Effect of Simulated Organic–Inorganic N Deposition on Leaf Stoichiometry, Chlorophyll Content, and Chlorophyll Fluorescence in <i>Torreya grandis</i>

Atmospheric nitrogen (N) deposition is coupled with organic nitrogen (ON) and inorganic nitrogen (IN); however, little is known about plant growth and the balance of elements in Torreya grandis growing under different ON/IN ratios. Here, we investigated the effects of ON/IN ratios (1/9, 3/7, 7/3, and 9/1) on leaf stoichiometry (LF), chlorophyll content, and chlorophyll fluorescence of T. grandis. We used ammonium nitrate as the IN source and an equal proportion of urea and glycine as the ON source. The different ON/IN ratios altered the stoichiometry and photochemical efficiency in T. grandis. Although the leaf P content increased significantly after treatment, leaf N and N:P maintained a certain homeostasis. Torreya grandis plants performed best at an ON/IN ratio of 3/7, with the highest values of chlorophyll-a, total chlorophyll, maximum photochemical efficiency, and photosynthetic performance index. Thus, both ON and IN types should be considered when assessing the responses of plant growth to increasing N deposition in the future. Our results also indicated that the leaf P concentration was positively correlated with Chl, Fv/Fm, and PIabs. This result further indicates the importance of the P element for plant growth against the background of nitrogen deposition. Overall, these results indicate that T. grandis might cope with changes in the environment by maintaining the homeostasis of element stoichiometry and the plasticity of PSII activity

The complete mitochondrial genome of the Riparia riparia (Passeriformes: Hirundinidae)

The Sand Martin (Riparia riparia) belongs to Hirundinidae. In this study, the complete mitochondrial genome of R. riparia was sequenced and characterized. The genome was 17,963 bases in length (GenBank accession no. OK537984) including 13 protein-coding genes, two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and two control regions. The overall base composition of R. riparia mitogenome was 30.5% for A, 31.8% for C, 14.5% for G, and 23.2% for T. Phylogenetic analysis revealed that R. riparia was genetically closest to the species of genus Tachycineta. R. riparia mitogenome could contribute to our understanding of the phylogeny and evolution of this species

HBXIP blocks myosin-IIA assembly by phosphorylating and interacting with NMHC-IIA in breast cancer metastasis

Tumor metastasis depends on the dynamic balance of the actomyosin cytoskeleton. As a key component of actomyosin filaments, non-muscle myosin-IIA disassembly contributes to tumor cell spreading and migration. However, its regulatory mechanism in tumor migration and invasion is poorly understood. Here, we found that oncoprotein hepatitis B X-interacting protein (HBXIP) blocked the myosin-IIA assemble state promoting breast cancer cell migration. Mechanistically, mass spectrometry analysis, co-immunoprecipitation assay and GST-pull down assay proved that HBXIP directly interacted with the assembly-competent domain (ACD) of non-muscle heavy chain myosin-IIA (NMHC-IIA). The interaction was enhanced by NMHC-IIA S1916 phosphorylation via HBXIP-recruited protein kinase PKCβII. Moreover, HBXIP induced the transcription of PRKCB, encoding PKCβII, by coactivating Sp1, and triggered PKCβII kinase activity. Interestingly, RNA sequencing and mouse metastasis model indicated that the anti-hyperlipidemic drug bezafibrate (BZF) suppressed breast cancer metastasis via inhibiting PKCβII-mediated NMHC-IIA phosphorylation in vitro and in vivo. We reveal a novel mechanism by which HBXIP promotes myosin-IIA disassembly via interacting and phosphorylating NMHC-IIA, and BZF can serve as an effective anti-metastatic drug in breast cancer