To further improve the quality of doctoral dissertations, to encourage Ph.D. students to devote themselves to original scientific research and their supervisors to guide and support their student, SJTU Excellent Ph.D. Dissertation Award was elected from all SJTU graduating Ph.D. students. One Ph.D. student from School of Life Sciences and Biotechnology (SLSB) has won the Excellent Doctoral Dissertation Award, and two were nominated. 

SJTU Excellent Ph.D. Dissertation Award Winner

Title: Microbial Genome-Centric Analysis for Understanding the Interactions among Gut Microbiota, Diet and Human Health

Student name: Guojun WU

Supervisor: Liping ZHAO

Abstract: We established the CCAI (Co-abundance, Correlation, Association and Identification) strategy for metagenomic analysis and applied it to study the roles of gut microbiome in the human health and disease at genome level. Our study showed that a diet rich in non-digestible carbohydrates improved the health in both Prader-Willi syndrome and simple obese children, which might result from the same mechanism by decreasing the gut microbiota involved in producing trimethylamine N-oxide and indoxyl sulfate and increasing the beneficial foundation members such as B. pseudocatenulatum. We found that the functions of the beneficial B. pseudocatenulatum were strain-specific. In addition, we found the diet diminished the gut resistome in the obese children. In the type 2 diabetes study, we showed that a high dietary fiber intervention promoted only a guild of short chain fatty acid-producing strains as the ecosystem service providers (ESPs). The ESP-index, which was calculated from the abundance and the diversity of the ESPs, could be used to predict the effects of the following treatment. Our results provide theoretical basis for personalized gut microbiota-targeted dietary intervention, which is a promising way to improve human health.

SJTU Excellent Ph.D. Dissertation Award Nominee 1

Title: The Molecular Mechanisms of Actin-binding Protein RMD in Regulating Root Morphology in Response to External Phosphate Availability  

tudent name: Guoqiang HUANG

Supervisor: Dabing ZHANG

Abstract: Root system, as the hidden half in the soil, plays critical roles in water and nutrient acquisition and plant anchorage. During the long time evolution, plants have developed sophisticated regulatory mechanisms to adapt to the environment. This work has deeply investigated the mechanism of RMD underlying the root system in response to external phosphate. Firstly, we observed the architecture of root system grown in different phosphate conditions. We found that the negative correlation existing between root growth angles with the external phosphate availability. However, rmd-1 lost the ability to response to external phosphate, exhibiting stable deep root system. Further studies showed that LP induced the AFs accumulation around the amyloplasts, dampened the sedimentation of amyloplasts, resulted in insensitive gravity-sensing process and asymmetric auxin distribution and finally caused slower gravitropism and shallow root system. Collectively, RMD regulates the root growth angle in response to external phosphate. This study elucidates the molecular mechanism of AFs underlying root growth angle in response to external phosphate, providing an important theoretical basis for culture rice with higher phosphate acquisition efficiency in future.

SJTU Excellent Ph.D. Dissertation Award Nominee 2

Title: The Mechanism Study of Septohippocampal GABAergic Projections Regulating Adult Hippocampal Neural Stem Cells and Neurogenesis

Student name: Bao Hechen

Supervisor: Li Weidong

Abstract: Adult hippocampal neurogenesis takes place in the dentate gyrus (DG) of hippocampus, a brain region highly involved in cognitive function and emotion regulation. Adult hippocampal neurogenesis continuously gives rise to adult-born neurons, and could be significantly regulated by external stimuli and experiences. Therefore, it is considered as one of the most extreme demonstrations of brain plasticity in the adult brain. In our study, we used various cutting-edge circuit approaches, and identified that the GABAergic projections from medial septum could significantly regulate the quiescence activity of hippocampal neural stem cells, intermediated by DG PV interneurons which can be uniquely depolarized by GABA. This study not only provides insights of how long-range neuronal network activity could regulate adult hippocampal neural stem cells and neurogenesis, but also offers a novel strategy to study the adult neurogenesis at circuit level. The septohippcampal circuit and DG PVs may also serve as potential therapeutic targets for various neuropsychiatric diseases in the future.