Unraveling the regulatory network of flower coloration in soybean:Insights into roles of GmMYBA3 and GmMYBR1

Anthocyanins play crucial roles in pollen protection and pollinator attraction in flowering plants.However,the mechanisms underlying flower color determination and whether floral anthocyanin regulators participate in other processes remain largely unresolved in soybeans(Glycine max).In this study,we investigated the genetic components and mechanisms governing anthocyanin biosynthesis in soybean flowers.Molecular and genetic studies have characterized two antagonistic regulators,the positive activator GmMYBA3 and the negative repressor GmMYBR1,that modulate the gene expression of anthocyanin biosynthesis in soybean flowers.Further findings revealed a regulatory interplay between GmMYBA3 and GmMYBR1 bridged by GmTT8a,highlighting the complexity of anthocyanin regulation in different soybean organs.Exploration of additional soybean cultivars demonstrated the universality of GmMYBA3 and GmMYBR1 in regulating floral anthocyanin biosynthesis-related genes,with GmF3’5’H identified as a crucial determinant of white flower color.This study provides a molecular mechanism underlying soybean flower color determination,paving the way for the molecular modification of soybean flowers to probably enhance their resistance to abiotic stresses and attractiveness to pollinators.

Cloning and Functional Characterization of Chalcone Isomerase Genes Involved in Anthocyanin Biosynthesis in Clivia miniata

Chalcone isomerase(CHI),catalyzing isomerization of chalcones,is a crucial enzyme in flavonoid biosynthesis.Three CHI genes were isolated from Clivia miniata and designated as CmCHI1,CmCHI2 and CmCHI3,respectively.Multiple sequence alignments and phylogenetic analysis showed that CmCHI1 and CmCHI2 were members of type I CHI proteins,whereas CmCHI3 belonged to type IV CHI proteins.Subcellular localization analysis found that all three CmCHIs had diffused distribution in the cytoplasm similar to green fluorescent protein(GFP).Anthocyanin biosynthesis and gene expression analysis demonstrated that CmCHIs were highly expressed in anthocyanin accumulated tissues.To further functionally characterize the role of CmCHIs,an in vitro enzymatic activity assay was carried out using the purified recombinant proteins.Results showed that CmCHI1 and CmCHI2 could completely convert the substrate naringenin chalcone(NC)into the product naringenin(NA),whereas CmCHI3 seemed nonfunctional as no increment of NA was detected.Further genetic transformation of Arabidopsis tt5-1 mutant validated that CmCHI1 and CmCHI2 rather than CmCHI3 could complement the chi deficient phenotypes.In summary,CmCHI1 and CmCHI2 are the real active CHI genes in Clivia miniata.The results not only broaden our knowledge on flavonoid biosynthesis in C.miniata but also lay a new foundation for further flavonoid modification in C.miniata.

Comparison of a Manual and an Automated Tracking Method for Tibetan Plateau Vortices

Tibetan Plateau vortices （TPVs） are mesoscale cyclones originating over the Tibetan Plateau （TP） dnring the extended summer season （April-September）. Most TPVs stay on the TP, but a small number can move off the TP to the east. TPVs are known to be one of the main precipitation-bearing systems on the TP and moving-off TPVs have been associated with heavy precipitation and flooding downstream of the TP （e.g., in Sichuan province or over the Yangtze River Valley）. Identifying and tracking TPVs is difficult because of their comparatively small horizontal extent （400-800 kin） and the limited availability of soundings over the TP, which in turn constitutes a challenge for short-term predictions of TPV-related impacts and for the climatological study of TPVs. In this study, （i） manual tracking （MT） results using radiosonde data from a network over and downstream of the TP are compared with （ii） results obtained by an automated tracking （AT） algorithm applied to ERA-Interim data. Ten MT-TPV cases are selected based on method （i） and matched to and compared with the corresponding AT-TPVs identified with method （ii）. Conversely, ten AT-TPVs are selected and compared with the corresponding MT-TPVs. In general, the comparison shows good results in cases where the underlying data are in good agreement, but considerable differences are also seen in some cases and explained in terms of differences in the tracking methods, data availability/coverage and disagreement between sounding and ERA-Interim data. Recommendations are given for future efforts in TPV detection and tracking, including in an operational weather forecasting context.

Improvement of cloud microphysical parameterization and its advantages in simulating precipitation along the Sichuan-Xizang Railway

The Sichuan-Xizang Railway is an important part of the railway network in China, and geological disasters, such as mountain floods and landslides, frequently occur in this region. Precipitation is an important cause of these disasters;therefore,accurate simulation of the precipitation in this region is highly important. In this study, the descriptions for uncertain processes in the cloud microphysics scheme are improved;these processes include cloud droplet activation, cloud-rain autoconversion, rain accretion by cloud droplets, and the entrainment-mixing process. In the default scheme, the cloud water content of different sizes corresponds to the same cloud droplet concentration, which is inconsistent with the actual content;this results in excessive cloud droplet size, unreasonable related conversion rates of microphysical process(such as cloud-rain autoconversion), and an overestimation of precipitation. Our new scheme overcomes the problem of excessive cloud droplet size. The processes of cloudrain autoconversion and rain accretion by cloud droplets are similar to the stochastic collection equation, and the mixing mechanism of cloud droplets is more consistent with that occurred during the actual physical process in the cloud. Based on the new and old schemes, multiple precipitation processes in the flood season of 2021 along the Sichuan-Xizang Railway are simulated, and the results are evaluated using ground observations and satellite data. Compared to the default scheme, the new scheme is more suitable for the simulation of cloud physics, reducing the simulation deviation of the liquid water path and droplet radius from 2 times to less than 1 time and significantly alleviating the overestimation of precipitation intensity and range of precipitation center. The average root-mean-square error is reduced by 22%. Our results can provide a scientific reference for improving precipitation forecasting and disaster prevention in this region.

The Tibetan Plateau Surface–Atmosphere Coupling System and Its Weather and Climate Effects: The Third Tibetan Plateau Atmospheric Science Experiment

The Tibetan Plateau(TP) is a key area affecting forecasts of weather and climate in China and occurrences of extreme weather and climate events over the world. The China Meteorological Administration, the National Natural Science Foundation of China, and the Chinese Academy of Sciences jointly initiated the Third Tibetan Plateau Atmospheric Science Experiment(TIPEX-Ⅲ) in 2013, with an 8–10-yr implementation plan. Since its preliminary field measurements conducted in 2013, routine automatic sounding systems have been deployed at Shiquanhe, Gaize, and Shenzha stations in western TP, where no routine sounding observations were available previously. The observational networks for soil temperature and soil moisture in the central and western TP have also been established. Meanwhile, the plateau-scale and regional-scale boundary layer observations, cloud–precipitation microphysical observations with multiple radars and aircraft campaigns, and tropospheric–stratospheric air composition observations at multiple sites, were performed. The results so far show that the turbulent heat exchange coefficient and sensible heat flux are remarkably lower than the earlier estimations at grassland, meadow, and bare soil surfaces of the central and western TP. Climatologically, cumulus clouds over the main body of the TP might develop locally instead of originating from the cumulus clouds that propagate northward from South Asia. The TIPEX-Ⅲ observations up to now also reveal diurnal variations, macro-and microphysical characteristics, and water-phase transition mechanisms, of cumulus clouds at Naqu station. Moreover, TIPEX-Ⅲ related studies have proposed a maintenance mechanism responsible for the Asian "atmospheric water tower" and demonstrated the effects of the TP heating anomalies on African, Asian, and North American climates. Additionally, numerical modeling studies show that the Γ distribution of raindrop size is more suitable for depicting the TP raindrop characteristics compared to the M–P distribution, the overestimation of sensible heat flux can be reduced via modifying the heat transfer parameterization over the TP, and considering climatic signals in some key areas of the TP can improve the skill for rainfall forecast in the central and eastern parts of China. Furthermore, the TIPEX-Ⅲ has been promoting the technology in processing surface observations, soundings, and radar observations, improving the quality of satellite retrieved soil moisture and atmospheric water vapor content products as well as high-resolution gauge–radar–satellite merged rainfall products, and facilitating the meteorological monitoring, forecasting, and data sharing operations.

Rapid screening of SARS-CoV-2 inhibitors via ratiometric fluorescence of RBD–ACE2 complexes in living cells by competitive binding

To the Editor:The current coronavirus disease-19(COVID-19)pandemic spurs the development of antiviral drugs for SARS-CoV-2,as the number of patients with viral infections continues to rise globally in the context of widespread vaccination.Targeting the interaction between the receptor binding domain(RBD)of SARS-CoV-2 spike protein and the host cell ACE2 is a promising therapeutic strategy to effectively inhibit viral entry.

A Practical and High-Affinity Fluorescent Probe for Butyrylcholinesterase:A Good Strategy for Binding Affinity Characterization

Butyrylcholinesterase(BChE)is regarded as a promising target for the treatment of Alzheimer's disease(AD),as its level significantly increases along with the progress of this disease.Therefore,the development of potent and high-affinity small-molecule BChE inhibi-tors may be a new strategy for the discovery of anti-AD drugs.However,the current Ellman's method is unable to evaluate the affinity of compounds with BChE,and has a few deficiencies in drug development.Herein,the first small-molecule fluorescence polarization(FP)probes for BChE were rationally designed based on a high affinity inhibitor.Studies indicated that probe F6 exhibited satisfactory fluorescence intensity and suitable fluorescent properties that were compatible with the filters in the FP system.Meanwhile,probe F6 exhibited potent binding affinity to BChE.It is feasible to be applied in detecting the affinity of non-fluorescent compounds to BChE,which lays a solid foundation for the development of small-molecule BChE inhibitors.At the same time,it also can be applied as a val-uable chemical tool for better understanding the molecular biological mechanism of BChE.