Programmed Degradation of Pericarp Cells in Wheat Grains Depends on Autophagy.

Wheat is one of the most important food crops in the world, with development of the grains directly determining yield and quality. Understanding grain development and the underlying regulatory mechanisms is therefore essential in improving the yield and quality of wheat. In this study, the developmental characteristics of the pericarp was examined in developing wheat grains of the new variety Jimai 70. As a result, pericarp thickness was found to be thinnest in grains at the top of the spike, followed by those in the middle and thickest at the bottom. Moreover, this difference corresponded to the number of cell layers in the pericarp, which decreased as a result of programmed cell death (PCD). A number of autophagy-related genes (ATGs) are involved in the process of PCD in the pericarp, and in this study, an increase in ATG8-PE expression was observed followed by the appearance of autophagy structures. Meanwhile, following interference of the key autophagy gene ATG8, PCD was inhibited and the thickness of the pericarp increased, resulting in small premature grains. These findings suggest that autophagy and PCD coexist in the pericarp during early development of wheat grains, with both processes increasing from the bottom to the top of the spike. Moreover, PCD was also found to rely on ATG8-mediated autophagy. The results of this study therefore provide a theoretical basis for in-depth studies of the regulatory mechanisms of wheat grain development.

Autophagic Survival Precedes Programmed Cell Death in Wheat Seedlings Exposed to Drought Stress.

Although studies have shown the concomitant occurrence of autophagic and programmed cell death (PCD) in plants, the relationship between autophagy and PCD and the factors determining this relationship remain unclear. In this study, seedlings of the wheat cultivar Jimai 22 were used to examine the occurrence of autophagy and PCD during polyethylene glycol (PEG)-8000-induced drought stress. Autophagy and PCD occurred sequentially, with autophagy at a relatively early stage and PCD at a much later stage. These findings suggest that the duration of drought stress determines the occurrence of PCD following autophagy. Furthermore, the addition of 3-methyladenine (3-MA, an autophagy inhibitor) and the knockdown of autophagy-related gene 6 (ATG6) accelerated PEG-8000-induced PCD, respectively, suggesting that inhibition of autophagy also results in PCD under drought stress. Overall, these findings confirm that wheat seedlings undergo autophagic survival under mild drought stress, with subsequent PCD only under severe drought.

Molecular and Cytogenetic Characterization of a Powdery Mildew-Resistant Wheat-Aegilops mutica Partial Amphiploid and Addition Line.

Aegilops mutica Boiss., a diploid species (2n = 2x = 14, TT), has been rarely studied before. In this research, a hexaploid wheat (cv. Chinese Spring)-Ae. mutica partial amphiploid and a wheat-Ae. mutica addition line were characterized by chromosome karyotyping, FISH using oligonucleotides Oligo-pTa535-1, Oligo-pSc119.2-1, and (GAA)8 as probes, and EST-based molecular markers. The results showed that the partial amphiploid strain consisted of 20 pairs of wheat chromosomes and 7 pairs of Ae. mutica chromosomes, with both wheat 7B chromosomes missing. EST-based molecular marker data suggested that the wheat-Ae. mutica addition line carries the 7T chromosome. Resistance tests indicated that both the partial amphiploid and the 7T addition line were highly resistant to powdery mildew, whereas the wheat control line Chinese Spring was highly susceptible, indicating the presence of a potentially new powdery mildew resistance gene on the Ae. mutica 7T chromosome. The karyotype, FISH patterns, and molecular markers can now be used to identify Ae. mutica chromatin in a wheat background, and the 7T addition could be used as a new powdery mildew resistance source for wheat breeding.

[Comparative study on the HPV infection rate of different esophageal squamous cell carcinoma in Anyang China].

OBJECTIVE: Comparative and statistical analysis the HPV infection rate between fresh tissue and Paraffin-embedded Specimens of esophageal squamous cell carcinoma,and comparative the testing results with others regions. METHODS: Extracted the total DNA from the novel fresh tissue and Paraffin-embedded Specimens; Detected the DNA by PCR with universal primer and Detected the HPV type with human papilloma virus nucleic acid amplification-based typing detection reagent kit (Hybribio); Compared the statistical result from the different specimens; analyzed the result between different region. RESULTS: HPV infection rate of fresh tissue is 82.6% with HPV16 (34.8%) and HPV18 (34.8%), and paraffin-embedded specimens is 78.2% with HPV16 (30.4%) and HPV18 (17.4%). CONCLUSION: The results provides the first evidence that there wasn't noticeable difference between HPV infection rate of the two specimens. So broader specimen source could be used for HPV testing.