Low-Temperature Signal Transduction: Induction of Cold Acclimation-Specific Genes of Alfalfa by Calcium at 25 degrees C

1995 ◽  
Vol 7 (3) ◽  
pp. 321 ◽  
Author(s):  
Antonio F. Monroy ◽  
Rajinder S. Dhindsa
1997 ◽  
pp. 15-28 ◽  
Author(s):  
Rajinder S. Dhindsa ◽  
Antonio F. Monroy ◽  
Veena Sangwan ◽  
Wojciech Kawczynski ◽  
Etienne Labbé

2002 ◽  
Vol 357 (1423) ◽  
pp. 831-847 ◽  
Author(s):  
Maggie Smallwood ◽  
Dianna J. Bowles

Plants are able to survive prolonged exposure to sub–zero temperatures; this ability is enhanced by pre–exposure to low, but above–zero temperatures. This process, known as cold acclimation, is briefly reviewed from the perception of cold, through transduction of the low–temperature signal to functional analysis of cold–induced gene products. The stresses that freezing of apoplastic water imposes on plant cells is considered and what is understood about the mechanisms that plants use to combat those stresses discussed, with particular emphasis on the role of the extracellular matrix.


2021 ◽  
Vol 22 (4) ◽  
pp. 1554
Author(s):  
Tawhidur Rahman ◽  
Mingxuan Shao ◽  
Shankar Pahari ◽  
Prakash Venglat ◽  
Raju Soolanayakanahally ◽  
...  

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.


2021 ◽  
Author(s):  
Devika Varma ◽  
Gert-Jan Reichart ◽  
Stefan Schouten

<p>For more than a decade TEX<sub>86</sub> and U<sup>K’</sup><sub>37</sub>, derived from ratios of biomarker lipids have widely been used as organic paleotemperature proxies. Yet, these proxies, especially TEX<sub>86</sub>, have several uncertainties associated with factors such as depth and seasonal biases which are complicating its application as an annual mean sea-surface temperature (SST) proxy. To constrain this impact, we performed a relatively simple modelling exercise where we use instrumental temperature and nutrient data from 40 locations across the globe to predict theoretical proxy values and compare them with measured core-top proxy values.</p><p>The model first uses instrumental nutrient and temperature data, and probability density functions to predict the theoretical depth occurrence of the source organisms of the two proxies. Additionally, seasonal bias was introduced by predicting seasonal occurrences using instrumental nutrient and chlorophyll data. This was used to calculate the depth- and season weighed temperature signal annually deposited in the sediment, which in turn was converted to theoretical proxy values using culture or mesocosm calibrations. This showed, as expected, that depth and seasonal biases introduced scatter in the correlation between theoretical proxy values and annual mean SST but still highly significant for both U<sup>K’</sup><sub>37</sub> (r<sup>2</sup>= 0.96), and TEX<sub>86</sub> (r<sup>2</sup>= 0.77). We find that the theoretical proxy values are much lower than measured proxy value for TEX<sub>86</sub>, which tentatively suggests that TEX<sub>86 </sub>might in fact be coming from shallower depths or that the mesocosm calibration is incorrect. Our model for U<sup>K’</sup><sub>37</sub> results in theoretical values similar to measured values except for low temperature locations. This might suggest an influence of seasonal bias towards more warmer summer seasons which is more pronounced in high latitudes than in tropics.</p>


2018 ◽  
pp. 57-71
Author(s):  
Rajinder S. Dhindsa ◽  
Antonio Monroy ◽  
Lawrence Wolfraim ◽  
Guangyuan Dong

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259455
Author(s):  
QianQian Zhuang ◽  
Shaopeng Chen ◽  
ZhiXin Jua ◽  
Yue Yao

Hosta ventricosa is a robust ornamental perennial plant that can tolerate low temperatures, and which is widely used in urban landscaping design in Northeast China. However, the mechanism of cold-stress tolerance in this species is unclear. A combination of transcriptomic and metabolomic analysis was used to explore the mechanism of low-temperature tolerance in H. ventricosa. A total of 12 059 differentially expressed genes and 131 differentially expressed metabolites were obtained, which were mainly concentrated in the signal transduction and phenylpropanoid metabolic pathways. In the process of low-temperature signal transduction, possibly by transmitting Ca2+ inside and outside the cell through the ion channels on the three cell membranes of COLD, CNGCs and CRLK, H. ventricosa senses temperature changes and stimulates SCRM to combine with DREB through the MAPK signal pathway and Ca2+ signal sensors such as CBL, thus strengthening its low-temperature resistance. The pathways of phenylpropanoid and flavonoid metabolism represent the main mechanism of low-temperature tolerance in this species. The plant protects itself from low-temperature damage by increasing its content of genistein, scopolentin and scopolin. It is speculated that H. ventricosa can also adjust the content ratio of sinapyl alcohol and coniferyl alcohol and thereby alter the morphological structure of its cell walls and so increase its resistance to low temperatures.When subjected to low-temperature stress, H. ventricosa perceives temperature changes via COLD, CNGCs and CRLK, and protection from low-temperature damage is achieved by an increase in the levels of genistein, scopolentin and scopolin through the pathways of phenylpropanoid biosynthesis and flavonoid biosynthesis.


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