Search

Axillary bud is an important aspect of plant morphology, contributing to the final tobacco yield. However, the mechanisms of axillary bud development in tobacco remain largely unknown. To investigate this aspect of tobacco biology, the metabolome and proteome of the axillary buds before and after topping were compared. A total of 569 metabolites were differentially abundant before and 1, 3, and 5 days after topping. KEGG analyses further revealed that the axillary bud was characterized by a striking enrichment of metabolites involved in flavonoid metabolism, suggesting a strong flavonoid biosynthesis activity in the tobacco axillary bud after topping. Additionally, 9035 differentially expressed proteins (DEPs) were identified before and 1, 3, and 5 days after topping. Subsequent GO and KEGG analyses revealed that the DEPs in the axillary bud were enriched in oxidative stress, hormone signal transduction, MAPK signaling pathway, and starch and sucrose metabolism. The integrated proteome and metabolome analysis revealed that the indole-3-acetic acid (IAA) alteration in buds control dormancy release and sustained growth of axillary bud by regulating proteins involved in carbohydrate metabolism, amino acid metabolism, and lipid metabolism. Notably, the proteins related to reactive oxygen species (ROS) scavenging and flavonoid biosynthesis were strongly negatively correlated with IAA content. These findings shed light on a critical role of IAA alteration in regulating axillary bud outgrowth, and implied a potential crosstalk among IAA alteration, ROS homeostasis, and flavonoid biosynthesis in tobacco axillary bud under topping stress, which could improve our understanding of the IAA alteration in axillary bud as an important regulator of axillary bud development. [ABSTRACT FROM AUTHOR]

We propose an algorithm that combines a pre-processing step applied to the a priori state vector prior to retrievals, with the modified damped Newton method (MDNM), to improve convergence. The initial constraint vector pre-processing step updates the initial state vector prior to the retrievals if the algorithm detects that the initial state vector is far from the true state vector in extreme cases where there are CO emissions. The MDNM uses the Levenberg-Marquardt parameter γ, which ensures a positive Hessian matrix, and a scale factor α, which adjusts the step size to optimize the stability of the convergence. While the algorithm iteratively searches for an optimized solution using observed spectral radiances, MDNM adjusts parameters γ and α to achieve stable convergence. We present simulated retrieval samples to evaluate the performance of our algorithm and comparing it to existing methods. The standard deviation of our retrievals adding random noise was less than 3.8 ppmv. After pre-processing the initial estimate when it was far from the true value, the CO retrieval errors in the boundary layers were within 1.2 ppmv. We tested the MDNM algorithm's performance using GOSAT L1b data with cloud screening. Our preliminary validations comparing the results to TCCON FTS measurements showed that the average bias was less than 1.8 ppm and the correlation coefficient was approximately 0.88, which was larger than for the GOSAT L2 product. [ABSTRACT FROM AUTHOR]

We introduce the path length probability density function (PPDF) method, which is based on an equivalence theorem and parameterizes the aerosol scattering effect by adding four factors to the atmospheric transmittance model. Using simulated observations in the O-A band, we examined the utility of the PPDF-based method to account for the aerosol scattering effect. First, observations were simulated using a forward model under different aerosol conditions; PPDF factors were then retrieved using an optimal estimation method; PPDF factors were used to reconstruct the observations; and finally, simulated true observations and reconstructions were compared. Analysis of the difference between the true observations and reconstructions confirmed the utility of the PPDF-based method. Additionally, the O band was demonstrated to be an efficient observing band for assisting the remote sensing of atmospheric trace gases in the near-infrared band. [ABSTRACT FROM AUTHOR]

This paper presents a rapid regression algorithm for the retrieval of methane (CH) profile from Atmospheric Infrared Sounder (AIRS) based on empirical orthogonal functions (EOF) and its validation. This algorithm was trained using the simulated radiance from an assemble of atmospheric profiles and can be utilized to derive the CH profile rapidly with the input of the AIRS cloud-clear radiance. Validation using hundreds of aircraft profiles demonstrates that the root mean square error (RMSE) is about 1.5 % in the AIRS sensitive region of 359-596 hPa, which is smaller than AIRS-V5 product (except in high latitudes). Comparison with the ground-based solar Fourier transform spectrometry observations showed that the RMSE of the retrieved CH total column amount is less than 3 %. This EOF-based regression method can be easily applied to other thermal infrared sounders for deriving CH and some other gases, and the derived profiles can be used as the first guess for further physical retrieval. [ABSTRACT FROM AUTHOR]

We propose a new method to estimate surface-level particulate matter (PM) concentrations by using satellite-retrieved Aerosol Optical Thickness (AOT). This method considers the distribution and variation of Planetary Boundary Layer (PBL) height and relative humidity (RH) at the regional scale. The method estimates surface-level particulate matter concentrations using the data simulated by an atmospheric boundary layer model RAMS and satellite-retrieved AOT. By incorporation MODIS AOT, PBL height and RH simulated by RAMS, this method is applied to estimate the surface-level PM concentrations in North China region. The result is evaluated by using 16 ground-based observations deployed in the research region, and the result shows a good agreement between estimated PM concentrations and observations, and the coefficient of determination R is 0.61 between the estimated PM concentrations and the observations. In addition, surface-level PM concentrations are also estimated by using MODIS AOT, ground-based LIDAR observations and RH measurements. A comparison between the two estimated PM concentrations shows that the new method proposed in this paper is better than the traditional method. The coefficient of determination R is improved from 0.32 to 0.62. [ABSTRACT FROM AUTHOR]

This article is intentionally published to make erratum to the print version and the online version of Vol.60 (2017) NO. 2 (). Citations of the following publications should be added to the list of Reference for TCCON data use: Wennberg P O, Roehl C M, Wunch D, Toon G C, Blavier J F, Washenfelder R A, Keppel-Aleks G, Allen N T, Ayers J. 2014. TCCON data from Park Falls, Wisconsin, USA, Release GGG2014R0. TCCON data archive, hosted by the Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA, http://dx.doi.org/10.14291/tccon.ggg2014.parkfalls01.R0/1149161 Wennberg P O, Wunch D, Roehl C M, Blavier J F, Toon G C, Allen N, Dowell P, Teske K, Martin C, Marti J. 2014. TCCON data from Lamont, Oklahoma, USA, Release GGG2014R0. TCCON data archive, hosted by the Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA, http://dx.doi.org/10.14291/tccon.ggg2014.lamont01.R0/1149159 We should have asked for approvals from relevant PIs before publication on the use of TCCON data and cited references by DOIs. We do apologize for the fault and will strictly follow the Data Use Policy in the future. [ABSTRACT FROM AUTHOR]

Understanding how inbreeding affects fitness is biologically important for conservation and pest management. Despite being a worldwide pest of many economically important cruciferous crops, the influence of inbreeding on diamondback moth, Plutella xylostella (L.), populations is currently unknown. Using age-stage-specific life tables, we quantified the inbreeding effects on fitness-related traits and demographic parameters of P. xylostella. Egg hatching rate, survival and fecundity of the inbred line significantly declined compared to those of the outbred line over time. The inbred P. xylostella line showed significantly lower intrinsic rate of increase (r), net reproduction rate (R0), and finite increase rate (λ), and increasing generation time (T). Inbreeding effects vary with developmental stages and the fitness-related traits can be profoundly affected by the duration of inbreeding. Our work provides a foundation for further studies on molecular and genetic bases of the inbreeding depression for P. xylostella. [ABSTRACT FROM AUTHOR]