Transcriptome profiling of fully open flowers in a frost-tolerant almond genotype in response to freezing stress.

Spring frost is a major limiting abiotic stress for the cultivation of almonds [Prunus dulcis (Mill.)] in Mediterranean areas or the Middle East. Spring frost, in particular, damages almond fully open flowers, resulting to significant reduction in yield. Little is known about the genetic factors expressed after frost stress in Prunus spp. as well as in almond fully open flowers. Here, we provide the molecular signature of pistils of fully open flowers from a frost-tolerant almond genotype. The level of frost tolerance in this genotype was determined for all three flowering stages and was confirmed by comparing it to two other cultivars using several physiological analyses. Afterwards, comprehensive expression profiling of genes expressed in fully open flowers was performed after being exposed to frost temperatures (during post-thaw period). Clean reads, 27,104,070 and 32,730,772, were obtained for non-frost-treated and frost-treated (FT) libraries, respectively. A total of 62.24 Mb was assembled, generating 50,896 unigenes and 66,906 transcripts. Therefore, 863 upregulated genes and 555 downregulated genes were identified in the FT library. Functional annotation showed that most of the upregulated genes were related to various biological processes involved in responding to abiotic stress. For the first time, a highly expressed cold-shock protein was identified in the reproductive organ of fruit trees. The expression of six genes was validated by RT-PCR. As the first comprehensive analysis of open flowers in a frost-tolerant almond genotype, this study represents a key step toward the molecular breeding of fruit tree species for frost tolerance.

Correction to: Transcriptome profiling of fully open flowers in a frost­tolerant almond genotype in response to freezing stress.

In the original publication of the article, the affiliation of the third author has been incorrectly published as University of Yazd. However, the correct affiliation is Yazd University.

Epstein-Barr virus DNA in colorectal carcinoma in Iranian patients.

Colorectal cancer is an often fatal cancer with a rapidly increasing incidence. Current mortality is estimated to be approximately 600,000 per year, and both environmental and genetic factors are involved in its etiology. Viral and bacterial factors have a proven role in the incidence of approximately 20% of cancers. In the present study, the Epstein-Barr virus (EBV) was detected in 50 colorectal adenocarcinomas, 12 colon adenomas, and 38 control tissue samples using polymerase chain reaction (PCR). Epstein-Barr virus DNA was identified in 19 of the adenocarcinoma tissues, 1 adenoma tissue and 24 control specimens. In total, 15.8% (3/18) of the colorectal samples in the well-differentiated grade, 79% (15/30) in the moderately differentiated, and 5.2% (1/2) in the poorly differentiated grade tested positive for viral infection. Epstein-Barr virus was more prevalent in the moderately differentiated grade. Statistical analysis did not suggest a significant association between EBV and the incidence of colorectal cancer. However, it appears that the virus stimulates progression of the malignancy.

Characterization of the newly isolated Geobacillus sp. T1, the efficient cellulase-producer on untreated barley and wheat straws.

A thermophile cellulase-producing bacterium was isolated and identified as closely related to Geobacillus subterraneus. The strain, named Geobacillus sp. T1, was able to grow and produce cellulase on cellobiose, microcrystalline cellulose, carboxymethylcellulose (CMC), barley straw, wheat straw and Whatman No. 1 filter paper. However, barley and wheat straws were significantly better substrates for cellulase production. When Geobacillus sp. T1 was cultivated in the presence of 0.5% barley straw, 0.1% Tween 80 and pH 6.5 at 50°C, the maximum level of free cellulase up to 143.50 U/mL was produced after 24h. This cellulase (≈ 54 kDa) was most active at pH 6.5 and 70°C. The enzyme in citrate phosphate buffer (10mM) was stable at 60°C for at least 1h. Geobacillus sp. T1 with efficient growth and cellulase production on straws seems a potential candidate for conversion of agricultural biomass to fuels.