l e t t e r sBamboo represents the only major lineage of grasses that is native to forests and is one of the most important nontimber forest products in the world. However, no species in the Bambusoideae subfamily has been sequenced. Here, we report a high-quality draft genome sequence of moso bamboo (P. heterocycla var. pubescens). The 2.05-Gb assembly covers 95% of the genomic region. Gene prediction modeling identified 31,987 genes, most of which are supported by cDNA and deep RNA sequencing data. Analyses of clustered gene families and gene collinearity show that bamboo underwent whole-genome duplication 7-12 million years ago. Identification of gene families that are key in cell wall biosynthesis suggests that the whole-genome duplication event generated more gene duplicates involved in bamboo shoot development. RNA sequencing analysis of bamboo flowering tissues suggests a potential connection between droughtresponsive and flowering genes.Bamboo is one of the most important non-timber forest products in the world. About 2.5 billion people depend economically on bamboo, and international trade in bamboo amounts to over 2.5 billion US dollars per year 1 . Bamboo has a rather striking life history, characterized by a prolonged vegetative phase lasting decades before flowering, thereby inhibiting genetic improvement. Recent genomic studies in bamboo have included genome-wide full-length cDNA sequencing 2 , chloroplast genome sequencing 3 , identification of syntenic genes between bamboo and other grasses 4 and phylogenetic analysis of Bambusoideae subspecies 5 . Fifty-nine simple sequence repeat markers from rice and sugarcane were used in the genetic diversity analyses of 23 bamboo species 6 , and 2 species-specific sequence-characterized amplified region markers were developed in the identification of different bamboo species 7 .Here, we report the draft genome of moso bamboo, a large woody bamboo that has ecological, economic and cultural value in Asia and accounts for ~70% of the total bamboo growth area. Comparative genome-wide analyses of bamboo to other grass species, including rice, maize and sorghum, yielded new genetic insights into the rapid and marked phenotypic and ecological divergence of bamboo and closely related grasses.The moso bamboo genome contains 24 pairs of chromosomes 8 (2n = 48) and is characteristic of a diploid (Supplementary Fig. 1a). We conducted a flow cytometry analysis and estimated that it had a genome size of 2.075 Gb (2C = 4.24 pg; Supplementary Fig. 1b), which was very close to that estimated in a previous report 9 .Because it is difficult to generate an inbred line of moso bamboo, owing to its infrequent sexual reproduction and the long periods of time between flowering intervals, we selected five plants from a single individual rhizome of the moso bamboo ecotype (P. heterocycla var. pubescens) and performed whole-genome shotgun sequencing. We generated 295 Gb of raw sequence data (approximately 147-fold coverage), including Illumina short reads and 10,327 pairs of BAC end ...

Prunus mume is an ornamental flower and fruit tree in Rosaceae. We investigated the GRAS gene family to improve the breeding and cultivation of P. mume and other Rosaceae fruit trees. The GRAS gene family encodes transcriptional regulators that have diverse functions in plant growth and development, such as gibberellin and phytochrome A signal transduction, root radial patterning, and axillary meristem formation and gametogenesis in the P. mume genome. Despite the important roles of these genes in plant growth regulation, no findings on the GRAS genes of P. mume have been reported. In this study, we discerned phylogenetic relationships of P. mume GRAS genes, and their locations, structures in the genome and expression levels of different tissues. Out of 46 identified GRAS genes, 45 were located on the 8 P. mume chromosomes. Phylogenetic results showed that these genes could be classified into 11 groups. We found that Group X was P. mume-specific, and three genes of Group IX clustered with the rice-specific gene Os4. We speculated that these genes existed before the divergence of dicotyledons and monocotyledons and were lost in Arabidopsis. Tissue expression analysis indicated that 13 genes showed high expression levels in roots, stems, leaves, flowers and fruits, and were related to plant growth and development. Functional analysis of 24 GRAS genes and an orthologous relationship analysis indicated that many functioned during plant growth and flower and fruit development. Our bioinformatics analysis provides valuable information to improve the economic, agronomic and ecological benefits of P. mume and other Rosaceae fruit trees.

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The effect of high temperature annealing (HTA) on crystalline quality improvement of h-BN films grown on sapphire substrates has been investigated. It is found that BN grown using conventional molecular beam epitaxy is disordered due to the growth temperature below 1000 °C. By annealing at a temperature of 1700 °C, thermodynamically stable crystalline h-BN could be obtained at wafer scale, where diffusion of atoms in the as-grown BN film is enhanced and the structural defect density decreases. The crystalline h-BN has been confirmed by x-ray diffraction, Raman scattering, and atomic force microscopy measurements. This work demonstrates that HTA is a simple and effective way to achieve wafer-scale crystalline h-BN films, which have numerous potential applications in next-generation two-dimensional devices and flexible III-nitride optoelectronic devices.