Impacts of climate change on climatically suitable regions of two invasive Erigeron weeds in China.

Introduction: Erigeron philadelphicus and Erigeron annuus are two ecologically destructive invasive plants from the Asteraceae family. Predicting the potential distribution pattern of two invasive alien Erigeron weeds can provide a scientific basis for prevent the further spread of these two weeds in China under climate change. Methods: Based on historical occurrence datasets and environmental variables, we optimized a MaxEnt model to predict the potential suitable habitats of E. philadelphicus and E. annuus. We also analyzed the shifts of distribution centroids and patterns under climate change scenarios. Results: The key variables that affect the potential geographical distribution of E. annuus and E. philadelphicus, respectively, are temperature seasonality and precipitation of the driest month. Moreover, topsoil sodicity and topsoil salinity also influence the distribution of E. philadelphicus. Under climate change, the overall suitable habitats for both invasive alien Erigeron weeds are expected to expand. The potential geographical distribution of E. annuus exhibited the highest expansion under the SSP245 climate scenario (medium forcing scenarios), whereas E. philadelphicus had the highest expansion under the SSP126 climate scenario (lower forcing scenarios) globally. The future centroid of E. annuus is projected to shift to higher latitudes specifically from Hubei to Hebei, whereas E. philadelphicus remains concentrated primarily in Hubei Province. The overlapping suitable areas of the two invasive alien Erigeron plants mainly occur in Jiangsu, Zhejiang, Fujian, Jiangxi, Hunan, Guizhou, and Chongqing, within China. Discussion: Climate change will enable E. annuus to expand into northeastern region and invade Yunnan Province whereas E. philadelphicus was historically the only suitable species. E. annuus demonstrates a greater potential for invasion and expansion under climate change, as it exhibits higher environmental tolerance. The predictive results obtained in this study can serve as a valuable reference for early warning systems and management strategies aimed at controlling the spread of these two invasive plants.

Chromosome-level genome assembly and annotation of the prickly nightshade Solanum rostratum Dunal.

The prickly nightshade Solanum rostratum, an annual malignant weed, is native to North America and has globally invaded 34 countries, causing serious threats to ecosystems, agriculture, animal husbandry, and human health. In this study, we constructed a chromosome-level genome assembly and annotation of S. rostratum. The contig-level genome was initially assembled in 898.42 Mb with a contig N50 of 62.00 Mb from PacBio high-fidelity reads. With Hi-C sequencing data scaffolding, 96.80% of the initially assembled sequences were anchored and orientated onto 12 pseudo-chromosomes, generating a genome of 869.69 Mb with a contig N50 of 72.15 Mb. We identified 649.92 Mb (72.26%) of repetitive sequences and 3,588 non-coding RNAs in the genome. A total of 29,694 protein-coding genes were predicted, with 28,154 (94.81%) functionally annotated genes. We found 99.5% and 91.3% complete embryophyta_odb10 genes in the pseudo-chromosomes genome and predicted gene datasets by BUSCO assessment. The present genomic resource provides essential information for subsequent research on the mechanisms of environmental adaptation of S. rostratum and host shift in Colorado potato beetles.

Iris lactea var. chinensis plant drought tolerance depends on the response of proline metabolism, transcription factors, transporters and the ROS-scavenging system.

BACKGROUND: Iris lactea var. chinensis, a perennial herbaceous species, is widely distributed and has good drought tolerance traits. However, there is little information in public databases concerning this herb, so it is difficult to understand the mechanism underlying its drought tolerance. RESULTS: In this study, we used Illumina sequencing technology to conduct an RNA sequencing (RNA-seq) analysis of I. lactea var. chinensis plants under water-stressed conditions and rehydration to explore the potential mechanisms involved in plant drought tolerance. The resulting de novo assembled transcriptome revealed 126,979 unigenes, of which 44,247 were successfully annotated. Among these, 1187 differentially expressed genes (DEGs) were identified from a comparison of the water-stressed treatment and the control (CK) treatment (T/CK); there were 481 upregulated genes and 706 downregulated genes. Additionally, 275 DEGs were identified in the comparison of the rehydration treatment and the water-stressed treatment (R/T). Based on Quantitative Real-time Polymerase Chain Reaction (qRT-PCR) analysis, the expression levels of eight randomly selected unigenes were consistent with the transcriptomic data under water-stressed and rehydration treatment, as well as in the CK. According to Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, proline metabolism-related DEGs, including those involved in the 'proline catabolic process', the 'proline metabolic process', and 'arginine and proline metabolism', may play important roles in plant drought tolerance. Additionally, these DEGs encoded 43 transcription factors (TFs), 46 transporters, and 22 reactive oxygen species (ROS)-scavenging system-related proteins. Biochemical analysis and histochemical detection showed that proline and ROS were accumulated under water-stressed conditions, which is consistent with the result of the transcriptomic analysis. CONCLUSIONS: In summary, our transcriptomic data revealed that the drought tolerance of I. lactea var. chinensis depends on proline metabolism, the action of TFs and transporters, and a strong ROS-scavenging system. The related genes found in this study could help us understand the mechanisms underlying the drought tolerance of I. lactea var. chinensis.

Assessment of Solid Pulmonary Nodules or Masses Using Zero Echo Time MR Lung Imaging: A Prospective Head-to-Head Comparison With CT.

Objective: The aim of this study is to determine the potential of zero echo time (ZTE) MR lung imaging in the assessment of solid pulmonary nodules or masses and diagnostic consistency to CT in terms of morphologic characterization. Methods: Our Institutional Review Board approved this prospective study. Seventy-one patients with solid pulmonary nodules or masses larger than 1 cm in diameter confirmed by chest CT were enrolled and underwent further lung ZTE-MRI scans within 7 days. ZTE-MRI and CT images were compared in terms of image quality and imaging features. Unidimensional diameter and three-dimensional volume measurements on both modalities were manually measured and compared using the Wilcoxon signed-rank test, intraclass correlation coefficient (ICC), Pearson's correlation analysis, and Bland-Altman analysis. Multivariable logistic regression analysis was used to identify the factors associated with significant inter-modality variation of volume. Results: Fifty-four of 71 (76.1%) patients were diagnosed with lung cancer. Subjective image quality was superior in CT compared with ZTE-MRI (p < 0.001). Inter-modality agreement for the imaging features was moderate for emphysema (kappa = 0.50), substantial for fibrosis (kappa = 0.76), and almost perfect (kappa = 0.88-1.00) for the remaining features. The size measurements including diameter and volume between ZTE-MRI and CT showed no significant difference (p = 0.36 for diameter and 0.60 for volume) and revealed perfect inter-observer (ICC = 0.975-0.980) and inter-modality (ICC = 0.942-0.992) agreements. Multivariable analysis showed that non-smooth margin [odds ratio (OR) = 6.008, p = 0.015] was an independent predictor for the significant inter-modality variation of volume. Conclusion: ZTE lung imaging is feasible as a part of chest MRI in the assessment and surveillance for solid pulmonary nodules or masses larger than 1 cm, presenting perfect agreement with CT in terms of morphologic characterization.

Multiple Leiomyomas in a Patient with Benign Metastasizing Leiomyoma: A Case Report.

INTRODUCTION: Benign metastasizing leiomyoma (BML) is a rare disease and mostly affects females with a history of uterine leiomyoma, and particularly the presence of multiple leiomyomas in BML patients is extremely rare. CASE PRESENTATION: This paper reported the clinical and imaging data of a BML patient with multiple leiomyomas involving bilateral pulmonary, mediastinum, pericardium, spine, peritoneum, and left thigh. Multiple BML lesions exhibited consistent imaging examinations, significantly improving the delayed phase enhancement. After multi-stage targeted therapy for multiple systemic metastases and the development of drug resistance, the patient was treated with hysterectomy and bilateral adnexectomy along with letrozole-based endocrine therapy. BML lesions, both pulmonary and mediastinum, became significantly smaller than before. CONCLUSION: This paper aims to analyze the imaging and clinical features of multiple leiomyomas in this BML case, thus strengthening the understanding of the rare type of leiomyoma for effective preoperative diagnosis and clinical treatment. Furthermore, it is noteworthy that gynecologists should avoid the manifestation of BML when performing uterine fibroids surgery.

Sandbur Drought Tolerance Reflects Phenotypic Plasticity Based on the Accumulation of Sugars, Lipids, and Flavonoid Intermediates and the Scavenging of Reactive Oxygen Species in the Root.

The perennial grass Cenchrus spinifex (common sandbur) is an invasive species that grows in arid and semi-arid regions due to its remarkable phenotypic plasticity, which confers the ability to withstand drought and other forms of abiotic stress. Exploring the molecular mechanisms of drought tolerance in common sandbur could lead to the development of new strategies for the protection of natural and agricultural environments from this weed. To determine the molecular basis of drought tolerance in C. spinifex, we used isobaric tags for relative and absolute quantitation (iTRAQ) to identify proteins differing in abundance between roots growing in normal soil and roots subjected to moderate or severe drought stress. The analysis of these proteins revealed that drought tolerance in C. spinifex primarily reflects the modulation of core physiological activities such as protein synthesis, transport and energy utilization as well as the accumulation of flavonoid intermediates and the scavenging of reactive oxygen species. Accordingly, plants subjected to drought stress accumulated sucrose, fatty acids, and ascorbate, shifted their redox potential (as determined by the NADH/NAD ratio), accumulated flavonoid intermediates at the expense of anthocyanins and lignin, and produced less actin, indicating fundamental reorganization of the cytoskeleton. Our results show that C. spinifex responds to drought stress by coordinating multiple metabolic pathways along with other adaptations. It is likely that the underlying metabolic plasticity of this species plays a key role in its invasive success, particularly in semi-arid and arid environments.

[Changes of chilling and heat accumulation of apple and their effects on the first flowering date in the main planting areas of northern China]. / ä¸­å›½åŒ—æ–¹ä¸»äº§åœ°è‹¹æžœå†·çƒ­ç§¯ç´¯å˜åŒ–åŠå ¶å¯¹å§‹èŠ±æœŸçš„å½±å“.

Studies on variations in chilling and heat accumulation in apple trees and their effects on first flowering date under climate change are important for guiding apple planting and productions. In this study, we carried out experiments in representative stations of apple planting areas in the northern China, including Fushan of Shandong, Wanrong of Shanxi, Xifeng of Gansu and Akesu of Xinjiang. The first flowering data and hourly temperature data during 1996-2018 were used to calculate the daily chilling and heat accumulation units by applying the dynamic model and growing degree hour model. Partial least squares regression (PLS) correlated daily chilling and heat units with the first flowering dates was used to identify the chilling and heat accumulation periods for apple flowering. We evaluated the impacts of temperatures during these periods on apples' flowering. Our results showed that the chilling accumulation period of apple trees in the examined sites started at October 1, ended in late February or mid-March, with chilling accumulations of 74.1-89.3 CP (chill portion). The heat accumulation periods were from late January to the first flowering dates with the heat accumulation of 4010-5770 GDH (growing degree hour). The chilling accumulation at Xifeng and Akesu was correlated positively with mean temperature during the respective accumulation period, with 3.8 and 5.0 CP enhancement following 1 ℃ increase during the accumulation period. Heat accumulation at all stations correlated positively with mean temperature during the respective accumulation period, with 725-967 GDH enhancement following a 1 ℃ increase during the accumulation period. Compared to the effects of chilling accumulation on tree flowering, the first flowering data of apples in the main planting areas were mainly affected by mean temperature during the heat accumulation period. Climate warming is beneficial for apple blossom and production in the areas with low mean temperature during the chilling accumulation period.

[Phenological responses of apple tree to climate warming in the main apple production areas in northern China]. / 中国北方苹果主产地苹果物候期对气候变暖的响应.

To reveal the spatio-temporal variation characteristics of apple's phenology and their critical response time period and intensity to the temperature change in the main production areas of northern China, we chose Fushan, Wanrong and Akesu to respresent the Bohai Gulf, the Loess Plateau and Xinjiang apple production areas, respectively. Apple's phenology data of buds opening (BO), first leaf unfolding (LU), first flowering (FF), fruit maturing (FM), end of leaf coloring (LC) and the end of leaf fall (LF) at the three stations during 1996-2018 were used to analyze the changes of phenological occurrence dates and different growth stage lengths. Partial least squares (PLS) regression was applied to identify the impacts of climate warming on different phenology events at daily resolution. Results showed that regional mean occurrence dates of apple's BO, LU and FF advanced by a rate of 0.36, 0.33 and 0.23 day per year, respectively. However, apple's LF postponed by 0.68 d·a-1. The FM and LC showed different trends among all the sites. The length of fruit growing period (FG) and that of tree growing period (TG) extended at average rates of 1.20 and 0.82 day per year. Apple's spring phenophases dates at all stations correlated negatively with mean temperature during early January to pre-phenophases date, with a 1 ℃ increase inducing an advancement of 3.70, 3.47 and 3.48 days for apple's BO, LU and FF, respectively. In contrast, apple's autumn phenophases correlated positively with mean temperature 21-72 days before the phenophases date, and its correlation with mean temperature was lower than the correlation for spring phenophases. Generally, the effect of temperature on spring phenophase was stronger than that of autumn phenophase, and the extension of FG and TG was mainly caused by the advance of spring phenophase. The responses of apple's phenophases to climate warming differed across all the stations. Temperature had the greatest impact on the development of apple industry in Akesu, less in Wanrong, and with the least influence in Fushan. Our results could provide theoretical basis for response to climate change for apple industry in different areas of China.

Double-Stranded RNAs High-Efficiently Protect Transgenic Potato from Leptinotarsa decemlineata by Disrupting Juvenile Hormone Biosynthesis.

RNA interference (RNAi) has been developed for plant pest control. In this study, hairpin-type double-stranded RNA (dsRNA) targeting the juvenile hormone (JH) acid methyltransferase ( JHAMT) gene ( dsJHAMT) was introduced in potato plants via Agrobacterium-mediated transformation. The results indicated that the transcriptional RNA of dsJHAMT accumulated in the transgenic plants. The transcripts and proteins of the L. decemlineata JHAMT gene were significantly reduced in larvae feeding on dsJHAMT transgenic foliage. The dsJHAMT had a significant negative effect on the growth and development of L. decemlineata, especially resulting in less oviposition. Importantly, in the field trials, transgenic plants are high-efficiently protected from insect damage mainly because surviving insects laid fewer or no eggs. Even full protection from beetle damage can be acquired by continuously lowering insect population size at large scale in the field over the years. Therefore, the transgenic plants expressing dsJHAMT successfully provided an additional option for plant pest control.

Analysis of the Role of the Drought-Induced Gene DRI15 and Salinity-Induced Gene SI1 in Alternanthera philoxeroides Plasticity Using a Virus-Based Gene Silencing Tool.

Alternanthera philoxeroides is a notoriously invasive weed that can readily adapt to different environmental conditions. Control of this weed is difficult, and it spreads easily and causes damage to native habitats and agriculture. In this study, our goal was to investigate the molecular mechanisms that lead to the ability of A. philoxeroides to invade new habitats, to adapt to environmental stresses, and to cause damage. We developed a simple and highly effective potato virus X-based virus-induced gene silencing (VIGS) approach. The VIGS approach was first used to silence the phytoene desaturase gene, which resulted in the expected photo-bleaching phenotype. Next, the VIGS approach was used to silence two additional genes, drought-induced protein gene 15 (ApDRI15) and salinity-induced protein gene 1 (ApSI1). When ApDRI15 was knocked down, the plants were more sensitive to drought stress than the control plants, with smaller leaves, shorter internodes, and lower biomass. The ApDRI15-silenced plants had lower relative water content, lower free proline levels, and higher water loss rates than the control. Silencing of ApSI1 significantly decreased tolerance to salinity, and the ApSI1-silenced plants were withered and smaller. These results indicate that the pgR107 VIGS approach is a simple and highly effective tool for dissecting gene function in A. philoxeroides. Further experiments with the VIGS approach will enhance our understanding of the molecular mechanisms of the adaptability and plasticity of A. philoxeroides and improve our ability to combat the damage caused by this weed.

iTRAQ Protein Profile Differential Analysis of Dormant and Germinated Grassbur Twin Seeds Reveals that Ribosomal Synthesis and Carbohydrate Metabolism Promote Germination Possibly Through the PI3K Pathway.

Grassbur is a destructive and invasive weed in pastures, and its burs can cause gastric damage to animals. The strong adaptability and reproductive potential of grassbur are partly due to a unique germination mechanism whereby twin seeds develop in a single bur: one seed germinates, but the other remains dormant. To investigate the molecular mechanism of seed germination in twin seeds, we used isobaric tags for relative and absolute quantitation (iTRAQ) to perform a dynamic proteomic analysis of germination and dormancy. A total of 1,984 proteins were identified, 161 of which were considered to be differentially accumulated. The differentially accumulated proteins comprised 102 up-regulated and 59 down-regulated proteins. These proteins were grouped into seven functional categories, ribosomal proteins being the predominant group. The authenticity and accuracy of the results were confirmed by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time reverse transcription-PCR (qPCR). A dynamic proteomic analysis revealed that ribosome synthesis and carbohydrate metabolism affect seed germination possibly through the phosphoinositide 3-kinase (PI3K) pathway. As the PI3K pathway is generally activated by insulin, analyses of seeds treated with exogenous insulin by qPCR, ELISA and iTRAQ confirmed that the PI3K pathway can be activated, which suppresses dormancy and promotes germination in twin grassbur seeds. Together, these results show that the PI3K pathway may play roles in stimulating seed germination in grassbur by modulating ribosomal synthesis and carbohydrate metabolism.

Method for wavelength stabilization of pulsed difference frequency laser at 1572 nm for CO(2) detection lidar.

High-accuracy on-line wavelength stabilization is required for differential absorption lidar (DIAL), which is ideal for precisely measuring atmospheric CO(2) concentration. Using a difference-frequency laser, we developed a ground-based 1.57-µm pulsed DIAL for performing atmospheric CO(2) measurements. Owing to the system complexity, lacking phase, and intensity instability, the stabilization method was divided into two parts-wavelength calibration and locking-based on saturated absorption. After obtaining the on-line laser position, accuracy verification using statistical theory and locking stabilization using a one-dimensional template matching method, namely least-squares matching (LSM), were adopted to achieve wavelength locking. The resulting system is capable of generating a stable wavelength.