摘要：In assessing an insect-resistant genetically engineered （IRGE） crop before its commercialization, researchers normally use so-called ＂Tier-1 assays＂ as the initial step to determine the effects of the crop on non-target organisms. In these tests, the insecticidal proteins （IPs） produced by the IRGEs are added to the diets of test organisms in the laboratory. Test organisms in such assays can be directly exposed to much higher concentrations of the test IPs than they would encounter in the field. The results of Tier-1 assays are thus more conservative than those generated in studies in which the organisms are exposed to the IPs by feeding on IRGE plant tissue or in the case of predators or parasites, by feeding on invertebrate prey or hosts that have fed on IRGE plant tissue. In this report, we consider three important factors that must be considered in Tier-1 assays： （i） methods for delivery of the IP to the test organisms; （ii） the need for and selection of compounds used as positive controls; and （iii） methods for monitoring the concentration, stability and bioactivity of the IP during the assay. We also analyze the existing data from Tier-1 assays regarding the toxicity of Bt Cry proteins to non-target arthropod species. The data indicate that the widely used Bt proteins have no direct toxicity to non-target organisms

摘要：Rice blast and bacterial blight are important diseases of rice(Oryza sativa)caused by the fungus Magnaporthe oryzae and the bacterium Xanthomonas oryzae ***(Xoo),*** rice varieties for broadspectrum resistance is considered the most effective and sustainable approach to controlling both *** dominant resistance genes have been extensively used in rice breeding and production,generating diseaseresistant varieties by altering susceptibility(S)genes that facilitate pathogen compatibility remains ***,using CRISPR/Cas9 technology,we generated loss-of-function mutants of the S genes Pi21 and Bsr-d1 and showed that they had increased resistance to *** also generated a knockout mutant of the S gene Xa5 that showed increased resistance to ***,a triple mutant of all three S genes had significantly enhanced resistance to both *** and ***,the triple mutant was comparable to the wild type in regard to key agronomic traits,including plant height,effective panicle number per plant,grain number per panicle,seed setting rate,and thousand-grain *** results demonstrate that the simultaneous editing of multiple S genes is a powerful strategy for generating new rice varieties with broadspectrum resistance.

摘要：Rapid and sensitive detection of various analytes is in high *** from its application in genome editing,CRISPR-Cas also shows promises in nucleic acid detection *** further exploit the potential of CRISPR-Cas for detection of diverse analytes,we present a versatile biosensing platform that couples the excellent affinity of aptamers for broad-range analytes with the collateral single-strand DNA cleavage activity of CRISPR-Cas12 *** demonstrated that the biosensors developed by this platform can be used to detect protein and small molecule in human serum with a complicated background,i.e.,the tumor marker alpha fetoprotein and cocaine with the detection limits of 0.07 fmol/L and 0.34 lmol/L,respectively,highlighting the advantages of simplicity,sensitivity,short detection time,and low cost compared with the state-of-the-art biosensing ***,this biosensing platform with plug-and-play design show great potential in the detection of diverse analytes.