Plant prime editing technique: a new genome editing tool for plants / 生物工程学报

The CRISPR/Cas9 based prime editing (PE) technique enables all 12 types of base substitutions and precise small DNA deletions or insertions without generating DNA double-strand breaks. Prime editing has been successfully applied in plants and plays important roles in plant precision breeding. Although plant prime editing (PPE) can substantially expand the scope and capabilities of precise genome editing in plants, its editing efficiency still needs to be further improved. Here, we review the development of PPE technique, and introduce structural composition, advantages and limitations of PPE. Strategies to improve the PPE editing efficiency, including the Tm-directed PBS length design, the RT template length, the dual-pegRNA strategy, the PlantPegDesigner website, and the strategies for optimizing the target proteins of PPE, were highlighted. Finally, the prospects of future development and application of PPE were discussed.

Ectopic expression of archaeal TRAM-encoding genes in rice improves its drought-tolerance / 生物工程学报

Drought stress affects the growth and development of rice, resulting in severe loss in yield and quality. Ectopic expression of the bacterial RNA chaperone, cold shock protein (Csp), can improve rice drought tolerance. Archaeal TRAM (TRM2 and MiaB) proteins have similar structure and biochemical functions as bacterial Csp. Moreover, DNA replication, transcription and translation of archaea are more similar to those in eukaryotes. To test if archaeal RNA chaperones could confer plant drought tolerance, we selected two TRAM proteins, Mpsy_3066 and Mpsy_0643, from a cold-adaptive methanogenic archaea Methanolobus psychrophilus R15 to study. We overexpressed the TRAM proteins in rice and performed drought treatment at seedling and adult stage. The results showed that overexpression both TRAM proteins could significantly improve the tolerance of rice to drought stress. We further demonstrated in rice protoplasts that the TRAMs could abolish misfolded RNA secondary structure and improve translation efficiency, which might explain how TRAMs improve drought tolerance transgenic rice. Our work supports that ectopic expression of archaeal TRAMs effectively improve drought tolerance in rice.

Analysis on injuries of drivers and passengers in motorcycle traffic accidents in Chongqing area / 重庆医学

Objective To investigate the characteristics of personal injuries in motorcycle accidents in Chongqing area to provide the reliable information and reference basis for reducing the injury and death risk of the motorcycle accidents.Methods Two hundreds and thirteen cases of motorcycle traffic accident occurred in Chongqing area from January 2015 to June 2016 were deeply collected,the collected contents included the basicinformation,driver information and personal injury,etc.Then accident data were statistically analyzed.Results The death rate of motorcycle drivers was higher than that of the pillion passengers.The death causes of craniocerebral injuries and craniocerebral injuries complicating thoracic and abdominal organ injuries accounted for 58.8％ and 20 ％ respectively,the proportions of head and neck,chest and back,lower extremity,upper extremity,abdominal and pelvic part and perineal part MAIS ≥2 were 71％,59％,33％,25％,20％ and 7％ respectively.The perineal injury rate of motorcycle drivers was higher than that of the pillion passengers.The ratio of occurrence rates between lower extremity fracture to upper extremity fracture was 1.8 ∶ 1,the persons in motorcycles-trucks accidents were easier to suffer from vehicle crushing.Conclusion Head and chest injuries are important causes leading to motorcycle drivers and pillion passengers' death and injury.The perineal injury can serve as an important basis for identifying the drivers and pillion passengers in partial motorcycle accidents.