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SUMMARY: Seed vigor has major impact on the rate and uniformity of seedling growth, crop yield, and quality. However, the epigenetic regulatory mechanism of crop seed vigor remains unclear. In this study, a (jumonji C) JmjC gene of the histone lysine demethylase OsJMJ718 was cloned in rice, and its roles in seed germination and its epigenetic regulation mechanism were investigated. OsJMJ718 was located in the nucleus and was engaged in H3K9 methylation. Histochemical GUS staining analysis revealed OsJMJ718 was highly expressed in seed embryos. Abiotic stress strongly induced the OsJMJ718 transcriptional accumulation level. Germination percentage and seedling vigor index of OsJMJ718 knockout lines (OsJMJ718‐CR) were lower than those of the wild type (WT). Chromatin immunoprecipitation followed by sequencing (ChIP‐seq) of seeds imbibed for 24 h showed an increase in H3K9me3 deposition of thousands of genes in OsJMJ718‐CR. ChIP‐seq results and transcriptome analysis showed that differentially expressed genes were enriched in ABA and ethylene signal transduction pathways. The content of ABA in OsJMJ718‐CR was higher than that in WT seeds. OsJMJ718 overexpression enhanced sensitivity to ABA during germination and early seedling growth. In the seed imbibition stage, ABA and ethylene content diminished and augmented, separately, suggesting that OsJMJ718 may adjust rice seed germination through the ABA and ethylene signal transduction pathways. This study displayed the important function of OsJMJ718 in adjusting rice seed germination and vigor, which will provide an essential reference for practical issues, such as improving rice vigor and promoting direct rice sowing production. Significance Statement: Understanding of the molecular mechanisms involved in seed vigor is an important objective in plant biology studies, and could be used to improve grain yields and seed quality. This study reported the important role of OsJMJ718 in regulating rice seed germination and vigor, which will provide an essential reference for practical issues, such as improving rice vigor and promoting direct rice sowing production. [ABSTRACT FROM AUTHOR]

Adverse environmental stresses affect plant growth and crop yields. Sheepgrass (Leymus chinensis (Trin.) Tzvel), an important forage grass that is widely distributed in the east of Eurasia steppe, has high tolerance to extreme low temperature. Many genes that respond to cold stress were identified in sheepgrass by RNA‐sequencing, but more detailed studies are needed to dissect the function of those genes. Here, we found that LcFIN2, a sheepgrass freezing‐induced protein 2, encoded a chloroplast‐targeted protein. Expression of LcFIN2 was upregulated by freezing, chilling, NaCl and abscisic acid (ABA) treatments. Overexpression of LcFIN2 enhanced the survival rate of transgenic Arabidopsis after freezing stress. Importantly, heterologous expression of LcFIN2 in rice exhibited not only higher survival rate but also accumulated various soluble substances and reduced membrane damage in rice under chilling stress. Furthermore, the chlorophyll content, the quantum photochemistry efficiency of photosystem II (ΦPSII), the non‐photochemical quenching (NPQ), the net photosynthesis rate (Pn) and the expression of some chloroplast ribosomal‐related and photosynthesis‐related genes were higher in the transgenic rice under chilling stress. These findings suggested that the LcFIN2 gene could potentially be used to improve low‐temperature tolerance in crops. [ABSTRACT FROM AUTHOR]

LcbHLH92, a pleiotropic gene from sheepgrass, negatively regulates anthocyanins/proanthocyandins and reduces seed dormancy in transgenic Arabidopsis. Sheepgrass (Leymus chinensis) is an important native forage grass, and it is widely grown in north China. Differential dormancy exists in sheepgrass germplasms with different seed colors. To decipher and find potential genes underlying this phenomenon, we compared the transcript profiles of yellow seeds with weak dormancy and brown seeds with strong dormancy. We identified a transcription factor gene LcbHLH92 which is negatively correlated with those of anthocyanin/proanthocyanidin-specific pathway genes, anthocyanidin synthase (ANS) and anthocyanidin reductase (ANR). LcbHLH92 had two transcripts, LcbHLH92a and LcbHLH92b, and their expression could be induced by abscisic acid, cold, and NaCl. Overexpression of LcbHLH92a or LcbHLH92b in Arabidopsis significantly inhibited the transcript levels of dihydroflavonol reductase (DFR) and ANS genes in leaves and seeds, which resulted in a decrease in anthocyanins and proanthocyanidins, respectively. Importantly, transgenic Arabidopsis seeds with a yellow color showed a higher germination rate than did the wild-type with a brown seed color. Moreover, LcbHLH92a and LcbHLH92b repressed the transcription of Transparent Testa8, ANS, DFR, and ANR, possibly by elevating the transcript levels of jasmonate-ZIM domain proteins through binding to their promoters. Together, our results demonstrate that LcbHLH92a and LcbHLH92b are negative regulators of the anthocyanin/proanthocyanidin pathway and influence seed dormancy. [ABSTRACT FROM AUTHOR]

Abstract: α1‐Antitrypsin (AAT) is widely used to treat patients with congenital AAT deficiency. Cohn Fraction IV (Cohn F IV) is normally discarded during the manufacturing process of albumin but contains approximately 33% of plasma AAT. We established a new process for large‐scale purification of AAT from it. liquid chromatography‐electrospray ionization‐tandem mass spectrometry and high‐performance liquid chromatography were applied for qualitative identification and composition analysis, respectively. Stabilizers were optimized for AAT activity protection during lyophilization and dry‐heat. Virus inactivation by dry‐heat and solvent/detergent (S/D) was validated on a range of viruses. AAT with purity of 95.54%, specific activity of 3,938.5 IU/mg, and yield of 26.79%, was achieved. More than 95% activity was reserved after S/D. More than 96% activity was obtained after lyophilization or dry‐heat. After S/D, pseudorabies virus (PRV) and vesicular stomatitis virus (VSV) were inactivated below detectable level within 1 H. Virus titer reductions of more than 5.50 log10 and 5.38 log10 were achieved for PRV and VSV, respectively. Porcine parvovirus and encephalomyocarditis virus were inactivated by 3.17 log10 and 5.88 log10 reduction after dry‐heat. The advantages of this process, including suitability for large‐scale production, high purity, better utilization of human plasma, viral safety, commercial and inexpensive chromatography medium, may facilitate its further application. [ABSTRACT FROM AUTHOR]

As a perennial forage crop broadly distributed in eastern Eurasia, sheepgrass ( Leymus chinensis ( Trin.) Tzvel) is highly tolerant to low-temperature stress. Previous report indicates that sheepgrass is able to endure as low as −47.5 °C,allowing it to survive through the cold winter season. However, due to the lack of sufficient studies, the underlying mechanism towards the extraordinary low-temperature tolerance is unclear. Although the transcription profiling has provided insight into the transcriptome response to cold stress, more detailed studies are required to dissect the molecular mechanism regarding the excellent abiotic stress tolerance. In this work, we report a novel transcript factor Lc FIN1 ( L. chinensis freezing-induced 1) from sheepgrass. Lc FIN1 showed no homology with other known genes and was rapidly and highly induced by cold stress, suggesting that Lc FIN1 participates in the early response to cold stress. Consistently, ectopic expression of Lc FIN1 significantly increased cold stress tolerance in the transgenic plants, as indicated by the higher survival rate, fresh weight and other stress-related indexes after a freezing treatment. Transcriptome analysis showed that numerous stress-related genes were differentially expressed in Lc FIN1-overexpressing plants, suggesting that Lc FIN1 may enhance plant abiotic stress tolerance by transcriptional regulation. Electrophoretic mobility shift assays and CHIP- qPCR showed that Lc CBF1 can bind to the CRT/ DRE cis-element located in the promoter region of Lc FIN1, suggesting that Lc FIN1 is directly regulated by Lc CBF1. Taken together, our results suggest that Lc FIN1 positively regulates plant adaptation response to cold stress and is a promising candidate gene to improve crop cold tolerance. [ABSTRACT FROM AUTHOR]