Dr. Anita Samuga
Dr. Udaya Kalluri
Dr. Xiaoe Liang
Cellulose biosynthesis is one of the most important biological processes on earth. Although we use several cellulose products every day, molecular details of how trees synthesize cellulose are still shrouded in mystery. Dr. Joshi's long-term CAREER goal is to advance a comprehensive understanding of cellulose biosynthesis in trees. Recent molecular genetic evidence suggests that plant genomes host a rather large cellulose synthase (CesA) gene family and multiple but distinct CesAs are involved in primary and secondary cell wall formation in Arabidopsis. Dr. Joshi's lab has isolated three secondary wall-related CesA genes from aspen namely, PtrCesA1, PtrCesA2 and PtrCesA3 that are coordinately expressed during the secondary cell wall formation. Here further research will be carried out to examine whether these three CesA genes are functionally associated with better quality cellulose production in trees.
The four main objectives of this proposal are: 1) to examine expression of PtrCesA1, PtrCesA2 and PtrCesA3 proteins in developing xylem tissues of aspen; 2) to delineate the spatial and temporal regulation of PtrCesA1, PtrCesA2 and PtrCesA3 genes; 3) to inhibit the expression of a specific PtrCesA gene in transgenic aspen trees through RNAi technology for functional analysis; and 4) to perform sense over-expression of three secondary CesAs to study the impact of such genetic manipulations on growth and wood characteristics of transgenic trees. This research will establish a firm experimental basis for metabolic engineering of secondary cell wall associated cellulose biosynthesis in trees that has many fundamental and commercial implications.
The educational goals of this CAREER project include: 1) graduate program development in Bioinformatics and Biotechnology; 2) establishment of a lecture series in Plant Molecular Genetics; 3) integration of research activities into undergraduate and graduate teaching and educational outreach activities; and 4) providing research training opportunities for at least two undergraduate students, two Ph. D graduate students and a postdoctoral researcher in the field of cellulose biogenesis in trees.