated OsWRKY87-overexpressing transgenic rice and found that the transgenic seedlings exhibited significantly improved drought and salinity stress tolerance. Subcellular localization in rice seedling protoplast revealed that OsWRKY87-GFP fusion protein mostly accumulated in the nucleus, suggesting that OsWRKY87 is a nucleus-localized protein, in line with the predicted function of OsWRKY87 as a transcription factor. In vivo interaction between SAPK10 and WRKY87 was demonstrated by Yeast two-hybrid-assay. In addition, phosphorylation assays showed that SAPK10 exhibits autophosphorylation activity on the 177th serine, enabling it to phosphorylate WRKY87. OsWRKY87 functioned as a transcriptional initiator, according to a yeast one-hybrid assay and a luciferase assay. Remarkably, gel mobility shift assay showed that phosphorylated WRKY87 enhances its DNA-binding ability to the W-box cis-element of ABF1 promoter and activated its transcription, thereby elevating the ABF1 transcription and improving drought and salinity tolerance. Overall, our findings revealed a novel 'SAPK10- WRKY87-ABF1' module, which synergistically interacts to improve drought and salt tolerance in rice (Oryza sativa).

Short-term effect of minimally invasive treatment for gastric stromal tumors / 中国内镜杂志

Objective To compare the short-term effect of laparoscopic surgery with open surgery for gastrointesti﹣nal stromal tumor. Methods 26 patients, whose tumor were localized and the pathologic diagnosis were gastrointesti﹣nal stromal tumor in stomach after surgery, were randomly divided into laparoscopic surgery group (n=12) and open surgery group (n= 14). The age and gender level, disease duration, clinical symptom, tumor location, and the lesion diameter were similar between the two groups (P> 0.05). Surgery achievement, intraoperative blood loss, operative time, postoperative hospital stay, postoperative flatus time, postoperative liquid time, and incidence rates of postoper﹣ative complications were compared between the two groups. Results All the patients get successful R0 resection. The volume of intraoperative blood loss, operative time, postoperative hospital stay, postoperative flatus time, and postop﹣erative liquid time in laparoscopic surgery group were lower than open surgery group (P 0.05). Conclusion Compared with open surgery, the short-term effect of laparoscopic surgery were better for patients whose gastrointestinal stromal tumor in stomach were localized, and it is worth of promoting clinical application.

Determination of Psoralen and Isopsoralen in Bushen Jiannao Soft Capsule by HPLC / 中国中医药信息杂志

Objective To establish a method for determination of psoralen and isopsoralen in Bushen Jiannao Soft Capsule. Methods The HPLC separation was performed on Diamonsil-C18 (250 mm?4.6 mm, 5 ?m) column with a mixture methanol-water (48∶52) as the mobile phase, at a flow rate of 1.0 mL/min. Detection wavelength was at 246 nm, and column temperature at 40 ℃. Results The linear response of psoralen and isopsoralen ranged from 0.010 08～0.252 ?g (r=0.999 8) and 0.009 14～0.228 5 ?g (r =0.999 9). The average recovery was 98.91% (RSD=1.74%) and 99.93% (RSD=1.27%) respectively. Conclusion The method is simple, accurate, and suitable for the determination of the psoralen and isopsoralen in the preparations.

Studies on HepG2 Growth Under Simulated Microgravity:to Establish a Method for Three-dimensional Cultivation In vitro as an Research Model / 生物化学与生物物理进展

Human hepatocarcinoma cells, HepG2 were cultured onto biodegradable polyglycolic acid (PGA) polymer scaffolds, which were cultured in a rotating cell culture system (RCCS) to form a three-dimensional (3D) multicellular culture in vitro. The RCCS can simulate microgravity effects with low shear stress and well exchanging for gas. Then the growth characteristics and some mechanism of the cells in RCCS were detected by scanning electron microscopy (SEM), transmission electron microscopy (TEM), RT-PCR and flow cytometry (FCM). The results indicate that the cells grew well with polyhedron morphology and lots of microvilli, mitochondria and tight junctions in this system, which means that this system is useful for cells to form 3D structure to mimic cell status in vivo. The expression of some cell adhesion molecules (CAMs) were changed markedly, which are closely associated with cancer invasion and metastasis. The characters of increased expression of integrin ?1(CD29), CD44, intercellular adhesion molecule-1(CD54) and depressed expression of E-cadherin presumably show that the HepG2 cells cultured in RCCS could recur some characters of primary liver cancer in vivo, the capacity of invasion and metastasis. It is necessary for acquiring perfect and external results to select an appropriate research model for studying in vitro. This 3D culture in vitro under simulated microgravity can provide a useful and reasonable model for oncology, anticancer drugs research and other research.