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Plant cells contain three organelles that harbor DNA: the nucleus, plastids, and mitochondria. Plastid transformation has emerged as an attractive platform for the generation of transgenic plants, also referred to as transplastomic plants. Plastid genomes have been genetically engineered to improve crop yield, nutritional quality, and resistance to abiotic and biotic stresses, as well as for recombinant protein production. Despite many promising proof-of-concept applications, transplastomic plants have not been commercialized to date. Sequence-specific nuclease technologies are widely used to precisely modify nuclear genomes, but these tools have not been applied to edit organelle genomes because the efficient homologous recombination system in plastids facilitates plastid genome editing. Unlike plastid transformation, successful genetic transformation of higher plant mitochondrial genome transformation was tested in several research group, but not successful to date. However, stepwise progress has been made in modifying mitochondrial genes and their transcripts, thus enabling the study of their functions. Here, we provide an overview of advances in organelle transformation and genome editing for crop improvement, and we discuss the bottlenecks and future development of these technologies., In addition to the nuclear genome, plants also contain mitochondrial and plastid genomes. This review highlights recent advances in organelle transformation and genome editing for crop improvement and discusses the bottlenecks and future development of these technologies.

The glass forming region in the quaternary system ZnO–B2O3–P2O5–RnOm has been determined. Glass transition temperature (Tg), glass density (ρ), thermal expansion coefficient (α) and weight loss percentage (WL) of these glasses were measured. The structure of (90−x−y)ZnO–xB2O3–yP2O5–10RnOm glass was characterized by infrared spectra (IR), Raman spectra and X-ray diffraction (XRD). Results of IR and Raman indicated that B2O3 participated in the glass network as a glass modifier and the IR band around 1440 cm−1 was ascribed to the vas(B–O–B) vibrations. Glass intensity increased with increase in B2O3 content. The disappearance of vs(P–O–P) vibration around 760 cm−1 indicated that P–O–B linkage was formed. XRD results revealed that the major crystalline phase changes with substitution of different amounts of B2O3: Zn2P2O7 for 45ZnO–xB2O3–35P2O5–10RnOm glass, where x=0–20, and BPO4 for 45ZnO–xB2O3–35P2O5–10RnOm glass, where x=30–40.

(30 − x /2)Li 2 O·(70 − x /2)B 2 O 3 · x Al 2 O 3 ( x = 0, 5 and 10) composite gels have been fabricated by the sol–gel method. LiOCH 3 , B(OC 4 H 9 ) 3 , and Al(OC 4 H 9 ) 3 were used as precursor for Li 2 O, B 2 O 3 , and Al 2 O 3 , respectively. B(OC 4 H 9 ) 3 and Al(OC 4 H 9 ) 3 were hydrolyzed separately and then mixed. The crystallization behavior and structure of the gels upon thermal treatment temperatures between 150 and 550 °C are characterized on the basis of SEM, XRD and IR analyses. Xerogel with x = 0 exhibits non-crystal features, whereas crystalline phases are found in the xerogels with x = 5 and 10. The crystalline phases are not found with increasing heat treatment temperatures from 150 to 450 °C, but crystalline phases appear present at 550 °C. The xerogel with x = 0, subject to thermal treatment below 450 °C, is found to be still amorphous, and a 550 °C heat treatment leads its structure changing from glassy to crystalline.

Prior international studies that investigate the relative usefulness of accounting information have focused either on the incremental information content of earnings reconciliation, or the relative information content of accounting numbers across countries. Using a sample of 13 countries, this paper extends the literature by providing empirical evidence on whether the value relevance of accounting numbers in different countries has changed over time and whether the patterns of changes differ across countries. In particular, the study analyzes factors that may cause the differences among countries. The study finds that there are differences in value relevance of accounting information across countries, and that these differences may be explained by disclosure practices and market efficiency.