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Increasing atmospheric nitrogen (N) deposition is an important driver of biodiversity change. By conducting an eight-year N addition experiment (0, 20, 50 and 100 kg N ha -1  yr -1 ), we investigated the long-term effect of simulated N deposition on understory species composition and richness in a boreal forest, northeast China. We found that moss cover decreased significantly with increasing N addition. N addition had no significant effect on vascular plants species richness but changed the plant community composition. The relative coverage of evergreen shrubs decreased, while that of graminoids increased under high-level N addition (100 kg N ha -1  yr -1 ). Under the high-level N treatment, Deyeuxia angustifolia cover increased significantly after 4 years, while that of Vaccinium vitis-idaea decreased significantly after 3 years and almost disappeared after 5 years. The negative effect of N addition on mosses and evergreen shrubs accumulated over time, while the positive effect on graminoids increased during the first 4 years and did not change significantly thereafter. Our results suggest that the effect of N deposition varies across functional groups and shifts over time., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Sugars will eventually be exported transporters (SWEETs) are a group of recently identified sugar transporters in plants that play important roles in diverse physiological processes. However, currently, limited information about this gene family is available in pineapple (Ananas comosus). The availability of the recently released pineapple genome sequence provides the opportunity to identify SWEET genes in a Bromeliaceae family member at the genome level. In this study, 39 pineapple SWEET genes were identified in two pineapple cultivars (18 AnfSWEET and 21 AnmSWEET) and further phylogenetically classified into five clades. A phylogenetic analysis revealed distinct evolutionary paths for the SWEET genes of the two pineapple cultivars. The MD2 cultivar might have experienced a different expansion than the F153 cultivar because two additional duplications exist, which separately gave rise to clades III and IV. A gene exon/intron structure analysis showed that the pineapple SWEET genes contained highly conserved exon/intron numbers. An analysis of public RNA-seq data and expression profiling showed that SWEET genes may be involved in fruit development and ripening processes. AnmSWEET5 and AnmSWEET11 were highly expressed in the early stages of pineapple fruit development and then decreased. The study increases the understanding of the roles of SWEET genes in pineapple., (Copyright © 2018 Elsevier Inc. All rights reserved.)