Effects of Sodium Nitroprussiate on the Metabolites and Key Enzyme Activities of Carbon-nitrogen Metabolism from Seed Germination to Seedling Period of Cherry Tomato

This study was conducted to elucidate the regulating mechanism of sodium nitroprussiate on seed germination and seedling growth of cherry tomato. After the treatment with different concentrations of sodium nitroprusside, the effects on the metabolites and key enzyme activities in carbon-nitrogen metabolism of cherry tomato cuhivar Zhuyun as an experimental material were investigated. The results showed that from seed germination to seedling period, the contents of starch and total nitrogen decreased, but the contents of soluble sugar, reducing sugar, sucrose and soluble protein increased firstly and then decreased; and free amino acids content increased gradually. Sodium nitroprusside made the contents of starch, sucrose and free amino acids higher than CK. From seed germination to seedling period in cherry tomato, the activities of amylase, glutamine synthetase （GS） and sucrose phosphate synthase （SPS） decreased; the activities of nitrate reductase （NR） and glutamate synthase （GOGAT） increased at first and decreased then; and the CK and the 0.25 mmol/L sodium nitroprusside treatments exhibited de- creased sucrose synthase （SS） activity, and the trend was increasing at first and decreasing then after the treatment with 0.50 and 1.00 mmol/L sodium nitroprus- side. Sodium nitroprusside treatment improved amylase activity; and the carbon-nitrogen ratio of the CK increased at first and decreased then, while the values of other treatments tended to decrease. In addition, sodium nitroprusside did not affect seed germination potential and germination rate, but significantly improved biomass accumulation, root length and height of seedlings. These data suggest that sodium nitroprusside could affect the conversion of starch and sugar accumulation, delay the decomposition of total nitrogen and soluble protein, and achieve the effects of accelerating the accumulation of free amino acids, and promoting seed germination and seedling growth, and 0.50 mmol/L sodium nitroprusside has the best effect.

Status and distribution changes of the endangered Green Peafowl (Pavo muticus) in China over the past three decades (1990s-2017)

Background: Understanding the changes in population dynamics, including demographics, distribution and threats, is essential for species status assessing. The endangered Green Peafowl(Pavo muticus) has experienced sharp population declines and distribution range diminishing both in China and Southeast Asia. Field population surveys have not been conducted in China since the 1990 s, which hindered conservation planning and decision-making.Methods: With interview and line transects methods, we figured out the population and distribution changes of Green Peafowl across its historical ranges over the past three decades in China during 2014-2017.Results: The Green Peafowl once habituated in 54 counties in China. Nearly 60% of the distribution counties were lost in the past three decades, with the left 22 counties distributed in central, southern and western Yunnan, SW China. Population decrease detected in all distribution areas except for Shuangbai and Xinping county where more than 60% of the total population is located. Only about 30% of the former bird population were recorded with the same interviewing method as 20 years ago. Three birds, 1 carcass, 6 calls and 12 footprints were detected along the 865 km line transects, indic-ating extremely low encounter rate of Green Peafowl in field. Sharp decreases in flock sizes were also detected, from 820 birds per flock in the 1990 s to 3-5 birds at present. Poaching and habitat conversion are two widespread and long-lasting threats, while poisoning caused mortality in the past and hydropower construction affect regional population's survival. Large flocks of 18–27 birds were discovered in the field, which increases our confidence of population recovery of this endangered pheasant in China.Conclusions: Only interviewed bird number and counts based on line transects were presented in this study, without further population estimation due to limitation of the data sets. Although the actual population of this cryptic bird must be underestimated, dramatic population declines and distribution concentrations of the endangered Green Peafowl occurred over the past 30 years in China undoubtedly.

Analysis on Composition and Diversity of Endophytes in Moringa oleifera

[Objectives] To explore the diversity of endophytes in Moringa oleifera,and provide a scientific basis for better protection,development and use of Moringa oleifera resources. [Methods] With Moringa oleifera stems and leaves as materials,the Illumina Mi Seq highthroughput sequencing technology was used to study the endophyte diversity. [Results] A total of 199 OTUs were measured in the samples,belonging to 12 phyla such as Proteobacteria,Actinobacteria,Acidobacteria,Gemmatimonadetes,Bacteroidetes,Chloroflexi,DeinococcusThermus,Verrucomicrobia,Candidatus Saccharibacteria and Cyanobacteria. [Conclusions]Gemmatimonas is the dominant population of endophyte in Moringa oleifera.

Effects of Heat Shock Factor AtHsfA1a on Caspase-3 Activity in Arabidopsis thaliana under High Temperature Stress

[ Objective] This study aimed to investigate the effects of heat shock factor AtHsfAla on Caspase-3 activity in Arabidopsis thaliana under high tempera-ture stress, thus revealing the relationship between heat shock factor AtHsfAl a and programmed cell death in A. thaliana. [ Method ] Different genotypes of A. thaliana （AtHsfAla-silenced transgenic and wild-type） seedlings were treated at 42 ℃. According to the fragmentation level of fluorogenic substrate Ac-DEVD- pNA, Caspase-3 activity was determined by spectrophotometry. [ Result] After high temperature treatment, Caspase-3 activity in A. thaliana was enhanced signifi-cantly. Caspase-3 activity in AtHsfAla-si／enced transgenic A. thaliana was higher than that in wild-type A. thaliana, which indicated that AtHsfAla could inhibit Caspase-3 activity in A. thaliana under high temperature stress. [ Conclusion] Under high temperature stress, heat shock factor AtHsfAla might exert inhibitory effects on programmed cell death by reducing Caspase-3 activity. This study provided the basis for clarifying the mechanism of stress resistance in plants.

Microarray-based Screening of Target Genes Regulated by Heat Shock Factor AtHsfA1a in Arabidopsis thaliana

[ Objective] This study aimed to screen target genes regulated by heat shock factor AtHsfAla in Arabidopsis thaliana. [ Method] Using AtHsfAla-in- serted mutant athsfala （SALK-068042） and wild-type A. thaliana seedlings as experimental materials, target genes regulated by heat shock factor AtHsfAla were screened by microarray assay. Differentially expressed genes were screened by multiple method. Specific functions of differentially expressed genes were analyzed by gene ontology （GO） analysis. Signal transduction pathways, in which differentia｜ly expressed genes were involved, were analyzed by pathway analysis. Gene-gene interaction network was constructed by Signal-Net. [ Result] A total of 3 672 differentially expressed genes were screened out. Up-regulated differentially expressed genes were involved in 198 functions and 7 signal transduction pathways; down-regulated differentially expressed genes were involved in 94 functions and 10 signal transduction pathways. In the signal transduction network, it was found that cwlNV4 and HXK3 had relatively high ability of mediation; AT1 G14240 and cwlNV4 ex- hibited the most interactions with other genes, which were located in key positions throughout the gene-gene interaction network. [ Conclusion] Heat shock factor AtHsfAla regulates a large number of target genes in A. thaliana.

Effects of Heat Shock Factor AtHsfA1a on Programmed Cell Death in Arabidopsis thaliana under Cold Stress

[Objective] This study aimed to investigate the effects of heat shock factor AtHsfAla on programmed cell death in Arabidopsis thaliana under cold stress. [ Method] AtHsfAla-silenced transgenic （NT） and wild-type （WT） A. thaliana seedlings were used as experimental materials to induce the formation of callus; the callus were cultured to single cells by suspension culture, subjected to cold stress, stained with DAPI, prepared into cell smears and observed under a fluorescence microscope. [ Result] Under cold stress, cell nucleus of wild-type A. thaliana displayed morphological changes, but no apoptotic bodies were found; apoptotic bodies were observed in AtHsfAla-silenced transgenic A. thaliana cells, and the cytoplasm was remarkably concentrated. [ Conclusion] Under cold stress, heat shock factor AtHsfAla exerted inhibitory effects on programmed cell death in A. thaliana, which was of great significance for clarifying the mechanism of stress responses in plants.