Polar Bismuth Selenite Iodate Oxide BiSeIO6 with Three Types of Lone Pair Cations in One Structure.

Novel bismuth selenite iodate oxide BiSeIO6 was synthesized in a mild hydrothermal condition. BiSeIO6 was crystallized in the polar space group Pna21 of an orthorhombic system. The crystal structure features a three-dimensional framework composed of three types of lone pair cations with distorted BiO7 polyhedra, SeO3 pyramids, and IO3 pyramids in one structure. Interestingly, BiSeIO6 exhibits a strong and phase-matchable second-harmonic generation (SHG) of ∼6 times that of KH2PO4 (KDP). Dipole moment analysis shows that all three local acentric groups of BiO7, SeO3, and IO3 cooperatively contribute to the large macroscopic polarization and thereby strong SHG efficiency of BiSeIO6. In addition, BiSeIO6 has a broad transparency range from 0.35 to 11 µm, indicating its promising nonlinear optical applications from visible to mid-infrared bands.

Comparative Transcriptome Analysis of High- and Low-Growth Genotypes of Eucalyptus urophylla in Response to Long-Term Nitrogen Deficiency.

Nutrients play important roles in the growth and development of most plant species. However, in perennial trees, the function of nutrients in different genotypes is poorly understood. Three different nutrient levels (low, sufficient, and high nutrient levels) were applied to two contrasting Eucalyptus urophylla cultivars (a high-growth cultivar ZQUA44 and a low-growth cultivar ZQUB15), and growth and expression levels were analyzed. Although the growth traits of both genotypes under nutrient starvation treatment were much lower than under abundant nutrients, tree height, crown width, and biomass of different ZQUA44 tissues were much higher than those of ZQUB15 at all three nutrient levels. Differentially expressed genes (DEGs) clustered into six subclusters based on their expression patterns, and functional annotation showed that the DEGs involved in glutathione metabolism and flavonoid biosynthesis may be responsible for nutrient starvation across different genotypes, while the DEGs involved in carotenoid biosynthesis and starch and sucrose metabolism may have a range of functions in different genotypes. The DEGs encoding the MYB-related family may be responsible for nutrient deficiency in all genotypes, while B3 may have different functions in different genotypes. Our results demonstrate that different genotypes may form different pathways to coordinate plant survival when they face abiotic stresses.

Integrated transcriptomic and gibberellin analyses reveal genes related to branch development in Eucalyptus urophylla.

Tree branches affect the planting density and basal scab, which act as important attributes in the yield and quality of trees. Eucalyptus urophylla is an important pioneer tree with characteristics of strong adaptability, fast growth, short rotation period, and low disease and pest pressures. In this study, we collected ZQUC14 and LDUD26 clones and compared their transcriptomes and metabolomes from mature xylem, phloem, and developing tissues to identify factors that may influence branch development. In total, 32,809 differentially expressed genes (DEGs) and 18 gibberellin (GA) hormones were detected in the five sampled tissues. Searches of the kyoto Encyclopedia of Genes and Genomes pathways identified mainly genes related to diterpenoid biosynthesis, plant MAPK signaling pathways, plant hormone signal transduction, glycerolipid metabolism, peroxisome, phenylpropanoid biosynthesis, ABC transporters, and brassinosteroid biosynthesis. Furthermore, gene expression trend analysis and weighted gene co-expression network analysis revealed 13 genes likely involved in diterpenoid biosynthesis, including five members of the 2OG-Fe(II) oxygenase superfamily, four cytochrome P450 genes, and four novel genes. In GA signal transduction pathways, 24 DEGs were found to positively regulate branch formation. These results provide a comprehensive analysis of branch development based on the transcriptome and metabolome, and help clarify the molecular mechanisms of E. urophylla.

Dominance of ammonia-oxidizing archaea community induced by land use change from Masson pine to eucalypt plantation in subtropical China.

A considerable proportion of Masson pine forests have been converted into eucalypt plantations in the last 30 years in Guangdong Province, subtropical China, for economic reasons, which may affect the ammonia-oxidizing archaea (AOA) community and the process of ammonia transformation. In order to determine the effects of forest conversion on AOA community, AOA communities in a Masson pine (Pinus massoniana) plantation and a eucalypt (Eucalyptus urophylla) plantation, which was converted from the Masson pine, were compared. Results showed that the land use change from the Masson pine to the eucalypt plantation decreased soil nutrient levels. A significant decrease of the potential nitrification rates (PNR) was also observed after the forest conversion (p < 5 %, n = 6). AOA were the only ammonia oxidizers in both plantations (no ammonia-oxidizing bacteria were detected). The detected AOA are affiliated with the genera Nitrosotalea and Nitrososphaera. A decrease of AOA abundance and an increase of the diversity were evident with the plantation conversion in the surface layer. AOA amoA gene diversity was negatively correlated with organic C and total N, respectively (p < 0.05, n = 12). AOA amoA gene abundance was negatively correlated with NH4 (+) and available P, respectively (p < 0.05, n = 12). However, AOA abundance was positively correlated with PNR, but not significantly (p < 0.05, n = 6), indicating AOA community change was only a partial reason for the decrease of PNR.