Impacts of Environmental Factors on Degradation of CrylAb Insecticidal Protein in Leaf-Blade Powders of Transgenic Bt Rice

The determination of the environmental fate of Bt insecticidal protein released by Bt rice plants in paddy soils is a key issue in its ecological risk assessment. In this study, the impacts of soil water content, pH, and temperature on the degradation of CrylAb protein expressed in the leaves of Bt rice KMD2 were studied in the laboratory. Three types of paddy soils were used, i.e., blue clayey paddy soil, pale paddy soil on quaternary red soil, and marine-fluvigenic yellow loamy paddy soil. Ground powders of KMD2 leaf blades were mixed with each type of soil, and degradation dynamics of Cry lAb were measured using enzyme-linked immunosorbent assay （ELISA）. The degradation rate of CrylAb was high at the early experimental stage, but slowed down steadily at middle and later stages, which could be described by exponential equations, with the half-life period of degradation determined as 1.8-4.0 d. The soil water content, pH, and temperature could affect the degradation of CrylAb, but the effects of soil pH and temperature were relatively greater. In general, CrylAb degradations were slower under lower soil pH and temperature conditions, especially for marine-fluvigenic yellow loamy paddy soil.     

Effects of Cyclic Electron Flow Inhibitor （Antimycin A） on Photosystem Photoinhibition of Sweet Pepper Leaves upon Exposure to Chilling Stress Under Low Irradiance

In chloroplast, there were two pathways involved in the cyclic electron flow around photosystem 1 （PS 1）. One was the NADH dehydrogenase （NDH）-dependent flow and the other was the ferredoxin quinone reductase-dependent flow. It was proposed that the NDH-dependent cyclic electron flow around PSI was related to the xanthophyll cycle-dependent non-photochemical quenching （NPQ） at chilling temperature under low irradiance （CL）. The function of the chloroplastic cyclic electron flow around PS 1 was examined by comparing sweet pepper （Capsicum annuum L.） control with its antimycin A （AA）-fed leaves upon exposure to CL stress. During CL stress, the maximum photochemical efficiency of PS2 （Fv/Fm） decreased markedly in both controls and AA-fed leaves, and P700＋ was also lower in AA-fed leaves than in controls. These results implied that cyclic electron flow around PS 1 functioned to protect the photosynthetic apparatus from CL stress. Under such stress, NPQ and PS2-driven electron transport rate were different between AA-fed leaves and controls. The lower NPQ in AA-fed leaves might be related to an inefficient proton gradient across thylakoid membranes （ApH） because of inhibiting cyclic electron flow around PS 1 under CL stress.     

Versuche zur Gewebekultur in der GattungLycopersicon Miller I. Übersicht

Zusammenfassung Übersicht zu Anwendungen der Gewebekulturtechnik (Kalluskultur, Sproß- und Pflanzenregeneration aus Explantaten, Antherenkultur, Embryokultur, mit Ausnahme von Protoplastentechniken) in der GattungLycopersicon Miller.

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Experiments on tissue culture in the genusLycopersicon Miller. I. Survey

Summary A survey is given concerning applications of tissue culture techniques (callus culture, shoot and plant regeneration from explants and calluses, anther culture, embryo culture, except protoplast techniques) in the genusLycopersicon Miller.

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Lycopersicon Miller. I.

Lycopersicon Miller ( ): , , .

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Herrn Prof. Dr. Dr. h. c. mult.Hans Stubbe mit herzlichen Glückwünschen zu seinem achtzigsten Geburtstag gewidmet.