Phytophthora capsici inflicts damage on numerous crop plants by secreting a series of pectinase including pectate lyase (PEL). Here, we report a pectate lyase gene (Pcpel1) from a genomic library of a highly virulent P. capsici strain SD33. Pcpel1 was identified as an open reading frame of 1233 bp encoding a protein of 410 amino acids with a predicted amino-terminal signal sequence of 21 amino acids. The predicted protein of Pcpel1 has a calculated molecular mass of 43.8 kDa and a pI value of 6.8. Analysis of the amino acid sequence suggested that it was a member of the polysaccharide lyase family 1 that shows pectate lyase activity. Moreover, heterologous expression of Pcpel1 in Pichia pastoris produced proteins with molecular mass 66 kDa, very likely due to differential glycosylation by the yeast. By western blotting and northern blotting analysis, Pcpel1 was strongly expressed during interaction of P. capsici with the host plant, suggesting its involvement in the process of host infection. The role of Pcpel1 in cell wall disassembly and host/parasite interaction is discussed.

In this letter, self-aligned dual implantation technique was successfully used to speed up the carrier transportation from sidewall quantum well (SQWL) to quantum wire (QWR) region in Vgroove A1GaAs/GaAs QWR structure. Photoluminescence (PL) and time resolved photoluminescence (TRPL) show that the lateral confinement was enhanced after intermixing by intennixing the necking region. Lifetime was obviously enlonged after selective intermixing, which comes from the enhanced lateral carrier confinement. Strong hot exciton relaxation process in QWRs region is observed after selective intermixing.

Photoexcitation and relaxation dynamics of photoinduced defects in the emeraldine base (EB ) form of polyaniline, poly (m-aniline ) (PMAn ) and the emeraldine salt (ES ) form of polyaniline embedded in polymethylmathacrylate (PMMA) has been measured using femtosecond time-resolved absorption saturation technology. The relaxation of photoexcitation, observed in EB, consists of two components : an initial ultrafast relaxation ('-'100 fs) and a following slow relaxation ('-30 ps) . A slower photoinduced bleaching compared with that in EB and 5-ps relaxation process were observed in PMAn. The ES/PMMA film exhibits the fastest ground recovery ('-'0. 5 ps) of photoexcitation. which is about two order of magnitude faster than that of EB and an order of magnitude faster than that of PMAn. This ultrafast polaron relaxation in ESIPMMA was observed for the first time. Optical bistability and multistability were obtained by the simulation of the excitation and relaxation processes observed in the three forms of polyaniline. The switching time is strongly affected by the relaxation dynamics of the photoexcited defects.

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