UDP-glucose pyrophosphorylase (UGPase) catalyzes the reversible production of glucose-1-phosphate and UTP to UDPglucose and pyrophosphate. The rice (Oryza sativa) genome contains two homologous UGPase genes, Ugp1 and Ugp2. We report a functional characterization of rice Ugp1, which is expressed throughout the plant, with highest expression in florets, especially in pollen during anther development. Ugp1 silencing by RNA interference or cosuppression results in male sterility. Expressing a double-stranded RNA interference construct in Ugp1-RI plants resulted in complete suppression of both Ugp1 and Ugp2, together with various pleiotropic developmental abnormalities, suggesting that UGPase plays critical roles in plant growth and development. More importantly, Ugp1-cosuppressing plants contained unprocessed introncontaining primary transcripts derived from transcription of the overexpression construct. These aberrant transcripts undergo temperature-sensitive splicing in florets, leading to a novel thermosensitive genic male sterility. Pollen mother cells (PMCs) of Ugp1-silenced plants appeared normal before meiosis, but during meiosis, normal callose deposition was disrupted. Consequently, the PMCs began to degenerate at the early meiosis stage, eventually resulting in complete pollen collapse. In addition, the degeneration of the tapetum and middle layer was inhibited. These results demonstrate that rice Ugp1 is required for callose deposition during PMC meiosis and bridges the apoplastic unloading pathway and pollen development.

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Atmospheric pressure cold plasma, with advantages such as high particle activity, no thermal damage, high efficiency and direct and friendly contact with human tissues, is considered to have great potential in biomedical applications. Therefore, 'plasma medicine' as a new interdiscipline has been developed in the past two decades. This review first briefly describes the development of typical plasma sources suitable for biomedical applications, and those with different discharge forms are simply compared, evaluated and summarized. Subsequently, measurement of the crucial gaseous reactive particles (e.g. OH and O) and their spatio-temporal distributions are introduced. Meanwhile, the generation and variation rules and the related critical macroscopic parameters of the plasma-induced aqueous reactive species are summarized. Finally, related studies in the last ten years on the mechanisms of the plasma-driven microbial inactivation and plasma-induced apoptosis of cancer cells are introduced. Moreover, some scientific problems that need to be urgently solved in the field of plasma medicine are also discussed. This review will provide useful guidance for future related research.

Uridine diphosphate (UDP)‐glucose pyrophosphorylases (UGPases, EC 2.7.7.9) are key enzymes in plant carbohydrate metabolism and cell‐wall biosynthesis, catalyzing the reversible production of glucose‐1‐phosphate and uridine triphosphate from UDP‐glucose and pyrophosphate. In the study presented here, two‐dimensional gel electrophoresis followed by peptide sequencing analysis using nanospray electrospray ionization tandem mass spectrometry showed that rice (Oryza sativa L.) UGPase undergoes N‐terminal acetylation, which may be a conserved modification of plant UGPases. We also obtained indications, using two‐dimensional gel electrophoresis in combination with western blot analysis, that multiple isoforms of UGPase are present in rice in vivo and are regulated tissue‐specifically. The rice genome contains two homologous UGPase genes, OsUgp1 and OsUgp2. We present evidence that both OsUgp1 and OsUgp2 are ubiquitously expressed throughout rice development, and that OsUgp1 is expressed at much higher levels than OsUgp2. In accordance with the gene expression patterns, the UGPase isoform derived from the OsUgp1 gene predominated in various rice tissues and exhibited qualitative variations (position shifts and presence/absence) between rice varieties B5 and Taichung native 1 (TN1). Our results demonstrate that these qualitative variations are attributable to a single amino acid substitution of Asp‐462 in B5 by His in TN1, corresponding to the allelic difference in the OsUgp1 gene between B5 and TN1.

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By using the method of dynamical systems, we continuously study the dynamical behavior for the first class of singular nonlinear traveling wave systems. As an example, the traveling wave solutions for a generalized coupled KdV equations are discussed. Exact explicit parametric representations of solitary wave solutions, periodic wave solutions and kink wave solutions are given.