CRISPR-Cas system: a powerful tool for genome engineering.

Targeted gene regulation on a genome-wide scale is a powerful strategy for interrogating, perturbing, and engineering cellular systems. Recent advances with the RNA-mediated Cas9 endonuclease derived from clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) systems have dramatically transformed our ability to specifically modify intact genomes of diverse cells and organisms. The CRISPR-Cas system has been adapted as an efficient, facile, and robust gene-targeting technology with the potential for high-throughput and multiplexed genome engineering. Exciting breakthroughs in understanding the mechanisms of the CRISPR-Cas system and its enormous potential for applications across basic science, agricultural and biotechnology.

Tapetum: regulation and role in sporopollenin biosynthesis in Arabidopsis.

Pollen acts as a biological protector for protecting male sperm from various harsh conditions and is covered by an outer cell wall polymer called the exine, a major constituent of which is sporopollenin. The tapetum is in direct contact with the developing gametophytes and plays an essential role in pollen wall and pollen coat formation. The precise molecular mechanisms underlying tapetal development remain highly elusive, but molecular genetic studies have identified a number of genes that control the formation, differentiation, and programmed cell death of tapetum and interactions of genes in tapetal development. Herein, several lines of evidence suggest that sporopollenin is built up via catalytic enzyme reactions in the tapetum. Furthermore, as based on genetic evidence, we review the currently accepted understanding of the molecular regulation of sporopollenin biosynthesis and examine unanswered questions regarding the requirements underpinning proper exine pattern formation.

Sequence mining and transcript profiling to explore differentially expressed genes associated with lipid biosynthesis during soybean seed development.

BACKGROUND: Soybean (Glycine max L.) is one of the most important oil crops in the world. It is desirable to increase oil yields from soybean, and so this has been a major goal of oilseed engineering. However, it is still uncertain how many genes and which genes are involved in lipid biosynthesis. RESULTS: Here, we evaluated changes in gene expression over the course of seed development using Illumina (formerly Solexa) RNA-sequencing. Tissues at 15 days after flowering (DAF) served as the control, and a total of 11592, 16594, and 16255 differentially expressed unigenes were identified at 35, 55, and 65 DAF, respectively. Gene Ontology analyses detected 113 co-expressed unigenes associated with lipid biosynthesis. Of these, 15 showed significant changes in expression levels (log2fold values ≥ 1) during seed development. Pathway analysis revealed 24 co-expressed transcripts involved in lipid biosynthesis and fatty acid biosynthesis pathways. We selected 12 differentially expressed genes and analyzed their expressions using qRT-PCR. The results were consistent with those obtained from Solexa sequencing. CONCLUSION: These results provide a comprehensive molecular biology background for research on soybean seed development, particularly with respect to the process of oil accumulation. All of the genes identified in our research have significance for breeding soybeans with increased oil contents.

Cloning of a vacuolar H(+)-pyrophosphatase gene from the halophyte Suaeda corniculata whose heterologous overexpression improves salt, saline-alkali and drought tolerance in Arabidopsis.

Salt, saline-alkali conditions, and drought are major environmental factors limiting plant growth and productivity. The vacuolar H(+)-translocating inorganic pyrophosphatase (V-H(+)-PPase) is an electrogenic proton pump that translocates protons into vacuoles in plant cells. Expression of V-H(+)-PPase increases in plants under a number of abiotic stresses, and is thought to have an important role in adaptation to abiotic stress. In this work, we report the isolation and characterization of the gene, ScVP, encoding a vacuolar inorganic pyrophosphatase (V-H(+)-PPase) from the halophyte, Suaeda corniculata. Semi-quantitative reverse transcription-polymerase chain reaction analysis showed that ScVP was induced in roots, stems and leaves under treatment with salt, saline-alkali and drought. Compared with wild-type (WT) Arabidopsis, transgenic plants overexpressing ScVP accumulated more Na(+) in leaves and roots, and showed increased tolerance to high salinity, saline-alkali and drought stresses. The germination percentage of transgenic Arabidopsis seeds was higher than that of WT seeds under the abiotic stresses. The root length of transgenic plants under salt stress was longer than that of WT plants. Furthermore, the rate of water loss during drought stress was higher in WT than in transgenic plants. Collectively, these results indicate that ScVP plays an important role in plant tolerance to salt, saline-alkali and drought stress.

Gene expression profiling of soybean leaves and roots under salt, saline-alkali and drought stress by high-throughput Illumina sequencing.

Salt, saline-alkali and drought stresses are major environmental constraints for the production and yield of soybean worldwide. To identify genes responsible for stress tolerance, the transcriptional profiles of genes in leaves and roots of seedlings (two-leaf stage) of the soybean inbred line HJ-1 were examined after 48 h under various stress conditions; salt (120 mM NaCl), saline-alkali (70 mM NaCl and 50mM NaHCO(3)) and drought (2% PEG 8000). Gene expression at the transcriptional level was investigated using high-throughput Illumina sequencing technology and bioinformatics tools. Under salt, saline-alkali and drought stress, 874, 1897, and 535 genes, respectively, were up-regulated in leaves, and 1822, 1731 and 1690 genes, respectively, were up-regulated in roots, compared with expression in the corresponding organ in control plants. Comparisons among salt, saline-alkali and drought stress yielded similar results in terms of the percentage of genes classified into each GO category. Moreover, 69 genes differentially expressed in both organs with similar expression patterns clustered together in the taxonomic tree across all conditions. Furthermore, comparison of gene expression among salt, saline-alkali and drought treated plants revealed that genes associated with calcium-signaling and nucleic acid pathways were up-regulated in the responses to all three stresses, indicating a degree of cross-talk among these pathways. These results could provide new insights into the stress tolerance mechanisms of soybean.