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The lack of a MIRNA set and genome sequence of wild rice ( Oryza rufipogon) has prevented us from determining the role of MIRNA genes in rice domestication., In this study, a genome, three small RNA populations and a degradome of O. rufipogon were sequenced by Illumina platform and the expression levels of microRNAs (mi RNAs) were investigated by mi RNA chips., A de novo O. rufipogon genome was assembled using c. 55× coverage of raw sequencing data and a total of 387 MIRNAs were identified in the O. rufipogon genome based on c. 5.2 million unique small RNA reads from three different tissues of O. rufipogon. Of these, O. rufipogon MIRNAs, 259 were not found in the cultivated rice, suggesting a loss of these MIRNAs in the cultivated rice. We also found that 48 MIRNAs were novel in the cultivated rice, suggesting that they were potential targets of domestication selection. Some mi RNAs showed significant expression differences between wild and cultivated rice, suggesting that expression of mi RNA could also be a target of domestication, as demonstrated for the miR164 family., Our results illustrated that MIRNA genes, like protein-coding genes, might have been significantly shaped during rice domestication and could be one of the driving forces that contributed to rice domestication. [ABSTRACT FROM AUTHOR]

A high-density haplotype map recently enabled a genome-wide association study (GWAS) in a population of indica subspecies of Chinese rice landraces. Here we extend this methodology to a larger and more diverse sample of 950 worldwide rice varieties, including the Oryza sativa indica and Oryza sativa japonica subspecies, to perform an additional GWAS. We identified a total of 32 new loci associated with flowering time and with ten grain-related traits, indicating that the larger sample increased the power to detect trait-associated variants using GWAS. To characterize various alleles and complex genetic variation, we developed an analytical framework for haplotype-based de novo assembly of the low-coverage sequencing data in rice. We identified candidate genes for 18 associated loci through detailed annotation. This study shows that the integrated approach of sequence-based GWAS and functional genome annotation has the potential to match complex traits to their causal polymorphisms in rice. [ABSTRACT FROM AUTHOR]

With 2 figures and 1 table This study used a double haploid (DH) population of 'Maybelle', a USA japonica variety susceptible to sheath blight (ShB), and 'Baiyeqiu', a Chinese indica landrace resistant to ShB, to identify quantitative trait loci (QTL) controlling rice ShB resistance. The DH population (251 lines) was inoculated with R. solani strain RH‐9. A molecular linkage map saturated with 227 markers was constructed. We detected a total of four QTL located on four different chromosomes (qShB1, qShB2, qShB3 and qShB5). The qShB1 QTL explained 8.9% of the phenotypic variation in 2007 and 13.2% in 2008. [ABSTRACT FROM AUTHOR]

ABSTRACT Tiller angle is a key agricultural trait that establishes plant architecture, which in turn strongly affects grain yield by influencing planting density in rice. The shoot gravity response plays a crucial role in the regulation of tiller angle in rice, but the underlying molecular mechanism is largely unknown. Here, we report the identification of the BIG TILLER ANGLE2 (BTA2), which regulates tiller angle by controlling the shoot gravity response in rice. Loss‐of‐function mutation of BTA2 dramatically reduced auxin content and affected auxin distribution in rice shoot base, leading to impaired gravitropism and therefore a big tiller angle. BTA2 interacted with AUXIN RESPONSE FACTOR7 (ARF7) to modulate rice tiller angle through the gravity signaling pathway. The BTA2 protein was highly conserved during evolution. Sequence variation in the BTA2 promoter of indica cultivars harboring a less expressed BTA2 allele caused lower BTA2 expression in shoot base and thus wide tiller angle during rice domestication. Overexpression of BTA2 significantly increased grain yield in the elite rice cultivar Huanghuazhan under appropriate dense planting conditions. Our findings thus uncovered the BTA2‐ARF7 module that regulates tiller angle by mediating the shoot gravity response. Our work offers a target for genetic manipulation of plant architecture and valuable information for crop improvement by producing the ideal plant type. [ABSTRACT FROM AUTHOR]

A comprehensive analytical method was developed for the simultaneous determination of 14 sexual hormones in health care products by ultra performance liquid chromatography-atmospheric pressure chemical ionization-triple quadrupole mass spectrometry (UPLC-APCI-MS/MS). The samples were extracted twice with acetonitrile and the extracts were purified using hydrophilic-lipophilic balance (HLB) cartridges. Chromatographic separation was achieved on a Hypersil Gold C18 column (100 mm×2.1 mm, 1.9 μm) by gradient elution with acetonitrile and 10 mmol/L ammonium acetate aqueous solution as the mobile phases. Compounds were detected by APCI-MS/MS with external standard calibration curve method. All the 14 sexual hormones showed a good linear trend in their respective concentration ranges and the correlation coefficients ( r ) were no less than 0.996. The limits of detection (LODs) ranged from 0.0990 μg/kg to 2.09 μg/kg. The limits of quantification (LOQs) were in the range of 0.495-5.23 μg/kg. The average recoveries of the 14 sexual hormones in the health care product samples ranged from 65.8% to 118.8% at the three spiked levels. The precisions ( n =6) ranged from 0.6% to 8.7% ( n =6). The method is simple, sensitive, accurate and precise, and is suitable for the determination of the illegal added sexual hormones in the health care products.

Purpose: To analyze the distributions and characteristics of initial prostate-specific antigen (PSA) and PSA velocity in Chinese men aged 50 years and younger without prostate cancer., Methods: The initial PSA test of men aged 50 years and younger, taken from January 2008 to December 2018 in two medical centers, was retrospectively analyzed. Cases with prostate cancer were excluded. The distributions of initial PSA and PSA velocity, and the correlations between these two values were estimated. Kaplan-Meier and log-rank test were used to estimate significant difference on the risk of PSA≥2.5 ng/mL after initial PSA measurement, stratified by median initial PSA (0.6 ng/mL)., Results: A total of 9461 men with non-prostate cancer were included in this study. The median initial PSA value was 0.7 ng/mL. A total of 853 men had their PSA measured two times or more and the median PSA velocity was 0.026 ng·mL-1·yr-1. There was no two-two direct correlation between initial PSA testing age, initial PSA, and PSA velocity. After a follow-up of up to 10 years from the baseline PSA test, the risk of PSA ≥ 2.5 ng/mL, stratified by median initial PSA (0.7 ng/mL), was significantly different (log-rank test, p<0.001)., Conclusion: More than 25% of the men aged ≤ 50 years should have regularly PSA screening based on current guidelines. However, the subsequent risk of being diagnosed with prostate cancer in these men is unknown. Men aged 50 years and younger with an initial PSA higher than the median (0.7 ng/mL) have a subsequent higher risk of abnormal PSA value.

In this paper, the effects of transgenes insertion on the outcross potentiality of rice varieties were assessed by pollen vigor and hybrid seed set. The in vitro pollen germination rates of five transgenic rice lines transformed respectively with bar, crylAb, BADH and Xa21 gene were investigated, and compared with their relative receptor rice varieties. The results showed that there existed a significant difference in in vitro pollen germination rates between receptor rice varieties, but no significant difference was found between transgenic rice varieties and their relative receptors. The in vitro pollen germination rate for transgenic rice varieties varied from 0.416 to 0.584, similar to that of their relative receptors (0.400-0.574). Investigation on the hybrid seed set of 26 hand-crosses showed that the inserted bar or crylAb gene had a significant effect on the hybrid seed set of receptors, while the effect of Xa21 gene was smaller. The hybrid seed set rate of non-transgenic rice in crosses with transgenic rice (pollen donor) was from 0.056 to 0.413, not different from that in crosses with their relative receptors (0.052-0.417). It's suggested that transgenes insertion had little effect on the outcross potentiality of rice varieties.