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By oligo microarray expression profiling, we identified a rice RING zinc-finger protein (RZFP), OsRZFP34, whose gene expression increased with high temperature or abscisic acid (ABA) treatment. As compared with the wild type, rice and Arabidopsis with OsRZFP34 overexpression showed increased relative stomata opening even with ABA treatment. Furthermore, loss-of-function mutation of OsRZFP34 and AtRZFP34 (At5g22920), an OsRZFP34 homolog in Arabidopsis, decreased relative stomata aperture under nonstress control conditions. Expressing OsRZFP34 in atrzfp34 reverted the mutant phenotype to normal, which indicates a conserved molecular function between OsRZFP34 and AtRZFP34. Analysis of water loss and leaf temperature under stress conditions revealed a higher evaporation rate and cooling effect in OsRZFP34-overexpressing Arabidopsis and rice than the wild type, atrzfp34 and osrzfp34. Thus, stomata opening, enhanced leaf cooling, and ABA insensitivity was conserved with OsRZFP34 expression. Transcription profiling of transgenic rice overexpressing OsRZFP34 revealed many genes involved in OsRZFP34-mediated stomatal movement. Several genes upregulated or downregulated in OsRZFP34-overexpressing plants were previously implicated in Ca(2+) sensing, K(+) regulator, and ABA response. We suggest that OsRZFP34 may modulate these genes to control stomata opening.

Formosan lily (Lilium formosanum), a species endemic in Taiwan, is characterized by showy and fragrant flowers. To understand the gene expression at its reproductive phase, we constructed a suppression subtractive cDNA library of immature flower buds, from which 1,324 expressed sequence tags (ESTs) were randomly selected and sequenced. These EST sequences were clustered into 974 nonredundant sequences. Based on BLAST searching, functions of 376 sequences (39%) were determined, and 80 sequences showed high similarities to genes encoding hypothetical proteins without known functions. Another 518 sequences did not show significant homology to any known sequences and were therefore classified as novel sequences. Further analyses of the 376 ESTs sequences revealed high abundance of stress-related and flowerdevelopment genes. The highly expressing stress-related transcripts include 39 with high similarities to lipid transfer proteins, five to ascorbate peroxidases, and five to heat shock proteins 70. Using real-time quantitative RT-PCR analysis, we further revealed the expression of these three genes in the immature flower buds and in the pistils or stamens of the blooming flower of Formosan lily collected from alpine regions. These results suggest that the flower of L. formosanum possesses a significantly elevated level of stress genes in response to alpine environment and the ESTs analyzed here represent a valuable resource for studying a resistance mechanism of the reproductive organs of Formosan lily.

Background/AimsDetailed characterization of the ultrastructural morphology of intercellular space in gastroesophageal reflux disease has not been fully studied. We aimed to investigate whether subtle alteration in intercellular space structure and tight junction proteins might differ among patients with gastroesophageal reflux disease.MethodsEsophageal biopsies at 5 cm above the gastroesophageal junction were obtained from 6 asymptomatic controls, 10 patients with reflux symptoms but without erosions, and 18 patients with erosions. The biopsies were morphologically evaluated by transmission electron microscopy, and by using immunohistochemistry for tight junction proteins (claudin-1 and claudin-2 proteins).ResultsThe expressions of tight junction proteins did not differ between asymptomatic controls and gastroesophageal reflux disease patients. In patients with gastroesophageal reflux disease, altered desmosomal junction morphology was only found in upper stratified squamous epithelium. Dilated intercellular space occurred only in upper stratified squamous epithelium and in patients with erosive esophagitis.ConclusionsThis study suggests that dilated intercellular space may not be uniformly present inside the esophageal mucosa and predominantly it is located in upper squamous epithelium. Presence of desmosomal junction alterations is associated with increased severity of gastroesophageal reflux disease. Besides dilated intercellular space, subtle changes in ultrastructural morphology of intercellular space allow better identification of inflamed esophageal mucosa relevant to acid reflux.