Drought-Stimulated Activity of Plasma Membrane Nicotinamide Adenine Dinucleotide Phosphate Oxidase and Its Catalytic Properties in Rice

The activity of plasma membrane （PM） nicotinamide adenine dinucleotide phosphate （NADPH） oxidase and its catalytic properties in rice was investigated under drought stress conditions. Drought stress led to decreased leaf relative water content （RWC） and, as a result of drought-induced oxidative stress, the activities of antioxidant enzymes increased significantly. More interestingly, the intensity of applied water stress was correlated with increased production of H2O2 and O2^- and elevated activity of PM NADPH oxidase, a key enzyme of reactive oxygen species generation in plants. Histochemical analyses also revealed increased H2O2 and O2^- production in drought-stressed leaves. Application of diphenylene iodonium （DPI）, an inhibitor of PM NADPH oxidase, did not alleviate drought-induced production of H2O2 and O2^-. Catalysis experiments indicated that the rice PM NADPH oxidase was partially fiavin-dependent. The pH and temperature optima for this enzyme were 9.8 and 40 ℃, respectively. In addition, drought stress enhanced the activity under alkaline pH and high temperature conditions. These results suggest that a complex regulatory mechanism, associated with the NADPH oxidase-H2O2 system, is involved in the response of rice to drought stress.

Impact of Cross-Strait Trade Liberalization:A Computable General Equilibrium Analysis

这篇论文使用一个可计算出来的一般平衡模型越过台湾海峡调查贸易自由化的潜在的经济效果。我们的模拟结果表明跨海峡的贸易自由化将特别地一般来说并且在台湾在这个区域为经济在外部贸易，国内投资和真实 GDP 上有重要积极影响。而且，从在香港上的台湾和中国大陆之间的自由贸易安排的形成的否定影响似乎相当小。这些结果建议跨海峡的贸易自由化是很可能的在这个区域为经济引起一种胜利胜利状况。

Anatomical and Chemical Alterations but not Photosynthetic Dynamics and Apoplastic Transport Changes are Involved in the Brittleness Culm Mutation of Rice

Brittleness culm is an important agronomic trait that has a potential usefulness in agricultural activity as animal forage although the developmental mechanism is not clear yet. In the present study, the anatomical and chemical characteristics as well as some ecophysiological features in the brittleness culm mutation of rice （Oryza sativa L.） were investigated. Compared with the wild type （WT）, the brittleness culm mutant （bcm） exhibited higher culm vascular bundle distance and lower culm wall thickness, leaf interveinal distance and leaf thickness. Ratio of bundle sheath cell/whole bundle and areas of whole vascular bundles and bundle sheath of leaves were reduced while ratios of xylem and phloem to whole bundles were elevated in bcm. The Fourier transform infrared （FTIR） microspectroscopy analysis and further histochemical and physiological measurements revealed that the different contents and depositions of cell wall components such as pectins, lignin, suberin and cellulose all participated in the mutation of brittleness. However, the mutant presented no significant changes in leaf photosynthetic dynamics and apoplastic transport ability. These results strongly indicate that the alterations in anatomical and chemical characteristics, rather than changes in major ecophysiological features such as photosynthesis and apoplastic transport were involved in the brittleness mutation of rice.

Cross-Strait Trade Relationship and the Changing Role of Hong Kong

This paper applies a computable general equilibrium model to investigate Hong Kong’s changing role during the evolution of the trade relationship across the Taiwan Strait since the 2000s,by examining several important events during the period.Specifically,we estimate the effects of WTO accession for China's Mainland and Taiwan in 2001,the formation of CEPA between China's Mainland and Hong Kong in 2004,as well as the initiation of ECFA between China's Mainland and Taiwan in 2010.The possible impact of a free trade agreement between Taiwan and Hong Kong is also investigated.Our simulation results indicate that Hong Kong has benefited significantly from the accession to the WTO by China's Mainland and Taiwan.Hong Kong could also gain from regional trade agreements with either China's Mainland or Taiwan.As for the initiation of ECFA,its negative impact on Hong Kong seems to be negligibly small.