Major Research Areas:
This laboratory is interested in two major research areas: large-scale cloning and analyses of genes involved in early cotton fiber development, and tuberculosis DNA vaccine development. Using cDNA prepared from 10dpa (days post anthesis) wild-type cotton fiber as tester and cDNA from a fuzzless-lintless (fl) mutant as driver, we applied the RDA method to recover 280 independent cDNA fragments related directly to early cotton fiber development. cDNA microarrays showed that 172 genes were significantly up-regulated in elongating cotton fibers as confirmed by in situ hybridization in representative cases. Twenty-nine cDNAs, including a putative vacuolar (H+)-ATPase catalytic subunit, a kinesin-like calmodulin binding protein, several arabinogalactan proteins and key enzymes involved in long chain fatty acid biosynthesis, accumulated to greater than 50-fold in 10 dpa fiber cells when compared to that in 0 dpa ovules. Various upstream pathways, such as auxin signal transduction, the MAP kinase pathway, and profilin- and expansin-induced cell wall loosening, were also activated during the fast fiber elongation period. The lab is also involved in cloning and expressional analyses of 8 large gene families (AP2-EREBP、bHLH、C3H-TYPE2(Zn)、E2F-DP、HMG-BOX、NIN-like、PCG、TCP) encoding Arabidopsis transcription factors. We have so far obtained about 250 full-length cDNAs and are currently working on yeast expression as well as gel mobility shift assays to study their DNA binding activities. We have done some work on elucidating molecular mechanisms of plant apical senescence using G2 pea as a model system. We showed that transgenic Arabidopsis plants carrying a putative chloroplast membrane-localized calcium channel protein (the PPF1 gene) in sense orientation flowered much later compared to control plants whereas antisense expression of this gene rendered the recipients a very rapid life cycle. The strength of this late-flowering phenotype correlated roughly with the level of PPF1 transcripts and with the calcium storage capacity in the chloroplasts of different transgenic lines. We suggest that PPF1 is a novel calcium ion carrier that regulates flowering time of higher plants by changing the Ca2+ storage capacity within chloroplasts. We have cloned five genes encoding different secreted antigens Ag85B, MPT-83, MPT-64, MPT-63 and ESAT-6 from Mycobacterium Tuberculosis. We are currently developing either combined or polyvalent DNA vaccines with different combinations. Experimental results obtained both from mice and from cows showed that immunization of combined DNA vaccines expressing 3 or 4 secreted antigens might produce significant protection against microbial invasion. Our data indicated that antigen-specific IFN-γlevels, rather than antibody levels, might be a better criteria for protective efficacy assessment.
  Published Papers Since 2000:
Yuxian Zhu, Ph D (Changjiang Professor)
Professor of Biochemistry and Molecular Biology
Director of national lab of protein engineering and plant genetic engineering
Add:College of Life Sciences,Peking University,
       beijing,100871,P.R.China
Tel:86-10-6275 1193(O)
Fax:86-10-6275 4427
E-mail:zhuyx@water.pku.edu.cn
Jianxun Feng Post doc
Shengwei Zhu Post doc
Qin Li Ph.D candidate
Baichen Wang Ph.D candidate
Hongbing Li Ph.D candidate
Yu Xu Ph.D candidate
Yu Pang Ph.D candidate
Xiang Ji Ph.D candidate
Pei Han Ph.D candidate
Li Wang Secretary of Zhulab
Dengchan Ye Lab assistant