Leymus racemosus

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Leymus racemosus
Leymus racemosus - Berlin Botanical Garden - IMG 8556.JPG
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Poaceae
Subfamily: Pooideae
Genus: Leymus
Species:
L. racemosus
Binomial name
Leymus racemosus
(Lam.) Tzvelev

Leymus racemosus is a species of perennial wild rye known by the common name mammoth wild rye. It is native to southeastern and eastern Europe, Middle Asia, Caucasus, Siberia, China, Mongolia, New Zealand, and parts of North America. Culms are 50–100 cm long, and 10–12 mm in diameter.

Wheat is the primary source of grain in the human food supply worldwide today. Especially with the current population boom, there is a strong pressure to increase wheat production to sustain the global food demand. [1] Several factors threaten crop expansion into new areas. Scientists have been investigating evolutionary relatives of wheat to incorporate into the modern cultivar to improve its resistance to biotic and abiotic stresses. [1] Leymus racemosus is one such relative that has shown tremendous potential in this regard. [1]

Leymus racemosus is a perennial grass species that inhabits a wide variety of terrains, such as wet forests, drylands, coasts and soils with high saline concentrations. [1] Introgression lines of L. racemosus have shown a stronger response to heat stress in terms of increased grain yields per spike. [2] This is significant because heat stress significantly limits wheat production in tropical climates. High temperatures impose morphological changes that decrease production. [2] Wheat grows optimally at temperatures between 18-24 degrees Celsius. [2] Studies have shown that wheat exposure to temperatures between 28-32 degrees Celsius for a week can decrease crop yield by 20%. [2] At the molecular level, this is linked to disrupting the thylakoid membranes on chloroplasts involved in photosynthesis. [2]

Leymus racemosus genes have also been shown to improve the modern cultivar's resistance to Fusarium Head Blight, a fungal infection that reduces grain quality and yield. [3] This disease is usually found in warm and humid climates where wheat grows; however, scab epidemics have become more pervasive across North America and Europe due to climate change. [3] Studies have isolated the specific genes that confer scab resistance, a disease characterized by lesions on the tuber, leaf or stem. [3] These genes were incorporated into modern wheat, which displayed higher resistance to the fungal infection as compared with wheat lines that were not modified with L. racemosus genes. [3]

Another major threat to the expansion of wheat is aluminum toxicity in soil, which represents 40% of the world's arable land. [4] Though the exact mechanism of aluminum toxicity is unclear, scientists know that it inhibits root cell growth by blocking Ca2+ channels, ultimately disrupting transport and communication within the plant. [4] Soil limiting is a practice used to deter Al toxicity by raising the pH of the soil. [4] However, this can be costly and difficult to implement on a large scale. [4] Thus, investigating the use of more tolerant plants is a noteworthy effort. L. racemosus genes helped prevent root growth reduction when incorporated into modern wheat cultivars. This indicates a higher tolerance of Al induced stress. [4]

Leymus racemosus genes have also been shown to have a positive impact on reducing nitrogen levels in an agricultural system through biological nitrification inhibition (BNI). [5] This finding is significant because nitrogen loss threatens the success of plants and currently the only way to prevent this problem is through the use of artificial inhibitors. [5] Studies have isolated genes that have high BNI properties from the L. racemosus plant that can be incorporated into modern cultivar as a novel strategy to mitigate the effects on nitrogen pollution on a wheat cultivation area. [5] Overall, L. racemosus is tolerant to many of the biotic and abiotic stressors that limit modern wheat growth. Studying this evolutionary ancestor is key because it provides answers to expanding wheat production and sustaining the global food demand, especially given the future threats of climate change and limited arable land.

Mammoth Wild Rye (Leymus racemosus) in Mongolia. Leymus racemosus (Lam.) Tzvel. 1.JPG
Mammoth Wild Rye (Leymus racemosus) in Mongolia.

Related Research Articles

<span class="mw-page-title-main">Wheat</span> Genus of grass cultivated for grain

Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus Triticum ; the most widely grown is common wheat. The archaeological record suggests that wheat was first cultivated in the regions of the Fertile Crescent around 9600 BC. Botanically, the wheat kernel is a caryopsis, a type of fruit.

<span class="mw-page-title-main">Fusarium ear blight</span> Fungal disease of cereals

Fusarium ear blight (FEB), is a fungal disease of cereals, including wheat, barley, oats, rye and triticale. FEB is caused by a range of Fusarium fungi, which infects the heads of the crop, reducing grain yield. The disease is often associated with contamination by mycotoxins produced by the fungi already when the crop is growing in the field. The disease can cause severe economic losses as mycotoxin-contaminated grain cannot be sold for food or feed.

<span class="mw-page-title-main">Khorasan wheat</span> Species of grass

Khorasan wheat or Oriental wheat is a tetraploid wheat species. The grain is twice the size of modern-day wheat, and has a rich, nutty flavor.

<span class="mw-page-title-main">Triticeae</span> Tribe of grasses

Triticeae is a botanical tribe within the subfamily Pooideae of grasses that includes genera with many domesticated species. Major crop genera found in this tribe include wheat, barley, and rye; crops in other genera include some for human consumption, and others used for animal feed or rangeland protection. Among the world's cultivated species, this tribe has some of the most complex genetic histories. An example is bread wheat, which contains the genomes of three species with only one being a wheat Triticum species. Seed storage proteins in the Triticeae are implicated in various food allergies and intolerances.

<span class="mw-page-title-main">Take-all</span> Fungal plant disease

Take-all is a plant disease affecting the roots of grass and cereal plants in temperate climates caused by the fungus Gaeumannomyces tritici. All varieties of wheat and barley are susceptible. It is an important disease in winter wheat in Western Europe particularly, and is favoured by conditions of intensive production and monoculture.

<i>Agropyron cristatum</i> Species of grass

Agropyron cristatum, the crested wheat grass, crested wheatgrass, fairway crested wheat grass, is a species in the family Poaceae. This plant is often used as forage and erosion control. It is well known as a widespread introduced species on the prairies of the United States and Canada.

<i>Fusarium culmorum</i> Fungal disease, head blight of wheat

Fusarium culmorum is a fungal plant pathogen and the causal agent of seedling blight, foot rot, ear blight, stalk rot, common root rot and other diseases of cereals, grasses, and a wide variety of monocots and dicots. In coastal dunegrass, F. culmorum is a nonpathogenic symbiont conferring both salt and drought tolerance to the plant.

Crown rot of wheat is caused by the fungal pathogen Fusarium pseudograminearum. F. pseudograminearum is a member of the fungal phylum Ascomycota and is also known as Gibberella coronicola (teleomorph). It is a monoecious fungus, meaning it does not require another host other than wheat to complete its life cycle. Although F. pseudograminearum can produce both anamorphic and teleomorphic states, the teleomorph is usually not present for crown rot of wheat. This Fusarium species has, until recently, been considered to be the same as the species known as Fusarium graminearum due to many similar characteristics. One of the only differences between the two species is that F. pseudograminearum lacks its sexual stage on the wheat host.

<span class="mw-page-title-main">Intensive crop farming</span> Modern form of farming

Intensive crop farming is a modern industrialized form of crop farming. Intensive crop farming's methods include innovation in agricultural machinery, farming methods, genetic engineering technology, techniques for achieving economies of scale in production, the creation of new markets for consumption, patent protection of genetic information, and global trade. These methods are widespread in developed nations.

In botany, drought tolerance is the ability by which a plant maintains its biomass production during arid or drought conditions. Some plants are naturally adapted to dry conditions, surviving with protection mechanisms such as desiccation tolerance, detoxification, or repair of xylem embolism. Other plants, specifically crops like corn, wheat, and rice, have become increasingly tolerant to drought with new varieties created via genetic engineering. From an evolutionary perspective, the type of mycorrhizal associations formed in the roots of plants can determine how fast plants can adapt to drought.

Microbial inoculants, also known as soil inoculants or bioinoculants, are agricultural amendments that use beneficial rhizosphericic or endophytic microbes to promote plant health. Many of the microbes involved form symbiotic relationships with the target crops where both parties benefit (mutualism). While microbial inoculants are applied to improve plant nutrition, they can also be used to promote plant growth by stimulating plant hormone production. Although bacterial and fungal inoculants are common, inoculation with archaea to promote plant growth is being increasingly studied.

<i>Leymus arenarius</i> Species of flowering plant in the grass family Poaceae

Leymus arenarius is a psammophilic (sand-loving) species of grass in the family Poaceae, native to the coasts of Atlantic and Northern Europe. Leymus arenarius is commonly known as sand ryegrass, sea lyme grass, or simply lyme grass.

<i>Thinopyrum intermedium</i> Species of flowering plant

Thinopyrum intermedium, known commonly as intermediate wheatgrass, is a sod-forming perennial grass in the Triticeae tribe of Pooideae native to Europe and Western Asia. It is part of a group of plants commonly called wheatgrasses because of the similarity of their seed heads or ears to common wheat. However, wheatgrasses generally are perennial, while wheat is an annual. It has gained the Royal Horticultural Society's Award of Garden Merit as an ornamental.

Biotic stress is stress that occurs as a result of damage done to an organism by other living organisms, such as bacteria, viruses, fungi, parasites, beneficial and harmful insects, weeds, and cultivated or native plants. It is different from abiotic stress, which is the negative impact of non-living factors on the organisms such as temperature, sunlight, wind, salinity, flooding and drought. The types of biotic stresses imposed on an organism depend the climate where it lives as well as the species' ability to resist particular stresses. Biotic stress remains a broadly defined term and those who study it face many challenges, such as the greater difficulty in controlling biotic stresses in an experimental context compared to abiotic stress.

<span class="mw-page-title-main">Plant breeding</span> Humans changing traits, ornamental/crops

Plant breeding is the science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals. The goals of plant breeding are to produce crop varieties that boast unique and superior traits for a variety of applications. The most frequently addressed agricultural traits are those related to biotic and abiotic stress tolerance, grain or biomass yield, end-use quality characteristics such as taste or the concentrations of specific biological molecules and ease of processing.

Breeding for drought resistance is the process of breeding plants with the goal of reducing the impact of dehydration on plant growth.

Plant breeding is process of development of new cultivars. Plant breeding involves development of varieties for different environmental conditions – some of them are not favorable. Among them, heat stress is one of such factor that reduces the production and quality significantly. So breeding against heat is a very important criterion for breeding for current as well as future environments produced by global climate change.

<i>Thinopyrum obtusiflorum</i> Species of grass

Thinopyrum obtusiflorum is a species of grass known by the common names tall wheatgrass, rush wheatgrass, and Eurasian quackgrass. It is native to Eurasia and it has been introduced to many other parts of the world, including much of the Americas and Australia.

<i>Leymus mollis</i> Species of grass

Leymus mollis is a species of grass known by the common names American dune grass, American dune wild-rye, sea lyme-grass, strand-wheat, and strand grass. Its Japanese name is hamaninniku. It is native to Asia, where it occurs in Japan, China, Korea, and Russia, and northern parts of North America, where it occurs across Canada and the northern United States, as well as Greenland. It can also be found in Iceland.

Gray leaf spot (GLS) is a foliar fungal disease that affects grasses. In grasses other than maize it is caused by Pyricularia grisea, which only infects perennial ryegrass, tall fescue, and St. Augustine grass in places with warm and rainy climates.

References

  1. 1 2 3 4 Mohammed, Yasir Serag Alnor; Tahir, Izzat Sidahmed Ali; Kamal, Nasrein Mohamed; Eltayeb, Amin Elsadig; Ali, Abdelbagi Mukhtar; Tsujimoto, Hisashi (2014-01-01). "Impact of wheat-Leymus racemosus added chromosomes on wheat adaptation and tolerance to heat stress". Breeding Science. 63 (5): 450–460. doi:10.1270/jsbbs.63.450. PMC   3949581 . PMID   24757384.
  2. 1 2 3 4 5 Harding, Scott A.; Guikema, James A.; Paulsen, Gary M. (1990-03-01). "Photosynthetic Decline from High Temperature Stress during Maturation of Wheat II. Interaction with Source and Sink Processes". Plant Physiology. 92 (3): 654–658. doi:10.1104/pp.92.3.654. ISSN   1532-2548. PMC   1062349 . PMID   16667330.
  3. 1 2 3 4 Chen, Peidu; Liu, Wenxuan; Yuan, Jianhua; Wang, Xiue; Zhou, Bo; Wang, Suling; Zhang, Shouzhong; Feng, Yigao; Yang, Baojun (2005-07-26). "Development and characterization of wheat- Leymus racemosus translocation lines with resistance to Fusarium Head Blight". Theoretical and Applied Genetics. 111 (5): 941–948. doi:10.1007/s00122-005-0026-z. ISSN   0040-5752. PMID   16044268. S2CID   22463753.
  4. 1 2 3 4 5 Mohammed, Yasir Serag Alnor; Eltayeb, Amin Elsadig; Tsujimoto, Hisashi (2013-01-01). "Enhancement of aluminum tolerance in wheat by addition of chromosomes from the wild relative Leymus racemosus". Breeding Science. 63 (4): 407–416. doi:10.1270/jsbbs.63.407. PMC   3859352 . PMID   24399913.
  5. 1 2 3 Subbarao, G. V.; Tomohiro, Ban; Masahiro, Kishii; Osamu, Ito; Samejima, H.; Wang, H. Y.; Pearse, S. J.; Gopalakrishnan, S.; Nakahara, K. (2007-09-11). "Can biological nitrification inhibition (BNI) genes from perennial Leymus racemosus (Triticeae) combat nitrification in wheat farming?" (PDF). Plant and Soil. 299 (1–2): 55–64. Bibcode:2007PlSoi.299...55S. doi:10.1007/s11104-007-9360-z. ISSN   0032-079X. S2CID   26024250.
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