scholarly journals JENIS DAN POPULASI BAKTERI ICE NUCLEATION ACTIVE PENYEBAB LUKA BEKU PADA DAUN JERUK KEPROK SOE DI DATARAN TINGGI MUTIS

2020 ◽  
Vol 3 (2) ◽  
pp. 127-135
Author(s):  
Hildegardis Missa ◽  
Anselmus Boy Baunsele
Keyword(s):  
Bacterial Population ◽  
Ice Nucleation ◽  
Test Method ◽  
Ice Formation ◽  
Frost Injury ◽  
Class B ◽  
Ina Bacteria ◽  
Three Stages ◽  
Active Bacteria ◽  
Ice Nucleation Activity

Research on ice nucleation-active bacteria causes frost injury from tropic areas has not been widely publicized. The purpose of this study was to determine the population of Ice Nucleation-Active Bacteria on Soe tangerines leaves and the class of Ice Nucleation-Active bacteria based on Ice formation temperatures. The collecting of Soe tangerine leaves used the purpose sampling method. Leaves with frost blotches were collected from three stages at altitudes of 1500, 1800, and 2000 meters above sea level (m asl). Bacterial isolation was carried out by the spread plate method on Nutrien Agar 2,5 % glycerol (NAG)  media. Ice Nucleation activity was determined by the tube nucleation test method. Estimation of INA bacterial population was conducted by the multiple-tube nucleation test with Thomas series .3.3.3. The result showed that the highest INA bacterial population was 6.9x104 which was found in leaves samples collected from stations 1800 and 2000 m asl, and the lowest population i.e. 5,4x103 on leaf samples from station 1500 m asl. Based on the temperature of ice formation, it was known that INA bacteria that attack the Soe tangerines leaves Mutis plateau are the INA bacteria class B and C.

scholarly journals Enhanced ice nucleation activity of coal fly ash aerosol particles initiated by ice-filled pores

2019 ◽  
Author(s):  
Nsikanabasi Silas Umo ◽  
Robert Wagner ◽  
Romy Ullrich ◽  
Alexei Kiselev ◽  
Harald Saathoff ◽  
...  
Keyword(s):  
Fly Ash ◽  
Significant Role ◽  
Coal Fly Ash ◽  
Aerosol Particles ◽  
Ice Nucleation ◽  
Temperature Cycling ◽  
Cloud Formation ◽  
Ice Formation ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

Abstract. Ice-nucleating particles (INPs), which are precursors for ice formation in clouds, can alter the microphysical and optical properties of clouds, hence, impacting the cloud lifetimes and hydrological cycles. However, the mechanisms with which these INPs nucleate ice when exposed to different atmospheric conditions are still unclear for some particles. Recently, some INPs with pores or permanent surface defects of regular or irregular geometries have been reported to initiate ice formation at cirrus temperatures via the liquid phase in a two-step process, involving the condensation and freezing of supercooled water inside these pores. This mechanism has therefore been labelled as pore condensation and freezing (PCF). The PCF mechanism allows formation and stabilization of ice germs in the particle without the formation of macroscopic ice. Coal fly ash (CFA) aerosol particles are known to nucleate ice in the immersion freezing mode and may play a significant role in cloud formation. In our current ice nucleation experiments with CFA particles, which we conducted in the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) aerosol and cloud simulation chamber at the Karlsruhe Institute of Technology, Germany, we partly observed a strong increase in the ice-active fraction for experiments performed at temperatures just below the homogeneous freezing of pure water, which could be related to the PCF mechanism. To further investigate the potential of CFA particles undergoing PCF mechanism, we performed a series of temperature-cycling experiments in AIDA. The temperature-cycling experiments involve exposing CFA particles to lower temperatures (down to ~ 228 K), then warming them up to higher temperatures (238 K–273 K) before investigating their ice nucleation properties. For the first time, we report the enhancement of the ice nucleation activity of the CFA particles for temperatures up to 263 K, from which we conclude that it is most likely due to the PCF mechanism. This indicates that ice germs formed in the CFA particles’ pores during cooling remains in the pores during the warming and induces ice crystallization as soon as the pre-activated particles experience ice-supersaturated conditions at warmer temperatures; hence, showing an enhancement in their ice-nucleating ability compared to the scenario where the CFA particles are directly probed at warmer temperatures without temporary cooling. The enhancement in the ice nucleation ability showed a positive correlation with the specific surface area and porosity of the particles. On the one hand, the PCF mechanism could be the prevalent nucleation mode for intrinsic ice formation at cirrus temperatures rather than the previously acclaimed deposition mode. On the other, the PCF mechanism can also play a significant role in mixed-phase cloud formation in a case where the CFA particles are injected from higher altitudes and then transported to lower altitudes after being exposed to lower temperatures.

scholarly journals Measurement of Ice Nucleation-Active Bacteria on Plants and in Precipitation by Quantitative PCR

2013 ◽  
Vol 80 (4) ◽  
pp. 1256-1267 ◽  
Author(s):  
Thomas C. J. Hill ◽  
Bruce F. Moffett ◽  
Paul J. DeMott ◽  
Dimitrios G. Georgakopoulos ◽  
William L. Stump ◽  
...  
Keyword(s):  
Quantitative Pcr ◽  
Pseudomonas Syringae ◽  
Xanthomonas Campestris ◽  
Ice Nucleation ◽  
Content Type ◽  
Biological Source ◽  
Ina Bacteria ◽  
A Minor ◽  
Ice Nucleation Activity ◽  
Effective Contribution

ABSTRACTIce nucleation-active (INA) bacteria may function as high-temperature ice-nucleating particles (INP) in clouds, but their effective contribution to atmospheric processes, i.e., their potential to trigger glaciation and precipitation, remains uncertain. We know little about their abundance on natural vegetation, factors that trigger their release, or persistence of their ice nucleation activity once airborne. To facilitate these investigations, we developed two quantitative PCR (qPCR) tests of theinagene to directly count INA bacteria in environmental samples. Each of two primer pairs amplified most alleles of theinagene and, taken together, they should amplify all known alleles. To aid primer design, we collected many new INA isolates. Alignment of their partialinasequences revealed new and deeply branching clades, including sequences fromPseudomonas syringaepv.atropurpurea,Ps. viridiflava,Pantoea agglomerans,Xanthomonas campestris, and possiblyPs. putida,Ps. auricularis, andPs. poae. qPCR of leaf washings recorded ∼108inagenes g−1fresh weight of foliage on cereals and 105to 107g−1on broadleaf crops. Much lower populations were found on most naturally occurring vegetation. In fresh snow,inagenes from various INA bacteria were detected in about half the samples but at abundances that could have accounted for only a minor proportion of INP at −10°C (assuming oneinagene per INA bacterium). Despite this, an apparent biological source contributed an average of ∼85% of INP active at −10°C in snow samples. In contrast, a thunderstorm hail sample contained 0.3 INA bacteria per INP active at −10°C, suggesting a significant contribution to this sample.

scholarly journals 993 THEORY AND APPLICATION OF GENETIC ENGINEERING FOR STRESS RESISTANCE AND AVOIDANCE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 571d-571
Author(s):  
Steven E. Lindow
Keyword(s):  
Population Size ◽  
Pseudomonas Syringae ◽  
Stress Resistance ◽  
Field Studies ◽  
Ice Nucleation ◽  
Site Directed Mutagenesis ◽  
Ice Formation ◽  
Bacterial Strains ◽  
Solanum Commersonii ◽  
Frost Injury

Genes determining the ability of the bacterium Pseudomonas syringae to catalyze ice formation have been cloned and characterized. Ice nucleation active (Ice+) strains of this species are common on plants and the supercooling ability of frost sensitive plants is inversely proportional to the logarithm of the population size of Ice+ bacteria at temperatures above -5C. Recombinant Ice- derivatives off. syringae were produced by site-directed mutagenesis using deletion containing ice genes cloned form this species. The Ice- strains colonized potatoes well in field studies, reduced the population size of Ice+ bacterial strains by about 50-fold, and reduced the incidence of frost injury an average of 82% in several radiative frosts of temperatures in the range of -3 to -5 C. The ice gene has also been introduced into Solanum commersonii to determine its effect on increasing the tolerance of ice formation in this frost tolerant species. Transgenic plants exhibit a much higher threshold ice nucleation temperature than the parental plants.

scholarly journals Preferential freezing avoidance localized in anthers and embryo sacs in wintering Daphne kamtschatica var. jezoensis flower buds visualized by MRI

2021 ◽  
Author(s):  
Masaya Ishikawa ◽  
Hiroyuki Ide ◽  
Tetsuya Tsujii ◽  
Timothy Stait-Gardner ◽  
Hikaru Kubo ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cold Hardiness ◽  
Ice Nucleation ◽  
Ice Formation ◽  
Resonance Imaging ◽  
Flower Buds ◽  
Male And Female ◽  
Nucleation Activity ◽  
Magnetic Resonance Imaging Mri ◽  
Ice Nucleation Activity

To explore diversity in cold hardiness mechanisms, high resolution magnetic resonance imaging (MRI) was used to visualize freezing behaviors in wintering flower buds of Daphne kamtschatica var. jezoensis, which have no bud scales surrounding well-developed florets. MRI images showed that anthers remained stably supercooled to -14 ∼ -21°C or lower whilst most other tissues froze by -7°C. Freezing of some anthers detected in MRI images at ∼ -21°C corresponded with numerous low temperature exotherms and also with the “all-or-nothing” type of anther injuries. In ovules/pistils, only embryo sacs remained supercooled at -7°C or lower, but slowly dehydrated during further cooling. Cryomicroscopic observation revealed ice formation in the cavities of calyx tubes and pistils but detected no ice in embryo sacs or in anthers. The distribution of ice nucleation activity in floral tissues corroborated the tissue freezing behaviors. Filaments likely work as the ice blocking barrier that prevents ice intrusion from extracellularly frozen calyx tubes to connecting unfrozen anthers. Unique freezing behaviors were demonstrated in Daphne flower buds: preferential freezing avoidance in male and female gametophytes and their surrounding tissues (by stable supercooling in anthers and by supercooling with slow dehydration in embryo sacs) whilst the remaining tissues tolerate extracellular freezing.

scholarly journals Ice Nucleation, Freezing Injury, and Colonization of `Totem' Strawberry Flowers with Ice-nucleation-active (INA) Bacteria

1998 ◽  
Vol 123 (2) ◽  
pp. 234-238 ◽  
Author(s):  
Michele R. Warmund ◽  
James T. English
Keyword(s):  
Pseudomonas Syringae ◽  
Ice Nucleation ◽  
Deionized Water ◽  
Freezing Injury ◽  
Nucleation Temperature ◽  
Ice Formation ◽  
Fragaria Ananassa ◽  
Naturally Occurring ◽  
Ina Bacteria ◽  
Wetness Period

INA bacteria were isolated from primary flowers of `Totem' strawberry (Fragaria ×ananassa Duch.) plants that had been previously inoculated with strain Cit 7 of Pseudomonas syringae van Hall or noninoculated to determine their relationship to ice-nucleation temperature and floral injury. Mean ice-nucleation temperature of inoculated and noninoculated flowers was -2.2 and -2.8 °C, respectively. Primary flowers of noninoculated plants survived lower temperatures than those of inoculated plants. In another experiment, noninoculated plants were misted with sterile deionized water and incubated for 0, 12, 24, 36, or 48 hours at 25 °C day/10 °C night, and naturally occurring INA bacteria were isolated from primary flowers. INA bacterial densities increased exponentially with increasing incubation period. The critical wetness period for INA bacteria to establish a sufficient density to increase the likelihood of floral injury at -2.5 °C was 24 hours. Longer wetness periods resulted in higher INA bacterial densities but did not increase the floral mortality rate. Thermal analysis demonstrated that the ice nucleation temperature was associated with strawberry floral injury. Thus, low temperature survival of flowers was adversely affected by moisture for ≥24 h due to the presence of a sufficient density of INA bacteria to incite ice formation and floral injury.

scholarly journals INA Gene Inactivation in Isolated Strains from Frozen Leaves and its Effects on Plant Freezing

2016 ◽  
Vol 49 (3) ◽  
pp. 63-70
Author(s):  
A. Yadollahpour ◽  
N.A. Bagheri ◽  
H. Rahimian
Keyword(s):  
Single Gene ◽  
Ice Nucleation ◽  
Economic Losses ◽  
Wild Type ◽  
Tn5 Transposon ◽  
Leaf Tissues ◽  
Nucleation Activity ◽  
Active Bacteria ◽  
Freezing Test ◽  
Ice Nucleation Activity

Abstract Freezing is a major environmental stress, which limits plant’s distribution, growth and productivity. Ice nucleation active bacteria can catalyze ice formation at temperatures as high as −2°C. A membrane protein confer the ability of ice nucleation, called ice-nucleating proteins (INPs), which is encoded by a single gene. Mutation in this gene will lead to delaying of ice nucleation. In this study, leaf tissues of several plants with freezing symptoms were collected from different locations and 40 bacterial isolates with yellow circular colonies and regular margins were isolated from samples. Finally, total of 12 isolates belong to Xanthomonas were selected for ice nucleate activity (INA) by Droplet-freezing test and presence of INA gene was surveyed by PCR. According to the obtained results, isolate 28 was targeted to mutagenesis by using Tn5 transposon. After mutagenesis, isolates with ability to grow on kanamycin, which lack of INAx gene in PCR were considered as mutated isolates and their freezing effects were evaluated on bean seedlings. Results showed that isolates with mutated INA gene cannot induce freezing on bean seedlings, while primary identified isolate (isolate 28) could do it. These results show that if we could replace wild type ice nucleation active bacteria with mutated forms (just different in ice nucleation activity), we could, probably, prevent freezing and subsequent economic losses.

scholarly journals 557 PB 374 EFFICACIES OF CRYOPROTECTANTS APPLIED TO STRAWBERRY PLANTS INOCULATED WITH ICE-NUCLEATION-ACTIVE BACTERIA

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 511d-511
Author(s):  
Michele R. Warmund ◽  
James T. English
Keyword(s):  
Low Temperature ◽  
Pseudomonas Syringae ◽  
Ice Nucleation ◽  
Freezing Injury ◽  
Fragaria Ananassa ◽  
Full Bloom ◽  
Ina Bacteria ◽  
Active Bacteria ◽  
Temperature Exposure ◽  
Low Temperature Exposure

Cryoprotectants were applied at labeled rates to primary flowers of `Honeoye' strawberry (Fragaria × ananassa Duch.) plants at full bloom to determine their effects on the floral organs. Frostgard at 50 ml/liter or KDL at 22 ml/liter injured pistils and resulted in misshapened fruit. Floral buds that were closed when cryoprotectants were applied were uninjured. In other experiments, efficacies of cryoprotectants were determined after floral tissues of `Honeoye' strawberry plants were inoculated or not inoculated with the ice-nucleation-active (INA) bacteria, Pseudomonas syringae van Hall and subjected to sub-freezing temperatures. None of the products protected primary or secondary flowers against freezing injury regardless of the occurrence of INA bacteria. INA bacteria were not recovered from primary flowers of treated plants that were killed by low temperature exposure, indicating that non-bacterial nuclei may incite freezing in these tissues.

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