Uptake of glucose from the rhizosphere, mediated by apple MdHT1.2, regulates carbohydrate allocation.

Plant roots can absorb sugars from the rhizosphere, which reduces the consumption of carbon derived from photosynthesis. However, the underlying mechanisms that roots use to control sugar absorption from soil are poorly understood. Here, we identified an apple (Malus × domestica Borkh.) hexose transporter, MdHT1.2, that functions on the root epidermis to absorb glucose (Glc) from the rhizosphere. Based on RNA-seq data, MdHT1.2 showed the highest expression level among 29 MdHT genes in apple roots. Biochemical analyses demonstrated that MdHT1.2 was mainly expressed in the epidermal cells of fine roots, and its protein was located on the plasma membrane. The roots of transgenic apple and Solanum lycopersicum lines overexpressing MdHT1.2 had an increased capability to absorb Glc when fed with [13C]-labeled Glc or 2-NBDG, whereas silencing MdHT1.2 in apple showed the opposite results. Further studies established that MdHT1.2-mediated Glc absorption from the rhizosphere changed the carbon assimilate allocation between apple shoot and root, which regulated plant growth. Additionally, a grafting experiment in tomato confirmed that increasing the Glc uptake capacity in the root overexpressing MdHT1.2 could facilitate carbohydrate partitioning to the fruit. Collectively, our study demonstrated that MdHT1.2 functions on the root epidermis to absorb rhizospheric Glc, which regulates the carbohydrate allocation for plant growth and fruit sugar accumulation.

P-type Polymers in Semitransparent Organic Photovoltaics.

P-type polymers are polymeric semiconducting materials that conduct holes and have extensive applications in optoelectronics such as organic photovoltaics. Taking the advantage of intrinsic discontinuous light absorption of organic semiconductors, semitransparent organic photovoltaics (STOPVs) present compelling opportunities in various potential applications such as building-integrated photovoltaics, agrivoltaics, automobiles, and wearable electronics. The characteristics of p-type polymers, including optical, electronic, and morphological properties, determine the performance of STOPVs, and the requirements for p-type polymers differ between opaque organic photovoltaics and STOPVs. Hence, in this Minireview, recent advances of p-type polymers used in STOPVs are systematically summarized, with emphasis on the effects of chemical structures, conformation structures, and aggregation structures of p-type polymers on the performance of STOPVs. Furthermore, new design concepts and guidelines are also proposed for p-type polymers to facilitate the future development of high-performance STOPVs.

An investigation on possible effect of leaching fractions physiological responses of hot pepper plants to irrigation water salinity.

BACKGROUND: The modification effect of leaching fraction (LF) on the physiological responses of plants to irrigation water salinity (ECiw) remains unknown. Here, leaf gas exchange, photosynthetic light-response and CO2-response curves, and total carbon (C) and nitrogen (N) accumulation in hot pepper leaves were investigated under three ECiw levels (0.9, 4.7 and 7.0 dS m- 1) and two LFs treatments (0.17 and 0.29). RESULTS: Leaf stomatal conductance was more sensitive to ECiw than the net photosynthesis rate, leading to higher intrinsic water use efficiency (WUE) in higher ECiw, whereas the LF did not affect the intrinsic WUE. Carbon isotope discrimination was inhibited by ECiw, but was not affected by LF. ECiw reduced the carboxylation efficiency, photosynthetic capacity, photorespiration rate, apparent quantum yield of CO2 and irradiance-saturated rate of gross photosynthesis; however, LF did not influence any of these responses. Total C and N accumulation in plants leaves was markedly increased with either decreasing ECiw or increasing LF. CONCLUSIONS: The present study shows that higher ECiw depressed leaf gas exchange, photosynthesis capacity and total C and N accumulation in leaves, but enhanced intrinsic WUE. Somewhat surprisingly, higher LF did not affect the intrinsic WUE but enhanced the total C and N accumulation in leaves.

[Clinical analysis on malignant clonal hematopoiesis in severe aplastic anemia patients with immunosuppressive therapy].

OBJECTIVE: To investigate the clinical characteristics and risk factors of monosomy 7 malignant clonal evolution in patients with severe aplastic anemia (SAA) treated with combined immunosuppressive therapy (IST). METHODS: The clinical data of SAA patients treated with IST who had monosomy 7 malignant clonal evolution from October 2004 to January 2012 were analyzed respectively. RESULTS: Six patients (4.2%) had monosomy 7 clonal evolutions. The median time to monosomy 7 was 36 (12-75) months after IST. All 6 patients were diagnosed myelodysplastic syndromes (MDS). Among them, 3 patients transformed to acute myeloid leukemia following MDS. The time was 24, 45 and 51 months after IST. The median following time was 42 (17-84) months. Four patients died during the following time. The median time from MDS to death was 9 (5-17) months. Among them, three patients died with infection, one died with cerebral hemorrhage. Six patients had the clinical characteristics that they had no response to IST after 6 months, high monocyte percentage in one month after IST combined with recombinant human granulocyte colony stimulating factor (rHu-GCSF) and agranulocytosis in 3 months after IST. CONCLUSION: Poor myeloid response to IST suggests malignant clonal hematopoiesis and poor prognosis in SAA patients.

Optimizing drip fertigation at different periods to improve yield, volatile compounds and cup quality of Arabica coffee.

How to improve and regulate coffee bean yield and quality through split fertilization in the whole life cycle of coffee is still unclear and deserves further study. A field experiment of 5-year-old Arabica coffee trees was conducted for 2 consecutive years from 2020 to 2022. The fertilizer (750 kg ha-1 year-1, N-P2O5-K2O:20%-20%-20%) was split in three times at early flowering (FL), the berry expansion (BE), and the berry ripening (BR). Taking equal fertilization throughout the growth cycle (FL250BE250BR250) as the control check, variable fertilizations including FL150BE250BR350, FL150BE350BR250, FL250BE150BR350, FL250BE350BR150, FL350BE150BR250, and FL350BE250BR150. Leaf net photosynthetic rate (A net), stomatal conductance (g s), transpiration rate (T r), leaf water use efficiency (LWUE), carboxylation efficiency (CE), partial factor productivity of fertilizer (PFP), bean yield, crop water use efficiency (WUE), bean nutrients, volatile compounds and cup quality, and the correlation of nutrients with volatile compounds and cup quality was evaluated. FL350BE250BR150 had the maximum A net and g s, followed by FL250BE350BR150. The highest dry bean yield and WUE were obtained from FL250BE350BR150, which increased by 8.86% and 8.47% compared with FL250BE250BR250 in two-year average. The ash, total sugar, fat, protein, caffeine and chlorogenic acid in FL250BE350BR150 were 6.47%, 9.48%, 3.60%, 14.02%, 4.85% and 15.42% higher than FL250BE250BR250. Cluster analysis indicated FL150BE350BR250, FL250BE350BR150, FL350BE150BR250 and FL350BE250BR150 under medium roasted degree increased pyrazines, esters, ketones and furans, FL150BE350BR250 and FL250BE350BR150 under dark roasted degree increased ketones and furans. The aroma, flavor, acidity and overall score of medium roasted coffee were higher than dark roasted coffee, while the body score of dark roasted coffee was higher than medium roasted coffee. The nutrient contents were correlated with the volatile compounds and cup quality. TOPSIS indicated that FL250BE350BR150 was the optimal fertilization mode in the xerothermic regions. The obtained optimum fertilization mode can provide a scientific basis for coffee fertilization optimization and management.

Parameter regionalization based on machine learning optimizes the estimation of reference evapotranspiration in data deficient area.

Reference evapotranspiration (ET0), as one important variable in climatology, hydrology, and agricultural science, plays an important role in the terrestrial hydrological cycle and agricultural irrigation. However, the ET0 estimation process is inaccurate due to the lack of weather stations and historical data. In this study, a new method of ET0 estimation was proposed to improve the ET0 estimation performance in regions with limited data. Four empirical models with different data requirements, Albrecht, Hargreaves-Samani, Priestley-Taylor, and Penman, were applied and optimized the parameters by the Shuffled Complex Evolution-University of Arizona algorithm with the ET0 calculated by the Penman-Monteith model as the reference value at 600 meteorological stations in China. Two machine learning models, Random Forest (RF) and Multiple Linear Regression (MLR) were used to establish the regionalization of the parameter of the empirical model. The result showed that parameter optimization could significantly improve ET0 estimation in different climate regions of China. The Penman model has the strongest physical foundation and the highest estimation accuracy, followed by the Hargeaves-Samani and Priestley-Taylor model. The mass-transfer-based model, Albrecht, could only estimate regional ET0 efficiently after parameter optimization. Based on the more advanced RF machine learning regionalization method that considers complex linear relationships of variables, ET0 estimation in regions lacking data could be improved efficiently. Machine learning could be used to describe the ET0 model parameters in different regions because of the similarity. The combination of machine learning and empirical model could provide a new method for ET0 estimation in data deficient regions.

Effects of clouds and aerosols on ecosystem exchange, water and light use efficiency in a humid region orchard.

Investigating the patterns of water and carbon dynamics in agro-ecosystems in response to clouds and aerosols can shed new insights in understanding the biophysical impacts of climate change on crop productivity and water consumption. In this study, the effects of clouds and aerosols as well as other environmental factors on ecosystem water and carbon fluxes were examined based on three-year eddy covariance measurements under different sky conditions (quantified as the clearness index, Kt, i.e., the ratio of global solar radiation to extraterrestrial solar radiation) in a kiwifruit plantation in the humid Sichuan Basin of China. Results showed that evapotranspiration (ET) and canopy transpiration (Tc, measured by sap flow sensors) increased, while ecosystem light use efficiency (eLUE) and ecosystem water use efficiency (eWUE) decreased with increasing Kt. GPP presented a parabolic relationship with increasing Kt. The path analysis revealed that surface conductance (Gs) and canopy conductance (Gc) were the most dominant variables directly regulated carbon (GPP) and water (ET and Tc) fluxes. The effect path of Kt on ET and Tc was converted from through diffuse photosynthetic active radiation (PARdif) to direct PAR (PARdir) when the sky became clearer. The effect path of Kt on GPP was primarily through PARdif under different sky conditions. The declined eWUE with increasing Kt was caused by the different responses of GPP and ET to PARdir under clear skies. The declined eLUE resulted from the sharp decrease in GPP/PARdir, which surpassed the slight increase of GPP/PARdif with increasing PAR. The Priestley-Taylor Jet Propulsion Laboratory ET model (PT-JPL) incorporating Kt with an exponential function produced more reliable Tc estimates but minor improvement in ET. Further, the LUE-GPP model incorporating Kt with a linear function obtained much better GPP estimates. Our study shed light on how sky conditions modulate water and carbon dynamics between the biosphere and atmosphere, highlighting the necessity of the inclusion of sky conditions for better modeling regional water and carbon budgets.

Evaluating how lodging affects maize yield estimation based on UAV observations.

Timely and accurate pre-harvest estimates of maize yield are vital for agricultural management. Although many remote sensing approaches have been developed to estimate maize yields, few have been tested under lodging conditions. Thus, the feasibility of existing approaches under lodging conditions and the influence of lodging on maize yield estimates both remain unclear. To address this situation, this study develops a lodging index to quantify the degree of lodging. The index is based on RGB and multispectral images obtained from a low-altitude unmanned aerial vehicle and proves to be an important predictor variable in a random forest regression (RFR) model for accurately estimating maize yield after lodging. The results show that (1) the lodging index accurately describes the degree of lodging of each maize plot, (2) the yield-estimation model that incorporates the lodging index provides slightly more accurate yield estimates than without the lodging index at three important growth stages of maize (tasseling, milking, denting), and (3) the RFR model with lodging index applied at the denting (R5) stage yields the best performance of the three growth stages, with R2 = 0.859, a root mean square error (RMSE) of 1086.412 kg/ha, and a relative RMSE of 13.1%. This study thus provides valuable insight into the precise estimation of crop yield and demonstra\tes that incorporating a lodging stress-related variable into the model leads to accurate and robust estimates of crop grain yield.

Increased Circulating CD4+CXCR5+ Cells and IgG4 Levels in Patients with Myelodysplastic Syndrome with Autoimmune Diseases.

OBJECTIVES: Immune abnormalities play an important role in the pathogenesis and progression of myelodysplastic syndrome (MDS). Some patients with MDS have autoimmune diseases (AI). Follicular helper T (Tfh) cells help B cells produce antibodies. The role of Tfh in MDS with AI has not been studied. METHODS: We enrolled 21 patients with MDS with AI and 21 patients with MDS without AI. The proportion of peripheral blood CD4+CXCR5+ cells and the PD1 expression on CD4+CXCR5+ cells were detected by flow cytometry. Serum levels of immunoglobulin G (IgG) and IgG4 were measured. The survival and progression of MDS to acute myeloid leukemia (AML) in MDS patients with or without AI were compared. RESULTS: MDS with AI accounted for 19.6% of all MDS cases in our study. The overall response rate was 81% (17/21) in MDS patients with AI for the first-line treatment. The proportion of circulating CD4+CXCR5+ cells was increased, but the expression of PD1 was decreased in MDS patients with AI. Serum IgG4 levels were also increased in MDS patients with AI. The proportion of peripheral blood CD4+CXCR5+ cells and the level of serum IgG4 decreased after therapy, but the expression of PD1 increased. There were no differences in overall survival and progress to acute myeloid leukemia between MDS with AI and without AI groups. CONCLUSION: CD4+CXCR5+ cells and IgG4 levels increased in patients with MDS and AI.

Excessive nitrogen application under moderate soil water deficit decreases photosynthesis, respiration, carbon gain and water use efficiency of maize.

The impact of water stress and nitrogen (N) nutrition on leaf respiration (R), carbon balance and water use efficiency (WUE) remains largely elusive. Therefore, the objective of the present study was to investigate the effect of soil water and N stresses on growth, physiological responses, leaf structure, carbon gain and WUE of maize. The plants were subjected to different soil water and N regimes to maturity. The results showed that the photosynthesis (An) and stomatal conductance (Gs) decreased significantly under the water stressed treatments across the N treatments mainly ascribed to the decreased plant water status. The moderate water stress reduced the photosynthetic capacity and activity and also caused damage to the structure of leaves, resulting in the significant reduction of An, and thus decreased WUEi. The dark respiration (Rd) was significantly decreased due to the damage of mitochondria, however, the Rd/An increased significantly and the carbon gain was seriously compromised, eventually inhibiting biomass growth under the moderately water stressed treatment. Increasing N dose further aggravated the severity of water deficit, decreased An, Gs and WUEi, damaged the structure and reduced the number of mitochondria of leaves, while increased Rd/An considerably under moderate water stress. Consequently, the biomass accumulation, carbon gain and plant level WUEp in the moderately water stressed treatment decreased markedly under the high N supply. Therefore, excessive N application should be avoided when plants suffer soil water stress in maize production.

Impaired Mitophagy of Nucleated Erythroid Cells Leads to Anemia in Patients with Myelodysplastic Syndromes.

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal stem cell disorders characterized by cytopenia and dysplasia. Anemia is the most common symptom in patients with MDS. Mitophagy and mitochondrial dysfunction might be involved in the development of MDS. In this study, we investigated the change of mitophagy in erythroid precursors in MDS patients. We found that NIX-mediated mitophagy was impaired in bone marrow nucleated red blood cells (NRBC) of MDS patients, associated with an increased amount of damaged mitochondria and increased ROS level which might lead to apoptosis and ineffective erythropoiesis. The results showed that the amount of mitochondria in GlycoA+ NRBC positively correlated with the count of ring sideroblasts in bone marrow samples. Meanwhile, the level of autophagy-associated marker LC3B in GlycoA+ NRBC had a positive correlation with hemoglobin (Hb) levels, and the amount of mitochondria in GlycoA+ NRBC had a negative correlation with Hb levels in high-risk MDS patients. Our results indicated that mitophagy might involve the pathogenesis of anemia associated with MDS. Autophagy might be a novel target in treatments of MDS patients.

Altered follicular helper T cell impaired antibody production in a murine model of myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are a group of clonal hematopoietic diseases which have a high risk of progressing to acute myeloid leukemia. MDS patients have immunologic deficiency, including T and B cells dysfunction. Follicular T helper cells (Tfh, CD4+CXCR5+) are an important subset of helper T cells which help to the formation of germinal centers and B cells differentiation. In this study, we investigated the proportion and function of Tfh using NUP98-HOXD13 transgenic (NHD13) mice model with MDS phenotype. The proportion of Tfh from bone marrow and spleen of NHD13 mice decreased compared with wild type (WT) mice tested by flow cytometry. In NHD13 mice spleens, there were decreased CXCR5+ cells and increased PD-1+ cells using immunohistochemistry. The active markers (ICOS, CD40L and OX40) expressed on Tfh of NHD13 mice were decreased. In contrast, PD-1 expression on Tfh of NHD13 mice was higher than that of WT mice. After coculture with Tfh from NHD13 mice, IgG and IgM production of B cells were decreased. In conclusion, the proportion and function of Tfh in the MDS mice model were altered. The dysfunction and reduction of Tfh may inhibit B cells differentiation and antibody production. Abnormal Tfh might contribute to the immune tolerance promoting the progression of MDS.

[Follicular Helper T Cells and Expression of PD-1 in Mice with Myelodysplastic Syndrome].

OBJECTIVE: To investigate the complete blood count, morphological changes, follicular T helper (Tfh) cells and expression of PD-1 in bone marrow and spleen of mice with myelodysplastic syndrome(MDS) and to explore their significance in pathogenesis of MDS. METHODS: The 10 male NUP98-HOXD13 transgenic mice and 10 male homologous wild-type C57BL/6J mice were used for experments. The complete blood count, morphological change of NUP98-HOXD13 transgenic mice and wild-type C57BL/6J were detected by routine methods. The level of Tfh cells and expression of PD-1 in bone marrow and spleen were measured by flow cytometry. The PD-1 mRNA of bone marrow mononuclear cells and spleen cells were analyzed by real-time PCR method. RESULTS: The counts of RBC, neutrophile and platelet in above- mentioned transgenic mice were less than that in wild type C57BL/6J mice. As compared with wild type C57BL/6J mice, the morphology of RBC and platelet in transgenic mice was some abnormal, including bi-nucleated erythrocytes, ringed mucleated neutrophil and erythroblastic islands. The count of Tfh cells in transgenic mice was less than that in wild type mice, but the expression of PD-1 was higher. The expression of BMMNC PD-1 mRNA was obviously higher than that in wild type mice. CONCLUSION: The pancytopenia and dysplasia, decrease of Tfh cells and increase of PD-1 expression have been observed in NUP98-HOXD13 transgenic mice, which may be one of important reasons for promoting malignant clone and leading to impair anti immune respones.

[Autophagy level of bone marrow mononuclear cells in patients with myelodysplastic syndromes].

OBJECTIVE: To investigate the change of autophagy level of bone marrow mononuclear cells（BMMNCs）in patients with myelodysplastic syndromes（MDS）. METHODS: Thirty- eight patients with MDS and 26 megaloblastic anemia patients were enrolled in this study. The autophagic vacuoles were observed by transmission electron microscopy （TEM） and the quantity of autophagic vacuoles was detected by monodansylcadaverine （MDC） staining. The LC3 protein positive cells were counted by immunofluorescence assays. The expression of Beclin 1, LC3A, mTOR mRNA were measured by real time PCR. The expression of Beclin 1 proteins were detected by Western blotting. RESULTS: The autophgic vacuoles of double membrane that surrounds lysosomes appeared in MDS patients. The percentage of MDC positive cells was significantly higher in MDS patients［（9.75±2.63）%ï¼½than that of controls［（2.90± 0.89）%, P＜0.05）. The percentage of LC3 protein cells was also increased in MDS patients（6.13±1.03）% vs（1.5±0.58）%, P＜0.05）. The expression of Beclin 1 and LC3A mRNA in low-risk and intermediate-1 MDS were higher compared with controls （3.61 ± 3.02 vs 1.55 ± 1.03 and 6.56 ± 3.97 vs 1.21 ± 0.95 respectively, both P＜0.05）. The expression of mTOR mRNA was down- regulated in low- risk and intermediate-1 MDS compared with controls（0.39±0.37 vs 1.50±1.03, P＜0.05）. There were no significant difference in expression of Beclin 1, LC3 and mTOR mRNA among intermediate-2 and high-risk MDS and controls. Beclin 1 protein expression was higher in low- risk and intermediate- 1 MDS patients（1.257 ± 0.197）than that of controls（0.528±0.086）and inermediate-2 and high-risk MDS patients（0.622±0.118）. CONCLUSION: The autophagy levels were increased in low- risk and intermediate- 1 MDS, while not enhanced in intermediate-2 MDS. Autophagy might be considered as a cell protective mechanism in MDS. The relatively defective autophagy in intermediate- 2 and high- risk MDS might contribute to disease's progression.