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Vegetation disturbance during infrastructure construction can cause serious ecological problems, especially in fragile environments. The Northern Shaanxi Loess Plateau is an oil industry base in China with a fragile ecosystem. Vegetation restoration on the disturbance area can effectively control soil erosion and ensure the safety of oil pipelines. In the linear disturbance area, surrounding vegetation traits and topography may play an important role in vegetation restoration by influencing propagules and recruitment microsites. This study aimed to reveal the influence of vegetation type and topography on vegetation restoration in the disturbance area along the oil pipeline. The results showed that 89 species were recorded, and they belonged to 30 families and 74 genera. These species were mainly native herbaceous plants, especially perennial herbs. The species number and species diversity index in the disturbance area had a positive relationship with the undisturbed area. The lateral undisturbed vegetation type and species reproductive strategies influenced the vegetation restoration in the disturbance area. The species that produce a large number of seeds or regenerate by rhizome recolonized quickly in the disturbance area. However, the shrubs and arbor species that need seeds for recruitment will take a long time for restoration. The topographic factor had an obvious influence on the vegetation restoration and species diversity in the disturbance areas. On the sunny and steep slopes, vegetation restoration was difficult and slow, and artificial measures were needed to control soil erosion and maintain soil moisture to help seedling recruitment and survival. [ABSTRACT FROM AUTHOR]

N6-methyladenosine (m6A) RNA modification plays important regulatory roles in plant development and adapting to the environment, which requires methyltransferases to achieve the methylation process. However, there has been no research regarding m6A RNA methyltransferases in cotton. Here, a systematic analysis of the m6A methyltransferase (METTL) gene family was performed on twelve cotton species, resulting in six METTLs identified in five allotetraploid cottons, respectively, and three to four METTLs in the seven diploid species. Phylogenetic analysis of protein-coding sequences revealed that METTL genes from cottons, Arabidopsis thaliana, and Homo sapiens could be classified into three clades (METTL3, METTL14, and METTL-like clades). Cis-element analysis predicated the possible functions of METTL genes in G. hirsutum. RNA-seq data revealed that GhMETTL14 (GH_A07G0817/GH_D07G0819) and GhMETTL3 (GH_A12G2586/GH_D12G2605) had high expressions in root, stem, leaf, torus, petal, stamen, pistil, and calycle tissues. GhMETTL14 also had the highest expression in 20 and 25 dpa fiber cells, implying a potential role at the cell wall thickening stage. Suppressing GhMETTL3 and GhMETTL14 by VIGS caused growth arrest and even death in G. hirsutum, along with decreased m6A abundance from the leaf tissues of VIGS plants. Overexpression of GhMETTL3 and GhMETTL14 produced distinct differentially expressed genes (DEGs) in A. thaliana, indicating their possible divergent functions after gene duplication. Overall, GhMETTLs play indispensable but divergent roles during the growth of cotton plants, which provides the basis for the systematic investigation of m6A in subsequent studies to improve the agronomic traits in cotton. [ABSTRACT FROM AUTHOR]

Objective: Roots can effectively reduce soil detachment. However, the dynamics of different root effects on soil detachment with root growth time are not clearly understood. Therefore, our objectives were to characterize the dynamics of soil detachment with root growth time and compare the effectiveness of roots of different types and planting densities on soil detachment. Materials and methods: A laboratory experiment was conducted to quantify and elucidate the effect of fibrous ryegrass (Lolium perenne L.) roots and alfalfa (Medicago sativa L.) taproots on soil detachment, with two planting densities at 4 different growth stages. Root parameters, soil properties, and the soil detachment rate (with a flow discharge of 3 L min−1 for 15 min on a 15° slope) were measured at days 28, 56, 84, and 112. Results and discussion: Root parameters increased with root growth time, and the fibrous roots varied more significantly than taproots. Soil bulk density decreased with root growth time, while the contents of soil organic matter and water-stable aggregates increased with root growth time. The effect of fibrous roots on soil properties was significantly greater than that of taproots. The absolute soil detachment rate and relative soil detachment rate from fibrous roots decreased by 53.35% and 51.98% from days 28 to 112 respectively, but those from taproots did not change significantly. Soil detachment under high-density cultivation was lower than that under low-density cultivation at the early growth stage but inversely later. Soil detachment decreased exponentially with root parameters, and the equation of root parameters and soil detachment in RL (ryegrass with a low planting density) best explained the soil detachment variation (91.3–96.1%). Conclusions: Plants with fibrous roots had greater effect on soil detachment reduction than those with taproots. Treatments with high planting density had a more significant influence on soil detachment reduction than did those with low planting density at the early growth stage, but the opposite was true later. This experiment helped to explain the mechanism and process of root growth affecting soil detachment and provided a fundamental basis for erosion management practices. [ABSTRACT FROM AUTHOR]

Sheet erosion has been the major erosion process on steep grassland since the Grain-for-Green project was implemented in 1999 in the Loess Plateau with serious soil erosion in China. Quantifying sheet erosion rate on steep grassland could provide scientific support for effectively controlling soil erosion and rationally managing grassland. Simulated rainfall experiments were conducted on grassland plot with vegetation coverage of 40% under complete combination of rainfall intensities of 0.7, 1.0, 1.5, 2.0 and 2.5 mm min−1 and slope gradients of 7°, 10°, 15°, 20° and 25°. Results showed that sheet erosion rate, varying from 0.0048 to 0.0578 kg m−2 min−1, was well described by binary power function equation (SE = 0.0026 I1.306S0.662) containing rainfall intensity and slope gradient with R2 = 0.940. The logarithmic equation of shear stress (SE = 0.084 + Ln (τ)) and the power function equation of stream power (SE = 1.141 ɷ1.073) could be used to predict sheet erosion rate. Stream power (R2 = 0.903) was a better predictor of sheet erosion than shear stress (R2 = 0.882). The stream power was an excellent hydrodynamic parameter for predicting sheet erosion rate. The study results can reveal the mechanism of sheet erosion process. [ABSTRACT FROM AUTHOR]

N6,2′-O-dimethyladenosine (m6Am), a terminal modification adjacent to the mRNA cap, is a newly discovered reversible RNA modification. Yet, a specific and sensitive tool to directly map transcriptome-wide m6Am is lacking. Here, we report m6Am-seq, based on selective in vitro demethylation and RNA immunoprecipitation. m6Am-seq directly distinguishes m6Am and 5′-UTR N6-methyladenosine (m6A) and enables the identification of m6Am at single-base resolution and 5′-UTR m6A in the human transcriptome. Using m6Am-seq, we also find that m6Am and 5′-UTR m6A respond dynamically to stimuli, and identify key functional methylation sites that may facilitate cellular stress response. Collectively, m6Am-seq reveals the high-confidence m6Am and 5′-UTR m6A methylome and provides a robust tool for functional studies of the two epitranscriptomic marks. m6Am is a dynamic and reversible RNA modification found on the mRNA cap. Here the authors report m6Am-seq to directly distinguish m6Am from m6A and identify functional methylation sites. [ABSTRACT FROM AUTHOR]