The WD40 Gene Family in Potato (Solanum Tuberosum L.): Genome-Wide Analysis and Identification of Anthocyanin and Drought-Related WD40s

WD40 proteins, also known as WD40 domain proteins, constitute a large gene family in eukaryotes and play multiple roles in cellular processes. However, systematic identification and analysis of WD40 proteins have not yet been reported in potato (Solanum tuberosum L.). In the present study, 178 potato WD40 (StWD40) genes were identified and their distribution on chromosomes, gene structure, and conserved motifs were assessed. According to their structural and phylogenetic protein features, these 178 StWD40 genes were classified into 14 clusters and 10 subfamilies. Collinearity analysis showed that segmental duplication events played a major role in the expansion of the StWD40 gene family. Synteny analysis indicated that 45 and 23 pairs of StWD40 genes were orthologous to Arabidopsis and wheat (Triticum aestivum), respectively, and that these gene pairs evolved under strong purifying selection. RNA-seq data from different tissues and abiotic stresses revealed tissue-specific expression and abiotic stress-responsive StWD40 genes in doubled monoploid potato (DM). Furthermore, we further analyzed the WD40 genes might be involved in anthocyanin biosynthesis and drought stress in tetraploid potato cultivars based on RNA-seq data. In addition, a protein interaction network of two homologs of Arabidopsis TTG1, which is involved in anthocyanin biosynthesis, was constructed to identify proteins that might be related to anthocyanin biosynthesis. The result showed that there were 112 pairs of proteins interacting with TTG1, with 27 being differentially expressed in pigmented tissues. This study indicates that WD40 proteins in potato might be related to anthocyanin biosynthesis and abiotic stress responses

First Discovering of Nanoscale Tectonics in Western of Qiongnan Paleo-Tethyan Suture Zone in North Margin of South China Sea and Its Geotectonic Significance

The western part of Qiongnan Paleo-Tethyan Suture Zone in the northern margin of the South China Sea is commonly known as the Jiusuo-Lingshui fault zone. At first, it was deduced as a near EW-direction tectonic boundary zone based on the data of geophysical field. Due to the lack of direct evidence of tectonic deformation, the existence and geological significance of the boundary zone have been controversial for a long time. Through field observation, indoor polarizing microscope and SEM (scanning electron microscope) tests on the basement rocks exposed along the near NS-direction profile of Xiaomei riverbed, Duzong reservoir, Junchang bridge, and Lipen reservoir, and Hainan Island, the authors discovered ductile shear structure in the boundary zone, crystalline quartz schist, granitic gneiss, meta-quartz sandstone, and porphyritic quartz rock. The sha = ear structures were formed by regional dynamic-thermal metamorphism and are the most common ductile deformation metamorphic rock in general orogenic belt. Furthermore, the microstructure and nano structure, which often developed in the ductile shear zone, were found through microscope and SEM. Moreover, the authors discussed nanoscale characteristics of Xiaomei ductile shear zone in Hainan Island. The study results showed that the three rocks of granite, quartz schist and granitic gneiss have many kinds of nano textures and structures. Based on field actual situation of the development degree of nano particles in this shear zone, it is known that these nano textures and structures are related to shearing action. Their formation mechanism may be as follows: one is thermal decomposition of layered silicate under shearing action, the other is brittle fracture after particle plastic deformation and grinding through shearing action. Based on analysis of the Xiaomei ductile shear zone, and after comparison of SEM test results carried out to the rock samples of ductile shear zone of Taroko deep fault zone in Taiwan, we found that the characteristics of the nano particles and ones in Xiaomei ductile shear zone are comparable. According to their relations with the regional deep fault, it could be speculated that Xiaomei ductile shear zone may be closely correlated with Jiusuo-Lingshui deep fault zone in the regional tectonic belonging. These study results can provide important evidence for determination of the tectonic property and spatial position of Jiusuo-Lingshui fault zone

Origin of Northeast Fujian Basalts and Limitations on the Heterogeneity of Mantle Sources for Cenozoic Alkaline Magmatism across SE China: Evidence from Zircon U-Pb Dating, Petrological, Whole-Rock Geochemical, and Isotopic Studies

Cenozoic alkali basalts in Southeast (SE) China generally are genetically related to intracontinental rifting. Hence, they can be used to probe the nature of their underlying mantle sources and aid studies of the tectonic background in this region. This paper focuses on the Shanhoujian alkali basalts located in Bailing County, northeastern Fujian, SE China. We herein report their petrology, whole-rock major, and trace element geochemistry, and Sr-Nd isotopic composition and provide a new zircon U-Pb age for the basalts (~40 Ma, Eocene). These data help to constrain the petrogenesis of alkali basalts, their mantle source, and tectonic settings. The basalts are characterized by high Mg# (58.21–63.52) with Na2O/K2O > 1. MgO content is weakly correlated with CaO and Cr content but shows no correlation with Ni and Fe2O3 (total). Such features suggest that fractionation of clinopyroxene rather than olivine was important. In terms of trace elements, the alkali basalts display: (1) enrichment in La, Ce, Rb, Ba, Nb, and Ta and depletion in K, Pb, Zr, Hf, and Ti and (2) notable fractionation of light rare earth elements from heavy rare earth elements. Determined (87Sr/86Sr)i is in the range of 0.7041–0.7040 and εNd (t) is between +3.2 and +3.3. The Shanhoujian alkali basalts show a notable affinity to oceanic island basalts (OIBs) with little assimilation of crustal materials. They were derived from a pyroxenite and carbonated peridotite mantle source metasomatized by sediments carried by the subduction plate at different depths. The primary magmas of these basalts were derived from partial melting of this metasomatized mantle source during upwelling of the asthenospheric mantle as an intracontinental rift formed through extension in this part of SE China