scholarly journals Cuticular Wax Composition is Essential for Plant Recovery Following Drought with Little Effect under Optimal Conditions

2021 ◽  
Author(s):  
Boaz Negin ◽  
Shelly Hen-Avivi ◽  
Efrat Almekias-Siegl ◽  
Lior Shachar ◽  
Asaph Aharoni
Keyword(s):  
Water Loss ◽  
Stomatal Closure ◽  
Extensive Study ◽  
Cuticular Lipids ◽  
Nicotiana Glauca ◽  
Surface Wax ◽  
Depth Analysis ◽  
Related Phenotype ◽  
Wax Crystal

Despite decades of extensive study, the role of cuticular lipids in sustaining plant fitness is far from being understood. To answer this fundamental question, we employed genome editing in tree tobacco (Nicotiana glauca) plants and generated mutations in 16 different cuticular lipids-related genes. We chose tree tobacco due to the abundant, yet simply composed epicuticular waxes deposited on its surface. Five out of 9 different mutants that displayed a cuticular lipids-related phenotype were selected for in depth analysis. They had either reduced total wax load or complete deficiency in certain wax components. This led to substantial modification in surface wax crystal structure and to elevated cuticular water loss. Remarkably, under non-stressed conditions, mutant plants with altered wax composition did not display elevated transpiration or reduced growth. However, once exposed to drought, plants lacking alkanes were not able to strongly reduce their transpiration, leading to leaf death and impaired recovery upon resuscitation, and even to stem cracking, a phenomenon typically found in trees experiencing drought stress. In contrast, plants deficient in fatty alcohols exhibited an opposite response, having reduced cuticular water loss and rapid recovery following drought. This deferential response was part of a larger trend, of no common phenotype connecting plants with a glossy appearance. We conclude that alkanes are essential under drought response and much less under normal non-stressed conditions, enabling plants to seal their cuticle upon stomatal closure, reducing leaf death and facilitating a speedy recovery.

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 Phosphorylation of Serine 11 and Serine 92 as New Positive Regulators of Human Snail1 Function: Potential Involvement of Casein Kinase-2 and the cAMP-activated Kinase Protein Kinase A

2010 ◽  
Vol 21 (2) ◽  
pp. 244-253 ◽  
Author(s):  
Matthew Reid MacPherson ◽  
Patricia Molina ◽  
Serhiy Souchelnytskyi ◽  
Christer Wernstedt ◽  
Jorge Martin-Pérez ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Tumor Metastasis ◽  
Epithelial Mesenchymal Transition ◽  
Cop9 Signalosome ◽  
Mesenchymal Transition ◽  
Depth Analysis ◽  
Positive Regulators

Snail1 is a major factor for epithelial-mesenchymal transition (EMT), an important event in tumor metastasis and in other pathologies. Snail1 is tightly regulated at transcriptional and posttranscriptional levels. Control of Snail1 protein stability and nuclear export by GSK3β phosphorylation is important for Snail1 functionality. Stabilization mechanisms independent of GSK3β have also been reported, including interaction with LOXL2 or regulation of the COP9 signalosome by inflammatory signals. To get further insights into the role of Snail1 phosphorylation, we have performed an in-depth analysis of in vivo human Snail1 phosphorylation combined with mutational studies. We identify new phosphorylation sites at serines 11, 82, and 92 and confirmed previously suggested phosphorylations at serine 104 and 107. Serines 11 and 92 participate in the control of Snail1 stability and positively regulate Snail1 repressive function and its interaction with mSin3A corepressor. Furthermore, serines 11 and 92 are required for Snail1-mediated EMT and cell viability, respectively. PKA and CK2 have been characterized as the main kinases responsible for in vitro Snail1 phosphorylation at serine 11 and 92, respectively. These results highlight serines 11 and 92 as new players in Snail1 regulation and suggest the participation of CK2 and PKA in the modulation of Snail1 functionality.

Speciation and changes in male gene expression in Drosophila

Genome ◽  
2020 ◽  
pp. 1-11
Author(s):  
Bahar Patlar ◽  
Alberto Civetta
Keyword(s):  
Gene Expression ◽  
Reproductive Isolation ◽  
Potential Role ◽  
Regulation Of Gene Expression ◽  
Drosophila Model ◽  
Depth Analysis ◽  
The Impact ◽  
Plastic Responses ◽  
Male Gene

It has long been acknowledged that changes in the regulation of gene expression may account for major organismal differences. However, we still do not fully understand how changes in gene expression evolve and how do such changes influence organisms’ differences. We are even less aware of the impact such changes might have in restricting gene flow between species. Here, we focus on studies of gene expression and speciation in the Drosophila model. We review studies that have identified gene interactions in post-mating reproductive isolation and speciation, particularly those that modulate male gene expression. We also address studies that have experimentally manipulated changes in gene expression to test their effect in post-mating reproductive isolation. We highlight the need for a more in-depth analysis of the role of selection causing disrupted gene expression of such candidate genes in sterile/inviable hybrids. Moreover, we discuss the relevance to incorporate more routinely assays that simultaneously evaluate the potential effects of environmental factors and genetic background in modulating plastic responses in male genes and their potential role in speciation.

Inhibition of cambial activity in Abies balsamea by internal water stress: role of abscisic acid

1975 ◽  
Vol 53 (24) ◽  
pp. 3041-3050 ◽  
Author(s):  
C. H. A. Little
Keyword(s):  
Abscisic Acid ◽  
Water Stress ◽  
Indoleacetic Acid ◽  
Stomatal Closure ◽  
Abies Balsamea ◽  
Cambial Activity ◽  
Inhibitory Effect ◽  
Internal Water ◽  
Endogenous Aba

In experiments with attached and detached shoots of balsam fir, Abies balsamea L., synthetic (±)abscisic acid (ABA) (1) reduced photosynthesis and transpiration by inducing stomatal closure, (2) inhibited indoleacetic acid (IAA) - induced cambial activity in photosynthesizing and non-photosynthesizing shoots, and (3) inhibited the basipetal movement of [14C]IAA. Neither gibberellic acid nor kinetin counteracted the inhibitory effect of (±)ABA on IAA-induced cambial activity. In addition it was demonstrated that increasing the internal water stress increased the level of endogenous ABA in the phloem–cambial region of bark peelings and decreased the basipetal movement of [14C]IAA through branch sections. On the basis of these findings it is proposed that internal water stress inhibits cambial activity, partly through increasing the level of ABA; the ABA acts to decrease the provision of carbohydrates and auxin that are required for cambial growth.

scholarly journals l-Aspartate: An Essential Metabolite for Plant Growth and Stress Acclimation

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1887
Author(s):  
Mei Han ◽  
Can Zhang ◽  
Peter Suglo ◽  
Shuyue Sun ◽  
Mingyao Wang ◽  
...  
Keyword(s):  
Plant Growth ◽  
Physiological Role ◽  
Tca Cycle ◽  
Extensive Study ◽  
Cell Compartments ◽  
Stress Acclimation ◽  
Whole Plant ◽  
Glycolysis Pathway ◽  
Acid Pathway

L-aspartate (Asp) serves as a central building block, in addition to being a constituent of proteins, for many metabolic processes in most organisms, such as biosynthesis of other amino acids, nucleotides, nicotinamide adenine dinucleotide (NAD), the tricarboxylic acid (TCA) cycle and glycolysis pathway intermediates, and hormones, which are vital for growth and defense. In animals and humans, lines of data have proved that Asp is indispensable for cell proliferation. However, in plants, despite the extensive study of the Asp family amino acid pathway, little attention has been paid to the function of Asp through the other numerous pathways. This review aims to elucidate the most important aspects of Asp in plants, from biosynthesis to catabolism and the role of Asp and its metabolic derivatives in response to changing environmental conditions. It considers the distribution of Asp in various cell compartments and the change of Asp level, and its significance in the whole plant under various stresses. Moreover, it provides evidence of the interconnection between Asp and phytohormones, which have prominent functions in plant growth, development, and defense. The updated information will help improve our understanding of the physiological role of Asp and Asp-borne metabolic fluxes, supporting the modular operation of these networks.

scholarly journals How to introduce new technologies to reduce nutrient losses: a case of Danish agricultural constructed wetlands

Water Policy ◽  
2017 ◽  
Vol 19 (3) ◽  
pp. 404-422 ◽  
Author(s):  
Florence Gathoni Gachango ◽  
Brian H. Jacobsen
Keyword(s):  
Constructed Wetlands ◽  
Implementation Strategy ◽  
New Technologies ◽  
Secondary Data ◽  
Policy Instrument ◽  
Nutrient Losses ◽  
Voluntary Approach ◽  
Depth Analysis ◽  
Environmental Measures

The Water Framework Directive (WFD) focuses on reduction of nutrients in individual water bodies. Innovative drainage filter technologies currently being tested in Denmark could facilitate nutrient reductions at the sub-river basins and catchment levels. The implementation strategy for these technologies, however, remains a challenge. Using both primary and secondary data, this paper presents an in-depth analysis of the role of these technologies in implementation of the WFD in Denmark. Concepts of impact assessment are used to identify the most suitable approach for incorporating these technologies into environmental measures based on a three-faceted policy instrument typology. A voluntary approach supported by investment subsidies, or incentives that could replace existing requirements, is deemed more appropriate.

scholarly journals Hormonal and Hydroxycinnamic Acids Profiles in Banana Leaves in Response to Various Periods of Water Stress

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jalel Mahouachi ◽  
María F. López-Climent ◽  
Aurelio Gómez-Cadenas
Keyword(s):  
Water Stress ◽  
Leaf Gas Exchange ◽  
Stomatal Closure ◽  
Photosynthetic Performance ◽  
Hydroxycinnamic Acids ◽  
Cinnamic Acids ◽  
Gas Exchange Parameters ◽  
Banana Leaves ◽  
Indole 3 Acetic Acid

The pattern of change in the endogenous levels of several plant hormones and hydroxycinnamic acids in addition to growth and photosynthetic performance was investigated in banana plants (Musa acuminatacv. “Grand Nain”) subjected to various cycles of drought. Water stress was imposed by withholding irrigation for six periods with subsequent rehydration. Data showed an increase in abscisic acid (ABA) and indole-3-acetic acid (IAA) levels, a transient increase in salicylic acid (SA) concentration, and no changes in jasmonic acid (JA) after each period of drought. Moreover, the levels of ferulic (FA) and cinnamic acids (CA) were increased, and plant growth and leaf gas exchange parameters were decreased by drought conditions. Overall, data suggest an involvement of hormones and hydroxycinnamic acids in plant avoidance of tissue dehydration. The increase in IAA concentration might alleviate the senescence of survival leaves and maintained cell elongation, and the accumulation of FA and CA could play a key role as a mechanism of photoprotection through leaf folding, contributing to the effect of ABA on inducing stomatal closure. Data also suggest that the role of SA similarly to JA might be limited to a transient and rapid increase at the onset of the first period of stress.

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