A mutation in CsGME encoding GDP-mannose 3,5-epimerase results in little and wrinkled leaf in cucumber.

KEY MESSAGE: Map-based cloning revealed that a mutation in a highly conserved amino acid of the CsGME gene encoding GDP-mannose 3,5-epimerase, causes the phenotype of little and wrinkled leaves in cucumbers. Leaf size is a critical determinant of plant architecture in cucumbers, yet only a few genes associated with this trait have been mapped or cloned. Here, we identified and characterized a mutant with little and wrinkled leaves, named lwl-1. Genetic analysis revealed that the phenotype of the lwl-1 was controlled by a single recessive gene. Through map-based cloning, the lwl-1 locus was narrowed down to a 12.22-kb region exclusively containing one fully annotated gene CsGME (CsaV3_2G004170). CsGME encodes GDP-mannose 3,5-epimerase, which is involved in the synthesis of ascorbic acid (ASA) and one of the components of pectin, RG-II. Whole-length sequencing of the 12.22 kb DNA fragment revealed the presence of only a non-synonymous mutation located in the sixth exon of CsGME in lwl-1, resulting in an amino acid alteration from Pro363 to Leu363. This mutation was unique among 118 inbred lines from cucumber natural populations. CsGME expression significantly reduced in various organs of lwl-1, accompanied by a significant decrease in ASA and pectin content in leaves. Both CsGME and Csgme proteins were localized to the cytoplasm. The mutant phenotype exhibited partial recovery after the application of exogenous boric acid. Silencing CsGME in cucumber through VIGS confirmed its role as the causal gene for lwl-1. Transcriptome profiling revealed that CsGME greatly affected the expression of genes related to the cell division process and cell plate formation. This study represents the first report to characterize and clone the CsGME in cucumber, indicating its crucial role in regulating leaf size and development.

An introduction to the orthodontic resident training program at Osaka Dental University and its reference value to orthodontic resident training in China / 口腔疾病防治

@#Orthodontic resident training has a long history abroad. Its purpose is to teach general practitioners in dentistry about basic knowledge and operating standards and to lay a solid foundation for the normalization and standardization of techniques. Osaka Dental University, established in 1911, is one of the oldest dental higher education facilities in Japan and Asia. Its systematic orthodontic resident training program has specific characteristics, including a thorough foundation in basic training, sufficient practice time in clinical work, and an emphasis on both clinical thinking ability and technical detail mastery. Recently, orthodontic resident training programs in China have achieved significant progress in a short period. In this manuscript, we introduce the orthodontic training program of Osaka Dental University in terms of enrollment, training arrangements, orthodontic basic education and clinical training in order to offer a reference for the continuous improvement of the standardized training system for resident doctors of stomatology in China.