|
 Nitric oxide (NO), serving as a critical signaling molecule, is involved in regulation of plant growth and development, and responsive processes to environmental stresses. Our research interests are focusing on dissecting nitric onide (NO) signal transduction pathway in which how plant cells perceive a NO signal and transfer this signal to nucleus to regulate the expression of down-stream genes. Another question we want to answer is the molecular mechanisms in which how plants regulate their senescing process.
Principal Investigator: Dr. Fang-Qing Guo, Professor. Email: fqguo@sibs.ac.cn
Staff: Dr. Zhong-Xiang Deng, Research Assistant
Postdoctoral Fellows: Dr. Yuan Guan
Graduate Students: Hai-Dong Yu; Fang Liu; Yun-Han Niu; Qi Shen; Xun-Liang Liu; Xiao-Ling Shang; Rong-Rong Xie; Yu-Ting Wang; Xiao-Fei Yang; Ji-Kai Li
Regulatory Mechanisms of NO in Modulating Protein Oxidization and Leaf Senescence of Arabidopsis
Previous results demonstrate that the level of oxidized proteins in detached leaves of Atnos1, a NO-deficient mutant, is much higher than that of wild type, which might result in the accelerated-senescence phenotype of Atnos1 detached leaves when kept in dark. Thus, Atnos1 mutant can be used to identify NO-regulated oxidized proteins. Our strategy is try to employ proteomics and oxidized protein labeling techniques to isolate the oxidized proteins, specially existed in the mutant leaves by comparing oxidized protein profiles between wild type and Atnos1 mutant. So far, several specific oxidized proteins were found in Atnos1 mutant leaves and next work is scheduled to analyze the sequence of these oxidized proteins using MS analysis. Up to now, more than 30 oxidized proteins have been identified. The functions of these isolated oxidized proteins in leaf senescence will be investigated by isolating the mutants or over-expression transgenic plants, in which the encoding genes are mutated or over-expressed.
Senescing Mechanism of Rice Floral Organs under Heat Stress
Heat stress is an increasing harmful effect on rice growth and development, especially at the flowering and pollinating stage. The optimum temperature for rice flowering is around 25-28℃. In recent years, harmful weather (≥35℃) during rice flowering appeared frequently, which resulted in a serious decrease of annual yield. As shown previously, 1-hour-35oC heat stress can induce the rapid senescence of anthers and stigmas of rice flowers, which in turn generally increases 10-fold un-filling rate of grains. The purpose of our project is to identify genes and proteins involved in the responses of rice flowers to heat stress by analyzing transcriptional and translational profiles under stress conditions. Functional analysis of the identified genes and proteins in response to heat stress will be carried out by isolating the mutants, RNAi lines and over-expression lines of the interesting candidate genes. We hope that our results will help breed the new heat-tolerant rice strains in future.
Major Publications:
Guo FQ, Crawford NM. (2005) Arabidopsis nitric oxide synthase1 is targeted to mitochondria and protects against oxidative damage and dark-induced senescence. The Plant Cell 17: 3436-3450. Crawford NM, Guo FQ. (2005) New insights into nitric oxide metabolism and regulatory functions. Trends in Plant Science 10: 195-200. Guo FQ, Okamoto M, Crawford NM. (2003) Identification of a plant nitric oxide synthase gene involved in hormonal signaling. Science 302: 100-103.
|
