Genome-wide identification and expression analysis of the KCS gene family in soybean (Glycine max) reveal their potential roles in response to abiotic stress

Very long chain fatty acids (VLCFAs) are fatty acids with chain lengths of 20 or more carbon atoms, which are the building blocks of various lipids that regulate developmental processes and plant stress responses. 3-ketoacyl-CoA synthase encoded by the KCS gene is the key rate-limiting enzyme in VLCFA biosynthesis, but the KCS gene family in soybean (Glycine max) has not been adequately studied thus far. In this study, 31 KCS genes (namely GmKCS1 - GmKCS31) were identified in the soybean genome, which are unevenly distributed on 14 chromosomes. These GmKCS genes could be phylogenetically classified into seven groups. A total of 27 paralogous GmKCS gene pairs were identified with their Ka/Ks ratios indicating that they had undergone purifying selection during soybean genome expansion. Cis-acting element analysis revealed that GmKCS promoters contained multiple hormone- and stress-responsive elements, indicating that GmKCS gene expression levels may be regulated by various developmental and environmental stimuli. Expression profiles derived from RNA-seq data and qRT-PCR experiments indicated that GmKCS genes were diversely expressed in different organs/tissues, and many GmKCS genes were found to be differentially expressed in the leaves under cold, heat, salt, and drought stresses, suggesting their critical role in soybean resistance to abiotic stress. These results provide fundamental information about the soybean KCS genes and will aid in their further functional elucidation and exploitation

Vanadium-Substituted Dawson-Type Polyoxometalate–TiO2 Nanowire Composite Film as Advanced Cathode Material for Bifunctional Electrochromic Energy-Storage Devices

Polyoxometalates (POMs) demonstrate potential for application in the development of integrated smart energy devices based on bifunctional electrochromic (EC) optical modulation and electrochemical energy storage. Herein, a nanocomposite thin film composed of a vanadium-substituted Dawson-type POM, i.e., K7[P2W17VO62]·18H2O, and TiO2 nanowires were constructed via the combination of hydrothermal and layer-by-layer self-assembly methods. Through scanning electron microscopy and energy-dispersive spectroscopy characterisations, it was found that the TiO2 nanowire substrate acts as a skeleton to adsorb POM nanoparticles, thereby avoiding the aggregation or stacking of POM particles. The unique three-dimensional core−shell structures of these nanocomposites with high specific surface areas increases the number of active sites during the reaction process and shortens the ion diffusion pathway, thereby improving the electrochemical activities and electrical conductivities. Compared with pure POM thin films, the composite films showed improved EC properties with a significant optical contrast (38.32% at 580 nm), a short response time (1.65 and 1.64 s for colouring and bleaching, respectively), an excellent colouration efficiency (116.5 cm2 C−1), and satisfactory energy-storage properties (volumetric capacitance = 297.1 F cm−3 at 0.2 mA cm−2). Finally, a solid-state electrochromic energy-storage (EES) device was fabricated using the composite film as the cathode. After charging, the constructed device was able to light up a single light-emitting diode for 20 s. These results highlight the promising features of POM-based EES devices and demonstrate their potential for use in a wide range of applications, such as smart windows, military camouflage, sensors, and intelligent systems

Prolonged impacts of extreme precipitation events weakened annual ecosystem CO2 sink strength in a coastal wetland

It remains unclear whether coastal wetlands could maintain the expected carbon sink role since extreme climate events are predicted to occur more frequently under future climate change. Among these extreme events, extreme precipitation may cause significant changes in ecosystem carbon stocks in coastal wetlands. However, the impacts of extreme precipitation events on carbon cycle processes and the mechanisms responsible for associated changes in the ecosystem carbon balance remain uncertain. To address this issue, we investigated the effects of extreme precipitation events on the ecosystem carbon dioxide (CO2) budget based on a 10-year eddy covariance dataset (2010-2019) at a coastal wetland in the Yellow River Delta. Results showed that this coastal wetland was a stable sink for CO2, with the annual net ecosystem CO2 exchange (NEE) ranged between -94.49 and -240.70 g C m(-2) yr(-1). Meanwhile, the interannual variability of the ecosystem CO2 sink strength in the dry stage was linked to the vegetation condition, and it was strongly affected by extreme precipitation events in the wet stage. During the wet stage, there was a clear trend of less negative daily NEE (i.e., lower CO2 uptake rate) in the years with extreme precipitation events occurring (extreme years) than in normal years, leading to the wet stage cumulative CO2 uptake being 56% lower in extreme years. Eventually, the coastal wetland became a weaker annual CO2 sink due to the prolonged impact of the extreme precipitation event. This research provides a timely study of the effect of extreme precipitation on ecosystem CO2 budget in coastal wetlands and should be of value to researchers attempting to assess the future impact of climate change on coastal ecosystems