scholarly journals Coping with darkness: The adaptive response of marine picocyanobacteria to repeated light energy deprivation

2021 ◽  
Author(s):  
Allison Coe ◽  
Steven J. Biller ◽  
Elaina Thomas ◽  
Konstantinos Boulias ◽  
Christina Bliem ◽  
...  
Keyword(s):  
Adaptive Response ◽  
Light Energy ◽  
Energy Deprivation

scholarly journals Coping with darkness: The adaptive response of marine picocyanobacteria to repeated light energy deprivation

2020 ◽  
Author(s):  
Allison Coe ◽  
Steven J. Biller ◽  
Elaina Thomas ◽  
Konstantinos Boulias ◽  
Christina Bliem ◽  
...  
Keyword(s):  
Adaptive Response ◽  
Euphotic Zone ◽  
Light Energy ◽  
Epigenetic Mechanism ◽  
Epigenetic Change ◽  
Deep Mixing ◽  
Dark Exposure ◽  
Dna Methylations ◽  
Energy Deprivation ◽  
Light:Dark Cycle

AbstractThe picocyanobacteria Prochlorococcus and Synechococcus are found throughout the ocean’s euphotic zone, where the daily light:dark cycle drives their physiology. Periodic deep mixing events can, however, move cells below this zone, depriving them of light for extended periods of time. Here we demonstrate that Prochlorococcus and Synechococcus can adapt to tolerate repeated periods of light energy deprivation. Cyanobacterial cultures kept in the dark for 3 days and then returned to the light initially required 18-26 days to resume growth, but after multiple rounds of dark exposure the strains began to regrow after only 1-2 days. This dark-tolerant phenotype was stable and heritable; cultures retained the trait across at least 18-21 generations even when grown in a standard 13:11 light:dark cycle. We found no genetic differences between the dark-tolerant and parental strains of Prochlorococcus NATL2A, indicating that an epigenetic change is responsible for the adaptation. To begin to explore this possibility, we asked whether DNA methylation – an epigenetic mechanism in bacteria – occurs in Prochlorococcus. LC-MS/MS analysis showed that while DNA methylations, including 6mA and 5mC, are found in some other Prochlorococcus strains, no methylations were detected in either the parental or dark-tolerant strain used in our experiments –i.e. the NATL2A strain. These findings suggest that Prochlorococcus utilizes a yet-to-be-determined epigenetic mechanism to adapt to the stress of extended light energy deprivation.

scholarly journals Light Energy Partitioning under Various Environmental Stresses Combined with Elevated CO2 in Three Deciduous Broadleaf Tree Species in Japan

Climate ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 79 ◽  
Author(s):  
Mitsutoshi Kitao ◽  
Hiroyuki Tobita ◽  
Satoshi Kitaoka ◽  
Hisanori Harayama ◽  
Kenichi Yazaki ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Tree Species ◽  
Adaptive Response ◽  
Environmental Stresses ◽  
Light Energy ◽  
Photochemical Quenching ◽  
N Limitation ◽  
Elevated O3 ◽  
Broadleaf Tree ◽  
Non Photochemical Quenching

Understanding plant response to excessive light energy not consumed by photosynthesis under various environmental stresses, would be important for maintaining biosphere sustainability. Based on previous studies regarding nitrogen (N) limitation, drought in Japanese white birch (Betula platyphylla var. japonica), and elevated O3 in Japanese oak (Quercus mongolica var. crispula) and Konara oak (Q. serrata) under future-coming elevated CO2 concentrations, we newly analyze the fate of absorbed light energy by a leaf, partitioning into photochemical processes, including photosynthesis, photorespiration and regulated and non-regulated, non-photochemical quenchings. No significant increases in the rate of non-regulated non-photochemical quenching (JNO) were observed in plants grown under N limitation, drought and elevated O3 in ambient or elevated CO2. This suggests that the risk of photodamage caused by excessive light energy was not increased by environmental stresses reducing photosynthesis, irrespective of CO2 concentrations. The rate of regulated non-photochemical quenching (JNPQ), which contributes to regulating photoprotective thermal dissipation, could well compensate decreases in the photosynthetic electron transport rate through photosystem II (JPSII) under various environmental stresses, since JNPQ+JPSII was constant across the treatment combinations. It is noteworthy that even decreases in JNO were observed under N limitation and elevated O3, irrespective of CO2 conditions, which may denote a preconditioning-mode adaptive response for protection against further stress. Such an adaptive response may not fully compensate for the negative effects of lethal stress, but may be critical for coping with non-lethal stress and regulating homeostasis. Regarding the three deciduous broadleaf tree species, elevated CO2 appears not to influence the plant responses to environmental stresses from the viewpoint of susceptibility to photodamage.

Structural and functional remodeling of mitochondria as an adaptive response to energy deprivation

2021 ◽  
pp. 148393
Author(s):  
Andrey V. Kuznetsov ◽  
Sabzali Javadov ◽  
Raimund Margreiter ◽  
Michael Grimm ◽  
Judith Hagenbuchner ◽  
...  
Keyword(s):  
Adaptive Response ◽  
Functional Remodeling ◽  
Energy Deprivation

Cardiomyocyte dedifferentiation - A (mal)adaptive response to hypoxia

2014 ◽  
Vol 62 (S 01) ◽  
Author(s):  
J. Pöling ◽  
T. Kubin ◽  
P. Gajawada ◽  
H. Lörchner ◽  
V. Polyakova ◽  
...  
Keyword(s):  
Adaptive Response

Light Energy Saving method of Lighting System Based on MISO FO Newton-based ES*

2020 ◽  
Author(s):  
Chun Yin ◽  
Sara Dadras ◽  
Yuhua Cheng ◽  
Xuegang Huang ◽  
Kai Chen ◽  
...  
Keyword(s):  
Energy Saving ◽  
Light Energy ◽  
Lighting System
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