Rice (Oryza sativa L.) is an important food crop. The appearance of lesion mimics in rice leads to phytohormone disorders, which affects rice adaptation to environmental stresses and ultimately reduces the yield and quality. To explore whether the changes in the adaptability of rice lesion-mimic mutants to stressful environments are caused by the disorder of phytohormone metabolism in plants. In this study, we screened an ethyl methane sulfonate-treated population of the japonica cultivar 'Taipei 309' for a mutant with rust-like spots on leaves at the early tillering stage and brown-red spots at maturity and named it rsl1 (rust spotted leaf 1). Compared with the wild type, rsl1 showed decreases in plant height, panicle length, primary branch number, secondary branch number, filled grains per panicle, seed-setting rate, and 1 000-grain weight, and an increase in number of effective panicles. Genetic analysis indicated that rsl1 was controlled by a single recessive nuclear gene. RSL1 was localized between two molecular markers, B7-7 and B7-9, on rice chromosome 7 by map-based cloning. PCR sequencing of the annotated genes in this interval revealed a mutation of C1683A on the eighth exon of SPL5 (LOC_Os07g10390) in rsl1, which resulted in premature termination of protein translation. Exogenous phytohormone treatments showed that rsl1 was less sensitive to salicylic acid (SA), abscisic acid (ABA), and indo-3-acetic acid (IAA) and more sensitive to methyl jasmonate (MeJA) and gibberellin acid (GA) than the wild type. In addition, the survival rate of rsl1 was lower than that of the wild type under salt, alkali, drought, and high temperature stresses, and it was higher than that of the wild type under cold stress. Quantitative real-time polymerase chain reaction (qRT-PCR) results showed that RSL1 was involved in the regulation of ABA, SA, MeJA, IAA, and GA-related genes under abiotic stresses. The present study showed that the RSL1 mutation led to the appearance of lesion mimics and affected the growth, development, and stress resistance of rsl1 under abiotic stresses. The study of the functional mechanism of this gene can provide theoretical guidance for the research on rice stress resistance.
Oryza/microbiology* ; Stress, Physiological/genetics* ; Plant Diseases/genetics* ; Cloning, Molecular ; Chromosome Mapping ; Plant Growth Regulators/metabolism* ; Plant Proteins/genetics* ; Mutation ; Cyclopentanes ; Genes, Plant ; Plant Leaves/genetics* ; Oxylipins

Rice (Oryza sativa L.), as a thermophilic crop, is highly susceptible to cold stress during its growth process. Chilling injury at the plumule stage and seedling stage often affects the morphological development and leads to yield reduction of rice. The exploration and utilization of cold tolerance genes are among the most direct and effective approaches to address cold stress in rice. To identify quantitative trait loci (QTLs) associated with cold tolerance at plumule and seedling stages, in this study, we measured the seedling rates and survived seedling rates of the indica rice cultivar 'HZ', the japonica cultivar 'Nekken2', and their 120 recombinant inbred lines (RILs) under cold stress. A previously constructed high-density genetic linkage map was used for the mapping of the QTLs conferring cold tolerance at the plumule and seedling stages. A total of 4 QTLs for plumule-stage cold tolerance and 9 QTLs for seedling-stage cold tolerance were detected, with the maximum limit of detection reaching 5.20. Notably, a genetically overlapping QTL for both plumule and seedling stages was identified on chromosome 8, spanning a physical interval of 24 432 953-25 295 129 bp. Candidate genes within the detected QTL intervals were screened, and quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to analyze the gene expression during the plumule and seedling stages. The results revealed that LOC_Os03g06570, LOC_Os03g07100, LOC_Os06g08280, LOC_Os08g38440, LOC_Os08g39100, and LOC_Os08g39540 exhibited significantly differential expression between the parental lines. These genes were either significantly downregulated or upregulated under cold stress. Among them, the first three gene (LOC_Os03g06570, LOC_Os03g07100, and LOC_Os06g08280) were hypothesized to be key candidates regulating the cold tolerance of rice seedlings, while the latter three genes (LOC_Os08g38440, LOC_Os08g39100, and LOC_Os08g39540) were identified as comprehensive regulators of cold tolerance during both plumule and seedling stages. These findings lay a foundation for the fine mapping and cloning of cold tolerance genes at the plumule and seedling stages, providing valuable insights for breeding cold-tolerant rice varieties.
Quantitative Trait Loci/genetics* ; Oryza/growth & development* ; Seedlings/growth & development* ; Cold Temperature ; Chromosome Mapping ; Gene Expression Regulation, Plant

Objective: To examine the association of hypertension onset age with diabetes, so as to provide insights into reducing the the risk of cardiovascular events. Methods: Permanent residents aged 35 to 75 years were selected through the program of early screening and comprehensive intervention for the high-risk cardiovascular disease population in Changning District and Baoshan District, Shanghai Municipality from 2016 to 2020. Demographic information, disease history, hypertension onset age, blood pressure and fasting blood glucose were collected through questionnaire surveys, physical examination and laboratory tests. The residents were divided into four groups based on the onset age of hypertension: <45, 45-<55, 55-<65 and ≥65 years old, and the residents with normal blood pressure were selected as control. The association of hypertension onset age with prediabetes and diabetes were identified using a multivariable logistic regression model. Results: A total of 25 228 residents were recruited, including 8 753 males (34.70%) and 16 475 females (65.30%). The prevalence of hypertension was 43.80%. There were 1 779, 3 274, 3 781 and 2 217 cases with hypertension onset age of <45, 45-<55, 55-<65 and ≥65 years old, respectively, and 14 177 residents with normal blood pressure. The prevalence of prediabetes and diabetes were 24.01% and 11.29%, respectively. Multivariable logistic regression analysis showed that after adjusting for confounding factors such as gender, marital status and educational level, compared with the normal blood pressure group, the risk of prediabetes was higher in the hypertension onset age groups of <45 (OR=1.345, 95%CI: 1.164-1.553), 45-<55 (OR=1.365, 95%CI: 1.212-1.536) and 55-<65 years old (OR=1.376, 95%CI: 1.239-1.527), and the risk of diabetes was higher in the hypertension onset age groups of <45 (OR=2.302, 95%CI: 1.906-2.775), 45-<55 (OR=2.349, 95%CI: 2.016-2.734), 55-<65 (OR=1.909, 95%CI: 1.667-2.184) and ≥65 years old (OR=1.315, 95%CI: 1.131-1.526). Conclusion There are statistically significant associations between hypertension onset age with prediabetes and diabetes.

Objective:To explore potential predictors of refractory Mycoplasma pneumoniae pneumonia (RMPP) in early stage. Methods:The prospective multicenter study was conducted in Zhejiang, China from May 1 st, 2019 to January 31 st, 2020. A total of 1 428 patients with fever >48 hours to <120 hours were studied. Their clinical data and oral pharyngeal swab samples were collected; Mycoplasma pneumoniae DNA in pharyngeal swab specimens was detected. Patients with positive Mycoplasma pneumoniae DNA results underwent a series of tests, including chest X-ray, complete blood count, C-reactive protein, lactate dehydrogenase (LDH), and procalcitonin. According to the occurrence of RMPP, the patients were divided into two groups, RMPP group and general Mycoplasma pneumoniae pneumonia (GMPP) group. Measurement data between the 2 groups were compared using Mann-Whitney U test. Logistic regression analyses were used to examine the associations between clinical data and RMPP. Receiver operating characteristic (ROC) curves were used to analyse the power of the markers for predicting RMPP. Results:A total of 1 428 patients finished the study, with 801 boys and 627 girls, aged 4.3 (2.7, 6.3) years. Mycoplasma pneumoniae DNA was positive in 534 cases (37.4%), of whom 446 cases (83.5%) were diagnosed with Mycoplasma pneumoniae pneumonia, including 251 boys and 195 girls, aged 5.2 (3.3, 6.9) years. Macrolides-resistant variation was positive in 410 cases (91.9%). Fifty-five cases were with RMPP, 391 cases with GMPP. The peak body temperature before the first visit and LDH levels in RMPP patients were higher than that in GMPP patients (39.6 (39.1, 40.0) vs. 39.2 (38.9, 39.7) ℃, 333 (279, 392) vs. 311 (259, 359) U/L, both P<0.05). Logistic regression showed the prediction probability π=exp (-29.7+0.667×Peak body temperature (℃)+0.004×LDH (U/L))/(1+exp (-29.7+0.667×Peak body temperature (℃)+0.004 × LDH (U/L))), the cut-off value to predict RMPP was 0.12, with a consensus of probability forecast of 0.89, sensitivity of 0.89, and specificity of 0.67; and the area under ROC curve was 0.682 (95% CI 0.593-0.771, P<0.01). Conclusion:In MPP patients with fever over 48 to <120 hours, a prediction probability π of RMPP can be calculated based on the peak body temperature and LDH level before the first visit, which can facilitate early identification of RMPP.

Objective To compare the efficacy of the emergency ESWL within 24 hours after the onset of renal colic and elective ESWL at 5 - 7 days after the onset of renal colic in the treatment for ureteral stones.Method From January 2008 to October 2009, 365 patients in the Second Hospital of Nanchang, with ureteral stones were admitted to our department for renal colic. They underwent emergency ESWL or elective ESWL with HK. ESWL- 108 energy electromagnetic shock wave lithotripter. Success rate of fragmentation, stone-free rate after 2 weeks of operation, pain recurrence rate, and complications were evaluated. The data were analyzed using SPSS 15.0. Results The success rate of fragmentation and the stone-free rate after 2 weeks of emergency ESWL were 96.76% and96.21%, respectively, which were higher than those (88.33% and 87.22%, respectively) of elective ESWL ( P ＜ 0. 05). The postoperative pain recurrence rate of emergency ESWL ( 4.32 % ) was lower than that (9.44%) of elective ESWL ( P ＜0.05). There was no difference of total complications between emergency ESWL (3.24%) and elective ESWL (2.78%) group (P ＞0.05). Conclusions Emergency ESWL is superior to selective ESWL and is the safe and effective method for the management of ureteral stones.

Objective To observe imaging characteristics and changes of vivo two-dimension multi-voxel proton magnetic resonance spectroscopy (~1H-MRS) in the rabbit models of VX2 hepatic carcinoma after high intensity focused ultrasound (HIFU) treatment. Methods VX2 hepatic carcinoma models were established in 20 New Zealand rabbits. Routine MR and 2-dimentional ~1H-MRS scanning were performed before and after HIFU treatment. The central regions of interest (ROI) of the VX2 tumor, tumor border and paratumor normal liver tissues were selected. The Cho/Cr and Lip/Cr of the same ROI before and after HIFU treatment were compared. Results Total 28 satisfied spectrogram diagram of ~1H-MRS were brought into statistical analysis. Of all the spectra, 6 metabolite peaks were detected as lipids (Lip), glutamine and glutamate complex (Glx), choline (Cho), lactate (Lac) and creatine (Cr). Cho and Lac peak in tumor center and tumor border regions after HIFU treatment were higher than those before HIFU treatment. Lip peak was lower than before, and major metabolites of paratumor normal liver tissues did not changed significantly. Statistical differences of Cho/Cr and Lipid/Cr of tumor center and border region were found between before and after HIFU treatment (P＜0.05). Conclusion Two-dimension multi-voxel ~1H-MRS can reflect major changes in the level of metabolites of different ROI for hepatic VX2 carcinoma after HIFU treatment.

Objective To discuss indications,operation method and clinical outcome of posterior short-segment pedicle fixation at the injured level for treatment of thoracolumbar spine fractures.Methods A total of 38 patients with thoracolumbar spine fractures were equally randomized to Group A(treated with classic short-segment pedicle screw fixation)and Group B(treated with short-segment pedicle screw fixation at the injured level)based on fixation methods(19 patients per group).Preoperative and postoperative JOA score,segmental lordosis(Cobb' s angle),R value(anterior fractured vertebral body height/mean normal vertebral body height×100%),VSA score and internal fixation condition were assessed and compared clinically.Results All patients were followed up for 6-37 months(mean 20.5 months),which showed no statistical difference upon Frankel scores of two operation modes,while the segmental lordosis,VAS score and R value in Group B were than those in Group A.There occurred nuts loosening in one patient and screw bending in one in Group A.There was no implant breakage,loosening or emersion in Group B.Conclusion Posterior short-segmental fixation at the injured level is an adequate and effective procedure for compression fractures and mild to moderate burst fractures of the thoracolumbar spine.

Objective To study the changes of the myocardial cell apoptosis in myocardial infarction of rabbits. Methods The model of rabbit with myocardial infarction was established.HE staining,TUNEL staining, immunohistro-chemistry staining, ultrathin section for electron microscope and DNA electronic gel phorensis were performed in samples of ischemia or infarction in different times.The position of apoptotic myocytes in different phases of ischemia were observed by light microscope and electronic microscope. Results After 30 minutes to 4 weeks ischemia.there were a few TUNEL positive nucleus of myocytes in the margin area of myocardial infarction;HE staining-found typical expressions of apoptosis,such as chromosome conglomeration,chromosome gathered at the edge or chromosome aggregation,dark-stained nucleus,cell shrinkage,were obvious in 4-8 hours.A lot of positive nucleus of myocytes stained by TUNEL were found in the early stages of myocardial ischemia in myocardial infarction.gradually ascended and then became hardly visible from 8 hours to 3 days.Nucleus swelling,karyorrhexis and karyolysis were found in the area of myocardial infarction.then cells were broken.DNA agarose electrophoresis found DNA fragment of most myocytes in 30 minutes of ischemia,just a few cardiocytes decomposed to the big segments.At 4hours of ischemia the most cardiocytes decomposed to big segments,and there were a blurry"ladder"in DNA strand breaks from 8 hours to 1 day.It showed that apoptotic cardiocytes existed in the margin area of myocadial infarction. Conclusions There are cardiocytes apoptosis in the margin area of infarction from 30 minutes to 4 weeks after myocardial ischemia.Maybe it relates to the reperfusion caused by collateralization establishment or infiltration from circumference.