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Sugarcane brown rust (SCBR), caused by Puccinia melanocephala, is a destructive fungal disease that has extensively spread in the sugarcane-cultivating regions across the world. Early monitoring plays an important role in predicting the P. melanocephala epidemic and managing SCBR. However, accurately identifying SCBR based on symptoms and urediniospore morphology at the initial stage is a challenge. Further, it is tedious, time-consuming, labor-intensive, and requires expensive equipment to detect P. melanocephala using PCR-based methods. Loop-mediated isothermal amplification (LAMP) technology is renowned for its speed, simplicity, and low equipment requirements for specifically and sensitively identifying many pathogens. Therefore, in this study, a novel and highly sensitive LAMP assay was developed for the specific detection of P. melanocephala in sugarcane. Here, the internal transcribed spacer (ITS) sequence of P. melanocephala was selected as the target gene for LAMP primer design. Based on the color change of SYBR Green I and gel electrophoresis, specific LAMP primers were screened. Further, the optimal reaction conditions for the LAMP assay were determined at 63 °C for 60 min. The LAMP assay showed a high degree of specificity for the detection of P. melanocephala in sugarcane, with no cross-reactivity with other fungal pathogens. The established LAMP protocol was highly sensitive and can be used to detect as low as 1 pg/μL of P. melanocephala plasmid DNA, which is comparable to that of nested PCR and ~100 times more sensitive than conventional PCR. Finally, the detection rate of the LAMP method was higher than that of conventional and nested PCR in field samples. [ABSTRACT FROM AUTHOR]

Soil labile organic carbon (LOC) is a valuable and sensitive parameter of the changes in soil carbon (C) pools and further affects soil structural stability. However, the influences of soil-aggregate stability on LOC fractions under erosion conditions are still unclear, especially under the collapsing gully area of south China. Soils of five positions of collapsing gully erosion, including the upper catchment (UC), collapsing wall (CW), colluvial deposit (CD), scour channel (SC) and alluvial fan (AF) from Acric Ferralsols were investigated and sampled. Soil aggregate stability and LOC fractions were measured and analyzed. Soil water-stable aggregate and passive C (passive-C) contents significantly increased by 67–76% and 8.7–13.0% at the UC, CW, CD and SC positions, respectively, while soil labile C (labile-C) content was lower at these positions as compared to the AF position (p < 0.05). Moreover, the UC position's soil C pool management index (CPMI) significantly increased by 37–40% compared to CW, CD, SC and AF soils, indicating that the soil of the UC position had a more stable C pool due to its stronger structural stability. SOC, silt, and amorphous iron oxide (Fea) contents significantly contributed to aggregate stability. We demonstrated that the depletion of soil aggregate stability could result in the decreases in soil LOC fractions, while soil properties of the OC but not the LOC pool regulated aggregate stability and thus affected soil structure across different collapsing gully erosion positions in the subtropical Acric Ferralsols region of south China. This study contributes to developing strategies to prevent soil erosion and improve global C cycle and soil quality, which could be beneficial to strengthen soil and water conservation, and improve soil fertility (e.g., SOC) and vegetation recovery, such as tea and tobacco. [ABSTRACT FROM AUTHOR]

Salinity is a major abiotic stressor that leads to productivity losses in rice (Oryza sativa L.). In this study, transcriptome profiling and heterosis-related genes were analyzed by ribonucleic acid sequencing (RNA-Seq) in seedlings of a mega rice hybrid, Liang-You-Pei-Jiu (LYP9), and its two parents 93–11 and Pei-ai64s (PA64s), under control and two different salinity levels, where we found 8292, 8037, and 631 salt-induced differentially expressed genes (DEGs), respectively. Heterosis-related DEGs were obtained higher after 14 days of salt treatment than after 7 days. There were 631 and 4237 salt-induced DEGs related to heterosis under 7-day and 14-day salt stresses, respectively. Gene functional classification showed the expression of genes involved in photosynthesis activity after 7-day stress treatment, and in metabolic and catabolic activity after 14 days. In addition, we correlated the concurrence of an expression of DEGs for the bHLH transcription factor and a shoot length/salinity-related quantitative trait locus qSL7 that we fine-mapped previously, providing a confirmed case of heterosis-related genes. This experiment reveals the transcriptomic divergence of the rice F1 hybrid and its parental lines under control and salt stress state, and enlightens about the significant molecular mechanisms developed over time in response to salt stress. [ABSTRACT FROM AUTHOR]