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•MdSIZ1 RNAi transgenic apple trees are drought tolerance than wild type—GL-3.•MdSIZ1 RNAi plants get enhanced ability to keep water and scavenge ROS under drought conditions.•MdSIZ1 may participate in apple drought tolerance by affecting ABA biosynthesis.Drought stress typically causes heavy losses in apple production and uncovering the mechanisms by which apple tolerates drought stress is important in apple breeding. MdSIZ1 is a SUMO (small ubiquitin-like modifier) E3 ligase that promotes SUMO binding to substrate proteins. Here, we demonstrate that MdSIZ1 in apple has a negative relationship with drought tolerance. MdSIZ1 RNAi transgenic apple trees had a higher survival rate after drought stress. During drought stress they had higher leaf water potential, reduced ion leakage, lower H2O2 and malondialdehyde contents, and higher catalase activity. In addition, MdSIZ1 RNAi transgenic plants had a higher net photosynthetic rate during the latter period of drought stress. Finally, the transgenic apple trees also altered expression levels of some microRNAs in response to drought stress. Taken together, these results indicate that apple MdSIZ1 negatively regulates drought stress by enhancing leaf water-holding capacity and antioxidant enzyme activity.

Although the application of biological materials has shown potential in improving the environment of salinized soil, the impact on the transformation of soil phosphorus forms in salinized soil, especially when combined with B. mucilaginosus (BM), has rarely been studied. Therefore, this study investigated soil's properties and phosphorus forms, as well as their relationship, in salinized soil after the application of different biological materials, including rice straw (RS), biochar (B), acidified biochar (AB), BM, RS+BM, B+BM, and AB+BM. A sequential extraction procedure was employed to determine the soil organic/inorganic phosphorus forms (Po/Pi). In our study, the contents of the soil's resin-P, NaHCO3-Pi, NaOH-Pi, and HCl-P increased by 50–341.66%, 4.08–184.63%, 37.45–163.45%, and 10.19–38.29%, respectively, with the application of the biological materials compared to with conventional fertilization (CK1). However, the contents of the soil's NaHCO3-Po, NaOH-Po, and residual-P significantly decreased in comparison to with CK1, particularly in the soils that received a combined application with biological materials and BM. Furthermore, the results from the statistical analysis revealed that the application of biological materials could increase the level of soil stable phosphorus, facilitate the transformation from soil stable phosphorus and soil unstable Po to soil unstable Pi, and enhance the effectiveness of soil phosphorus, especially when combined with BM, particularly in soil with AB+BM. [ABSTRACT FROM AUTHOR]

In order to explore the influence of vegetation on homogeneity of surface particle size distribution (PSD) and heterogeneity of soil structure, observations, theory, and multifractal results were synthesized to highlight the evolution of the soil particle composition in the Jilantai Salt Lake Protection System (Jilantai system) after long‐term wind‐sand activities and its soil structure characteristics. From flowing sand dune to saline‐alkali wasteland areas, the mean grain size and surface particle sorting degree gradually increased and decreased, respectively, whereas the shape of the particle frequency curve gradually changed from extremely positive deviation to negative deviation, and the peak shape of the curve gradually changed from narrow to wide. Furthermore, the inhomogeneity of the soil particle composition gradually decreased, whereas the range of the soil PSD gradually increased, and the soil increasingly became fine‐grained. Therefore, the contents of clay and silt in shelterbelt soil increased by 16% and 18.36%, respectively, over 1986 levels. Additionally, clay and silt play a vital role in determining soil particle parameters such as standard deviation (SD), skewness (SKI), and monofractal (D), while vegetation factors are the main controlling factors of clay and silt. In conclusion, the Jilantai system could increase heterogeneity and homogeneity and decrease the concentration of soil PSD by changing the sedimentary environment, while this affect depends largely on the fractional vegetation cover, vegetation height, and light penetrating porosity. Moreover, the multifractal and particle parameters could describe the soil structure characteristics and sedimentary process, respectively, after long‐term wind‐sand activities. [ABSTRACT FROM AUTHOR]

The improvement effect of willow (Salix matsudana cv. zhuliu) cultivation on coastal saline soil and the main factors affecting soil properties were studied. Three treatments were designed: willow seeding site (SS), willow afforestation site (AS) and natural control site (CK). The results showed that soil pH and ECe decreased from 8.50 to 7.43 and from 6.8 dS/m to 0.8 dS/m at 0–20 cm layer, respectively. Willow cultivation significantly increased soil organic matter both in SS (3.64 g kg−1 – 4.05 g kg −1) and AS (2.82 g kg−1 – 3.92 g kg −1) treatments. The soil total nitrogen and available potassium of different treatments were increased with time and ranked AS > SS > CK. The AS16 treatment has a higher soil enzyme activity (soil urease, catalase, sucrase and phosphatase) and soil microbial population (bacteria, fungi and actinomycetes). Redundancy analysis suggested that soil pH and salinity were the key factors (85.4%) determining soil microbial quantities. Principal component analysis showed that the soil improvement by willow cultivation was significantly affected by soil enzyme activity, and AS16 had a better effect on costal saline soil especially in reducing soil salinity and improving microbial environment [ABSTRACT FROM AUTHOR]