scholarly journals A novel maize gene, glossy6 involved in epicuticular wax deposition and drought tolerance

2018 ◽  
Author(s):  
LI Li ◽  
Yicong Du ◽  
Cheng He ◽  
Charles R. Dietrich ◽  
Jiankun Li ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Intracellular Trafficking ◽  
Epicuticular Wax ◽  
Epicuticular Waxes ◽  
Wild Type ◽  
Terrestrial Plants ◽  
Surface Waxes ◽  
Extracellular Transport ◽  
Plant Surfaces ◽  
Wax Load

SUMMARYEpicuticular waxes, long-chain hydrocarbon compounds, form the outermost layer of plant surfaces in most terrestrial plants. The presence of epicuticular waxes protects plants from water loss and other environmental stresses. Cloning and characterization of genes involved in the regulation, biosynthesis, and extracellular transport of epicuticular waxes on to the surface of epidermal cells have revealed the molecular basis of epicuticular wax accumulation. However, intracellular trafficking of synthesized waxes to the plasma membrane for cellular secretion is poorly understood. Here, we characterized a maize glossy (gl6) mutant that exhibited decreased epicuticular wax load, increased cuticle permeability, and reduced seedling drought tolerance relative to wild type. We combined an RNA-sequencing based mapping approach (BSR-Seq) and chromosome walking to identify the gl6 candidate gene, which was confirmed via the analysis of multiple independent mutant alleles. The gl6 gene represents a novel maize glossy gene containing a conserved, but uncharacterized domain. Functional characterization suggests that the GL6 protein may be involved in the intracellular trafficking of epicuticular waxes, opening a door to elucidating the poorly understood process by which epicuticular wax is transported from its site of biosynthesis to the plasma membrane.SIGNIFICANCE STATEMENTPlant surface waxes provide an essential protective barrier for terrestrial plants. Understanding the composition and physiological functions of surface waxes, as well as the molecular basis underlying wax accumulation on plant surfaces provides opportunities for the genetic optimization of this protective layer. Genetic studies have identified genes involved in wax biosynthesis, extracellular transport, as well as spatial and temporal regulation of wax accumulation. In this study, a maize mutant, gl6 was characterized that exhibited reduced wax load on plant surfaces, increased water losses, and reduced seedling drought tolerance compared to wild type controls. The gl6 gene is a novel gene harboring a conserved domain with an unknown function. Quantification and microscopic observation of wax accumulation as well as subcellular localization of the GL6 protein provided evidence that gl6 may be involved in the intracellular trafficking of waxes, opening a door for studying this necessary yet poorly understood process for wax loading on plant surfaces.

scholarly journals Maize glossy6 is involved in cuticular wax deposition and drought tolerance

2019 ◽  
Vol 70 (12) ◽  
pp. 3089-3099 ◽  
Author(s):  
Li Li ◽  
Yicong Du ◽  
Cheng He ◽  
Charles R Dietrich ◽  
Jiankun Li ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Drought Tolerance ◽  
Intracellular Trafficking ◽  
Cuticular Wax ◽  
Terrestrial Plants ◽  
Wax Deposition ◽  
Cuticular Waxes ◽  
Extracellular Transport ◽  
Wax Load

Abstract Cuticular waxes, long-chain hydrocarbon compounds, form the outermost layer of plant surfaces in most terrestrial plants. The presence of cuticular waxes protects plants from water loss and other environmental stresses. Cloning and characterization of genes involved in the regulation, biosynthesis, and extracellular transport of cuticular waxes onto the surface of epidermal cells have revealed the molecular basis of cuticular wax accumulation. However, intracellular trafficking of synthesized waxes to the plasma membrane for cellular secretion is poorly understood. Here, we characterized a maize glossy (gl6) mutant that exhibited decreased epicuticular wax load, increased cuticle permeability, and reduced seedling drought tolerance relative to wild-type. We combined an RNA-sequencing-based mapping approach (BSR-Seq) and chromosome walking to identify the gl6 candidate gene, which was confirmed via the analysis of multiple independent mutant alleles. The gl6 gene represents a novel maize glossy gene containing a conserved, but uncharacterized, DUF538 domain. This study suggests that the GL6 protein may be involved in the intracellular trafficking of cuticular waxes, opening the door to elucidating the poorly understood process by which cuticular wax is transported from its site of biosynthesis to the plasma membrane.

The maize epicuticular wax layer provides UV protection

2003 ◽  
Vol 30 (1) ◽  
pp. 75 ◽  
Author(s):  
Lacy M. Long ◽  
H. Prinal Patel ◽  
Wendy C. Cory ◽  
Ann E. Stapleton
Keyword(s):  
Ultraviolet Radiation ◽  
Stratospheric Ozone ◽  
Epicuticular Wax ◽  
Ultraviolet B ◽  
Epicuticular Waxes ◽  
Wild Type ◽  
Terrestrial Plants ◽  
Significant Difference ◽  
Epicuticular Wax Layer ◽  
Wax Production

As surface ultraviolet-B (UV-B) radiation levels increase due to the decline in the protective stratospheric ozone layer, ultraviolet radiation sunscreens will become more important for all plant species that grow in sunlight. Epicuticular waxes, which cover the aerial portions of all terrestrial plants, are ideally located to be sunscreens. The sun-screening ability of maize (Zea mays L.) epicuticular waxes was tested using the glossy1 mutant, which is specifically defective in juvenile wax production. A significant difference between the glossy1 mutant and wild type was seen in UV-induced leaf rolling and in some measurements of UV-induced DNA damage levels under enhanced UV. Isolated epicuticular wax layers absorbed significant amounts of UV, and leaves with wax absorbed more UV than leaves with little wax. Thus, by some measures, the epicuticular waxy layer acts as an ultraviolet radiation protectant in maize.

scholarly journals Overexpression of the pitaya phosphoethanolamine N-methyltransferase gene (HpPEAMT) enhanced simulated drought stress in tobacco

2021 ◽  
Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen
Keyword(s):  
Drought Stress ◽  
Stress Response ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Transgenic Tobacco ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Transgenic Tobacco Plants ◽  
Wild Type ◽  
Tobacco Plants

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.

Surfactant-Induced Phytotoxicity

1994 ◽  
Vol 8 (3) ◽  
pp. 519-525 ◽  
Author(s):  
Richard H. Falk ◽  
Richard Guggenheim ◽  
Gerhard Schulke
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tissue Damage ◽  
Epicuticular Wax ◽  
Morphological Alteration ◽  
Epicuticular Waxes ◽  
Common Purslane ◽  
Morphology Changes ◽  
Cryo Scanning Electron Microscopy ◽  
Scanning Electron

The leaves of tall morningglory, giant duckweed, and common purslane were treated with nine surfactants at a concentration of 0.1% and examined after 24 hr using cryo-scanning electron microscopy for phytotoxicity as evidenced by tissue damage and epicuticular wax morphology changes. In some instances, tissue damage could be discerned; however, the effects of a particular surfactant were not uniform across the three species. Morphological alteration of epicuticular waxes was not observed. Gas chromatographic analyses of the epicuticular waxes of the species used in the study reveal component differences and may, in part, explain the lack of uniform response across species for a particular surfactant.

scholarly journals The Maize Clade A PP2C Phosphatases Play Critical Roles in Multiple Abiotic Stress Responses

2019 ◽  
Vol 20 (14) ◽  
pp. 3573 ◽  
Author(s):  
Zhenghua He ◽  
Jinfeng Wu ◽  
Xiaopeng Sun ◽  
Mingqiu Dai
Keyword(s):  
Drought Tolerance ◽  
Stress Responses ◽  
Transgenic Arabidopsis ◽  
Expression Patterns ◽  
Survival Rates ◽  
Wild Type ◽  
Multiple Stresses ◽  
Core Components ◽  
Leaf Water Loss ◽  
Natural Variations

As the core components of abscisic acid (ABA) signal pathway, Clade A PP2C (PP2C-A) phosphatases in ABA-dependent stress responses have been well studied in Arabidopsis. However, the roles and natural variations of maize PP2C-A in stress responses remain largely unknown. In this study, we investigated the expression patterns of ZmPP2C-As treated with multiple stresses and generated transgenic Arabidopsis plants overexpressing most of the ZmPP2C-A genes. The results showed that the expression of most ZmPP2C-As were dramatically induced by multiple stresses (drought, salt, and ABA), indicating that these genes may have important roles in response to these stresses. Compared with wild-type plants, ZmPP2C-A1, ZmPP2C-A2, and ZmPP2C-A6 overexpression plants had higher germination rates after ABA and NaCl treatments. ZmPP2C-A2 and ZmPP2C-A6 negatively regulated drought responses as the plants overexpressing these genes had lower survival rates, higher leaf water loss rates, and lower proline accumulation compared to wild type plants. The natural variations of ZmPP2C-As associated with drought tolerance were also analyzed and favorable alleles were detected. We widely studied the roles of ZmPP2C-A genes in stress responses and the natural variations detected in these genes have the potential to be used as molecular markers in genetic improvement of maize drought tolerance.

Environmental Physiology of Sorghum. I. Environmental and Genetic Control of Epicuticular Wax Load 1

Crop Science ◽  
1983 ◽  
Vol 23 (3) ◽  
pp. 552-558 ◽  
Author(s):  
W. R. Jordan ◽  
R. L. Monk ◽  
F. R. Miller ◽  
D. T. Rosenow ◽  
L. E. Clark ◽  
...  
Keyword(s):  
Genetic Control ◽  
Epicuticular Wax ◽  
Environmental Physiology ◽  
Wax Load

Environmental Physiology of Sorghum. II. Epicuticular Wax Load and Cuticular Transpiration 1

Crop Science ◽  
1984 ◽  
Vol 24 (6) ◽  
pp. 1168-1173 ◽  
Author(s):  
W. R. Jordan ◽  
P. J. Shouse ◽  
A. Blum ◽  
F. R. Miller ◽  
R. L. Monk
Keyword(s):  
Epicuticular Wax ◽  
Cuticular Transpiration ◽  
Environmental Physiology ◽  
Wax Load

scholarly journals CsCYT75B1, a Citrus CYTOCHROME P450 Gene, Is Involved in Accumulation of Antioxidant Flavonoids and Induces Drought Tolerance in Transgenic Arabidopsis

Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 161 ◽  
Author(s):  
Muhammad Junaid Rao ◽  
Yuantao Xu ◽  
Xiaomei Tang ◽  
Yue Huang ◽  
Jihong Liu ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Transgenic Arabidopsis ◽  
Wild Type ◽  
Ros Scavenging ◽  
Cytochrome P450 Gene ◽  
P450 Gene ◽  
Large Gene ◽  
Transgenic Lines

CYTOCHROME P450s genes are a large gene family in the plant kingdom. Our earlier transcriptome data revealed that a CYTOCHROME P450 gene of Citrus sinensis (CsCYT75B1) was associated with flavonoid metabolism and was highly induced after drought stress. Here, we characterized the function of CsCYT75B1 in drought tolerance by overexpressing it in Arabidopsis thaliana. Our results demonstrated that the overexpression of the CsCYT75B1 gene significantly enhanced the total flavonoid contents with increased antioxidant activity in transgenic Arabidopsis. The gene expression results showed that several genes that are responsible for the biosynthesis of antioxidant flavonoids were induced by 2–12 fold in transgenic Arabidopsis lines. After 14 days of drought stress, all transgenic lines displayed an enhanced tolerance to drought stress along with accumulating antioxidant flavonoids with lower superoxide radicals and reactive oxygen species (ROS) than wild type plants. In addition, drought-stressed transgenic lines possessed higher antioxidant enzymatic activities than wild type transgenic lines. Moreover, the stressed transgenic lines had significantly lower levels of electrolytic leakage than wild type transgenic lines. These results demonstrate that the CsCYT75B1 gene of sweet orange functions in the metabolism of antioxidant flavonoid and contributes to drought tolerance by elevating ROS scavenging activities.

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