Dendrocalamus sinicus is the world’s largest bamboo species with strong woody culms, and known for its fast-growing culms. As an economic bamboo species, it was popularized for multi-functional applications including furniture, construction, and industrial paper pulp. To comprehensively elucidate the molecular processes involved in its culm elongation, Illumina paired-end sequencing was conducted. About 65.08 million high-quality reads were produced, and assembled into 81,744 unigenes with an average length of 723 bp. A total of 64,338 (79%) unigenes were annotated for their functions, of which, 56,587 were annotated in the NCBI non-redundant protein database and 35,262 were annotated in the Swiss-Prot database. Also, 42,508 and 21,009 annotated unigenes were allocated to gene ontology (GO) categories and clusters of orthologous groups (COG), respectively. By searching against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG), 33,920 unigenes were assigned to 128 KEGG pathways. Meanwhile, 8,553 simple sequence repeats (SSRs) and 81,534 single-nucleotide polymorphism (SNPs) were identified, respectively. Additionally, 388 transcripts encoding lignin biosynthesis were detected, among which, 27 transcripts encoding Shikimate O-hydroxycinnamoyltransferase (HCT) specifically expressed in D. sinicus when compared to other bamboo species and rice. The phylogenetic relationship between D. sinicus and other plants was analyzed, suggesting functional diversity of HCT unigenes in D. sinicus. We conjectured that HCT might lead to the high lignin content and giant culm. Given that the leaves are not yet formed and culm is covered with sheaths during culm elongation, the existence of photosynthesis of bamboo culm is usually neglected. Surprisedly, 109 transcripts encoding photosynthesis were identified, including photosystem I and II, cytochrome b6/f complex, photosynthetic electron transport and F-type ATPase, and 24 transcripts were characterized as antenna proteins that regarded as the main tool for capturing light of plants, implying stem photosynthesis plays a key role during culm elongation due to the unavailability of its leaf. By real-time quantitative PCR, the expression level of 6 unigenes was detected. The results showed the expression level of all genes accorded with the transcriptome data, which confirm the reliability of the transcriptome data. As we know, this is the first study underline the D. sinicus transcriptome, which will deepen the understanding of the molecular mechanisms of culm development. The results may help variety improvement and resource utilization of bamboos.

Abstract:A critical component of the forest ecosystem, the understorey supports the vast majority of wildlife habitat and total ecosystem floristic diversity. Remote sensing data have been developed to provide information at different scales for surveys of forest ecosystems, but obtaining information about the understorey remains a challenge. As rapid and efficient tools for forest structure attribute estimation, Airborne Laser Scanning (ALS) and Terrestrial Laser Scanning (TLS) have attracted much attention. We examine the relationship between ALS and TLS data and detect changes in the forest understorey caused by forest-tending events in the study area. We conducted trials in five plots within a young Khasi pine (Pinus kesiya Royle ex Gord.) plantation in Yunnan province, China, before and after forest tending. We collected bi-temporal ALS data in this area and TLS data from 10 scanning stations. Canopy height profiles were retrieved from ALS and TLS data, and understorey material volume retrieved from filled TLS voxels volume agreed well with the understorey point clouds percentile distribution (PD) obtained from ALS data. The PD value for the understorey from ALS multiplied by the percentage of ALS return points in the overstorey had a stronger correlation (R 2 = 0.90) with the TLS-derived understorey material volume than did the ALS PD value for the understorey only (R 2 = 0.71). Taking the effect of the overstorey into consideration will improve evaluations of forest understorey parameters from ALS data. This study confirmed the potential of TLS as a validation tool to assess the accuracy of forest understorey material volume estimation at large scales using ALS data.

ABSTRACT. Moso bamboo (Phyllostachys heterocycla) is the most important bamboo species in China and is famous for its fast-growing culms. To investigate the possible relationship between internode development and endogenous hormones, the concentrations of indole-3-acetic acid (IAA), zeatin riboside (ZR), gibberellins (GA 3 ), and abscisic acid (ABA) were analyzed in culm samples from plants at different developmental stages during a single growing season and, at the same time, anatomical structure was closely monitored. Cell division was the dominant process in internode development during early development, while cell elongation predominated at later stages. There was a negative correlation between the rates of cell division and cell elongation. The four endogenous hormones (IAA, ZR, GA 3 , and ABA) displayed fluctuations in their levels at different developmental stages but their peak activities were not synchronous. Cell division rate had a significant positive correlation with ZR concentration. Cell elongation had a significant positive correlation with the ratio of promoting hormones (IAA, GA 3 , and ZR) to inhibitory hormone (ABA) concentrations. We conclude 11313 Hormonal equilibrium linked to culm development ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 11312-11323 (2015) that hormonal equilibrium might regulate the division and elongation of bamboo culms.

RESEARCHS eed moisture content and storage temperature are usually considered to be the main factors in retaining seed viability. In 1976, the International Board of Plant Genetic Resources recommended a moisture content of 5 ± 1% and a storage temperature of -18°C as the ideal conditions for long-term preservation of germplasm resources. At present, refrigeration is the most common means of seed storage. In many developing countries, due to limited financial power, refrigerated storage is not an option, so finding the best way to store seeds under ambient conditions has merit.In an extremely dry state, some seeds remain viable for hundreds to thousands of years (Steiner and Ruckenbauer, 1995;Telewski and Zeevaart, 2002). A number of studies have shown that storage of some seeds dehydrated to <5% moisture content (the traditional safe moisture content) at the normal temperature can achieve good results, even better than those achieved by storing seeds at low temperature (Buitink and Leprince, 2004). Thus, ultra-dry storage was produced, which is a technique for decreasing seed moisture content under 5%. Actually, drying or cooling a seed increases the intracellular viscosity, which results in slowed chemical and physical reactions ABSTRACT In this study, the feasibility of ultra-dry storage of Barbados nut (Jatropha curcas L.) seeds was investigated. The J. curcas seeds were dehydrated to six different moisture contents (1.33-6.98%) and stored at ambient temperature for 3 yr. Then, the indices related to seed vigor were measured. To explore the mechanism of ultradry storage, some physiological and biochemical indicators, including electrical conductivity (EC); contents of proline (Pro) and malondialdehyde (MDA); activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR); total soluble sugar content; and fatty acid composition, were determined. Results indicated that moisture content and prehumidification method significantly affected seed germination and vigor. The ultra-dried seeds showed a higher germination percentage than nondehydrated seeds. The germination percentage of ultra-dried seeds was negatively correlated with EC and MDA content and positively correlated with the activities of five antioxidant enzymes. As compared with the nondehydrated seeds, the ultra-dried seeds had lower soluble sugar and higher unsaturated fatty acids contents. The moisture content of 4.06% was found to be the optimal ultra-drying treatment, which is beneficial to enhance the activity of antioxidant enzymes and reduce lipid peroxidation of cell membranes, thereby slowing the decline in viability of J. curcas seeds.

The timely and accurate mapping of the spatial distribution of grasslands is crucial for maintaining grassland habitats and ensuring the sustainable utilization of resources. We used Google Earth Engine (GEE) and Sentinel-2 data for mountain grassland extraction in Yunnan, China. The differences in the normalized vegetation index in the time-series data of different ground objects were compared. February to March, during grassland senescence, was the optimum phenological stage for grassland extraction. The spectral, textural of Sentinel-2, and topographic features of the Shuttle Radar Topography Mission (SRTM) were used for the classification. The features were optimized using the recursive feature elimination (RFE) feature importance selection algorithm. The overall accuracy of the random forest (RF) classification algorithm was 91.2%, the producer’s accuracy of grassland was 96.7%, and the user’s accuracy of grassland was 89.4%, exceeding that of the cart classification (Cart), support vector machine (SVM), and minimum distance classification (MDC). The SWIR1 and elevation were the most important features. The results show that Yunnan has abundant grassland resources, accounting for 18.99% of the land area; most grasslands are located in the northwest at altitudes above 3200 m and in the Yuanjiang River regions. This study provides a new approach for feature optimization and grassland extraction in mountainous areas, as well as essential data for the further investigation, evaluation, protection, and utilization of grassland resources.