Elymus natans is a dominant native species widely planted to restore the heavily degraded alpine meadows in Qinghai-Tibetan plateau. The objective of this study was to determine how E. natans establishment affected the quality and fertility of a heavily degraded soil. Soil samples (at depths of 0-10, 10-20 and 20-30 cm) were collected from the 3-and 7-year-old E. natans re-vegetated grasslands, and in the heavily degraded alpine meadow (control). The establishment of E. natans promoted plant cover and aboveground biomass. Compared to the non-reseeded meadow, the concentration of total organic C increased by 13% in the soil under 3-year-old reseeded E. natans grassland at 0-10 cm, and by 7-33% in the soil under 7-year-old reseeded E. natans grassland at 0-10, 10-20 and 20-30 cm depths. Rapid increases in total and available N were also observed in two E. natans re-vegetated grasslands, especially in the 0-10 cm soil layer. Across three sampling depths, total P concentration was increased by 17-35% and 18-54% in 3-and 7-year-old reseeded soil respectively, compared to the soil of control. After 3 years of E. natans growth, microbial biomass C increased by 13-58% at 0-10 and 10-20 cm layers; while it increased by 43-87% in 7-year-old reseeded treatment at 0-10, 10-20 and 20-30 cm depths relative to control. A similar increasing trend was observed for microbial biomass N and P generally. Significant increase in neutral phosphatase, urease, catalase and dehydrogenase was also found in 3-and 7-year-old re-vegetated grasslands compared with heavily degraded meadow. Our results suggest a significant positive impact of E. natans establishment on soil quality. Thus, E. natans establishment could be an effective and applicable measure in restoring heavily degraded alpine meadow in the region of Qinghai-Tibetan Plateau.

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Background and aims In semiarid ecosystems, changes in plant communities are promoted under shrub canopies during restoration, but the link between shrub community restoration dynamics and changes in soil microbe communities is still unclear.Methods We characterized the community structure and plant interactions of soil microbes by combining different methodological approaches (including high-throughput sequencing of the 16S rRNA gene and ITS gene, analysis of phospholipid fatty acids (PLFAs) and chloroform fumigation) and the key driving factors along a successional gradient of Sophora moorcroftiana shrub community in the middle reaches of the Yarlung Zangbo River.Results Soil microbial biomass carbon (MBC) and nitrogen (MBN), total PLFAs, and alpha diversity increased signi cantly as the successional stage advanced, and MBC and MBN were positively correlated with the carbon and nitrogen contents in the soil. Mantel test showed that successional stage-induced changes in soil microbial beta diversity were mainly associated with shrub coverage and soil physicochemical properties. The relative abundances of bacterial PLFAs, particularly those of gram-negative bacteria, such as Bacteroidetes, Alphaproteobacteria and Betaproteobacteria, signi cantly decreased with succession; the opposite was true for Acidobacteria, Planctomycetes, Gemmatimonadetes Deltaproteobacteria and Gammaproteobacteria. However, the proportion of fungi did not signi cantly differ among the four successional stages; the dominant phyla were Ascomycota and Basidiomycota. ConclusionWe suggest that shrubs directly shape soil microbial communities or indirectly affect such communities by altering soil substrates. Our ndings advance the current understanding of sand-stabilizing plant-soil interactions during natural restoration and the reversal of deserti cation in stressful desert ecosystems.

. 2015. Proteome response of wild wheat relative Kengyilia thoroldiana to drought stress. Can. J. Plant Sci. 95: 237Á249. Wild relatives of crops provide plant breeders with a broad pool of potentially useful genetic sources. The genus Kengyilia, being a member of the tribe Triticeae, is related to wheat, barley, and other cereals and forage grasses. We studied proteomic changes in K. thoroldiana seedlings in response to drought stress after withholding water for 0, 3, 6, 9 and 15 d. To determine the proteomic changes that occurred in leaves of K. thoroldiana under drought stress, two-dimensional gel electrophoresis (2-DE) and mass spectrometry were performed to identify protein expression changes. Seventy proteins showing reproducible and significant expression changes were identified. Among them, 28 proteins were up-regulated, whereas seven proteins were down-regulated. Based on databaseannotated functions, these 70 proteins were categorized as energy metabolism, stress response, antioxidative enzyme, transcript and signal transduction, predicted proteins, and chloroplast-related proteins. Cluster analysis further showed that the up-regulated proteins were mainly stress response proteins and antioxidative enzymes. These results suggest that K. thoroldiana may resist drought stress by increasing the expression of stress response proteins and by producing antioxidative enzymes to remove reactive oxygen species. We conclude that the K. thoroldiana drought stress response mechanism could represent a useful genetic resource for related studies in wheat.Key words: Proteome, wild wheat relative, Kengyilia thoroldiana, drought stress Yang, S., Li, X., Ma, Y., Sun, X., Yang, Y. et Yang, Y. 2015. Re´action du prote´ome du parent sauvage du ble´Kengyilia thoroldiana au stress duˆa`la se´cheresse. Can. J. Plant Sci. 95: 237Á249. Les parents sauvages des plantes cultive´es offrent aux phytoge´ne´ticiens un vaste re´servoir de ge`nes potentiellement utiles. Le genre Kengyilia, qui fait partie de la tribu des Tritice´es, est apparente´au ble´, a`l'orge ainsi qu'a`d'autres ce´re´ales et gramine´es fourrage`res. Les auteurs ont e´tudie´les changements prote´omiques subis par les plantules de K. thoroldiana a`la suite de la se´cheresse apre`s les avoir prive´s d'eau pendant 0, 3, 6, 9 ou 15 jours. Pour ve´rifier les changements prote´omiques survenus dans les feuilles de K. thoroldiana a`la suite du stress duˆa`la se´cheresse, ils ont identifie´les modifications subies par les prote´ines au moyen de l'e´lectrophore`se bidirectionnelle sur ge´lose et de la spectrome´trie de masse. Soixante-dix prote´ines exprimant des changements importants et reproductibles ont ainsi e´te´identifie´es. Parmi elles, 28 e´taient re´gule´es en amont et sept en aval. D'apre`s leurs fonctions, annote´es dans les bases de donne´es, ces 70 prote´ines ont e´te´cate´gorise´es parmi celles qui touchent au me´tabolisme de l'e´nergie, a`la re´action au stress, aux enzymes antioxydants et a`la transduction des transcriptions et des signaux ainsi que