Knockout Mutants of OsPUB7 Generated Using CRISPR/Cas9 Revealed Abiotic Stress Tolerance in Rice.

Plants produce and accumulate stress-resistant substances when exposed to abiotic stress, which involves a protein conversion mechanism that breaks down stress-damaged proteins and supplies usable amino acids. Eukaryotic protein turnover is mostly driven by the ubiquitination pathway. Among the three enzymes required for protein degradation, E3 ubiquitin ligase plays a pivotal role in most cells, as it determines the specificity of ubiquitination and selects target proteins for degradation. In this study, to investigate the function of OsPUB7 (Plant U-box gene in Oryza sativa), we constructed a CRISPR/Cas9 vector, generated OsPUB7 gene-edited individuals, and evaluated resistance to abiotic stress using gene-edited lines. A stress-tolerant phenotype was observed as a result of drought and salinity stress treatment in the T2OsPUB7 gene-edited null lines (PUB7-GE) lacking the T-DNA. In addition, although PUB7-GE did not show any significant change in mRNA expression analysis, it showed lower ion leakage and higher proline content than the wild type (WT). Protein-protein interaction analysis revealed that the expression of the genes (OsPUB23, OsPUB24, OsPUB66, and OsPUB67) known to be involved in stress increased in PUB7-GE and this, by forming a 1-node network with OsPUB66 and OsPUB7, acted as a negative regulator of drought and salinity stress. This result provides evidence that OsPUB7 will be a useful target for both breeding and future research on drought tolerance/abiotic stress in rice.

Phylogenetic relationship of a fossil macaque (Macaca cf. robusta) from the Korean Peninsula to extant species of macaques based on zygomaxillary morphology.

Little is known about the biogeographical and evolutionary histories of macaques (Macaca spp.) in East Asia because the phylogenetic positions of fossil species remain unclear. Here we examined the zygomaxillary remains of a fossil macaque (M. cf. robusta) from the Durubong Cave Complex, South Korea, that dates back to the late Middle to Late Pleistocene, to infer its phylogenetic relationship to extant species. We took 195 fixed- and semi-landmarks from the zygomaxillary regions of the fossil specimen and from 147 specimens belonging to 14 extant species. We then conducted a generalized Procrustes analysis followed by a multivariate statistical analysis to evaluate the phenetic affinities of the fossil to the extant species and reconstructed the most parsimonious phylogenetic tree using a phylogenetic morphometric approach. We found that the fossil was most similar to Macaca fuscata (Japanese macaque) in the zygomaxillary morphospace although it was at the limit of the range of variation for this species. The second closest in the morphospace was the continental Macaca mulatta (rhesus macaque). Parsimonious reconstruction confirmed that the fossil was most closely related to M. fuscata, even after controlling for the effects of allometry. These findings suggest that in the late Middle to Late Pleistocene, close relatives of M. fuscata that looked like the extant species were distributed on the Korean Peninsula, where no species of macaques are found today. Thus, some morphological characteristics of M. fuscata may have developed before its ancestor dispersed into the Japanese archipelago.

The First Domesticated 'Cheongju Sorori Rice' Excavated in Korea.

Archaeological excavations led by Yung-jo Lee and Jong-yoon Woo were carried out twice at the Sorori paleolithic site, Cheongju, in the Republic of Korea, at the upper stream of the Geumgang river, the Miho riverside. A total of 127 rice seeds were excavated, including 18 ancient rice and 109 Quasi-rice, in 1998 and 2001. At the first excavation, eleven short japonica-type ancient rice and one slender smooth ancient rice with two kinds of Quasi-rice were excavated. The average length of the 11 short rice grains obtained from the first and second excavation was 7.19 mm and the average width was 3.08 mm, respectively. The Quasi-rice are apparently different from the rice and do not have bi-peak protuberances on their glume surface. At the second excavation, six short ancient rice chaffs and some Quasi-rice 2 were found. These short-grained ancient rice were comparable to the ancient rice that were excavated at the Illsan Neolithic site. Geologists and radiologists confirmed that the peat layer in which the rice found was older than 15,000 years. In this study, the morphological characteristics, crushing, and DNA band patterns related to the genetic polymorphism of rice grains in Cheongju Sorori were compared and analyzed for genetic similarities and differences with wild rice, weed rice, and modern rice. The morphological, ecological, and physiological variations in rice grains excavated from the Sorori site were presumed to denote the origin of rice domestication in Korea. It is also suggested that the results of the DNA sequencing of excavated rice are very important clues in estimating the origin of the early domestication of rice.