scholarly journals The UV RESISTANCE LOCUS 8-Mediated UV-B Response Is Required Alongside CRYPTOCHROME1 For Plant Survival Under Sunlight In The Field

2021 ◽  
Author(s):  
Reinhold Stockenhuber ◽  
Reiko Akiyama ◽  
Nicolas Tissot ◽  
Misako Yamazaki ◽  
Michele Wyler ◽  
...  

As sessile organisms, plants are subjected to fluctuating sunlight including potentially detrimental ultraviolet-B radiation (UV-B). In Arabidopsis thaliana, experiments under controlled conditions have shown that UV RESISTANCE LOCUS 8 (UVR8) controls photomorphogenic responses for acclimation and tolerance to UV-B; however, its long-term impacts on plant performance remain poorly understood in naturally fluctuating environments. Here we quantified the survival and reproduction of different Arabidopsis mutant genotypes in diverse field and laboratory conditions. We found that uvr8 mutants produced more fruits than wild type in growth chambers with artificial low UV-B conditions but not in natural field conditions. Importantly, independent double mutants of UVR8 and the blue-light photoreceptor gene CRYPTOCHROME 1 (CRY1) in two genetic backgrounds showed a drastic reduction in fitness in the field. UV-B attenuation experiments in field conditions and supplemental UV-B in growth chambers demonstrated that UV-B caused the conditional cry1 uvr8 lethality phenotype. RNA sequencing in different conditions revealed a large number of genes with statistical interaction of UVR8 and CRY1 mutations in the presence of UV-B in the field. Among them, Gene Ontology analysis identified enrichment of categories related to UV-B response, oxidative stress, photoprotection and DNA damage repair. Our study demonstrates the functional importance of the UVR8-mediated response across life stages in natura, which is partially redundant with CRY1, and provides an integral picture of gene expression associated with plant environmental responses under diverse environmental conditions.

2000 ◽  
Vol 77 (11) ◽  
pp. 1648-1654
Author(s):  
Laura A Hyatt ◽  
Ann S Evans ◽  
Carol C Baskin

Patterns of germination over time were investigated in a short-lived desert perennial species, Lesquerella fendleri (Gray) S. Wats. Field-collected seeds were either buried in the field in cloth bags or stored in a glass jar under laboratory conditions. Regular germination tests were conducted under a range of alternating temperatures (buried seeds) or under differing water regimes (laboratory-stored seeds). Testing revealed Lesquerella fendleri to have an annual dormancy-nondormancy cycle, which was manifest regardless of seed storage conditions, suggesting that cycles may be partially endogenously regulated. Increasing seed germinability in field-stored seeds (maximum of 30% in year 1 and 95% in year 2) leads to the formation of a seed bank for at least 1 year and enhances the possibility of spreading germination events through time. This allows parent plants to maximize fitness in randomly fluctuating environments. The existence of two seedling flushes in the field and single germinability peaks in growth chambers suggests that dormancy cycling may support the formation of a metapopulation with subpopulations which are, although physically intermingled, genetically distinct.


2014 ◽  
Vol 164 (4) ◽  
pp. 2220-2230 ◽  
Author(s):  
Vanesa Tossi ◽  
Lorenzo Lamattina ◽  
Gareth I. Jenkins ◽  
Raúl O. Cassia

2014 ◽  
Vol 7 (5) ◽  
pp. 773-791 ◽  
Author(s):  
Rossella Fasano ◽  
Nathalie Gonzalez ◽  
Alessandra Tosco ◽  
Fabrizio Dal Piaz ◽  
Teresa Docimo ◽  
...  

2019 ◽  
Vol 66 (1) ◽  
pp. 111-120
Author(s):  
Michał Starczewski ◽  
Piotr Żmijewski ◽  
Katarzyna Witek ◽  
Andrzej Klusiewicz

AbstractThe main goal of the study was to evaluate the impact of different roller skiing techniques (classical CT and skating ST) performed under field conditions on physical capacity variables in cross-country skiers. The second purpose was to evaluate the possibility to use the test results conducted under field and laboratory conditions interchangeably to determine training loads. Eight international-level cross-country skiers (4 male, 4 female) with 8.8 ± 1.3 years of skiing experience took part in the study. The athletes performed three graded tests to exhaustion: two under field conditions (roller skiing CT and ST techniques) and one in the laboratory: treadmill running (TR). All tests were conducted within a period of two weeks to compare general and specific physical capacity outcomes. ANOVA demonstrated significant differences in the threshold heart rate (HRAT4) (ST 175.3 ± 10.8 bpm, CT 175.8 ± 10.9 bpm, TR 181.5 ± 11.1 bpm; p = 0.004), maximal oxygen uptake (VO2max) (ST 64.0 ± 4.65 ml/kg/min, CT 61.5 ± 5.09 ml/kg/min, TR 65.9 ± 2.30 ml/kg/min; p = 0.008) and maximal HR (ST 189.3 ± 10.9 bpm, CT 188.9 ± 10.6 bpm, TR 199.5 ± 10.3 bpm; p = 0.002). No significant differences were observed between classical and skating roller skiing techniques for maximal and threshold values except for threshold velocity (CT 13.4 ± 1.11 km/h vs. ST 14.7 ± 1.17 km/h p = 0.002). Maximal velocity was not measured. The main finding of the study is that it is possible to use threshold HR values obtained in roller skiing tests performed using the classical or skating techniques interchangeably to determine roller skiing training loads. The results of the study indicate that there is a need to verify maximal treadmill running exertion variables in specific roller skiing tests.


Sociobiology ◽  
2015 ◽  
Vol 62 (3) ◽  
pp. 351
Author(s):  
Yong-Qing Tian ◽  
Dong-Mei Cheng ◽  
Zhi-Xiang Zhang

We evaluated the bioactivities of compounds from Cicuta virosa L. var. latisecta Celak. against red imported fire ants (Solenopsis invicta Buren) under field and laboratory conditions. The compounds were as follows: methanol extract; petroleum ether, chloroform, and ethyl acetate fractions from the methanol extract; and the active compound isoimperatorin, which was isolated from the chloroform-fraction. The 7 d LC50 values of the methanol extract, petroleum ether, chloroform, and ethyl acetate fractions and isoimperatorin toward micrergates were 111.20, 214.45, 40.90, 569.67, and 25.73 mg/kg, res­pectively. The corresponding LC50 values toward macrergates were 155.78, 308.38, 75.01, 776.75, and 42.77 mg/kg, res­pectively. Under field conditions, baits containing 0.2% methanol extract, 0.1% chloroform fraction, and 0.05% isoimperatorin efficiently controlled S. invicta, with effectiveness percentages of 95.56%, 97.78%, and 95.56%, respectively on the 30th day after bait application. Such effectiveness percentages were not significantly different from that obtained using the positive control fipronil. The present study showed that C. virosa L. var. latisecta has potential as a natural control agent for the red imported fire ants.


Plant Science ◽  
2020 ◽  
Vol 301 ◽  
pp. 110679
Author(s):  
Xiao-Min Ge ◽  
Xin Hu ◽  
Jun Zhang ◽  
Qin-Mei Huang ◽  
Yuan Gao ◽  
...  

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