The role of 24-epibrassinolide in the regulation of photosynthetic characteristics and nitrogen metabolism of tomato seedlings under a combined low temperature and weak light stress

2016 ◽  
Vol 107 ◽  
pp. 344-353 ◽  
Author(s):  
Sheng Shu ◽  
Yuanyuan Tang ◽  
Yinghui Yuan ◽  
Jin Sun ◽  
Min Zhong ◽  
...  
Keyword(s):  
Low Temperature ◽  
Nitrogen Metabolism ◽  
Light Stress ◽  
Photosynthetic Characteristics ◽  
Tomato Seedlings ◽  
Weak Light

scholarly journals Substrate Application of 5-Aminolevulinic Acid Enhanced Low-temperature and Weak-light Stress Tolerance in Cucumber (Cucumis sativus L.)

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 472 ◽  
Author(s):  
Ali Anwar ◽  
Jun Wang ◽  
Xianchang Yu ◽  
Chaoxing He ◽  
Yansu Li
Keyword(s):  
Low Temperature ◽  
Stress Tolerance ◽  
Antioxidant Enzyme ◽  
Aminolevulinic Acid ◽  
Light Stress ◽  
Photochemical Quenching ◽  
Antioxidant Enzyme Activities ◽  
Cucumber Seedlings ◽  
Chl A ◽  
Weak Light

5-Aminolevulinic acid (ALA) is a type of nonprotein amino acid that promotes plant stress tolerance. However, the underlying physiological and biochemical mechanisms are not fully understood. We investigated the role of ALA in low-temperature and weak-light stress tolerance in cucumber seedlings. Seedlings grown in different ALA treatments (0, 10, 20, or 30 mg ALA·kg−1 added to substrate) were exposed to low temperature (16/8 ˚C light/dark) and weak light (180 μmol·m−2·s−1 photosynthetically active radiation) for two weeks. Treatment with ALA significantly alleviated the inhibition of plant growth, and enhanced leaf area, and fresh and dry weight of the seedlings under low-temperature and weak-light stress. Moreover, ALA increased chlorophyll (Chl) a, Chl b, and Chl a+b contents. Net photosynthesis rate, stomatal conductance, transpiration rate, photochemical quenching, non-photochemical quenching, actual photochemical efficiency of photosystem II, and electron transport rate were significantly increased in ALA-treated seedlings. In addition, ALA increased root activity and antioxidant enzyme (superoxide dismutase, peroxidase, and catalase) activities, and reduced reactive oxygen species (hydrogen peroxide and superoxide radical) and malondialdehyde accumulation in the root and leaf of cucumber seedlings. These findings suggested that ALA incorporation in the substrate alleviated the adverse effects of low-temperature and weak-light stress, and improved Chl contents, photosynthetic capacity, and antioxidant enzyme activities, and thus enhanced cucumber seedling growth.

scholarly journals α-Tocopherol Is Essential for Acquired Chill-Light Tolerance in the Cyanobacterium Synechocystis sp. Strain PCC 6803

2007 ◽  
Vol 190 (5) ◽  
pp. 1554-1560 ◽  
Author(s):  
Yang Yang ◽  
Chuntao Yin ◽  
Weizhi Li ◽  
Xudong Xu
Keyword(s):  
Escherichia Coli ◽  
Low Temperature ◽  
Light Stress ◽  
Wild Type ◽  
Regulated Expression ◽  
Synechocystis Sp ◽  
Pcc 6803

ABSTRACT Unlike Escherichia coli, the cyanobacterium Synechocystis sp. strain PCC 6803 is insensitive to chill (5°C) in the dark but rapidly losses viability when exposed to chill in the light (100 μmol photons m−2 s−1). Preconditioning at a low temperature (15°C) greatly enhances the chill-light tolerance of Synechocystis sp. strain PCC 6803. This phenomenon is called acquired chill-light tolerance (ACLT). Preconditioned wild-type cells maintained a substantially higher level of α-tocopherol after exposure to chill-light stress. Mutants unable to synthesize α-tocopherol, such as slr1736, slr1737, slr0089, and slr0090 mutants, almost completely lost ACLT. When exposed to chill without light, these mutants showed no or a slight difference from the wild type. When complemented, the slr0089 mutant regained its ACLT. Copper-regulated expression of slr0090 from P petE controlled the level of α-tocopherol and ACLT. We conclude that α-tocopherol is essential for ACLT of Synechocystis sp. strain PCC 6803. The role of α-tocopherol in ACLT may be based largely on a nonantioxidant activity that is not possessed by other tocopherols or pathway intermediates.

scholarly journals Dissecting the Roles of Cuticular Wax in Plant Resistance to Shoot Dehydration and Low-Temperature Stress in Arabidopsis

2021 ◽  
Vol 22 (4) ◽  
pp. 1554
Author(s):  
Tawhidur Rahman ◽  
Mingxuan Shao ◽  
Shankar Pahari ◽  
Prakash Venglat ◽  
Raju Soolanayakanahally ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Low Temperature ◽  
Cold Acclimation ◽  
Water Loss ◽  
Cuticular Wax ◽  
Dehydration Stress ◽  
Wax Deposition ◽  
Cuticular Waxes ◽  
Gas Chromatography Mass Spectroscopy

Cuticular waxes are a mixture of hydrophobic very-long-chain fatty acids and their derivatives accumulated in the plant cuticle. Most studies define the role of cuticular wax largely based on reducing nonstomatal water loss. The present study investigated the role of cuticular wax in reducing both low-temperature and dehydration stress in plants using Arabidopsis thaliana mutants and transgenic genotypes altered in the formation of cuticular wax. cer3-6, a known Arabidopsis wax-deficient mutant (with distinct reduction in aldehydes, n-alkanes, secondary n-alcohols, and ketones compared to wild type (WT)), was most sensitive to water loss, while dewax, a known wax overproducer (greater alkanes and ketones compared to WT), was more resistant to dehydration compared to WT. Furthermore, cold-acclimated cer3-6 froze at warmer temperatures, while cold-acclimated dewax displayed freezing exotherms at colder temperatures compared to WT. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis identified a characteristic decrease in the accumulation of certain waxes (e.g., alkanes, alcohols) in Arabidopsis cuticles under cold acclimation, which was additionally reduced in cer3-6. Conversely, the dewax mutant showed a greater ability to accumulate waxes under cold acclimation. Fourier Transform Infrared Spectroscopy (FTIR) also supported observations in cuticular wax deposition under cold acclimation. Our data indicate cuticular alkane waxes along with alcohols and fatty acids can facilitate avoidance of both ice formation and leaf water loss under dehydration stress and are promising genetic targets of interest.

The Role of Li2CO3and PbO in the Low-Temperature Sintering of Sr, K, Nb (SKN)-Doped PZT

2009 ◽  
Vol 92 (6) ◽  
pp. 1203-1207 ◽  
Author(s):  
Niall J. Donnelly ◽  
Thomas R. Shrout ◽  
Clive A. Randall
Keyword(s):  
Low Temperature ◽  
Low Temperature Sintering

Spin-Lattice Coupling and Peculiarities of Magnetic Behavior of Ferrimagnetic Ludwigites Mn0.52+M1.52+Mn3+BO5(M=Cu, Ni)

2015 ◽  
Vol 233-234 ◽  
pp. 133-136 ◽  
Author(s):  
Leonard Bezmaternykh ◽  
Evgeniya Moshkina ◽  
Evgeniy Eremin ◽  
Maxim Molokeev ◽  
Nikita Volkov ◽  
...  
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Magnetic Anisotropy ◽  
Single Crystals ◽  
Magnetic Behavior ◽  
Temperature Hysteresis ◽  
Spin Lattice ◽  
Field Magnetization ◽  
Lattice Coupling

Temperature-field and orientational magnetization dependences of single crystals were measured. Both samples demonstrate significant field-depending temperature hysteresis and low-temperature counter field magnetization. The correlation of orientational dependences of these effects and magnetic anisotropy is analyzed; the role of spin-lattice interactions is discussed.

Role of Surface Reconstruction and External Ion Beam in the Growth Kinetics of III-V Molecular Beam Epitaxy

1987 ◽  
Vol 94 ◽  
Author(s):  
S. B. Ogale ◽  
M. Thomsen ◽  
A. Madhukar
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Surface Reconstruction ◽  
Molecular Beam ◽  
Ion Beam ◽  
Growth Front ◽  
Kinetic Rates ◽  
Kinetics Of ◽  
Low Temperature Epitaxy

ABSTRACTComputer simulations of III-V molecular beam epitaxy (MBE) show that surface reconstruction induced modulation of kinetic rates could give rise to ordering in alloys. Results are also presented for the possible influence of an external ion beam in achieving low temperature epitaxy as well as smoother growth front under usual conditions.

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