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• Aluminum (Al) affected the contents of N-containing compounds in Citrus. • Al affected the activities of N metabolism–related enzymes in Citrus. • Al differentially affected N metabolism between Citrus sinensis and C. grandis. • Increased leaf GOGAT might be an index of Al–tolerance in Citrus plants. Citrus are mostly planted in tropical/subtropical acidic soil areas, and are susceptible to aluminum (Al) toxicity, which affects tree growth and fruit quality. However, the effects of Al stress on the nitrogen (N) metabolism in different Al-tolerant Citrus varieties, and whether N metabolism is related to Al-tolerance in different Citrus varieties, were remained unveiled. In the current study, Al-tolerant "Xuegan" (Citrus sinensis) and Al-sensitive "Sour pummelo" (C. grandis), were irrigated with different nutrient solutions with or without Al. Al decreased the dry weights (DW) of leaves, stems and roots, as well as the N content, the N accumulation, total soluble proteins (TSPs) and total free amino acids (TFAAs) of different tissues of C. grandis , but it increased the ratio of root DW to shoot DW. In contrast, Al did not change the parameters mentioned above, except for decreasing the content and accumulation of N in C. sinensis roots. Al did not change the content of NO 3 – in different position leaves and roots, but decreased the content of NH 4 + in C. grandis. Al decreased the content of NO 3 – in different position leaves and roots, but except for the lower leaf, Al did not change that of NH 4 + in C. sinensis. Although Al affected the activities and gene expression levels of N metabolism–related enzymes in the leaves and roots of these two Citrus species, the effects of Al on these parameters were more pronounced in C. grandis than in C. sinensis. Results from correlation analysis (CoA) and principal components analysis (PCA) indicated that the increased root DW/shoot DW and NO 3 --N content in the roots and middle/upper leaves might be the related indicators of Al toxicity, whereas the enhanced activity of leaf GOGAT might be related to the Al–tolerance in Citrus plants. In conclusion, this study preliminarily revealed that the impact of Al on N metabolism and the response of N metabolism–related indicators to Al stress in Citrus , providing scientific reference for high-yield and high-quality cultivation of Citrus grown in acidic soil areas. [Display omitted] [ABSTRACT FROM AUTHOR]

High temperature stress is one of the primary abiotic stresses that restrict fruit tree production. Grapevine (Vitis vinifera) with high economic value throughout the world is a cultivated fruit crop, and its growth and development is often influenced by high temperature stress. Studying the heat stress-response mechanism of grapevine has great significance for understanding the acclimation to heat stress. In this study, we identified a series of heat stress responsive miRNAs and analyzed their function during the heat tolerance response. CK (control group, 25 °C) and heat treatment stress (TS, 45 °C) small RNA (sRNA) libraries were constructed and sequenced by high-throughput sequencing in 'Thompson seedless' grapevine. 873 known-miRNAs and 86 novel-miRNAs were identified, of which 88 known and three novel miRNAs were expressed differentially under heat stress. 322 genes were predicted to be targeted by the miRNAs. Eight selected miRNAs and its targets were confirmed by real time quantitative PCR (RT - qPCR), indicating that these "miRNA - target" were responsive to heat stress. In addition, most of the predicted target genes were negatively regulated by corresponding miRNAs. Gene function and pathway analyses indicated that these genes probably play crucial roles in heat stress tolerance. Vvi-miR167b transiently overexpression in grapevine leaves decreased target gene vvARF6 , vvARF6-like and vvARF8 expression. The function of vvi-miR167 was verified by ectopic transformation in Arabidopsis thaliana , and the heat tolerance in transgenic lines was enhanced significantly, suggesting that the vvi-miR167 plays a positive regulatory role in grape thermostability. Comparison of miRNA expression patterns between heat treatment stress and CK can help elucidate the heat stress response and resistance mechanisms in grapes. In conclusion, these results gave us useful information to better understand the heat stress-response during domestication as well as for breeding new cultivars with heat stress resistance in fruit trees. • Our study provides an overview of small RNA transcriptomic changes that occur during heat stress response in 'Thompson seedless' grapevine. • The function of Vvvi-miR167 by ectopic transformation was confirmed in Arabidopsis thaliana , and the enhanced heat tolerance in transgenic lines was observed, suggesting that differentially expressed Vvvi-miR167 plays a positive regulatory role in grapevine thermostability. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, the cDNA of Père David’s deer APRIL (miAPRIL) was successfully amplified, and nucleotide sequence analysis showed that the open reading frame (ORF) of miAPRIL consists of 753 bases encoding 250-amino acids. Phylogenetic analysis exhibited high homology with the even-toed ungulates (artiodactyla). The extracellular soluble domain of the miAPRIL (misAPRIL) fragment was cloned into the expression vector pET43.1a and transformed into Escherichia coli BL21 (DE3) for recombinant expression. SDS–PAGE and western blotting analysis indicated that misAPRIL protein expression was successfully achieved. Indirect immunofluorescence staining demonstrated that misAPRIL has the ability to bind to the surface of Père David’s deer lymphocytes. Flow cytometry analysis revealed that misAPRIL was able to enhance lymphocytes survival in a dose-dependent manner. [Copyright &y& Elsevier]