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

2020 ◽  
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 ◽  
Leaf Water Loss

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 non-stomatal 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. 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. FTIR spectroscopy 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.

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.

scholarly journals Genetic resistance of Eucalyptus globulus to autumn gum moth defoliation and the role of cuticular waxes

2002 ◽  
Vol 32 (11) ◽  
pp. 1961-1969 ◽  
Author(s):  
T H Jones ◽  
B M Potts ◽  
R E Vaillancourt ◽  
N W Davies
Keyword(s):  
Genetic Variation ◽  
Eucalyptus Globulus ◽  
Field Trial ◽  
Genetic Resistance ◽  
Cuticular Wax ◽  
Wax Esters ◽  
Broad Sense ◽  
Broad Sense Heritability ◽  
Cuticular Waxes

This study investigated the association between resistance of Eucalyptus globulus Labill. to autumn gum moth (Mnesempala privata Guenée) defoliation and cuticular wax compounds. In a field trial consisting of clonally replicated F2 families of E. globulus, situated in Tasmania, Australia, significant genetic variation in resistance was detected in two of three F2 families. The broad-sense heritability for defoliation within families ranged from 0.24 to 0.33. The 15 most resistant and the 15 most susceptible genotypes within each variable family were compared for their relative levels of 26 cuticular wax compounds. While no significant correlation between resistance and total wax yield estimates was found, significant differences were detected between resistant and susceptible classes in the relative quantities of several aliphatic phenylethyl and benzyl wax esters within both families. This association does not appear to be a response induced by defoliation. The broad-sense heritabilities of the variation in these compounds were high (0.82–0.94). Our findings suggest that these wax compounds are a mechanism of genetic resistance to autumn gum moth in E. globulus.

scholarly journals Metabolic Reprogramming and Its Role in Plant Cold Acclimation

2019 ◽  
Author(s):  
Lisa Fürtauer ◽  
Jakob Weiszmann ◽  
Wolfram Weckwerth ◽  
Thomas Nägele
Keyword(s):  
Low Temperature ◽  
Carbohydrate Metabolism ◽  
Cold Acclimation ◽  
Current Knowledge ◽  
Abiotic Factors ◽  
Freezing Temperature ◽  
Metabolic Reprogramming ◽  
Plant Distribution ◽  
Growth And Yield

Plants have evolved tightly regulated strategies to adapt and acclimate to a changing environment to ensure their survival. Various environmental factors affect plant distribution, growth and yield. Low temperature belongs to those abiotic factors which significantly constrain range boundaries of plant species. Exposing plants to low but non-freezing temperature induces a multigenic processes termed cold acclimation, which finally results in an increased freezing tolerance. Cold acclimation comprises reprogramming of the transcriptome, proteome and metabolome and affects communication and signaling between subcellular organelles. Reprogramming of the central carbohydrate metabolism plays a key role in cold acclimation. This review summarizes current knowledge about the role of carbohydrate metabolism in plant cold acclimation. A focus is laid on subcellular metabolic reprogramming, its thermodynamic constraints under low temperature and mathematical modelling of metabolism.

scholarly journals Cuticular wax coverage and its transpiration barrier properties in Quercus coccifera L. leaves: does the environment matter?

2019 ◽  
Vol 40 (7) ◽  
pp. 827-840 ◽  
Author(s):  
Amauri Bueno ◽  
Domingo Sancho-Knapik ◽  
Eustaquio Gil-Pelegrín ◽  
Jana Leide ◽  
José Javier Peguero-Pina ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Lipid Composition ◽  
Water Loss ◽  
Vapour Pressure Deficit ◽  
Barrier Properties ◽  
Cuticular Wax ◽  
Atmospheric Conditions ◽  
Cuticular Lipid ◽  
Quercus Coccifera ◽  
Cuticular Waxes

Abstract Plants prevent uncontrolled water loss by synthesizing, depositing and maintaining a hydrophobic layer over their primary aerial organs—the plant cuticle. Quercus coccifera L. can plastically respond to environmental conditions at the cuticular level. When exposed to hot summer conditions with high vapour-pressure deficit (VPD) and intense solar radiation (Mediterranean atmospheric conditions; MED), this plant species accumulates leaf cuticular waxes even over the stomata, thereby decreasing transpirational water loss. However, under mild summer conditions with moderate VPD and regular solar radiation (temperate atmospheric conditions; TEM), this effect is sharply reduced. Despite the ecophysiological importance of the cuticular waxes of Q. coccifera, the wax composition and its contribution to avoiding uncontrolled dehydration remain unknown. Thus, we determined several leaf traits for plants exposed to both MED and TEM conditions. Further, we qualitatively and quantitatively investigated the cuticular lipid composition by gas chromatography. Finally, we measured the minimum leaf conductance (gmin) as an indicator of the efficacy of the cuticular transpiration barrier. The MED leaves were smaller, stiffer and contained a higher load of cuticular lipids than TEM leaves. The amounts of leaf cutin and cuticular waxes of MED plants were 1.4 times and 2.6 times higher than that found for TEM plants, respectively. In detail, MED plants produced higher amounts of all compound classes of cuticular waxes, except for the equivalence of alkanoic acids. Although MED leaves contained higher cutin and cuticular wax loads, the gmin was not different between the two habitats. Our findings suggest that the qualitative accumulation of equivalent cuticular waxes might compensate for the higher wax amount of MED plants, thereby contributing equally to the efficacy of the cuticular transpirational barrier of Q. coccifera. In conclusion, we showed that atmospheric conditions profoundly affect the cuticular lipid composition of Q. coccifera leaves, but do not alter its transpiration barrier properties.

The role of triacylglycerol as a reservoir of polyunsaturated fatty acids for the rapid production of chloroplastic lipids in certain microalgae

2000 ◽  
Vol 28 (6) ◽  
pp. 740-743 ◽  
Author(s):  
Z. Cohen ◽  
I. Khozin-Goldberg ◽  
D. Adlerstein ◽  
C. Bigogno
Keyword(s):  
Fatty Acids ◽  
Low Temperature ◽  
Polyunsaturated Fatty Acids ◽  
Monounsaturated Fatty Acids ◽  
Wild Type ◽  
Induced Stress ◽  
Rapid Production ◽  
Nitrate Starvation ◽  
Red Microalga

Many microalgae are known to accumulate triacylglycerols (TAGs), especially under nitrate starvation. Generally, these TAGs are predominantly constructed of saturated and monounsaturated fatty acids. In contrast, the TAGs of the red microalga Porphyridium cruentum are rich in arachidonic acid (AA, 20: 4 ω 6) and eicosapentaenoic acid (EPA, 20: 5 ω 3). A mutant of this alga, impaired of growth at suboptimal temperatures, was shown to have reduced levels of EPA and of the eukaryotic molecular species of monogalactosyldiacylglycerol (MGDG) and an elevated level of TAG. Labelling experiments have shown that labelling of wild-type TAGs decreased, whereas that of the mutant remained high. Contemporarily, eukaryotic MGDG of the mutant was less labelled. Similarly, TAGs of the green alga T12, which can grow at a low temperature, are extremely rich in AA. We have labelled exponentially growing cultures of T12 kept at 25 °C with radioactive AA and cultivated the cultures for a further 12 h at 25 °C, 12 °C or 4 °C. At low temperatures, labelled AA was transferred from TAGs to polar lipids. These findings may indicate that polyunsaturated fatty acids that can be incorporated into the membranes, enabling the organism to quickly respond to low-temperature-induced stress.

scholarly journals Plants in a cold climate

2002 ◽  
Vol 357 (1423) ◽  
pp. 831-847 ◽  
Author(s):  
Maggie Smallwood ◽  
Dianna J. Bowles
Keyword(s):  
Functional Analysis ◽  
Extracellular Matrix ◽  
Low Temperature ◽  
Cold Acclimation ◽  
Prolonged Exposure ◽  
Plant Cells ◽  
Cold Climate ◽  
Gene Products ◽  
Temperature Signal

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.

The role of neutral lipids in the physiology and ecology of subarctic Dicranum elongatum

1981 ◽  
Vol 59 (10) ◽  
pp. 1902-1909 ◽  
Author(s):  
Pirjo Karunen
Keyword(s):  
Fatty Acids ◽  
Low Temperature ◽  
Neutral Lipids ◽  
Saturated Fatty Acids ◽  
Fatty Acid Content ◽  
Steryl Esters ◽  
The Common ◽  
Growth Chambers ◽  
Dim Light

Temperature (1–23 °C) had little effect on the percentage composition of fatty acids in the common and acetylenic triglycerides of Dicranum elongatum Schleich., though the triglyceride contents in both green and senescent parts were highly dependent on temperature. Field material collected in October from low temperature and dim light plus dark conditions, when exposed to light (140 μE m−2 s−1) in growth chambers, showed increased amounts of acetylenic triglycerides most prominently at low temperature, and decreased amounts of the common triglycerides most prominently at the highest temperature. An overall increase of triglycerides (common plus acetylenic) was found only at low temperature (1 and 6 °C).In contrast to the triglycerides, the fatty acid content of the combined steryl plus wax esters increased only slightly (9%) at low temperature (1 °C). At elevated temperature (17 and 23 °C) the content in both green and senescent parts decreased in conjunction with growth. Temperature (1–17 °C) had no great effect on the proportions of the alkyl or acyl moieties of the esters. At 23 °C, however, a clear decrease was found in the proportions of 20:4 ω6 and 18:3 ω3, along with an increase in the proportion of saturated fatty acids. This was most pronounced in the green segment, where the proportion of the steryl esters was lowest.

Understanding the Role of Populus ECERIFERUM2-Likes in the Biosynthesis of Very-Long-Chain Fatty Acids for Cuticular Waxes

2021 ◽  
Author(s):  
Eliana Gonzales-Vigil ◽  
Michelle E vonLoessl ◽  
Jeff Y Chen ◽  
Sitong Li ◽  
Tegan M Haslam ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Populus Trichocarpa ◽  
Cuticular Wax ◽  
Cuticular Waxes ◽  
Elongation Complex ◽  
Glucuronidase Reporter ◽  
Chain Lengths ◽  
Long Chain ◽  
Condensing Enzyme

Abstract Cuticular waxes are derived from very-long-chain fatty acid (VLCFA) precursors made by the concerted action of four enzymes that form the fatty acid (FA) elongation complex. The condensing enzyme of the complex confers specificity to substrates of different chain lengths, yet on its own cannot account for the biosynthesis of VLCFAs longer than 28 carbons (C28). Recent evidence from Arabidopsis thaliana points to a synergistic role of clade II BAHD acyltransferases and condensing enzymes in the elongation of VLCFAs beyond C28. In Populus trichocarpa, clade II is composed of seven uncharacterized paralogous genes (PtCER2-like1–7). In the present study, five of these genes were heterologously expressed in yeast and their respective FA profiles were determined. PtCER2-likes differentially altered the accumulation of C28 and C30 FAs when expressed in the presence of the condensing enzyme AtCER6. Among these, PtCER2-like5 produced the highest levels of C28 FAs in yeast and its expression was localized to the epidermis in β-glucuronidase-reporter poplar lines, consistent with a role in cuticular wax biosynthesis. Complementation of the A. thaliana cer2-5 mutant with PtCER2-like5 increased the levels of C28-derived cuticular waxes at the expense of C30-derived components. Together, these results demonstrate that the role of CER2-likes in cuticular wax biosynthesis is conserved in Populus clade II BAHD acyltransferases.

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