Mycorrhizae Aided Nitrogen Nutrition and Drought Tolerance in Plants

Mycorrhizas are known to improve host plant nutritional status as a consequence of water transport from the soil to the host plant through the external mycelium as a direct effect or improved host plant nutrition primarily, phosphorus as an indirect effect. The direct hyphal water transport is quantified to be meager and a major part of the benefits of mycorrhizal symbiosis is indirect and nutritionally related. In arid and semi-arid regions where drought occurrence is very frequent and soil moisture content is highly restricted, mycorrhizas can assist in exploiting the soil beyond the rhizosphere that helps the host plant to withstand drought stress conditions. The drought tolerance in mycorrhiza-inoculated plants is quite complex and such response is due to a series of processes such as improved nitrogen (N) availability in soils, extensive root surface area and cationic exchange capacity, collective N assimilatory pathways in plant-mycorrhizal system, luxuriant uptake of nutrients besides remobilization of nutrients to support grain growth. These physiological, biochemical, nutritional and morphological changes in the mycorrhizas associated host plants have contributed to the ability of the host plants to survive under limited water environments. Despite mycorrhiza-assisted and N nutritionally enabled host plant drought tolerance is evident, more research is required to gain insights into the mechanisms involved. This review highlights the role of mycorrhizas on N dynamics in the rhizosphere and enhanced host plant N nutrition that collectively contributes to the sustained crop productivity under drought stress conditions.

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Arbuscular mycorrhizal symbiosis increases relative apoplastic water flow in roots of the host plant under both well-watered and drought stress conditions

Annals of Botany ◽

10.1093/aob/mcs007 ◽

2012 ◽

Vol 109 (5) ◽

pp. 1009-1017 ◽

Cited By ~ 111

Author(s):

Gloria Bárzana ◽

Ricardo Aroca ◽

José Antonio Paz ◽

François Chaumont ◽

Mari Carmen Martinez-Ballesta ◽

...

Keyword(s):

Drought Stress ◽

Host Plant ◽

Water Flow ◽

Arbuscular Mycorrhizal ◽

Stress Conditions ◽

Arbuscular Mycorrhizal Symbiosis ◽

Mycorrhizal Symbiosis

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Genetic Diversity of Selected Rice Genotypes under Water Stress Conditions

Plants ◽

10.3390/plants10010027 ◽

2020 ◽

Vol 10 (1) ◽

pp. 27

Author(s):

Mahmoud M. Gaballah ◽

Azza M. Metwally ◽

Milan Skalicky ◽

Mohamed M. Hassan ◽

Marian Brestic ◽

...

Keyword(s):

Genetic Diversity ◽

Water Stress ◽

Drought Stress ◽

Drought Tolerance ◽

Ssr Markers ◽

Similarity Index ◽

Stress Conditions ◽

Yield Potential ◽

Drought Tolerant ◽

Rice Genotypes

Drought is the most challenging abiotic stress for rice production in the world. Thus, developing new rice genotype tolerance to water scarcity is one of the best strategies to achieve and maximize high yield potential with water savings. The study aims to characterize 16 rice genotypes for grain and agronomic parameters under normal and drought stress conditions, and genetic differentiation, by determining specific DNA markers related to drought tolerance using Simple Sequence Repeats (SSR) markers and grouping cultivars, establishing their genetic relationship for different traits. The experiment was conducted under irrigated (normal) and water stress conditions. Mean squares due to genotype × environment interactions were highly significant for major traits. For the number of panicles/plants, the genotypes Giza179, IET1444, Hybrid1, and Hybrid2 showed the maximum mean values. The required sterility percentage values were produced by genotypes IET1444, Giza178, Hybrid2, and Giza179, while, Sakha101, Giza179, Hybrid1, and Hybrid2 achieved the highest values of grain yield/plant. The genotypes Giza178, Giza179, Hybrid1, and Hybrid2, produced maximum values for water use efficiency. The effective number of alleles per locus ranged from 1.20 alleles to 3.0 alleles with an average of 1.28 alleles, and the He values for all SSR markers used varied from 0.94 to 1.00 with an average of 0.98. The polymorphic information content (PIC) values for the SSR were varied from 0.83 to 0.99, with an average of 0.95 along with a highly significant correlation between PIC values and the number of amplified alleles detected per locus. The highest similarity coefficient between Giza181 and Giza182 (Indica type) was observed and are susceptible to drought stress. High similarity percentage between the genotypes (japonica type; Sakha104 with Sakha102 and Sakha106 (0.45), Sakha101 with Sakha102 and Sakha106 (0.40), Sakha105 with Hybrid1 (0.40), Hybrid1 with Giza178 (0.40) and GZ1368-S-5-4 with Giza181 (0.40)) was also observed, which are also susceptible to drought stress. All genotypes are grouped into two major clusters in the dendrogram at 66% similarity based on Jaccard’s similarity index. The first cluster (A) was divided into two minor groups A1 and A2, in which A1 had two groups A1-1 and A1-2, containing drought-tolerant genotypes like IET1444, GZ1386-S-5-4 and Hybrid1. On the other hand, the A1-2 cluster divided into A1-2-1 containing Hybrid2 genotype and A1-2-2 containing Giza179 and Giza178 at coefficient 0.91, showing moderate tolerance to drought stress. The genotypes GZ1368-S-5-4, IET1444, Giza 178, and Giza179, could be included as appropriate materials for developing a drought-tolerant variety breeding program. Genetic diversity to grow new rice cultivars that combine drought tolerance with high grain yields is essential to maintaining food security.

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Identification of Two Novel Wheat Drought Tolerance-Related Proteins by Comparative Proteomic Analysis Combined with Virus-Induced Gene Silencing

International Journal of Molecular Sciences ◽

10.3390/ijms19124020 ◽

2018 ◽

Vol 19 (12) ◽

pp. 4020 ◽

Cited By ~ 8

Author(s):

Xinbo Wang ◽

Yanhua Xu ◽

Jingjing Li ◽

Yongzhe Ren ◽

Zhiqiang Wang ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Gene Silencing ◽

Proteomic Analysis ◽

Crop Yields ◽

Stress Conditions ◽

Virus Induced Gene Silencing ◽

Knock Down ◽

Comparative Proteomic Analysis ◽

Related Proteins

Drought is a major adversity that limits crop yields. Further exploration of wheat drought tolerance-related genes is critical for the genetic improvement of drought tolerance in this crop. Here, comparative proteomic analysis of two wheat varieties, XN979 and LA379, with contrasting drought tolerance was conducted to screen for drought tolerance-related proteins/genes. Virus-induced gene silencing (VIGS) technology was used to verify the functions of candidate proteins. A total of 335 differentially abundant proteins (DAPs) were exclusively identified in the drought-tolerant variety XN979. Most DAPs were mainly involved in photosynthesis, carbon fixation, glyoxylate and dicarboxylate metabolism, and several other pathways. Two DAPs (W5DYH0 and W5ERN8), dubbed TaDrSR1 and TaDrSR2, respectively, were selected for further functional analysis using VIGS. The relative electrolyte leakage rate and malonaldehyde content increased significantly, while the relative water content and proline content significantly decreased in the TaDrSR1- and TaDrSR2-knock-down plants compared to that in non-knocked-down plants under drought stress conditions. TaDrSR1- and TaDrSR2-knock-down plants exhibited more severe drooping and wilting phenotypes than non-knocked-down plants under drought stress conditions, suggesting that the former were more sensitive to drought stress. These results indicate that TaDrSR1 and TaDrSR2 potentially play vital roles in conferring drought tolerance in common wheat.

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Dark Septate Endophyte Improves Drought Tolerance of Ormosia hosiei Hemsley & E. H. Wilson by Modulating Root Morphology, Ultrastructure, and the Ratio of Root Hormones

Forests ◽

10.3390/f10100830 ◽

2019 ◽

Vol 10 (10) ◽

pp. 830 ◽

Cited By ~ 3

Author(s):

Yan Liu ◽

Xiaoli Wei

Keyword(s):

Water Stress ◽

Drought Stress ◽

Host Plant ◽

Drought Resistance ◽

Root Morphology ◽

Stress Conditions ◽

Root Tip ◽

Root Weight ◽

Root Cells ◽

Water Capacity

Dark septate endophytes (DSEs) are known to help host plants survive drought stress; however, how DSEs enhance host plant drought resistance under water stress conditions remains unclear. The objective of this study was to inoculate Ormosia hosiei seedlings with a DSE strain (Acrocalymma vagum) to investigate the effects of DSE inoculation on root morphology, ultrastructure, and the endogenous hormone content under drought stress conditions and to elucidate the drought resistance mechanism involved in the DSE–host-plant association. The inoculated seedlings were grown under three different soil water conditions (well watered—75% field water capacity, moderate water—55% field water capacity, or low water—35% field water capacity) for 114 days. Fresh root weight, root volume, root surface area, root fork, and root tip number were significantly higher in inoculated seedlings than in noninoculated seedlings. Furthermore, the root architecture of the inoculated seedlings changed from herringbone branching to dichotomous branching. Mitochondria and other organelles in root cells of inoculated seedlings remained largely undamaged under water stress, whereas organelles in root cells of noninoculated seedlings were severely damaged. The abscisic acid (ABA) and indole-3-acetic acid (IAA) content and IAA/ABA ratio of inoculated seedlings were significantly higher than those of noninoculated seedlings, whereas the content of gibberellic acid (GA) and the ratios of GA/ABA, zeatin riboside (ZR)/ABA, and ZR/IAA in inoculated seedlings were lower than those of noninoculated seedlings. DSE inoculation could help plants adapt to a drought stress environment by altering root morphology, reducing ultrastructural damage, and influencing the balance of endogenous hormones, which could be of great significance for the cultivation and preservation of the O. hosiei tree.

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Microbial Diversity of Upland Rice Roots and Their Influence on Rice Growth and Drought Tolerance

Microorganisms ◽

10.3390/microorganisms8091329 ◽

2020 ◽

Vol 8 (9) ◽

pp. 1329

Author(s):

Zhiqiang Pang ◽

Ying Zhao ◽

Peng Xu ◽

Diqiu Yu

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Plant Growth ◽

Upland Rice ◽

Oryza Sativa L ◽

Soluble Sugar ◽

Stress Conditions ◽

Rice Roots ◽

Microbial Resources

Among abiotic stresses, drought is one of the most important factors limiting plant growth. To increase their drought tolerance and survival, most plants interact directly with a variety of microbes. Upland rice (Oryza sativa L.) is a rice ecotype that differs from irrigated ecotype rice; it is adapted to both drought-stress and aerobic conditions. However, its root microbial resources have not been explored. We isolated bacteria and fungi from roots of upland rice in Xishuangbanna, China. Four hundred sixty-two endophytic and rhizospheric isolates (337 bacteria and 125 fungi) were distributed. They were distributed among 43 genera on the basis of 16S rRNA and internal transcribed spacer (ITS) gene sequence analysis. Notably, these root microbes differed from irrigated rice root microbes in irrigated environments; for example, members of the Firmicutes phylum were enriched (by 28.54%) in the roots of the upland plants. The plant growth-promoting (PGP) potential of 217 isolates was investigated in vitro. The PGP ability of 17 endophytic and 10 rhizospheric isolates from upland rice roots was evaluated under well-irrigated and drought-stress conditions, and 9 fungal strains increased rice seedling shoot length, shoot and root fresh weight (FW), antioxidant capability, and proline (Pro) and soluble sugar contents. Our work suggests that fungi from upland rice roots can increase plant growth under irrigated and drought-stress conditions and can serve as effective microbial resources for sustainable agricultural production in arid regions.

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Evaluation of wild barley species as possible sources of drought tolerance for arid environments

Plant Genetic Resources ◽

10.1017/s1479262117000168 ◽

2017 ◽

Vol 16 (3) ◽

pp. 209-217 ◽

Cited By ~ 3

Author(s):

Mohammad Barati ◽

Mohammad Mahdi Majidi ◽

Fateme Mostafavi ◽

Aghafakhr Mirlohi ◽

Maryam Safari ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Wild Species ◽

Wild Barley ◽

Principal Component ◽

Kernel Weight ◽

Stress Conditions ◽

Wild Plants ◽

Arid Environments ◽

Barley Genotypes

AbstractIn this study, agro-morphological and yield-related traits associated with drought tolerance in 80 barley genotypes belonging to 15 wild species together with the cultivated one, and their potential to improve adaptation to different levels of drought stress conditions (moisture environments) were studied. There was significant genetic variation among the genotypes and species for all of the measured traits, as well as differential responses of genotypes across environments. The results indicated high variation for grain yield (GY) under drought stress among the genotypes, and that some of the wild genotypes had consistently superior specific adaptation to the water stress conditions. The genotypes belong to wild barley species, especially Hordeum murinum and Hordeum marinum had lower GY but relatively higher yield stability under different environments. Traits such as number of seed per plant and hundred kernel weight were positively correlated with GY in all of the environments. High negative correlation between GY and days to ripening was observed only under intense drought environment, showing drought escape as a strategy of wild plants under highly stressed conditions. Grouping of the genotypes by principal component analysis completely separated cultivated barley and its progenitor (Hordeum vulgare ssp. spontaneum) from other wild genotypes; however, the other wild species were slightly separated from each other. In addition, the Iranian and foreign genotypes did not completely separate from each other. The identified wild barley genotypes with favourable characters and high drought tolerance could be used in genetic studies and barley improvement programmes especially for drought stress.

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Pengaruh biostimulan terhadap toleransi kekeringan dan pertumbuhan tanaman tebu varietas Kidang Kencana di rumah kaca (Effect of biostimulants on drought tolerance and growth of sugarcane var. Kidang Kencana at green house)

E-Journal Menara Perkebunan ◽

10.22302/iribb.jur.mp.v1i1.287 ◽

2018 ◽

Vol 86 (1) ◽

Author(s):

Dian Mutiara AMANAH ◽

Soekarno Mismana PUTRA

Keyword(s):

Drought Stress ◽

Humic Acid ◽

Drought Tolerance ◽

Plant Height ◽

Vegetative Growth ◽

Sugar Yield ◽

Stress Conditions ◽

Growth And Yield ◽

Segment Number ◽

Increasing Demand

Increasing productivity and sugar yield of sugarcane are required to meet the increasing demand for sugar. Biostimulants application is one of the effort to increase the productivity and rendement of sugar, especially at drought stress conditions. The purpose of this study was to determine the effect of biostimulants on the performance of sugarcane var. Kidang Kencana known susceptible to drought stress. The research was conducted in the greenhouse with several biostimulant treatments i.e. P0: Control, P1: Citorin-R, P2: Citorin-R and Citorin-S (1x spray) P3: Citorin-R and Citorin -S (2x spray), P4: Citorin-R, Citorin-S (1x spray) and Humic Acid, P5: Citorin-R, Citorin-S (1x spray), Humic Acid and Mycorrhiza, P6: Citorin-R, Citorin-S (2x spray), Humic Acid and Mycorrhiza. All treatments were subjected with drought stress started from 4 months after planting. The biostimulant treatments resulted in better growth and yield on treated-biostimulan compared to these of control. The best treatment for the vegetative growth and the productive parameters was P6. The plant height, stems diameter, segment number, weight, and sap volume at P6 were respectively 32.2%, 5.5%, 24.0%, 53.2% and 44.7% higher than the control. The best treatment for the sugar yield was P5 and the productivity parameters was P6 respectively, 42.5% and 70.5% higher than the control. The best treatments contained Citorin biostimulant. Humic Acid and Mycorrhiza which increased growth and sugar yield of Kidang Kencana sugarcane at drought stress conditions.[Keywords: drought stress Kidang Kencana variety, plant biostimulant, productivity, sugar yield]. AbstrakPeningkatan produktivitas dan rendemen gula tanaman tebu diperlukan untuk memenuhi kebutuhan gula yang terus meningkat. Aplikasi biostimulan merupakan salah satu upaya untuk meningkatkan produktivitas dan rendemen gula khususnya pada kondisi tercekam kekeringan. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh pemberian beberapa produk biostimulan terhadap produktivitas tanaman tebu varietas Kidang Kencana yang rentan cekaman kekeringan. Penelitian dilakukan di rumah kaca dengan perlakuan beberapa perlakuan biostimulan pada tanaman tebu, yaitu P0: Kontrol, P1: Citorin-R, P2: Citorin-R dan Citorin-S (1x semprot) P3: Citorin-R dan Citorin-S (2x semprot), P4: Citorin-R, Citorin-S (1x semprot) dan Asam Humat, P5: Citorin-R, Citorin-S (1x semprot), Asam Humat dan Mikoriza, P6: Citorin-R, Citorin-S (2x semprot), Asam Humat dan Mikoriza. Seluruh perlakuan diberi kondisi cekaman kekeringan pada 4 bulan setelah tanam. Perlakuan biostimulan memberikan pengaruh serta hasil yang lebih baik dibandingkan dengan kontrol baik fase vegetatif maupun produktif. Perlakuan terbaik selama fase vegetatif hingga 5 bulan setelah tanam adalah P6. Tinggi batang panen, diameter batang panen, jumlah ruas batang, bobot batang dan volume nira pada P6 meningkat 32,2%, 5,5%, 24,0%, 53,2% dan 44,7% lebih tinggi dibandingkan dengan kontrol. Perlakuan terbaik untuk parameter rendemen gula adalah P5 dan produktivitas gula adalah P6, masing-masing 42,5% dan 70,5% lebih tinggi dibandingkan kontrol. Perlakuan terbaik tersebut mengandung komponen biostimulan yaitu Citorin, Asam Humat dan Mikoriza yang dapat meningkatkan pertumbuhan dan rendemen gula tanaman tebu Kidang Kencana pada kondisi cekaman kekeringan. [Kata kunci: cekaman kekeringan, varietas Kidang Kencana, biostimulan tanaman, produktivitas, rendemen gula].

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Drought Effects on Growth, Water Content, and Organic Osmoprotectants in Promising Almond Genotypes with Different Drought Tolerance

10.21203/rs.3.rs-206134/v1 ◽

2021 ◽

Author(s):

Shabnam Gohari ◽

Ali Imani ◽

AliReza Talaei ◽

Vahid Abdossi ◽

Mohamad Reza Asghari

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Water Content ◽

Light Stress ◽

Stress Conditions ◽

Growth And Yield ◽

Leaf Water Content ◽

Severe Stress ◽

Drought Adaptation ◽

Genotype A

Abstract Background Almonds ( Prunus amygdalus Batsch, syn. P. dulcis (Mill.) DA Webb) is a valuable nut crops species that is widely is cultivated in arid and semi-arid regions of Iran, due to drought tolerance and dehydration under drought stress. Almonds show physiological adaptations for survival in drought stress conditions, but the degree Drought adaptation varies between cultivars. However, to date, its morphological and physiological responses to drought, and the underlying mechanisms are not well understood. This study was aimed to investigate the morphological and physiological changes of almond genotypes under drought stress. almond genotypes were planted in pots and subjected to four levels of soil water treatments: above 80% (control), 60% (light stress), and 40% (severe stress) of field capacity. Results Within the total stress period (0–30 days), almond genotypes grew rapidly in the light stress, whereas severe stress had a negative impact on growth. So that, in this study, 10 selected almond genotypes using some morphological traits such as: plant height, trunk diameter at the top of the graft, new branch growth length, leaf yellowness and some physiological indicators under drought stress conditions such as Chlorophyll index was evaluated based on SPAD criterion, relative leaf water content, measurement of chlorophyll fluorescence and Organic Osmoprotectants to identify drought-resistant and sensitive genotypes under drought stress conditions. Among the selected genotypes studied, genotype A-7-100 was the most resistant and genotype A-124-1 was the most sensitive to drought stress. Conclusions Our results show that almond genotypes adapt to drought mainly by avoidance mechanisms, and its morphological and physiological characteristics are inhibited under severe stress, However, the degree of drought adaptation varies between different cultivars. These findings might help limited water resources to be fully used for increased the percentage of kernel and finally increased the growth and yield of plants under water stress.

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Elucidating the Mechanisms Underlying Enhanced Drought Tolerance in Plants Mediated by Arbuscular Mycorrhizal Fungi

Frontiers in Microbiology ◽

10.3389/fmicb.2021.809473 ◽

2021 ◽

Vol 12 ◽

Author(s):

Shen Cheng ◽

Ying-Ning Zou ◽

Kamil Kuča ◽

Abeer Hashem ◽

Elsayed Fathi Abd_Allah ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Mycorrhizal Fungi ◽

Host Plants ◽

Molecular Mechanisms ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Host Cells ◽

Future Research ◽

Symbiotic Association

Plants are often subjected to various environmental stresses during their life cycle, among which drought stress is perhaps the most significant abiotic stress limiting plant growth and development. Arbuscular mycorrhizal (AM) fungi, a group of beneficial soil fungi, can enhance the adaptability and tolerance of their host plants to drought stress after infecting plant roots and establishing a symbiotic association with their host plant. Therefore, AM fungi represent an eco-friendly strategy in sustainable agricultural systems. There is still a need, however, to better understand the complex mechanisms underlying AM fungi-mediated enhancement of plant drought tolerance to ensure their effective use. AM fungi establish well-developed, extraradical hyphae on root surfaces, and function in water absorption and the uptake and transfer of nutrients into host cells. Thus, they participate in the physiology of host plants through the function of specific genes encoded in their genome. AM fungi also modulate morphological adaptations and various physiological processes in host plants, that help to mitigate drought-induced injury and enhance drought tolerance. Several AM-specific host genes have been identified and reported to be responsible for conferring enhanced drought tolerance. This review provides an overview of the effect of drought stress on the diversity and activity of AM fungi, the symbiotic relationship that exists between AM fungi and host plants under drought stress conditions, elucidates the morphological, physiological, and molecular mechanisms underlying AM fungi-mediated enhanced drought tolerance in plants, and provides an outlook for future research.

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Novel Insights into Host Receptors and Receptor-mediated Signaling that Regulate Arbuscular Mycorrhizal Symbiosis

Journal of Experimental Botany ◽

10.1093/jxb/eraa538 ◽

2020 ◽

Author(s):

Fahad Nasir ◽

Ali Bahadur ◽

Xiaolong Lin ◽

Yingzhi Gao ◽

Chunjie Tian

Keyword(s):

Host Plant ◽

Host Plants ◽

Agronomic Traits ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Land Plant ◽

Physical Contact ◽

Mycorrhizal Symbiosis ◽

Downstream Signaling ◽

Am Symbiosis

Abstract More than 80% of land plant species benefit from symbiotic partnerships with arbuscular mycorrhizal (AM) fungi that assist in nutrient acquisition and enhance the ability of host plants to adapt to environmental constraints. Host-generated plasma membrane-residing receptor-like kinases and the α/β-hydrolases, e.g. DWARF14-LIKE (D14L), a putative karrikin receptor, are used to detect the presence of AM fungi prior to physical contact between the host and fungus. Detection induces the activation of symbiosis-related transcriptional programming, enabling the successful establishment of AM symbiosis. In order to prevent hyper-colonization and to maintain a mutually beneficial association, the host plants precisely monitor and control AM symbiosis during the post-symbiotic stage via different molecular strategies. While previous studies have elucidated how host plant receptors and receptor-mediated signaling regulate AM symbiosis, the molecular details underlying these processes remain poorly understood. The recent identification of a rice (Oryza sativa) CHITIN-ELICITOR RECEPTOR-KINASE 1 (OsCERK1) interaction partner MYC FACTOR RECEPTOR 1 (OsMYR1), as well as new insights into D14L-receptor- and SUPER NUMERIC NODULES 1 (SUNN1) receptor-mediated signaling have improved our understanding of how host plant receptors and their corresponding signaling regulate AM symbiosis. The present review summarizes these and other current findings that have increased our limited understanding of receptor-mediated signaling mechanisms involved in the regulation of AM symbiosis. The identified receptors and/or their downstream signaling components could potentially be used to engineer economically-important crops with improved agronomic traits by conferring the ability to control the colonization of AM fungi in a precise manner.

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