Editorial

4 pages, 202 KiB

Open AccessEditorial

by Maria-Cecilia D. Costa and Jill M. Farrant

Plants 2019, 8(12), 553; https://doi.org/10.3390/plants8120553 - 28 Nov 2019

Cited by 12 | Viewed by 3614

Extreme weather events are one of the biggest dangers posed by climate breakdown. As the temperatures increase, droughts and desertification will render whole regions inhospitable to agriculture. At the same time, other regions might suffer significant crop losses due to floods. Usually, regional [...] Read more.

Extreme weather events are one of the biggest dangers posed by climate breakdown. As the temperatures increase, droughts and desertification will render whole regions inhospitable to agriculture. At the same time, other regions might suffer significant crop losses due to floods. Usually, regional food shortages can be covered by surpluses from elsewhere on the planet. However, the climate breakdown could trigger sustained food supply disruptions globally. Therefore, it is necessary to develop more stress-resilient crop alternatives by both breeding new varieties and promoting underutilized crop species (orphan crops). The articles in this special issue cover responses of staple crops and orphan crops to abiotic stresses relevant under the climate breakdown, such as heat, water, high salinity, nitrogen, and heavy metal stresses. This information will certainly complement a toolkit that can help inform, support, and influence the design of measures to deal with the climate crisis. Full article

(This article belongs to the Special Issue Molecular Mechanisms and Genetics of Plant Resistance to Abiotic Stress)

Research

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12 pages, 1399 KiB

Open AccessEditor’s ChoiceArticle

Transient Heat Waves May Affect the Photosynthetic Capacity of Susceptible Wheat Genotypes Due to Insufficient Photosystem I Photoprotection

by Erik Chovancek, Marek Zivcak, Lenka Botyanszka, Pavol Hauptvogel, Xinghong Yang, Svetlana Misheva, Sajad Hussain and Marian Brestic

Plants 2019, 8(8), 282; https://doi.org/10.3390/plants8080282 - 12 Aug 2019

Cited by 49 | Viewed by 4413

Abstract

We assessed the photosynthetic responses of eight wheat varieties in conditions of a simulated heat wave in a transparent plastic tunnel for one week. We found that high temperatures (up to 38 °C at midday and above 20 °C at night) had a [...] Read more.

We assessed the photosynthetic responses of eight wheat varieties in conditions of a simulated heat wave in a transparent plastic tunnel for one week. We found that high temperatures (up to 38 °C at midday and above 20 °C at night) had a negative effect on the photosynthetic functions of the plants and provided differentiation of genotypes through sensitivity to heat. Measurements of gas exchange showed that the simulated heat wave led to a 40% decrease in photosynthetic activity on average in comparison to the control, with an unequal recovery of individual genotypes after a release from stress. Our results indicate that the ability to recover after heat stress was associated with an efficient regulation of linear electron transport and the prevention of over-reduction in the acceptor side of photosystem I. Full article

(This article belongs to the Special Issue Molecular Mechanisms and Genetics of Plant Resistance to Abiotic Stress)

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21 pages, 7588 KiB

Open AccessArticle

Comparative Transcriptome Analysis of Waterlogging-Sensitive and Tolerant Zombi Pea (Vigna vexillata) Reveals Energy Conservation and Root Plasticity Controlling Waterlogging Tolerance

by Pimprapai Butsayawarapat, Piyada Juntawong, Ornusa Khamsuk and Prakit Somta

Plants 2019, 8(8), 264; https://doi.org/10.3390/plants8080264 - 02 Aug 2019

Cited by 24 | Viewed by 4868

Abstract

Vigna vexillata (zombi pea) is an underutilized legume crop considered to be a potential gene source in breeding for abiotic stress tolerance. This study focuses on the molecular characterization of mechanisms controlling waterlogging tolerance using two zombi pea varieties with contrasting waterlogging tolerance. [...] Read more.

Vigna vexillata (zombi pea) is an underutilized legume crop considered to be a potential gene source in breeding for abiotic stress tolerance. This study focuses on the molecular characterization of mechanisms controlling waterlogging tolerance using two zombi pea varieties with contrasting waterlogging tolerance. Morphological examination revealed that in contrast to the sensitive variety, the tolerant variety was able to grow, maintain chlorophyll, form lateral roots, and develop aerenchyma in hypocotyl and taproots under waterlogging. To find the mechanism controlling waterlogging tolerance in zombi pea, comparative transcriptome analysis was performed using roots subjected to short-term waterlogging. Functional analysis indicated that glycolysis and fermentative genes were strongly upregulated in the sensitive variety, but not in the tolerant one. In contrast, the genes involved in auxin-regulated lateral root initiation and formation were expressed only in the tolerant variety. In addition, cell wall modification, aquaporin, and peroxidase genes were highly induced in the tolerant variety under waterlogging. Our findings suggest that energy management and root plasticity play important roles in mitigating the impact of waterlogging in zombi pea. The basic knowledge obtained from this study can be used in the molecular breeding of waterlogging-tolerant legume crops in the future. Full article

(This article belongs to the Special Issue Molecular Mechanisms and Genetics of Plant Resistance to Abiotic Stress)

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19 pages, 2266 KiB

Open AccessArticle

Different Roles of Heat Shock Proteins (70 kDa) During Abiotic Stresses in Barley (Hordeum vulgare) Genotypes

by Simone Landi, Giorgia Capasso, Fatma Ezzahra Ben Azaiez, Salma Jallouli, Sawsen Ayadi, Youssef Trifa and Sergio Esposito

Plants 2019, 8(8), 248; https://doi.org/10.3390/plants8080248 - 26 Jul 2019

Cited by 24 | Viewed by 3425

Abstract

In this work, the involvement of heat shock proteins (HSP70) in barley (Hordeum vulgare) has been studied in response to drought and salinity. Thus, 3 barley genotypes usually cultivated and/or selected in Italy, 3 Middle East/North Africa landraces and genotypes and [...] Read more.

In this work, the involvement of heat shock proteins (HSP70) in barley (Hordeum vulgare) has been studied in response to drought and salinity. Thus, 3 barley genotypes usually cultivated and/or selected in Italy, 3 Middle East/North Africa landraces and genotypes and 1 improved genotype from ICARDA have been studied to identify those varieties showing the best stress response. Preliminarily, a bioinformatic characterization of the HSP70s protein family in barley has been made by using annotated Arabidopsis protein sequences. This study identified 20 putative HSP70s orthologs in the barley genome. The construction of un-rooted phylogenetic trees showed the partition into four main branches, and multiple subcellular localizations. The enhanced HSP70s presence upon salt and drought stress was investigated by both immunoblotting and expression analyses. It is worth noting the Northern Africa landraces showed peculiar tolerance behavior versus drought and salt stresses. The drought and salinity conditions indicated the involvement of specific HSP70s to counteract abiotic stress. Particularly, the expression of cytosolic MLOC_67581, mitochondrial MLOC_50972, and encoding for HSP70 isoforms showed different expressions and occurrence upon stress. Therefore, genotypes originated in the semi-arid area of the Mediterranean area can represent an important genetic source for the improvement of commonly cultivated high-yielding varieties. Full article

(This article belongs to the Special Issue Molecular Mechanisms and Genetics of Plant Resistance to Abiotic Stress)

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16 pages, 2947 KiB

Open AccessArticle

Morphological and Transcriptome Analysis of Wheat Seedlings Response to Low Nitrogen Stress

by Jun Wang, Ke Song, Lijuan Sun, Qin Qin, Yafei Sun, Jianjun Pan and Yong Xue

Plants 2019, 8(4), 98; https://doi.org/10.3390/plants8040098 - 15 Apr 2019

Cited by 40 | Viewed by 5085

Abstract

Nitrogen (N) is one of the essential macronutrients that plays an important role in plant growth and development. Unfortunately, low utilization rate of nitrogen has become one of the main abiotic factors affecting crop growth. Nevertheless, little research has been done on the [...] Read more.

Nitrogen (N) is one of the essential macronutrients that plays an important role in plant growth and development. Unfortunately, low utilization rate of nitrogen has become one of the main abiotic factors affecting crop growth. Nevertheless, little research has been done on the molecular mechanism of wheat seedlings resisting or adapting to low nitrogen environment. In this paper, the response of wheat seedlings against low nitrogen stress at phenotypic changes and gene expression level were studied. The results showed that plant height, leaf area, shoot and root dry weight, total root length, and number under low nitrogen stress decreased by 26.0, 28.1, 24.3, 38.0, 41.4, and 21.2 percent, respectively compared with plants under normal conditions. 2265 differentially expressed genes (DEGs) were detected in roots and 2083 DEGs were detected in leaves under low nitrogen stress (N-) compared with the control (CK). 1688 genes were up-regulated and 577 genes were down-regulated in roots, whilst 505 genes were up-regulated and 1578 were down-regulated in leaves. Among the most addressed Gene Ontology (GO) categories, oxidation reduction process, oxidoreductase activity, and cell component were mostly represented. In addition, genes involved in the signal transduction, carbon and nitrogen metabolism, antioxidant activity, and environmental adaptation were highlighted. Our study provides new information for further understanding the response of wheat to low nitrogen stress. Full article

(This article belongs to the Special Issue Molecular Mechanisms and Genetics of Plant Resistance to Abiotic Stress)

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10 pages, 1712 KiB

Open AccessArticle

Effect of Selenium on the Responses Induced by Heat Stress in Plant Cell Cultures

by Massimo Malerba and Raffaella Cerana

Plants 2018, 7(3), 64; https://doi.org/10.3390/plants7030064 - 11 Aug 2018

Cited by 27 | Viewed by 5392

Abstract

High temperatures are a significant stress factor for plants. In fact, many biochemical reactions involved in growth and development are sensitive to temperature. In particular, heat stress (HS) represents a severe issue for plant productivity and strategies to obtain high yields under this [...] Read more.

High temperatures are a significant stress factor for plants. In fact, many biochemical reactions involved in growth and development are sensitive to temperature. In particular, heat stress (HS) represents a severe issue for plant productivity and strategies to obtain high yields under this condition are important goals in agriculture. While selenium (Se) is a nutrient for humans and animals, its role as a plant micronutrient is still questioned. Se can prevent several abiotic stresses (drought, heat, UV, salinity, heavy metals), but the action mechanisms are poorly understood. Se seems to regulate reactive oxygen species (ROS) and to inhibit heavy metals transport. In addition, it has been demonstrated that Se is essential for a correct integrity of cell membranes and chloroplasts, especially the photosynthetic apparatus. Previous results showed that in tobacco (Nicotiana tabacum cv. Bright-Yellow 2) cultures HS (5 min at 50 °C) induced cell death with apoptotic features, accompanied by oxidative stress and changes in the levels of stress-related proteins. In this work we investigated the effect of Se on the responses induced by HS. The obtained results show that Se markedly reduces the effects of HS on cell vitality, cytoplasmic shrinkage, superoxide anion production, membrane lipids peroxidation, activity of caspase-3-like proteases, and the levels of some stress-related proteins (Hsp90, BiP, 14-3-3s, cytochrome c). Full article

(This article belongs to the Special Issue Molecular Mechanisms and Genetics of Plant Resistance to Abiotic Stress)

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15 pages, 1094 KiB

Open AccessArticle

Identification of Genomic Regions Contributing to Protein Accumulation in Wheat under Well-Watered and Water Deficit Growth Conditions

by Ibrahim S. Elbasyoni, Sabah M. Morsy, Raghuprakash K. Ramamurthy and Atef M. Nassar

Plants 2018, 7(3), 56; https://doi.org/10.3390/plants7030056 - 11 Jul 2018

Cited by 7 | Viewed by 4358

Abstract

Sustaining wheat production under low-input conditions through development and identifying genotypes with enhanced nutritional quality are two current concerns of wheat breeders. Wheat grain total protein content, to no small extent, determines the economic and nutritive value of wheat. Therefore, the objectives of [...] Read more.

Sustaining wheat production under low-input conditions through development and identifying genotypes with enhanced nutritional quality are two current concerns of wheat breeders. Wheat grain total protein content, to no small extent, determines the economic and nutritive value of wheat. Therefore, the objectives of this study are to identify accessions with high and low grain protein content (GPC) under well-watered and water-deficit growth conditions and to locate genomic regions that contribute to GPC accumulation. Spring wheat grains obtained from 2111 accessions that were grown under well-watered and water-deficit conditions were assessed for GPC using near-infrared spectroscopy (NIR). Results indicated significant influences of moisture, genotype, and genotype × environment interaction on the GPC accumulation. Furthermore, genotypes exhibited a wide range of variation for GPC, indicating the presence of high levels of genetic variability among the studied accessions. Around 366 (166 with high GPC and 200 with low GPC) wheat genotypes performed relatively the same across environments, which implies that GPC accumulation in these genotypes was less responsive to water deficit. Genome-wide association mapping results indicated that seven single nucleotide polymorphism (SNPs) were linked with GPC under well-watered growth conditions, while another six SNPs were linked with GPC under water-deficit conditions only. Moreover, 10 SNPs were linked with GPC under both well-watered and water-deficit conditions. These results emphasize the importance of using diverse, worldwide germplasm to dissect the genetic architecture of GPC in wheat and identify accessions that might be potential parents for high GPC in wheat breeding programs. Full article

(This article belongs to the Special Issue Molecular Mechanisms and Genetics of Plant Resistance to Abiotic Stress)

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Review

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12 pages, 536 KiB

Open AccessReview

Towards an Understanding of the Molecular Basis of Nickel Hyperaccumulation in Plants

by Llewelyn Van der Pas and Robert A. Ingle

Plants 2019, 8(1), 11; https://doi.org/10.3390/plants8010011 - 04 Jan 2019

Cited by 49 | Viewed by 6646

Abstract

Metal hyperaccumulation is a rare and fascinating phenomenon, whereby plants actively accumulate high concentrations of metal ions in their above-ground tissues. Enhanced uptake and root-to-shoot translocation of specific metal ions coupled with an increased capacity for detoxification and sequestration of these ions are [...] Read more.

Metal hyperaccumulation is a rare and fascinating phenomenon, whereby plants actively accumulate high concentrations of metal ions in their above-ground tissues. Enhanced uptake and root-to-shoot translocation of specific metal ions coupled with an increased capacity for detoxification and sequestration of these ions are thought to constitute the physiological basis of the hyperaccumulation phenotype. Nickel hyperaccumulators were the first to be discovered and are the most numerous, accounting for some seventy-five percent of all known hyperaccumulators. However, our understanding of the molecular basis of the physiological processes underpinning Ni hyperaccumulation has lagged behind that of Zn and Cd hyperaccumulation, in large part due to a lack of genomic resources for Ni hyperaccumulators. The advent of RNA-Seq technology, which allows both transcriptome assembly and profiling of global gene expression without the need for a reference genome, has offered a new route for the analysis of Ni hyperaccumulators, and several such studies have recently been reported. Here we review the current state of our understanding of the molecular basis of Ni hyperaccumulation in plants, with an emphasis on insights gained from recent RNA-Seq experiments, highlight commonalities and differences between Ni hyperaccumulators, and suggest potential future avenues of research in this field. Full article

(This article belongs to the Special Issue Molecular Mechanisms and Genetics of Plant Resistance to Abiotic Stress)

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32 pages, 3671 KiB

Open AccessReview

Quinoa Abiotic Stress Responses: A Review

by Leonardo Hinojosa, Juan A. González, Felipe H. Barrios-Masias, Francisco Fuentes and Kevin M. Murphy

Plants 2018, 7(4), 106; https://doi.org/10.3390/plants7040106 - 29 Nov 2018

Cited by 163 | Viewed by 19337

Abstract

Quinoa (Chenopodium quinoa Willd.) is a genetically diverse Andean crop that has earned special attention worldwide due to its nutritional and health benefits and its ability to adapt to contrasting environments, including nutrient-poor and saline soils and drought stressed marginal agroecosystems. Drought [...] Read more.

Quinoa (Chenopodium quinoa Willd.) is a genetically diverse Andean crop that has earned special attention worldwide due to its nutritional and health benefits and its ability to adapt to contrasting environments, including nutrient-poor and saline soils and drought stressed marginal agroecosystems. Drought and salinity are the abiotic stresses most studied in quinoa; however, studies of other important stress factors, such as heat, cold, heavy metals, and UV-B light irradiance, are severely limited. In the last few decades, the incidence of abiotic stress has been accentuated by the increase in unpredictable weather patterns. Furthermore, stresses habitually occur as combinations of two or more. The goals of this review are to: (1) provide an in-depth description of the existing knowledge of quinoa’s tolerance to different abiotic stressors; (2) summarize quinoa’s physiological responses to these stressors; and (3) describe novel advances in molecular tools that can aid our understanding of the mechanisms underlying quinoa’s abiotic stress tolerance. Full article

(This article belongs to the Special Issue Molecular Mechanisms and Genetics of Plant Resistance to Abiotic Stress)

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