scholarly journals The Flora Compositions of Nitrogen-Fixing Bacteria and the Differential Expression of nifH Gene in Pennisetum giganteum z.x.lin Roots

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Biaosheng Lin ◽  
Jiamin Liu ◽  
Xue Zhang ◽  
Changren Weng ◽  
Zhanxi Lin
Keyword(s):  
Copy Number ◽  
Nifh Gene ◽  
Seedling Stage ◽  
Growth Stages ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Relative Expression ◽  
Ct Value ◽  
Jointing Stage ◽  
Different Growth Stages

The flora compositions of nitrogen-fixing bacteria in roots of Pennisetum giganteum z.x.lin at different growth stages and the expression and copy number of nitrogen-fixing gene nifH were studied by Illumina Miseq second-generation sequencing technology and qRT-PCR. The results showed that there were more than 40,000~50,000 effective sequences in 5 samples from the roots of P. giganteum, with Proteobacteria and Cyanobacteria as the dominant nitrogen-fixing bacteria based on the OTU species annotations for each sample and Bradyrhizobium as the core bacterial genera. The relative expression and quantitative change of nifH gene in roots of P. giganteum at different growth stages were consistent with the changes in the flora compositions of nitrogen-fixing microbia. Both revealed a changing trend with an initial increase and a sequential decrease, as well as changing order as jointing stage>maturation stage>tillering stage>seedling stage>dying stage. The relative expression and copy number of nifH gene were different in different growth stages, and the difference among groups basically reached a significant level ( p < 0.05 ). The relative expression and copy number of nifH gene at the jointing stage were the highest, and the 2-△△CT value was 4.43 folds higher than that at the seedling stage, with a copy number of 1.32 × 10 7 /g. While at the dying stage, it was the lowest, and the 2-△△CT value was 0.67 folds, with a copy number of 0.31 × 10 7 /g.

scholarly journals High diversity of nitrogen-fixing bacteria in the upper reaches of the Heihe River, northwestern China

2013 ◽  
Vol 10 (8) ◽  
pp. 5589-5600 ◽  
Author(s):  
X. S. Tai ◽  
W. L. Mao ◽  
G. X. Liu ◽  
T. Chen ◽  
W. Zhang ◽  
...  
Keyword(s):  
Water Conservation ◽  
Bacterial Communities ◽  
Nifh Gene ◽  
Qilian Mountains ◽  
Northwestern China ◽  
Heihe River ◽  
Meadow Soil ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Gene Copies

Abstract. Vegetation plays a key role in water conservation in the southern Qilian Mountains (northwestern China), located in the upper reaches of the Heihe River. Nitrogen-fixing bacteria are crucial for the protection of the nitrogen supply for vegetation in the region. In the present study, nifH gene clone libraries were established to determine differences between the nitrogen-fixing bacterial communities of the Potentilla parvifolia shrubland and the Carex alrofusca meadow in the southern Qilian Mountains. All of the identified nitrogen-fixing bacterial clones belonged to the Proteobacteria. At the genus level, Azospirillum was only detected in the shrubland soil, while Thiocapsa, Derxia, Ectothiorhodospira, Mesorhizobium, Klebsiella, Ensifer, Methylocella and Pseudomonas were only detected in the meadow soil. The phylogenetic tree was divided into five lineages: lineages I, II and III mainly contained nifH sequences obtained from the meadow soils, while lineage IV was mainly composed of nifH sequences obtained from the shrubland soils. The Shannon–Wiener index of the nifH genes ranged from 1.5 to 2.8 and was higher in the meadow soils than in the shrubland soils. Based on these analyses of diversity and phylogeny, the plant species were hypothesised to influence N cycling by enhancing the fitness of certain nitrogen-fixing taxa. The number of nifH gene copies and colony-forming units (CFUs) of the cultured nitrogen-fixing bacteria were lower in the meadow soils than in the shrubland soils, ranging from 0.4 × 107 to 6.9 × 107 copies g−1 soil and 0.97 × 106 to 12.78 × 106 g−1 soil, respectively. Redundancy analysis (RDA) revealed that the diversity and number of the nifH gene copies were primarily correlated with aboveground biomass in the shrubland soil. In the meadow soil, nifH gene diversity was most affected by altitude, while copy number was most impacted by soil-available K. These results suggest that the nitrogen-fixing bacterial communities beneath Potentilla were different from those beneath Carex.

Endophytic nitrogen fixation – a possible ‘hidden’ source of nitrogen for lodgepole pine trees growing at unreclaimed gravel mining sites

2019 ◽  
Vol 95 (11) ◽  
Author(s):  
Kiran Preet Padda ◽  
Akshit Puri ◽  
Chris Chanway
Keyword(s):  
Nitrogen Fixation ◽  
Lodgepole Pine ◽  
Nifh Gene ◽  
Control Treatment ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Mining Sites ◽  
Greenhouse Study ◽  
Gravel Mining ◽  
Pine Trees

ABSTRACT Lodgepole pine (Pinus contorta var. latifolia) trees have been thriving on unreclaimed gravel mining sites in British Columbia, Canada, with tissue nitrogen-content and growth-rate unaffected by extremely low soil nitrogen-levels. This indicates that pine trees could be accessing a hidden nitrogen source to fulfill their nitrogen requirements – possibly via endophytic nitrogen-fixation. Endophytic bacteria originally isolated from native pine trees growing at gravel sites were selected (n = 14) for in vitro nitrogen-fixation assays and a year long greenhouse study to test the overall hypothesis that naturally occurring endophytic nitrogen-fixing bacteria sustain pine tree growth under nitrogen-limited conditions. Each of the 14 bacteria colonized the internal tissues of pine trees in the greenhouse study and fixed significant amounts of nitrogen from atmosphere (23%–53%) after one year as estimated through 15N isotope dilution assay. Bacterial inoculation also significantly enhanced the length (31%–64%) and biomass (100%–311%) of pine seedlings as compared to the non-inoculated control treatment. In addition, presence of the nifH gene was confirmed in all 14 bacteria. Our results support the possibility that pine trees associate with nitrogen-fixing bacteria, capable of endophytic colonization, to survive at unreclaimed gravel mining pits and this association could potentially be utilized for effective reclamation of highly disturbed sites in a sustainable manner.

scholarly journals Nitrogen-Fixing Bacteria Associated with Peltigera Cyanolichens and Cladonia Chlorolichens

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3077 ◽  
Author(s):  
Katerin Almendras ◽  
Jaime García ◽  
Margarita Carú ◽  
Julieta Orlando
Keyword(s):  
Bacterial Communities ◽  
Fragment Length Polymorphism ◽  
Multivariate Analyses ◽  
Nifh Gene ◽  
Shannon Index ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Symbiotic Interaction ◽  
Different Types ◽  
Terricolous Lichens

Lichens have been extensively studied and described; however, recent evidence suggests that members of the bacterial community associated with them could contribute new functions to the symbiotic interaction. In this work, we compare the nitrogen-fixing guild associated with bipartite terricolous lichens with different types of photobiont: Peltigera cyanolichens and Cladonia chlorolichens. Since cyanobacteria contribute nitrogen to the symbiosis, we propose that chlorolichens have more diverse bacteria with the ability to fix nitrogen compared to cyanolichens. In addition, since part of these bacteria could be recruited from the substrate where lichens grow, we propose that thalli and substrates share some bacteria in common. The structure of the nitrogen-fixing guild in the lichen and substrate bacterial communities of both lichens was determined by terminal restriction fragment length polymorphism (TRFLP) of the nifH gene. Multivariate analyses showed that the nitrogen-fixing bacteria associated with both types of lichen were distinguishable from those present in their substrates. Likewise, the structure of the nitrogen-fixing bacteria present in the cyanolichens was different from that of chlorolichens. Finally, the diversity of this bacterial guild calculated using the Shannon index confirms the hypothesis that chlorolichens have a higher diversity of nitrogen-fixing bacteria than cyanolichens.

Cold tolerance in rice varieties at different growth stages

2009 ◽  
Vol 60 (4) ◽  
pp. 328 ◽  
Author(s):  
C. Ye ◽  
S. Fukai ◽  
I. Godwin ◽  
R. Reinke ◽  
P. Snell ◽  
...  
Keyword(s):  
Low Temperature ◽  
Cold Tolerance ◽  
High Elevation ◽  
Temperature Tolerance ◽  
Seedling Stage ◽  
Growth Stages ◽  
Rice Varieties ◽  
Low Temperature Tolerance ◽  
Wide Range ◽  
Different Growth Stages

Low temperature is a common production constraint in rice cultivation in temperate zones and high-elevation environments, with the potential to affect growth and development from germination to grain filling. There is a wide range of genotype-based differences in cold tolerance among rice varieties, these differences often reflecting growth conditions in the place of origin, as well as breeding history. However, improving low temperature tolerance of varieties has been difficult, due to a lack of clarity of the genetic basis to low temperature tolerance for different growth stages of the rice plant. Seeds or plants of 17 rice varieties of different origins were exposed to low temperature during germination (15°C), seedling, booting, and flowering stages (18.5°C), to assess their cold tolerance at different growth stages. Low temperature at the germination stage reduced both the percentage and speed of germination. Varieties from China (B55, Banjiemang, and Lijianghegu) and Hungary (HSC55) were more tolerant of low temperature than other varieties. Most of the varieties showed moderate levels of low temperature tolerance during the seedling stage, the exceptions being some varieties from Australia (Pelde, YRL39, and YRM64) and Africa (WAB160 and WAB38), which were susceptible to low temperature at the seedling stage. Low temperature at booting and flowering stages reduced plant growth and caused a significant decline in spikelet fertility. Some varieties from China (B55, Bangjiemang, Lijiangheigu), Japan (Jyoudeki), the USA (M103, M104), and Australia (Quest) were tolerant or moderately tolerant, while the remaining varieties were susceptible or moderately susceptible to low temperature at booting and flowering stages. Three varieties from China (B55, Lijianghegu, Banjiemang) and one from Hungary (HSC55) showed consistent tolerance to low temperature at all growth stages. These varieties are potentially important gene donors for breeding and genetic studies. The cold tolerance of the 17 rice varieties assessed at different growth stages was correlated. Screening for cold tolerance during early growth stages can therefore potentially be an effective way for assessing cold tolerance in breeding programs.

Phylogenetic diversity of nitrogen-fixing bacteria and thenifHgene from mangrove rhizosphere soil

2012 ◽  
Vol 58 (4) ◽  
pp. 531-539 ◽  
Author(s):  
Jianyin Liu ◽  
Mengjun Peng ◽  
Youguo Li
Keyword(s):  
Phylogenetic Trees ◽  
Rhizosphere Soil ◽  
Nifh Gene ◽  
Soil Samples ◽  
Community Diversity ◽  
Nitrogen Fixing ◽  
Pcr Cloning ◽  
Nitrogen Fixing Bacteria ◽  
Soil Dna ◽  
Mangrove Ecosystems

Nine types of nitrogen-fixing bacterial strains were isolated from 3 rhizosphere soil samples taken from mangrove plants in the Dongzhaigang National Mangrove Nature Reserve of China. Most isolates belonged to Gammaproteobacteria Pseudomonas , showing that these environments constituted favorable niches for such abundant nitrogen-fixing bacteria. New members of the diazotrophs were also found. Using a soil DNA extraction and PCR-cloning-sequencing approach, 135 clones were analyzed by restriction fragment length polymorphism (RFLP) analysis, and 27 unique nifH sequence phylotypes were identified, most of which were closely related to sequences from uncultured bacteria. The diversity of nitrogen-fixing bacteria was assessed by constructing nifH phylogenetic trees from sequences of all isolates and clones in this work, together with related nifH sequences from other mangrove ecosystems in GenBank. The nifH diversity varied among soil samples, with distinct biogeochemical properties within a mangrove ecosystem. When comparing different mangrove ecosystems, the nifH gene sequences from a specific site tended to cluster as individual groups. The results provided interesting data and novel information on our understanding of diazotroph community diversity in the mangrove ecosystems.

Differential effects of certain phenoxyacetic acid compounds and phenylcarbamates on plant species. II. Effects of foliage applications with special reference to yields of wheat

1950 ◽  
Vol 1 (4) ◽  
pp. 401 ◽  
Author(s):  
RM Moore
Keyword(s):  
Sodium Salt ◽  
Butyl Ester ◽  
Seedling Stage ◽  
Dichlorophenoxyacetic Acid ◽  
Growth Stages ◽  
Phenoxyacetic Acid ◽  
Grain Yields ◽  
Triticum Vulgare ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Different Growth Stages

The effects of foliage sprays of various phenoxyacetic acid derivatives and of isopropyl n-phenylcarbamate on a dicotyledon, Phaseolus vulgaris, were compared. The carbamate was without effect and although all phenoxyacetic acid compounds were markedly toxic, they differed in the rapidity of their action. Wheat (Triticum vulgare) exhibited differential responses to phenoxyacetic acid compounds and to isopropyl phenylcarbaniate at different growth stages. Applications of four phenoxyacetic acid compounds to wheat at different stages of development, from late seedling to flowering, showed that grain yields were reduced most markedly by applications in the seedling stage; the butyl ester and amine salt of 2,4-dichlorophenoxyacetic acid were more toxic than the sodium salt. 0.1 per cent. foliage sprays of isopropyl phenylcarbamate had no effect on wheat in the late seedling or tillering stages, but severely depressed the yield of grain when applied at flowering. Barley (Hordeum vulgare) responded similarly. Higher concentrations applied to wheat at pre-shooting also reduced grain yields. Flax (Linum sitatissimum), although susceptible to pre-emergence treatment, was not affected by foliage sprays of isopropyl phenylcarbamate at any growth-stage. 0.1 per cent. applications of 2,4-dichlorophenoxyacetic acid as the sodium salt reduced flax yields only when applied at the seedling stage.

Evaluation of the diversity of nitrogen-fixing bacteria in soybean rhizosphere by nifH gene analysis

Microbiology ◽  
2012 ◽  
Vol 81 (5) ◽  
pp. 621-629 ◽  
Author(s):  
A. K. Kizilova ◽  
L. V. Titova ◽  
I. K. Kravchenko ◽  
G. A. Iutinskaya
Keyword(s):  
Nifh Gene ◽  
Gene Analysis ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria

The Effect of Magnaporthe Grisea Toxin on Photosystem in Rice

2013 ◽  
Vol 726-731 ◽  
pp. 4454-4458
Author(s):  
Li Qiong Tang ◽  
Jun Yi ◽  
Yun Gao Hu ◽  
Ling Zhang ◽  
Guo Tao Yang
Keyword(s):  
Magnaporthe Grisea ◽  
Photosynthetic Pigment ◽  
Growth Stages ◽  
Booting Stage ◽  
Chl A ◽  
Physiological Races ◽  
Resistant Varieties ◽  
Pigment Contents ◽  
Jointing Stage ◽  
Different Growth Stages

Understanding the toxic effect of Magnaporthe oryzae on rice to breed resistant varieties is important for environment protection. The effects of four M. Oryzae physiological races were conducted on the photosynthesis and photosynthetic pigment contents relating to hybrid rice. The results suggest that Pn、E、chl a/chl b and Car content at all growth stages, Ci and Gs at tillering stage, the content of Chl a, Chl b, Chl (a+b) at tillering stage and jointing stage are decreased significantly by the M. oryzae toxins , while Ci and Gs at jointing stage and booting stage, the content of Chl a, Chl b and Chl (a+b) at booting stage show a significant increase in their values. Photosynthesis of rice are inhibited by stomatal and non-stomatal factors in rice treated by M. Oryzae toxins. The response of rice at different growth stages is statistically different for various M. Oryzae physiological races.

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