Soil-water storage to a depth of 5 m along a 500-km transect on the Chinese Loess Plateau

Soil-water storage (SWS) is an important indicator of the sustainability of regional water resources and is the foundation for developing strategies of land-use management around the world, especially in areas with deficits of soil water. An investigation of the characteristics of SWS at large regional scales can provide valuable information. We measured SWS and available soil-water storage (ASWS) to a depth of 5 m along a 500-km transect across two climatic regions on the Chinese Loess Plateau (CLP). SWS5 m tended to decrease from southeast to northwest and was 320 mm higher in the subhumid than the semiarid zone. SWS5 m and ASWS(5 m) were lower in the dry than the rainy season, but SWS1 m and ASWS(1 m) did not differ significantly between the two seasons except in the 0-100 cm layer. SWS1 m and ASWS(1 m) tended to increase with depth in the semiarid zone and did not change substantially with depth in the subhumid zone. SWS5 m and ASWS(5 m) varied with land use, in the orders cropland > orchard > forest in the subhumid zone and grassland > shrubland > forest in the semiarid zone. Climatic conditions and soil textures were predominant factors affecting SWS at the transect scale. SWS5 m and ASWS(5 m) in the subhumid zone were dependent on clay content, elevation, latitude and the interaction of latitude and temperature, while clay content played a dominant role in the semiarid Zone. Understanding this information is helpful for assessing regional water resources, optimizing the rational use of land and modeling eco-hydrological processes on the CLP and possibly in other water-limited regions around the world. (C) 2016 Elsevier B.V. All rights reserved

Cytpchrome P450 CYP4G68 Is Associated with Imidacloprid and Thiamethoxam Resistance in Field Whitefly, Bemisia tabaci (Hemiptera: Gennadius)

The superfamily cytochrome P450s is involved in the evolution of insecticide resistance. However, whether CYP4G68, a differentially expressed gene identified from our transcriptomics analysis, confers resistance to the world’s heavily used insecticide class neonicotinoids is unknown. Hence, we explored the role of CYP4G68 in conferring imidacloprid and thiamethoxam resistance in Bemisia tabaci. The species B. tabaci MED developed low-to-high resistance to imidacloprid and thiamethoxam. Exposure to imidacloprid and thiamethoxam significantly increased the expression of CYP4G68. Moreover, quantitative real-time PCR analysis demonstrated that CYP4G68 was remarkably overexpressed in imidacloprid-resistant and thiamethoxam-resistant strains compared to susceptible strains. Further correlation analysis showed that CYP4G68 expression was significantly positively correlated with the associated resistance level in various strains of B. tabaci. These results suggest that the enhanced expression of CYP4G68 appears to mediate imidacloprid and thiamethoxam resistance in B. tabaci. Additionally, silencing CYP4G68 via RNA interference strongly increased the susceptibility of B. tabaci MED to imidacloprid and thiamethoxam. Collectively, this work revealed that CYP4G68 plays a vital role in imidacloprid and thiamethoxam resistance in B. tabaci MED. These findings will not only advance our understanding of the role of P450s in insecticide resistance but also provide a great potential target for the sustainable control of destructive insect pests such as whiteflies.</jats:p

Epitranscriptomic regulation of insecticide resistance

A cytochrome P450 that confers insecticide resistance in whitefly is regulated by an epitranscriptomic mechanism.</jats:p

Cytpchrome P450 CYP4G68 Is Associated with Imidacloprid and Thiamethoxam Resistance in Field Whitefly, Bemisia tabaci (Hemiptera: Gennadius)

The superfamily cytochrome P450s is involved in the evolution of insecticide resistance. However, whether CYP4G68, a differentially expressed gene identified from our transcriptomics analysis, confers resistance to the world&rsquo;s heavily used insecticide class neonicotinoids is unknown. Hence, we explored the role of CYP4G68 in conferring imidacloprid and thiamethoxam resistance in Bemisia tabaci. The species B. tabaci MED developed low-to-high resistance to imidacloprid and thiamethoxam. Exposure to imidacloprid and thiamethoxam significantly increased the expression of CYP4G68. Moreover, quantitative real-time PCR analysis demonstrated that CYP4G68 was remarkably overexpressed in imidacloprid-resistant and thiamethoxam-resistant strains compared to susceptible strains. Further correlation analysis showed that CYP4G68 expression was significantly positively correlated with the associated resistance level in various strains of B. tabaci. These results suggest that the enhanced expression of CYP4G68 appears to mediate imidacloprid and thiamethoxam resistance in B. tabaci. Additionally, silencing CYP4G68 via RNA interference strongly increased the susceptibility of B. tabaci MED to imidacloprid and thiamethoxam. Collectively, this work revealed that CYP4G68 plays a vital role in imidacloprid and thiamethoxam resistance in B. tabaci MED. These findings will not only advance our understanding of the role of P450s in insecticide resistance but also provide a great potential target for the sustainable control of destructive insect pests such as whiteflies

Cytpchrome P450 <i>CYP4G68</i> Is Associated with Imidacloprid and Thiamethoxam Resistance in Field Whitefly, <i>Bemisia tabaci</i> (Hemiptera: Gennadius)

The superfamily cytochrome P450s is involved in the evolution of insecticide resistance. However, whether CYP4G68, a differentially expressed gene identified from our transcriptomics analysis, confers resistance to the world’s heavily used insecticide class neonicotinoids is unknown. Hence, we explored the role of CYP4G68 in conferring imidacloprid and thiamethoxam resistance in Bemisia tabaci. The species B. tabaci MED developed low-to-high resistance to imidacloprid and thiamethoxam. Exposure to imidacloprid and thiamethoxam significantly increased the expression of CYP4G68. Moreover, quantitative real-time PCR analysis demonstrated that CYP4G68 was remarkably overexpressed in imidacloprid-resistant and thiamethoxam-resistant strains compared to susceptible strains. Further correlation analysis showed that CYP4G68 expression was significantly positively correlated with the associated resistance level in various strains of B. tabaci. These results suggest that the enhanced expression of CYP4G68 appears to mediate imidacloprid and thiamethoxam resistance in B. tabaci. Additionally, silencing CYP4G68 via RNA interference strongly increased the susceptibility of B. tabaci MED to imidacloprid and thiamethoxam. Collectively, this work revealed that CYP4G68 plays a vital role in imidacloprid and thiamethoxam resistance in B. tabaci MED. These findings will not only advance our understanding of the role of P450s in insecticide resistance but also provide a great potential target for the sustainable control of destructive insect pests such as whiteflies