Cytological, physiological, and transcriptomic analyses of golden leaf coloration in Ginkgo biloba L

Ginkgo biloba is grown worldwide as an ornamental plant for its golden leaf color.However,the regulatory mechanism of leaf coloration in G.biloba remains unclear.Here,we compared G.biloba gold-colored mutant leaves and normal green leaves in cytological,physiological and transcriptomic terms.We found that chloroplasts of the mutant were fewer and smaller,and exhibited ruptured thylakoid membranes,indistinct stromal lamellae and irregularly arranged vesicles.Physiological experiments also showed that the mutant had a lower chlorophyll,lower flavonoid and higher carotenoid contents(especially lutein).We further used transcriptomic sequencing to identify 116 differentially expressed genes(DEGs)and 46 transcription factors(TFs)involved in chloroplast development,chlorophyll metabolism,pigment biosynthesis and photosynthesis.Among these,the chlorophyll biosynthesis-related PPO showed down-regulation,while chlorophyll degradation-related NYC/NOL had up-regulated expression in mutant leaves.Z-ISO,ZDS,and LCYE,which are involved in carotenoid biosynthesis were up-regulated.Quantitative real-time PCR(RT-qPCR)further confirmed the altered expression levels of these genes at three stages.The alteration of PPO and NYC/NOL gene expression might affect chlorophyll biosynthesis and promote degradation of chlorophyll b to chlorophyll a,while the up-regulated genes Z-ISO,ZDS and LCYE enhanced carotenoid accumulation.Consequently,changes in the ratio of carotenoids to chlorophylls were the main factors driving the golden leaf coloration in the mutant G.biloba.

Constant Color-leaved Species in Tibet and Their Application in Landscaping

To analyze the basic conditions of constant colored-leaved tree species in Tibet, this study applied the "biological five-point method" to investigate the plant communities layer by layer, investigated landscape plant species and their landscaping application in Tibet. The results showed that(a) there are 40 constant color-leaved species(including varieties) in Tibet, belonging to 35 genera, 22 families, including 26 tree species and 16 shrub species. In terms of color, 22 species are yellow, 9 purple, 7 red and 2 others, occupying 55.00%, 22.50%, 17.50% and 5.00% of the total constant color-leaved species, respectively.(b) In the tree layer, the species ranking the top 2 of the importance value list are Prunus cerasifera Ehrhar f. atropurpurea Rehd. and Photiniax serrulata ‘Rubens' with an importance value of 26.063 and 9.035; in the shrub layer, the species ranking the top 3 of the importance value list are Ligustrum × vicaryi Hort, Berberis thunbergi var. atropurpurea Chenault, Platycladus orientalis cv. Aurea Nana with an importance value of 22.577, 18.987 and 10.529.(c) The most-applied species belong to the Rosaceae(9), Leguminosae(5), and Oleaceae(3), accounting for 22.50%, 12.50% and 7.50% of the total investigated constant color-leaved species, respectively.(d) Most of the investigated species grow well, but some of them including Berberis thunbergii var. atropurpurea Chenault grow moderately, Loropetalum chinense var. rubrum, Aucuba chinensis var. iegata grow poorly, and the causes of poor growth should be explored further or application of these species should be controlled. In addition, pertinent suggestions were put forward in view of major problems in the application of constant color-leaved species in Tibet.

Publisher Correction: Cytological, physiological, and transcriptomic analyses of golden leaf coloration in Ginkgo biloba L

Correction to:Horticulture Research(2018)5:12;https://doi.org/10.1038/s41438-018-0015-4;Article published online 1 March 2018.In the original publication of this article[1]not all authors were listed correctly.In this correction article the full author list is given.The original publication has been corrected.

Construction of Evaluation Index System of Tourism Carrying Capacity of the Jokhang Temple Scenic Spot

Based on the in-depth study on the theory of tourism carrying capacity at home and abroad, author of this paper defined the concept and connotation of tourism carrying capacity, and proposed the evaluation index system of tourism carrying capacity. He also conducted a systematic analysis of tourism resources in the Jokhang Temple scenic spot, constructed an evaluation index system of tourism carrying capacity of the Jokhang Temple scenic spot, pointed out the status quo of its carrying capacity and factors constraining the carrying capacity through quantitative calculation, and put forward suggestions to regulate its carrying capacity.

Study on Diversity of Undergrowth Plant Community in Cibagou Nature Reserve

The forest community diversity along the altitudinal gradient was analyzed in the Cibagou National Nature Reserve. Results showed that the forest types of Cibagou Gorge could be divided into six types: Castanopsis hystrix forest;camphor and acer mixed forest, blue Japanese oak broad-leaved mixed forest, blue Japanese oak forest, Populus simonii mixed forest;Quercus aquifolioides forest. The total coverage of undergrowth vegetation altitude was the lowest at 1749 m, only 30%, and plant species numbers in the sample was only 5. The total coverage of the plant was the highest at 2327 m altitude, the value was 95%, and the number of species in experiment plot was 14. The species richness of Margalef increased first and then decreased with the increase of altitude gradient at 1749 m to 2880 m, and the Shannon-wiener species diversity index increased, but the difference was not significant, Pielou species evenness and Sheldon species evenness index decreased first and then increased with altitude.

Photosynthetic Characteristics of Three Fig Cultivars in Nyingchi, Tibet

The photosynthetic characteristics of three excellent fig cultivars introduced, Branswick, Qingpi and Xinjiang Zaohuang, were compared in the paper, in order to provide reference for the cultivation and breeding of different fig cultivars in Tibet. The daily variation of photosynthetic parameters of the three excellent fig cultivars, Branswick, Qingpi and Xinjiang Zaohuang, which were introduced and cultivated by XiZang Agriculture and Animal Husbandry College in Bayi District, Nyingchi City, Tibet, were measured and compared. The results showed that the net photosynthetic rates (Pn) of three fig cultivars were Qingpi > Branswick > Xinjiang Zaohuang, and the daily variation curves of net photosynthetic rate were all of unimodal pattern. The daily variation curves of transpiration rate (Tr), water utilization efficiency (WUE) and efficiency for solar energy utilization (Pn/Par) of different fig cultivars showed unimodal pattern;the daily variation curve of intercellular CO2 content (Ci) showed decline pattern;the daily variation curve of stomatal conductance (Gs) showed bimodal pattern;Pn had extremely positive correlation with Tr, WUE, Gs, Par, Pn/Par and Ta.

Evaluation of Tourism Environmental Carrying Capacity of Pai Town-Medog County Hiking Route

Based on the actual situation of Pai-Medog hiking route, the tourism environmental carrying capacity of this route was calculated in this study. According to the analysis and calculation results and referring to the common control measures of tourism environmental carrying capacity, corresponding control measures were put forward for the Pai-Medog hiking route.

A Study on the Transfer of Rural Surplus Labor in Nyingchi City

This paper studies the surplus labor transfer in Nyingchi City,obtains the first-hand information of the surplus labor transfer through the typical survey,and analyzes the current situation and characteristics of surplus labor transfer. From " transfer channel", " transfer industry" and " transfer space",this paper analyzes the factors affecting the transfer of local surplus farming and animal husbandry labor,discusses the obstacles to surplus farming and animal husbandry labor in Nyingchi City,and finally makes some recommendations for the transfer of rural surplus labor in Nyingchi City.

The Effect of Higher Warming on Vegetation Indices and Biomass Production is Dampened by Greater Drying in an Alpine Meadow on the Northern Tibetan Plateau

In order to understand whether or not the response of vegetation indices and biomass production to warming varies with warming magnitude,an experiment of field warming at two magnitudes was conducted in an alpine meadow on the northern Tibetan Plateau beginning in late June,2013.The normalized difference vegetation index（NDVI）,green normalized difference vegetation index（GNDVI） and soil adjusted vegetation index（SAVI） data were obtained using a Tetracam Agricultural Digital Camera in 2013–2014.The gross primary production（GPP） and aboveground plant biomass（AGB） were modeled using the surface measured NDVI and climatic data during the growing seasons（i.e.June–September） in 2013–2014.Both low and high warming significantly increased air temperature by 1.54 and 4.00°C,respectively,and significantly increased vapor pressure deficit by 0.13 and 0.31 kP a,respectively,in 2013-2014.There were no significant differences of GNDVI,AGB and ANPP among the three warming treatments.The high warming significantly reduced average NDVI by 23.3%（-0.06）,while the low warming did not affect average NDVI.The low and high warming significantly decreased average SAVI by 19.0%（-0.04） and 27.4%（-0.05）,respectively,and average GPP by 24.2%（i.e.0.21 g C m^（-2） d^（-1）） and 44.0%（i.e.0.39 g C m^（–2） d^（-1））,respectively.However,the differences of the average NDVI,SAVI,and GPP between low and high warming were negligible.Our findings suggest that a greater drying may dampen the effect of a higher warming on vegetation indices and biomass production in alpine meadow on the northern Tibetan Plateau.

Biodegradation of 2-ethylhexyl-4-methoxycinnamate in river sediments and its impact on microbial communities

Numerous studies have evaluated the toxicity and endocrine disrupting properties of organic UV filters for aquatic organisms,but little is known about their biodegradation in river sediments and their impact on microorganisms.We have set up the sterile and microbiological systems in the laboratory,adding 2-ethylhexyl-4-methoxycinnamate(EHMC),one of organic UV filters included in the list of high yield chemicals,at concentrations of 2,20 and 200μg/L,and characterized the microbial community composition and diversity in sediments.Monitoring of EHMC degradation within 30 days revealed that the half-life in the microbial system(3.49 days)was much shorter than that in the sterile system(7.55 days).Two potential degradation products,4-mercaptobenzoic acid and 3-methoxyphenol were identified in the microbial system.Furthermore,high-throughput 16s and 18s rRNA gene sequencing showed that Proteobacteria dominated the sediment bacterial assemblages followed by Chloroflexi,Acidobacteria,Bacteroidetes and Nitrospirae;Eukaryota_uncultured fungus dominated the sediment fungal assemblages.Correlation analysis demonstrated that two bacterium genera(Anaerolineaceae_uncultured and Burkholderiaceae_uncultured)were significantly correlated with the biodegradation of EHMC.These results illustrate the biodegradability of EHMC in river sediments and its potential impact on microbial communities,which can provide useful information for eliminating the pollution of organic UV filters in natural river systems and assessing their potential ecological risks.

CASCIRE surveillance network and work on avian influenza viruses

Studies on influenza virus by Chinese Academy of Sciences(CAS)could be traced back as early as 2005 by the CAS Key Laboratory of Pathogenic Microbiology and Immunology(CASPMI),who discovered that Qinghai-like Clade 2.2H5N1 subtype highly pathogenic avian influenza virus(HPAIV)first caused severe outbreak in wild birds in Qinghai Lake(Liu et al.,2005).

Fecal consumption by adults of altricial birds in relation to the temporal change in nestling gut microbiota

Nest sanitation behavior of altricial birds has been selected to reduce the exposure of young to pathogens,parasites,or predators,and thus to maintain the health and safety of nestlings(Guigueno and Sealy 2012).During the process of nest sanitation,caregivers either carry away the fecal sacs of nestlings or directly eat them.Given that adults endure higher risk of being infected by pathogens during fecal consumption(Potti et al.2007),it remains a puzzle about why adults consume the nestling feces when they can transport them.Several hypotheses have been proposed to explain the fecal consumption behavior of altricial birds,including the nutrition hypothesis(Gliick 1988),economic hypothesis(Hurd et al.1991),and predation hypothesis(Ibanez-Alamo et al.2013).