Dr. Yihua Zhou 

　　Principle Investigator

　　State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China

　　Email: yhzhou@genetics.ac.cn

　　Education

　　B.S. 1985-1989, Department of Biology, Beijing Normal University

　　M.S. 1989-1992, Department of Biology, Beijing Normal University

　　Ph. D. 1996-1999, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences.

　　Postdoctoral research experience 2001-2002, Department of Forestry, Michigan Technological University.

　　Research Interests

　　(1) Functional characterization of genes involved in secondary wall biosynthesis, aiming to improve lodge resistance in crops

　　Lodge resistance is an important trait that is highly associated with crop yield. Many genes have been found responsible for this trait, in which genes involved in secondary wall biosynthesis make a great contribution, as physicochemical property of secondary wall determines the mechanical strength of plants. My laboratory is mainly interested in molecular mechanism of secondary wall formation in rice developing internodes, focusing on functional characterization of genes involved in secondary wall biosynthesis and remolding. Therefore, we systematically screen rice brittle culm mutants (bc) and functionally characterize the genes related to mechanical properties and cell wall biosynthesis. Till now, eight genes: BC1 (Liu et al., 2013), BC15 (Wu et al., 2012), BC13 (Song et al., 2012), BC14 (Zhang et al., 2011), BC3 (Xiong et al., 2010), BC12 (Zhang et al., 2010), and BC11 (Zhang et al., 2009) have been identified, which have drawn the major framework of cell wall biosynthesis and allow us stride a step in controlling mechanical strength of rice plants via molecular breeding.

　　On the other hand, we also focus on identifying the transcriptional regulatory network for secondary wall formation in rice internodes. Through performing RNA-sequencing in the developing rice internodes, we have screened more than ten candidate transcription factors. Using reverse genetic approach, several transcription factors are being characterized. The primary regulatory network of secondary wall formation in rice internodes has been revealed. All those findings will shed lights on the transcriptional regulation of lodge resistance. Moreover, we performed genome wide association analyses (GWAS) in hundreds of rice varieties. Several SNPs that associated with cell wall composition and lodge resistance have been identified. Functional characterization of candidate genes will provide clues for the improvement of this agronomic trait.

　　(2) Hemicellulose biosynthesis and modification

　　Xylan and mixed-linkage glucan (MLG) are major hemicelluloses present in rice cell wall. Both polymers have β-1,4-xylosyl or glucosyl backbone, respectively. Xylan backbone is further O-acetylated, which determines xylan physicochemical property. However, the molecular mechanisms about how both hemicellolosic polymers are synthesized in plants and by which components control the acetyl modification on xylan are poorly understood. Our laboratory focuses on identifying the critical genes required for xylan synthesis and understanding their biological functions in rice growth. We have found several glycosyltransferases functioning in xylan synthesis through genetic characterization. We also found that several plant-specific Trichome Birefringence-Like (TBL) genes and Brittle Sheath1 (BS1) and BS1-like genes are involved in acetylation and deacetylation of hemicellulose xylan (submitted). This study will shed light on understanding the metabolic pathways that modulate the xylan abundance and acetyl-ester levels and their corresponding significance in plant growth and economic values.

　　For the synthesis of MLG, we have identified some natural rice varieties that present high level of MLG. We propose to use forward genetic approach to clone the candidate gene, aiming to clarify the new mechanisms for MLG biosynthesis and its function.

　　(3) Cell wall biology and plant growth

　　Cell wall is a basis structure of plant cells. Physicochemical properties of cell wall highly fit with their roles of cells across different growth and development stages. Therefore, plant cell walls play many important roles during plant growth and development. Deficiency in cell wall biosynthesis often exhibits abnormalities in plant growth. However, the underlying mechanisms of how plants apperceive signals to initiate cell wall formation and remodeling and how the signaling pathways transmit are largely unknown. In the recent years, our laboratory is focusing on characterizing cell wall-related genes required for plant growth and identifying the signaling transduction pathways that regulate cell wall formation and plant growth. For example, OsCSLD4 (Li et al., 2009) and BC12 (Zhang et al., 2010) function in plant height control, MGP4 (Liu et al., 2011) plays a role in pollen tube elongation, and ILA1 (Ning et al., 2011) is critical for rice leaf angle control.

　　Gibberellin (GA) is an important phytohormone. Our recent work found that GA can regulate secondary wall cellulose biosynthesis. A signal transduction pathway that contains SLR1-NAC29/31-MYB61-secondary wall CESAs has been identified, which is conserved in many plant species (Huang et al., 2015). Those findings forward our knowledge about the relationship between plant growth and cell wall biosynthesis.